| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Russell King | 5641 | 38.19% | 51 | 15.09% |
| Alan Cox | 1951 | 13.21% | 38 | 11.24% |
| Peter Hurley | 1488 | 10.07% | 35 | 10.36% |
| Jiri Slaby | 685 | 4.64% | 27 | 7.99% |
| Ilpo Järvinen | 548 | 3.71% | 12 | 3.55% |
| Andy Shevchenko | 427 | 2.89% | 10 | 2.96% |
| Ricardo Ribalda Delgado | 284 | 1.92% | 3 | 0.89% |
| Jason Wessel | 276 | 1.87% | 1 | 0.30% |
| Nicolas Ferre | 265 | 1.79% | 1 | 0.30% |
| Lino Sanfilippo | 254 | 1.72% | 4 | 1.18% |
| Al Viro | 235 | 1.59% | 7 | 2.07% |
| Guennadi Liakhovetski | 196 | 1.33% | 2 | 0.59% |
| Lukas Wunner | 169 | 1.14% | 6 | 1.78% |
| Dmitry Safonov | 136 | 0.92% | 2 | 0.59% |
| Rob Herring | 134 | 0.91% | 3 | 0.89% |
| Uwe Kleine-König | 113 | 0.77% | 2 | 0.59% |
| Pali Rohár | 104 | 0.70% | 1 | 0.30% |
| Johan Hovold | 96 | 0.65% | 9 | 2.66% |
| Greg Kroah-Hartman | 93 | 0.63% | 5 | 1.48% |
| Tomas Hlavacek | 68 | 0.46% | 2 | 0.59% |
| Geert Uytterhoeven | 58 | 0.39% | 5 | 1.48% |
| Maciej W. Rozycki | 51 | 0.35% | 1 | 0.30% |
| Vignesh R | 49 | 0.33% | 1 | 0.30% |
| Tycho Andersen | 49 | 0.33% | 1 | 0.30% |
| Ingo Molnar | 47 | 0.32% | 3 | 0.89% |
| Andrew Morton | 47 | 0.32% | 5 | 1.48% |
| Hui Wang | 46 | 0.31% | 1 | 0.30% |
| Pavel Machek | 44 | 0.30% | 1 | 0.30% |
| David Woodhouse | 43 | 0.29% | 3 | 0.89% |
| Arjan van de Ven | 43 | 0.29% | 2 | 0.59% |
| Alexey Dobriyan | 42 | 0.28% | 2 | 0.59% |
| Rafael Gago | 42 | 0.28% | 1 | 0.30% |
| Vijaya Krishna Nivarthi | 40 | 0.27% | 2 | 0.59% |
| George G. Davis | 36 | 0.24% | 1 | 0.30% |
| David Gibson | 32 | 0.22% | 1 | 0.30% |
| Samir Virmani | 32 | 0.22% | 1 | 0.30% |
| Jeremy Kerr | 31 | 0.21% | 2 | 0.59% |
| Max Filippov | 31 | 0.21% | 1 | 0.30% |
| Sergey Senozhatsky | 31 | 0.21% | 1 | 0.30% |
| Anton Vorontsov | 31 | 0.21% | 1 | 0.30% |
| Chen Gang S | 31 | 0.21% | 1 | 0.30% |
| Alexander Shiyan | 31 | 0.21% | 1 | 0.30% |
| Grant C. Likely | 31 | 0.21% | 1 | 0.30% |
| Masahiro Yamada | 30 | 0.20% | 1 | 0.30% |
| Sudip Mukherjee | 29 | 0.20% | 2 | 0.59% |
| Joakim Nordell | 28 | 0.19% | 1 | 0.30% |
| Sebastian Andrzej Siewior | 26 | 0.18% | 2 | 0.59% |
| Fabio Estevam | 24 | 0.16% | 1 | 0.30% |
| Noam Camus | 24 | 0.16% | 1 | 0.30% |
| George Spelvin | 24 | 0.16% | 2 | 0.59% |
| Al Cooper | 23 | 0.16% | 1 | 0.30% |
| Corbin Atkinson | 22 | 0.15% | 1 | 0.30% |
| Serge Semin | 21 | 0.14% | 1 | 0.30% |
| Stanislav Brabec | 21 | 0.14% | 1 | 0.30% |
| Doug Anderson | 19 | 0.13% | 2 | 0.59% |
| Sergei Shtylyov | 19 | 0.13% | 2 | 0.59% |
| Alexey Kardashevskiy | 19 | 0.13% | 1 | 0.30% |
| Thomas Pfaff | 18 | 0.12% | 1 | 0.30% |
| David Daney | 18 | 0.12% | 1 | 0.30% |
| Linus Walleij | 18 | 0.12% | 1 | 0.30% |
| Håvard Skinnemoen | 17 | 0.12% | 1 | 0.30% |
| Josh Boyer | 17 | 0.12% | 1 | 0.30% |
| David Howells | 17 | 0.12% | 1 | 0.30% |
| James Bottomley | 17 | 0.12% | 1 | 0.30% |
| Federico Vaga | 15 | 0.10% | 1 | 0.30% |
| Björn Helgaas | 14 | 0.09% | 1 | 0.30% |
| Alex Dewar | 13 | 0.09% | 1 | 0.30% |
| Yinghai Lu | 12 | 0.08% | 3 | 0.89% |
| Tomasz Moń | 12 | 0.08% | 1 | 0.30% |
| Kees Cook | 11 | 0.07% | 2 | 0.59% |
| André Goddard Rosa | 10 | 0.07% | 2 | 0.59% |
| Andrew Victor | 10 | 0.07% | 1 | 0.30% |
| Ning Jiang | 10 | 0.07% | 1 | 0.30% |
| Jeffy Chen | 9 | 0.06% | 1 | 0.30% |
| Alexander Sverdlin | 8 | 0.05% | 2 | 0.59% |
| Ondrej Mosnáček | 8 | 0.05% | 1 | 0.30% |
| Linus Torvalds | 8 | 0.05% | 2 | 0.59% |
| Maximilian Attems | 7 | 0.05% | 1 | 0.30% |
| Deepak Saxena | 7 | 0.05% | 2 | 0.59% |
| Kevin Cernekee | 7 | 0.05% | 2 | 0.59% |
| xiaojiangfeng | 6 | 0.04% | 1 | 0.30% |
| Govindraj Raja | 5 | 0.03% | 1 | 0.30% |
| John Stultz | 5 | 0.03% | 1 | 0.30% |
| Colin Ian King | 5 | 0.03% | 1 | 0.30% |
| Krzysztof Kozlowski | 4 | 0.03% | 1 | 0.30% |
| Matthias Andree | 4 | 0.03% | 1 | 0.30% |
| Sergey Organov | 4 | 0.03% | 1 | 0.30% |
| Yin Kangkai | 4 | 0.03% | 1 | 0.30% |
| Roy Zang | 3 | 0.02% | 1 | 0.30% |
| Ram Gupta | 3 | 0.02% | 1 | 0.30% |
| Simon Glass | 3 | 0.02% | 1 | 0.30% |
| Fabian Frederick | 3 | 0.02% | 1 | 0.30% |
| Pantelis Antoniou | 3 | 0.02% | 1 | 0.30% |
| Richard Henderson | 3 | 0.02% | 1 | 0.30% |
| Huang Shijie | 2 | 0.01% | 1 | 0.30% |
| Lucas Stach | 2 | 0.01% | 1 | 0.30% |
| Benjamin Herrenschmidt | 2 | 0.01% | 1 | 0.30% |
| Gustavo A. R. Silva | 2 | 0.01% | 1 | 0.30% |
| Paul Cercueil | 2 | 0.01% | 1 | 0.30% |
| Alan Stern | 2 | 0.01% | 1 | 0.30% |
| Kay Sievers | 2 | 0.01% | 1 | 0.30% |
| Christoph Hellwig | 2 | 0.01% | 1 | 0.30% |
| Hariprasad Kelam | 1 | 0.01% | 1 | 0.30% |
| Jeff Dike | 1 | 0.01% | 1 | 0.30% |
| Arnd Bergmann | 1 | 0.01% | 1 | 0.30% |
| Michal Simek | 1 | 0.01% | 1 | 0.30% |
| Randy Dunlap | 1 | 0.01% | 1 | 0.30% |
| Steven Cole | 1 | 0.01% | 1 | 0.30% |
| Total | 14770 | 338 |
// SPDX-License-Identifier: GPL-2.0+ /* * Driver core for serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Copyright 1999 ARM Limited * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. */ #include <linux/module.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/slab.h> #include <linux/sched/signal.h> #include <linux/init.h> #include <linux/console.h> #include <linux/gpio/consumer.h> #include <linux/of.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/device.h> #include <linux/serial.h> /* for serial_state and serial_icounter_struct */ #include <linux/serial_core.h> #include <linux/sysrq.h> #include <linux/delay.h> #include <linux/mutex.h> #include <linux/math64.h> #include <linux/security.h> #include <linux/irq.h> #include <linux/uaccess.h> /* * This is used to lock changes in serial line configuration. */ static DEFINE_MUTEX(port_mutex); /* * lockdep: port->lock is initialized in two places, but we * want only one lock-class: */ static struct lock_class_key port_lock_key; #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) /* * Max time with active RTS before/after data is sent. */ #define RS485_MAX_RTS_DELAY 100 /* msecs */ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, struct ktermios *old_termios); static void uart_wait_until_sent(struct tty_struct *tty, int timeout); static void uart_change_pm(struct uart_state *state, enum uart_pm_state pm_state); static void uart_port_shutdown(struct tty_port *port); static int uart_dcd_enabled(struct uart_port *uport) { return !!(uport->status & UPSTAT_DCD_ENABLE); } static inline struct uart_port *uart_port_ref(struct uart_state *state) { if (atomic_add_unless(&state->refcount, 1, 0)) return state->uart_port; return NULL; } static inline void uart_port_deref(struct uart_port *uport) { if (atomic_dec_and_test(&uport->state->refcount)) wake_up(&uport->state->remove_wait); } #define uart_port_lock(state, flags) \ ({ \ struct uart_port *__uport = uart_port_ref(state); \ if (__uport) \ spin_lock_irqsave(&__uport->lock, flags); \ __uport; \ }) #define uart_port_unlock(uport, flags) \ ({ \ struct uart_port *__uport = uport; \ if (__uport) { \ spin_unlock_irqrestore(&__uport->lock, flags); \ uart_port_deref(__uport); \ } \ }) static inline struct uart_port *uart_port_check(struct uart_state *state) { lockdep_assert_held(&state->port.mutex); return state->uart_port; } /** * uart_write_wakeup - schedule write processing * @port: port to be processed * * This routine is used by the interrupt handler to schedule processing in the * software interrupt portion of the driver. A driver is expected to call this * function when the number of characters in the transmit buffer have dropped * below a threshold. * * Locking: @port->lock should be held */ void uart_write_wakeup(struct uart_port *port) { struct uart_state *state = port->state; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ BUG_ON(!state); tty_port_tty_wakeup(&state->port); } EXPORT_SYMBOL(uart_write_wakeup); static void uart_stop(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; port = uart_port_lock(state, flags); if (port) port->ops->stop_tx(port); uart_port_unlock(port, flags); } static void __uart_start(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->uart_port; if (port && !uart_tx_stopped(port)) port->ops->start_tx(port); } static void uart_start(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; port = uart_port_lock(state, flags); __uart_start(tty); uart_port_unlock(port, flags); } static void uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) { unsigned long flags; unsigned int old; if (port->rs485.flags & SER_RS485_ENABLED) { set &= ~TIOCM_RTS; clear &= ~TIOCM_RTS; } spin_lock_irqsave(&port->lock, flags); old = port->mctrl; port->mctrl = (old & ~clear) | set; if (old != port->mctrl) port->ops->set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); } #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) static void uart_port_dtr_rts(struct uart_port *uport, int raise) { if (raise) uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); else uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); } /* * Startup the port. This will be called once per open. All calls * will be serialised by the per-port mutex. */ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, int init_hw) { struct uart_port *uport = uart_port_check(state); unsigned long flags; unsigned long page; int retval = 0; if (uport->type == PORT_UNKNOWN) return 1; /* * Make sure the device is in D0 state. */ uart_change_pm(state, UART_PM_STATE_ON); /* * Initialise and allocate the transmit and temporary * buffer. */ page = get_zeroed_page(GFP_KERNEL); if (!page) return -ENOMEM; uart_port_lock(state, flags); if (!state->xmit.buf) { state->xmit.buf = (unsigned char *) page; uart_circ_clear(&state->xmit); uart_port_unlock(uport, flags); } else { uart_port_unlock(uport, flags); /* * Do not free() the page under the port lock, see * uart_shutdown(). */ free_page(page); } retval = uport->ops->startup(uport); if (retval == 0) { if (uart_console(uport) && uport->cons->cflag) { tty->termios.c_cflag = uport->cons->cflag; tty->termios.c_ispeed = uport->cons->ispeed; tty->termios.c_ospeed = uport->cons->ospeed; uport->cons->cflag = 0; uport->cons->ispeed = 0; uport->cons->ospeed = 0; } /* * Initialise the hardware port settings. */ uart_change_speed(tty, state, NULL); /* * Setup the RTS and DTR signals once the * port is open and ready to respond. */ if (init_hw && C_BAUD(tty)) uart_port_dtr_rts(uport, 1); } /* * This is to allow setserial on this port. People may want to set * port/irq/type and then reconfigure the port properly if it failed * now. */ if (retval && capable(CAP_SYS_ADMIN)) return 1; return retval; } static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw) { struct tty_port *port = &state->port; int retval; if (tty_port_initialized(port)) return 0; retval = uart_port_startup(tty, state, init_hw); if (retval) set_bit(TTY_IO_ERROR, &tty->flags); return retval; } /* * This routine will shutdown a serial port; interrupts are disabled, and * DTR is dropped if the hangup on close termio flag is on. Calls to * uart_shutdown are serialised by the per-port semaphore. * * uport == NULL if uart_port has already been removed */ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) { struct uart_port *uport = uart_port_check(state); struct tty_port *port = &state->port; unsigned long flags; char *xmit_buf = NULL; /* * Set the TTY IO error marker */ if (tty) set_bit(TTY_IO_ERROR, &tty->flags); if (tty_port_initialized(port)) { tty_port_set_initialized(port, 0); /* * Turn off DTR and RTS early. */ if (uport && uart_console(uport) && tty) { uport->cons->cflag = tty->termios.c_cflag; uport->cons->ispeed = tty->termios.c_ispeed; uport->cons->ospeed = tty->termios.c_ospeed; } if (!tty || C_HUPCL(tty)) uart_port_dtr_rts(uport, 0); uart_port_shutdown(port); } /* * It's possible for shutdown to be called after suspend if we get * a DCD drop (hangup) at just the right time. Clear suspended bit so * we don't try to resume a port that has been shutdown. */ tty_port_set_suspended(port, 0); /* * Do not free() the transmit buffer page under the port lock since * this can create various circular locking scenarios. For instance, * console driver may need to allocate/free a debug object, which * can endup in printk() recursion. */ uart_port_lock(state, flags); xmit_buf = state->xmit.buf; state->xmit.buf = NULL; uart_port_unlock(uport, flags); free_page((unsigned long)xmit_buf); } /** * uart_update_timeout - update per-port frame timing information * @port: uart_port structure describing the port * @cflag: termios cflag value * @baud: speed of the port * * Set the @port frame timing information from which the FIFO timeout value is * derived. The @cflag value should reflect the actual hardware settings as * number of bits, parity, stop bits and baud rate is taken into account here. * * Locking: caller is expected to take @port->lock */ void uart_update_timeout(struct uart_port *port, unsigned int cflag, unsigned int baud) { unsigned int size = tty_get_frame_size(cflag); u64 frame_time; frame_time = (u64)size * NSEC_PER_SEC; port->frame_time = DIV64_U64_ROUND_UP(frame_time, baud); } EXPORT_SYMBOL(uart_update_timeout); /** * uart_get_baud_rate - return baud rate for a particular port * @port: uart_port structure describing the port in question. * @termios: desired termios settings * @old: old termios (or %NULL) * @min: minimum acceptable baud rate * @max: maximum acceptable baud rate * * Decode the termios structure into a numeric baud rate, taking account of the * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600 * baud. * * If the new baud rate is invalid, try the @old termios setting. If it's still * invalid, we try 9600 baud. * * The @termios structure is updated to reflect the baud rate we're actually * going to be using. Don't do this for the case where B0 is requested ("hang * up"). * * Locking: caller dependent */ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, struct ktermios *old, unsigned int min, unsigned int max) { unsigned int try; unsigned int baud; unsigned int altbaud; int hung_up = 0; upf_t flags = port->flags & UPF_SPD_MASK; switch (flags) { case UPF_SPD_HI: altbaud = 57600; break; case UPF_SPD_VHI: altbaud = 115200; break; case UPF_SPD_SHI: altbaud = 230400; break; case UPF_SPD_WARP: altbaud = 460800; break; default: altbaud = 38400; break; } for (try = 0; try < 2; try++) { baud = tty_termios_baud_rate(termios); /* * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... * Die! Die! Die! */ if (try == 0 && baud == 38400) baud = altbaud; /* * Special case: B0 rate. */ if (baud == 0) { hung_up = 1; baud = 9600; } if (baud >= min && baud <= max) return baud; /* * Oops, the quotient was zero. Try again with * the old baud rate if possible. */ termios->c_cflag &= ~CBAUD; if (old) { baud = tty_termios_baud_rate(old); if (!hung_up) tty_termios_encode_baud_rate(termios, baud, baud); old = NULL; continue; } /* * As a last resort, if the range cannot be met then clip to * the nearest chip supported rate. */ if (!hung_up) { if (baud <= min) tty_termios_encode_baud_rate(termios, min + 1, min + 1); else tty_termios_encode_baud_rate(termios, max - 1, max - 1); } } /* Should never happen */ WARN_ON(1); return 0; } EXPORT_SYMBOL(uart_get_baud_rate); /** * uart_get_divisor - return uart clock divisor * @port: uart_port structure describing the port * @baud: desired baud rate * * Calculate the divisor (baud_base / baud) for the specified @baud, * appropriately rounded. * * If 38400 baud and custom divisor is selected, return the custom divisor * instead. * * Locking: caller dependent */ unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud) { unsigned int quot; /* * Old custom speed handling. */ if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) quot = port->custom_divisor; else quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); return quot; } EXPORT_SYMBOL(uart_get_divisor); /* Caller holds port mutex */ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, struct ktermios *old_termios) { struct uart_port *uport = uart_port_check(state); struct ktermios *termios; int hw_stopped; /* * If we have no tty, termios, or the port does not exist, * then we can't set the parameters for this port. */ if (!tty || uport->type == PORT_UNKNOWN) return; termios = &tty->termios; uport->ops->set_termios(uport, termios, old_termios); /* * Set modem status enables based on termios cflag */ spin_lock_irq(&uport->lock); if (termios->c_cflag & CRTSCTS) uport->status |= UPSTAT_CTS_ENABLE; else uport->status &= ~UPSTAT_CTS_ENABLE; if (termios->c_cflag & CLOCAL) uport->status &= ~UPSTAT_DCD_ENABLE; else uport->status |= UPSTAT_DCD_ENABLE; /* reset sw-assisted CTS flow control based on (possibly) new mode */ hw_stopped = uport->hw_stopped; uport->hw_stopped = uart_softcts_mode(uport) && !(uport->ops->get_mctrl(uport) & TIOCM_CTS); if (uport->hw_stopped) { if (!hw_stopped) uport->ops->stop_tx(uport); } else { if (hw_stopped) __uart_start(tty); } spin_unlock_irq(&uport->lock); } static int uart_put_char(struct tty_struct *tty, unsigned char c) { struct uart_state *state = tty->driver_data; struct uart_port *port; struct circ_buf *circ; unsigned long flags; int ret = 0; circ = &state->xmit; port = uart_port_lock(state, flags); if (!circ->buf) { uart_port_unlock(port, flags); return 0; } if (port && uart_circ_chars_free(circ) != 0) { circ->buf[circ->head] = c; circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); ret = 1; } uart_port_unlock(port, flags); return ret; } static void uart_flush_chars(struct tty_struct *tty) { uart_start(tty); } static int uart_write(struct tty_struct *tty, const unsigned char *buf, int count) { struct uart_state *state = tty->driver_data; struct uart_port *port; struct circ_buf *circ; unsigned long flags; int c, ret = 0; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ if (!state) { WARN_ON(1); return -EL3HLT; } port = uart_port_lock(state, flags); circ = &state->xmit; if (!circ->buf) { uart_port_unlock(port, flags); return 0; } while (port) { c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); if (count < c) c = count; if (c <= 0) break; memcpy(circ->buf + circ->head, buf, c); circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); buf += c; count -= c; ret += c; } __uart_start(tty); uart_port_unlock(port, flags); return ret; } static unsigned int uart_write_room(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; unsigned int ret; port = uart_port_lock(state, flags); ret = uart_circ_chars_free(&state->xmit); uart_port_unlock(port, flags); return ret; } static unsigned int uart_chars_in_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; unsigned int ret; port = uart_port_lock(state, flags); ret = uart_circ_chars_pending(&state->xmit); uart_port_unlock(port, flags); return ret; } static void uart_flush_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ if (!state) { WARN_ON(1); return; } pr_debug("uart_flush_buffer(%d) called\n", tty->index); port = uart_port_lock(state, flags); if (!port) return; uart_circ_clear(&state->xmit); if (port->ops->flush_buffer) port->ops->flush_buffer(port); uart_port_unlock(port, flags); tty_port_tty_wakeup(&state->port); } /* * This function performs low-level write of high-priority XON/XOFF * character and accounting for it. * * Requires uart_port to implement .serial_out(). */ void uart_xchar_out(struct uart_port *uport, int offset) { serial_port_out(uport, offset, uport->x_char); uport->icount.tx++; uport->x_char = 0; } EXPORT_SYMBOL_GPL(uart_xchar_out); /* * This function is used to send a high-priority XON/XOFF character to * the device */ static void uart_send_xchar(struct tty_struct *tty, char ch) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; port = uart_port_ref(state); if (!port) return; if (port->ops->send_xchar) port->ops->send_xchar(port, ch); else { spin_lock_irqsave(&port->lock, flags); port->x_char = ch; if (ch) port->ops->start_tx(port); spin_unlock_irqrestore(&port->lock, flags); } uart_port_deref(port); } static void uart_throttle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; upstat_t mask = UPSTAT_SYNC_FIFO; struct uart_port *port; port = uart_port_ref(state); if (!port) return; if (I_IXOFF(tty)) mask |= UPSTAT_AUTOXOFF; if (C_CRTSCTS(tty)) mask |= UPSTAT_AUTORTS; if (port->status & mask) { port->ops->throttle(port); mask &= ~port->status; } if (mask & UPSTAT_AUTORTS) uart_clear_mctrl(port, TIOCM_RTS); if (mask & UPSTAT_AUTOXOFF) uart_send_xchar(tty, STOP_CHAR(tty)); uart_port_deref(port); } static void uart_unthrottle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; upstat_t mask = UPSTAT_SYNC_FIFO; struct uart_port *port; port = uart_port_ref(state); if (!port) return; if (I_IXOFF(tty)) mask |= UPSTAT_AUTOXOFF; if (C_CRTSCTS(tty)) mask |= UPSTAT_AUTORTS; if (port->status & mask) { port->ops->unthrottle(port); mask &= ~port->status; } if (mask & UPSTAT_AUTORTS) uart_set_mctrl(port, TIOCM_RTS); if (mask & UPSTAT_AUTOXOFF) uart_send_xchar(tty, START_CHAR(tty)); uart_port_deref(port); } static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; int ret = -ENODEV; /* * Ensure the state we copy is consistent and no hardware changes * occur as we go */ mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport) goto out; retinfo->type = uport->type; retinfo->line = uport->line; retinfo->port = uport->iobase; if (HIGH_BITS_OFFSET) retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; retinfo->irq = uport->irq; retinfo->flags = (__force int)uport->flags; retinfo->xmit_fifo_size = uport->fifosize; retinfo->baud_base = uport->uartclk / 16; retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : jiffies_to_msecs(port->closing_wait) / 10; retinfo->custom_divisor = uport->custom_divisor; retinfo->hub6 = uport->hub6; retinfo->io_type = uport->iotype; retinfo->iomem_reg_shift = uport->regshift; retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; ret = 0; out: mutex_unlock(&port->mutex); return ret; } static int uart_get_info_user(struct tty_struct *tty, struct serial_struct *ss) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; return uart_get_info(port, ss) < 0 ? -EIO : 0; } static int uart_set_info(struct tty_struct *tty, struct tty_port *port, struct uart_state *state, struct serial_struct *new_info) { struct uart_port *uport = uart_port_check(state); unsigned long new_port; unsigned int change_irq, change_port, closing_wait; unsigned int old_custom_divisor, close_delay; upf_t old_flags, new_flags; int retval = 0; if (!uport) return -EIO; new_port = new_info->port; if (HIGH_BITS_OFFSET) new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET; new_info->irq = irq_canonicalize(new_info->irq); close_delay = msecs_to_jiffies(new_info->close_delay * 10); closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(new_info->closing_wait * 10); change_irq = !(uport->flags & UPF_FIXED_PORT) && new_info->irq != uport->irq; /* * Since changing the 'type' of the port changes its resource * allocations, we should treat type changes the same as * IO port changes. */ change_port = !(uport->flags & UPF_FIXED_PORT) && (new_port != uport->iobase || (unsigned long)new_info->iomem_base != uport->mapbase || new_info->hub6 != uport->hub6 || new_info->io_type != uport->iotype || new_info->iomem_reg_shift != uport->regshift || new_info->type != uport->type); old_flags = uport->flags; new_flags = (__force upf_t)new_info->flags; old_custom_divisor = uport->custom_divisor; if (!capable(CAP_SYS_ADMIN)) { retval = -EPERM; if (change_irq || change_port || (new_info->baud_base != uport->uartclk / 16) || (close_delay != port->close_delay) || (closing_wait != port->closing_wait) || (new_info->xmit_fifo_size && new_info->xmit_fifo_size != uport->fifosize) || (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) goto exit; uport->flags = ((uport->flags & ~UPF_USR_MASK) | (new_flags & UPF_USR_MASK)); uport->custom_divisor = new_info->custom_divisor; goto check_and_exit; } if (change_irq || change_port) { retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); if (retval) goto exit; } /* * Ask the low level driver to verify the settings. */ if (uport->ops->verify_port) retval = uport->ops->verify_port(uport, new_info); if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || (new_info->baud_base < 9600)) retval = -EINVAL; if (retval) goto exit; if (change_port || change_irq) { retval = -EBUSY; /* * Make sure that we are the sole user of this port. */ if (tty_port_users(port) > 1) goto exit; /* * We need to shutdown the serial port at the old * port/type/irq combination. */ uart_shutdown(tty, state); } if (change_port) { unsigned long old_iobase, old_mapbase; unsigned int old_type, old_iotype, old_hub6, old_shift; old_iobase = uport->iobase; old_mapbase = uport->mapbase; old_type = uport->type; old_hub6 = uport->hub6; old_iotype = uport->iotype; old_shift = uport->regshift; /* * Free and release old regions */ if (old_type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); uport->iobase = new_port; uport->type = new_info->type; uport->hub6 = new_info->hub6; uport->iotype = new_info->io_type; uport->regshift = new_info->iomem_reg_shift; uport->mapbase = (unsigned long)new_info->iomem_base; /* * Claim and map the new regions */ if (uport->type != PORT_UNKNOWN && uport->ops->request_port) { retval = uport->ops->request_port(uport); } else { /* Always success - Jean II */ retval = 0; } /* * If we fail to request resources for the * new port, try to restore the old settings. */ if (retval) { uport->iobase = old_iobase; uport->type = old_type; uport->hub6 = old_hub6; uport->iotype = old_iotype; uport->regshift = old_shift; uport->mapbase = old_mapbase; if (old_type != PORT_UNKNOWN) { retval = uport->ops->request_port(uport); /* * If we failed to restore the old settings, * we fail like this. */ if (retval) uport->type = PORT_UNKNOWN; /* * We failed anyway. */ retval = -EBUSY; } /* Added to return the correct error -Ram Gupta */ goto exit; } } if (change_irq) uport->irq = new_info->irq; if (!(uport->flags & UPF_FIXED_PORT)) uport->uartclk = new_info->baud_base * 16; uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | (new_flags & UPF_CHANGE_MASK); uport->custom_divisor = new_info->custom_divisor; port->close_delay = close_delay; port->closing_wait = closing_wait; if (new_info->xmit_fifo_size) uport->fifosize = new_info->xmit_fifo_size; check_and_exit: retval = 0; if (uport->type == PORT_UNKNOWN) goto exit; if (tty_port_initialized(port)) { if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || old_custom_divisor != uport->custom_divisor) { /* * If they're setting up a custom divisor or speed, * instead of clearing it, then bitch about it. */ if (uport->flags & UPF_SPD_MASK) { dev_notice_ratelimited(uport->dev, "%s sets custom speed on %s. This is deprecated.\n", current->comm, tty_name(port->tty)); } uart_change_speed(tty, state, NULL); } } else { retval = uart_startup(tty, state, 1); if (retval == 0) tty_port_set_initialized(port, true); if (retval > 0) retval = 0; } exit: return retval; } static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; int retval; down_write(&tty->termios_rwsem); /* * This semaphore protects port->count. It is also * very useful to prevent opens. Also, take the * port configuration semaphore to make sure that a * module insertion/removal doesn't change anything * under us. */ mutex_lock(&port->mutex); retval = uart_set_info(tty, port, state, ss); mutex_unlock(&port->mutex); up_write(&tty->termios_rwsem); return retval; } /** * uart_get_lsr_info - get line status register info * @tty: tty associated with the UART * @state: UART being queried * @value: returned modem value */ static int uart_get_lsr_info(struct tty_struct *tty, struct uart_state *state, unsigned int __user *value) { struct uart_port *uport = uart_port_check(state); unsigned int result; result = uport->ops->tx_empty(uport); /* * If we're about to load something into the transmit * register, we'll pretend the transmitter isn't empty to * avoid a race condition (depending on when the transmit * interrupt happens). */ if (uport->x_char || ((uart_circ_chars_pending(&state->xmit) > 0) && !uart_tx_stopped(uport))) result &= ~TIOCSER_TEMT; return put_user(result, value); } static int uart_tiocmget(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; struct uart_port *uport; int result = -EIO; mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport) goto out; if (!tty_io_error(tty)) { result = uport->mctrl; spin_lock_irq(&uport->lock); result |= uport->ops->get_mctrl(uport); spin_unlock_irq(&uport->lock); } out: mutex_unlock(&port->mutex); return result; } static int uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; struct uart_port *uport; int ret = -EIO; mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport) goto out; if (!tty_io_error(tty)) { uart_update_mctrl(uport, set, clear); ret = 0; } out: mutex_unlock(&port->mutex); return ret; } static int uart_break_ctl(struct tty_struct *tty, int break_state) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; struct uart_port *uport; int ret = -EIO; mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport) goto out; if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl) uport->ops->break_ctl(uport, break_state); ret = 0; out: mutex_unlock(&port->mutex); return ret; } static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state) { struct tty_port *port = &state->port; struct uart_port *uport; int flags, ret; if (!capable(CAP_SYS_ADMIN)) return -EPERM; /* * Take the per-port semaphore. This prevents count from * changing, and hence any extra opens of the port while * we're auto-configuring. */ if (mutex_lock_interruptible(&port->mutex)) return -ERESTARTSYS; uport = uart_port_check(state); if (!uport) { ret = -EIO; goto out; } ret = -EBUSY; if (tty_port_users(port) == 1) { uart_shutdown(tty, state); /* * If we already have a port type configured, * we must release its resources. */ if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); flags = UART_CONFIG_TYPE; if (uport->flags & UPF_AUTO_IRQ) flags |= UART_CONFIG_IRQ; /* * This will claim the ports resources if * a port is found. */ uport->ops->config_port(uport, flags); ret = uart_startup(tty, state, 1); if (ret == 0) tty_port_set_initialized(port, true); if (ret > 0) ret = 0; } out: mutex_unlock(&port->mutex); return ret; } static void uart_enable_ms(struct uart_port *uport) { /* * Force modem status interrupts on */ if (uport->ops->enable_ms) uport->ops->enable_ms(uport); } /* * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change * - mask passed in arg for lines of interest * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) * Caller should use TIOCGICOUNT to see which one it was * * FIXME: This wants extracting into a common all driver implementation * of TIOCMWAIT using tty_port. */ static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) { struct uart_port *uport; struct tty_port *port = &state->port; DECLARE_WAITQUEUE(wait, current); struct uart_icount cprev, cnow; int ret; /* * note the counters on entry */ uport = uart_port_ref(state); if (!uport) return -EIO; spin_lock_irq(&uport->lock); memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); uart_enable_ms(uport); spin_unlock_irq(&uport->lock); add_wait_queue(&port->delta_msr_wait, &wait); for (;;) { spin_lock_irq(&uport->lock); memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); spin_unlock_irq(&uport->lock); set_current_state(TASK_INTERRUPTIBLE); if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { ret = 0; break; } schedule(); /* see if a signal did it */ if (signal_pending(current)) { ret = -ERESTARTSYS; break; } cprev = cnow; } __set_current_state(TASK_RUNNING); remove_wait_queue(&port->delta_msr_wait, &wait); uart_port_deref(uport); return ret; } /* * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) * Return: write counters to the user passed counter struct * NB: both 1->0 and 0->1 transitions are counted except for * RI where only 0->1 is counted. */ static int uart_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount) { struct uart_state *state = tty->driver_data; struct uart_icount cnow; struct uart_port *uport; uport = uart_port_ref(state); if (!uport) return -EIO; spin_lock_irq(&uport->lock); memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); spin_unlock_irq(&uport->lock); uart_port_deref(uport); icount->cts = cnow.cts; icount->dsr = cnow.dsr; icount->rng = cnow.rng; icount->dcd = cnow.dcd; icount->rx = cnow.rx; icount->tx = cnow.tx; icount->frame = cnow.frame; icount->overrun = cnow.overrun; icount->parity = cnow.parity; icount->brk = cnow.brk; icount->buf_overrun = cnow.buf_overrun; return 0; } #define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \ SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \ SER_RS485_TERMINATE_BUS) static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485) { u32 flags = rs485->flags; /* Don't return -EINVAL for unsupported legacy flags */ flags &= ~SER_RS485_LEGACY_FLAGS; /* * For any bit outside of the legacy ones that is not supported by * the driver, return -EINVAL. */ if (flags & ~port->rs485_supported.flags) return -EINVAL; /* Asking for address w/o addressing mode? */ if (!(rs485->flags & SER_RS485_ADDRB) && (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST))) return -EINVAL; /* Address given but not enabled? */ if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv) return -EINVAL; if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest) return -EINVAL; return 0; } static void uart_sanitize_serial_rs485_delays(struct uart_port *port, struct serial_rs485 *rs485) { if (!port->rs485_supported.delay_rts_before_send) { if (rs485->delay_rts_before_send) { dev_warn_ratelimited(port->dev, "%s (%d): RTS delay before sending not supported\n", port->name, port->line); } rs485->delay_rts_before_send = 0; } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) { rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY; dev_warn_ratelimited(port->dev, "%s (%d): RTS delay before sending clamped to %u ms\n", port->name, port->line, rs485->delay_rts_before_send); } if (!port->rs485_supported.delay_rts_after_send) { if (rs485->delay_rts_after_send) { dev_warn_ratelimited(port->dev, "%s (%d): RTS delay after sending not supported\n", port->name, port->line); } rs485->delay_rts_after_send = 0; } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) { rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY; dev_warn_ratelimited(port->dev, "%s (%d): RTS delay after sending clamped to %u ms\n", port->name, port->line, rs485->delay_rts_after_send); } } static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485) { u32 supported_flags = port->rs485_supported.flags; if (!(rs485->flags & SER_RS485_ENABLED)) { memset(rs485, 0, sizeof(*rs485)); return; } /* Pick sane settings if the user hasn't */ if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) && !(rs485->flags & SER_RS485_RTS_ON_SEND) == !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { dev_warn_ratelimited(port->dev, "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n", port->name, port->line); rs485->flags |= SER_RS485_RTS_ON_SEND; rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; supported_flags |= SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND; } rs485->flags &= supported_flags; uart_sanitize_serial_rs485_delays(port, rs485); /* Return clean padding area to userspace */ memset(rs485->padding0, 0, sizeof(rs485->padding0)); memset(rs485->padding1, 0, sizeof(rs485->padding1)); } static void uart_set_rs485_termination(struct uart_port *port, const struct serial_rs485 *rs485) { if (!(rs485->flags & SER_RS485_ENABLED)) return; gpiod_set_value_cansleep(port->rs485_term_gpio, !!(rs485->flags & SER_RS485_TERMINATE_BUS)); } int uart_rs485_config(struct uart_port *port) { struct serial_rs485 *rs485 = &port->rs485; int ret; uart_sanitize_serial_rs485(port, rs485); uart_set_rs485_termination(port, rs485); ret = port->rs485_config(port, NULL, rs485); if (ret) memset(rs485, 0, sizeof(*rs485)); return ret; } EXPORT_SYMBOL_GPL(uart_rs485_config); static int uart_get_rs485_config(struct uart_port *port, struct serial_rs485 __user *rs485) { unsigned long flags; struct serial_rs485 aux; spin_lock_irqsave(&port->lock, flags); aux = port->rs485; spin_unlock_irqrestore(&port->lock, flags); if (copy_to_user(rs485, &aux, sizeof(aux))) return -EFAULT; return 0; } static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, struct serial_rs485 __user *rs485_user) { struct serial_rs485 rs485; int ret; unsigned long flags; if (!port->rs485_config) return -ENOTTY; if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) return -EFAULT; ret = uart_check_rs485_flags(port, &rs485); if (ret) return ret; uart_sanitize_serial_rs485(port, &rs485); uart_set_rs485_termination(port, &rs485); spin_lock_irqsave(&port->lock, flags); ret = port->rs485_config(port, &tty->termios, &rs485); if (!ret) port->rs485 = rs485; spin_unlock_irqrestore(&port->lock, flags); if (ret) return ret; if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) return -EFAULT; return 0; } static int uart_get_iso7816_config(struct uart_port *port, struct serial_iso7816 __user *iso7816) { unsigned long flags; struct serial_iso7816 aux; if (!port->iso7816_config) return -ENOTTY; spin_lock_irqsave(&port->lock, flags); aux = port->iso7816; spin_unlock_irqrestore(&port->lock, flags); if (copy_to_user(iso7816, &aux, sizeof(aux))) return -EFAULT; return 0; } static int uart_set_iso7816_config(struct uart_port *port, struct serial_iso7816 __user *iso7816_user) { struct serial_iso7816 iso7816; int i, ret; unsigned long flags; if (!port->iso7816_config) return -ENOTTY; if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user))) return -EFAULT; /* * There are 5 words reserved for future use. Check that userspace * doesn't put stuff in there to prevent breakages in the future. */ for (i = 0; i < 5; i++) if (iso7816.reserved[i]) return -EINVAL; spin_lock_irqsave(&port->lock, flags); ret = port->iso7816_config(port, &iso7816); spin_unlock_irqrestore(&port->lock, flags); if (ret) return ret; if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816))) return -EFAULT; return 0; } /* * Called via sys_ioctl. We can use spin_lock_irq() here. */ static int uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; struct uart_port *uport; void __user *uarg = (void __user *)arg; int ret = -ENOIOCTLCMD; /* * These ioctls don't rely on the hardware to be present. */ switch (cmd) { case TIOCSERCONFIG: down_write(&tty->termios_rwsem); ret = uart_do_autoconfig(tty, state); up_write(&tty->termios_rwsem); break; } if (ret != -ENOIOCTLCMD) goto out; if (tty_io_error(tty)) { ret = -EIO; goto out; } /* * The following should only be used when hardware is present. */ switch (cmd) { case TIOCMIWAIT: ret = uart_wait_modem_status(state, arg); break; } if (ret != -ENOIOCTLCMD) goto out; /* rs485_config requires more locking than others */ if (cmd == TIOCGRS485) down_write(&tty->termios_rwsem); mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport || tty_io_error(tty)) { ret = -EIO; goto out_up; } /* * All these rely on hardware being present and need to be * protected against the tty being hung up. */ switch (cmd) { case TIOCSERGETLSR: /* Get line status register */ ret = uart_get_lsr_info(tty, state, uarg); break; case TIOCGRS485: ret = uart_get_rs485_config(uport, uarg); break; case TIOCSRS485: ret = uart_set_rs485_config(tty, uport, uarg); break; case TIOCSISO7816: ret = uart_set_iso7816_config(state->uart_port, uarg); break; case TIOCGISO7816: ret = uart_get_iso7816_config(state->uart_port, uarg); break; default: if (uport->ops->ioctl) ret = uport->ops->ioctl(uport, cmd, arg); break; } out_up: mutex_unlock(&port->mutex); if (cmd == TIOCGRS485) up_write(&tty->termios_rwsem); out: return ret; } static void uart_set_ldisc(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *uport; struct tty_port *port = &state->port; if (!tty_port_initialized(port)) return; mutex_lock(&state->port.mutex); uport = uart_port_check(state); if (uport && uport->ops->set_ldisc) uport->ops->set_ldisc(uport, &tty->termios); mutex_unlock(&state->port.mutex); } static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { struct uart_state *state = tty->driver_data; struct uart_port *uport; unsigned int cflag = tty->termios.c_cflag; unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; bool sw_changed = false; mutex_lock(&state->port.mutex); uport = uart_port_check(state); if (!uport) goto out; /* * Drivers doing software flow control also need to know * about changes to these input settings. */ if (uport->flags & UPF_SOFT_FLOW) { iflag_mask |= IXANY|IXON|IXOFF; sw_changed = tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; } /* * These are the bits that are used to setup various * flags in the low level driver. We can ignore the Bfoo * bits in c_cflag; c_[io]speed will always be set * appropriately by set_termios() in tty_ioctl.c */ if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios.c_ospeed == old_termios->c_ospeed && tty->termios.c_ispeed == old_termios->c_ispeed && ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && !sw_changed) { goto out; } uart_change_speed(tty, state, old_termios); /* reload cflag from termios; port driver may have overridden flags */ cflag = tty->termios.c_cflag; /* Handle transition to B0 status */ if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); /* Handle transition away from B0 status */ else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { unsigned int mask = TIOCM_DTR; if (!(cflag & CRTSCTS) || !tty_throttled(tty)) mask |= TIOCM_RTS; uart_set_mctrl(uport, mask); } out: mutex_unlock(&state->port.mutex); } /* * Calls to uart_close() are serialised via the tty_lock in * drivers/tty/tty_io.c:tty_release() * drivers/tty/tty_io.c:do_tty_hangup() */ static void uart_close(struct tty_struct *tty, struct file *filp) { struct uart_state *state = tty->driver_data; if (!state) { struct uart_driver *drv = tty->driver->driver_state; struct tty_port *port; state = drv->state + tty->index; port = &state->port; spin_lock_irq(&port->lock); --port->count; spin_unlock_irq(&port->lock); return; } pr_debug("uart_close(%d) called\n", tty->index); tty_port_close(tty->port, tty, filp); } static void uart_tty_port_shutdown(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = uart_port_check(state); char *buf; /* * At this point, we stop accepting input. To do this, we * disable the receive line status interrupts. */ if (WARN(!uport, "detached port still initialized!\n")) return; spin_lock_irq(&uport->lock); uport->ops->stop_rx(uport); spin_unlock_irq(&uport->lock); uart_port_shutdown(port); /* * It's possible for shutdown to be called after suspend if we get * a DCD drop (hangup) at just the right time. Clear suspended bit so * we don't try to resume a port that has been shutdown. */ tty_port_set_suspended(port, 0); /* * Free the transmit buffer. */ spin_lock_irq(&uport->lock); buf = state->xmit.buf; state->xmit.buf = NULL; spin_unlock_irq(&uport->lock); free_page((unsigned long)buf); uart_change_pm(state, UART_PM_STATE_OFF); } static void uart_wait_until_sent(struct tty_struct *tty, int timeout) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long char_time, expire, fifo_timeout; port = uart_port_ref(state); if (!port) return; if (port->type == PORT_UNKNOWN || port->fifosize == 0) { uart_port_deref(port); return; } /* * Set the check interval to be 1/5 of the estimated time to * send a single character, and make it at least 1. The check * interval should also be less than the timeout. * * Note: we have to use pretty tight timings here to satisfy * the NIST-PCTS. */ char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL); if (timeout && timeout < char_time) char_time = timeout; if (!uart_cts_enabled(port)) { /* * If the transmitter hasn't cleared in twice the approximate * amount of time to send the entire FIFO, it probably won't * ever clear. This assumes the UART isn't doing flow * control, which is currently the case. Hence, if it ever * takes longer than FIFO timeout, this is probably due to a * UART bug of some kind. So, we clamp the timeout parameter at * 2 * FIFO timeout. */ fifo_timeout = uart_fifo_timeout(port); if (timeout == 0 || timeout > 2 * fifo_timeout) timeout = 2 * fifo_timeout; } expire = jiffies + timeout; pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", port->line, jiffies, expire); /* * Check whether the transmitter is empty every 'char_time'. * 'timeout' / 'expire' give us the maximum amount of time * we wait. */ while (!port->ops->tx_empty(port)) { msleep_interruptible(jiffies_to_msecs(char_time)); if (signal_pending(current)) break; if (timeout && time_after(jiffies, expire)) break; } uart_port_deref(port); } /* * Calls to uart_hangup() are serialised by the tty_lock in * drivers/tty/tty_io.c:do_tty_hangup() * This runs from a workqueue and can sleep for a _short_ time only. */ static void uart_hangup(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; struct uart_port *uport; unsigned long flags; pr_debug("uart_hangup(%d)\n", tty->index); mutex_lock(&port->mutex); uport = uart_port_check(state); WARN(!uport, "hangup of detached port!\n"); if (tty_port_active(port)) { uart_flush_buffer(tty); uart_shutdown(tty, state); spin_lock_irqsave(&port->lock, flags); port->count = 0; spin_unlock_irqrestore(&port->lock, flags); tty_port_set_active(port, 0); tty_port_tty_set(port, NULL); if (uport && !uart_console(uport)) uart_change_pm(state, UART_PM_STATE_OFF); wake_up_interruptible(&port->open_wait); wake_up_interruptible(&port->delta_msr_wait); } mutex_unlock(&port->mutex); } /* uport == NULL if uart_port has already been removed */ static void uart_port_shutdown(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = uart_port_check(state); /* * clear delta_msr_wait queue to avoid mem leaks: we may free * the irq here so the queue might never be woken up. Note * that we won't end up waiting on delta_msr_wait again since * any outstanding file descriptors should be pointing at * hung_up_tty_fops now. */ wake_up_interruptible(&port->delta_msr_wait); if (uport) { /* Free the IRQ and disable the port. */ uport->ops->shutdown(uport); /* Ensure that the IRQ handler isn't running on another CPU. */ synchronize_irq(uport->irq); } } static int uart_carrier_raised(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; int mctrl; uport = uart_port_ref(state); /* * Should never observe uport == NULL since checks for hangup should * abort the tty_port_block_til_ready() loop before checking for carrier * raised -- but report carrier raised if it does anyway so open will * continue and not sleep */ if (WARN_ON(!uport)) return 1; spin_lock_irq(&uport->lock); uart_enable_ms(uport); mctrl = uport->ops->get_mctrl(uport); spin_unlock_irq(&uport->lock); uart_port_deref(uport); if (mctrl & TIOCM_CAR) return 1; return 0; } static void uart_dtr_rts(struct tty_port *port, int raise) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; uport = uart_port_ref(state); if (!uport) return; uart_port_dtr_rts(uport, raise); uart_port_deref(uport); } static int uart_install(struct tty_driver *driver, struct tty_struct *tty) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + tty->index; tty->driver_data = state; return tty_standard_install(driver, tty); } /* * Calls to uart_open are serialised by the tty_lock in * drivers/tty/tty_io.c:tty_open() * Note that if this fails, then uart_close() _will_ be called. * * In time, we want to scrap the "opening nonpresent ports" * behaviour and implement an alternative way for setserial * to set base addresses/ports/types. This will allow us to * get rid of a certain amount of extra tests. */ static int uart_open(struct tty_struct *tty, struct file *filp) { struct uart_state *state = tty->driver_data; int retval; retval = tty_port_open(&state->port, tty, filp); if (retval > 0) retval = 0; return retval; } static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; int ret; uport = uart_port_check(state); if (!uport || uport->flags & UPF_DEAD) return -ENXIO; /* * Start up the serial port. */ ret = uart_startup(tty, state, 0); if (ret > 0) tty_port_set_active(port, 1); return ret; } static const char *uart_type(struct uart_port *port) { const char *str = NULL; if (port->ops->type) str = port->ops->type(port); if (!str) str = "unknown"; return str; } #ifdef CONFIG_PROC_FS static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) { struct uart_state *state = drv->state + i; struct tty_port *port = &state->port; enum uart_pm_state pm_state; struct uart_port *uport; char stat_buf[32]; unsigned int status; int mmio; mutex_lock(&port->mutex); uport = uart_port_check(state); if (!uport) goto out; mmio = uport->iotype >= UPIO_MEM; seq_printf(m, "%d: uart:%s %s%08llX irq:%d", uport->line, uart_type(uport), mmio ? "mmio:0x" : "port:", mmio ? (unsigned long long)uport->mapbase : (unsigned long long)uport->iobase, uport->irq); if (uport->type == PORT_UNKNOWN) { seq_putc(m, '\n'); goto out; } if (capable(CAP_SYS_ADMIN)) { pm_state = state->pm_state; if (pm_state != UART_PM_STATE_ON) uart_change_pm(state, UART_PM_STATE_ON); spin_lock_irq(&uport->lock); status = uport->ops->get_mctrl(uport); spin_unlock_irq(&uport->lock); if (pm_state != UART_PM_STATE_ON) uart_change_pm(state, pm_state); seq_printf(m, " tx:%d rx:%d", uport->icount.tx, uport->icount.rx); if (uport->icount.frame) seq_printf(m, " fe:%d", uport->icount.frame); if (uport->icount.parity) seq_printf(m, " pe:%d", uport->icount.parity); if (uport->icount.brk) seq_printf(m, " brk:%d", uport->icount.brk); if (uport->icount.overrun) seq_printf(m, " oe:%d", uport->icount.overrun); if (uport->icount.buf_overrun) seq_printf(m, " bo:%d", uport->icount.buf_overrun); #define INFOBIT(bit, str) \ if (uport->mctrl & (bit)) \ strncat(stat_buf, (str), sizeof(stat_buf) - \ strlen(stat_buf) - 2) #define STATBIT(bit, str) \ if (status & (bit)) \ strncat(stat_buf, (str), sizeof(stat_buf) - \ strlen(stat_buf) - 2) stat_buf[0] = '\0'; stat_buf[1] = '\0'; INFOBIT(TIOCM_RTS, "|RTS"); STATBIT(TIOCM_CTS, "|CTS"); INFOBIT(TIOCM_DTR, "|DTR"); STATBIT(TIOCM_DSR, "|DSR"); STATBIT(TIOCM_CAR, "|CD"); STATBIT(TIOCM_RNG, "|RI"); if (stat_buf[0]) stat_buf[0] = ' '; seq_puts(m, stat_buf); } seq_putc(m, '\n'); #undef STATBIT #undef INFOBIT out: mutex_unlock(&port->mutex); } static int uart_proc_show(struct seq_file *m, void *v) { struct tty_driver *ttydrv = m->private; struct uart_driver *drv = ttydrv->driver_state; int i; seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); for (i = 0; i < drv->nr; i++) uart_line_info(m, drv, i); return 0; } #endif static void uart_port_spin_lock_init(struct uart_port *port) { spin_lock_init(&port->lock); lockdep_set_class(&port->lock, &port_lock_key); } #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) /** * uart_console_write - write a console message to a serial port * @port: the port to write the message * @s: array of characters * @count: number of characters in string to write * @putchar: function to write character to port */ void uart_console_write(struct uart_port *port, const char *s, unsigned int count, void (*putchar)(struct uart_port *, unsigned char)) { unsigned int i; for (i = 0; i < count; i++, s++) { if (*s == '\n') putchar(port, '\r'); putchar(port, *s); } } EXPORT_SYMBOL_GPL(uart_console_write); /** * uart_get_console - get uart port for console * @ports: ports to search in * @nr: number of @ports * @co: console to search for * Returns: uart_port for the console @co * * Check whether an invalid uart number has been specified (as @co->index), and * if so, search for the first available port that does have console support. */ struct uart_port * __init uart_get_console(struct uart_port *ports, int nr, struct console *co) { int idx = co->index; if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && ports[idx].membase == NULL)) for (idx = 0; idx < nr; idx++) if (ports[idx].iobase != 0 || ports[idx].membase != NULL) break; co->index = idx; return ports + idx; } /** * uart_parse_earlycon - Parse earlycon options * @p: ptr to 2nd field (ie., just beyond '<name>,') * @iotype: ptr for decoded iotype (out) * @addr: ptr for decoded mapbase/iobase (out) * @options: ptr for <options> field; %NULL if not present (out) * * Decodes earlycon kernel command line parameters of the form: * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> * * The optional form: * * earlycon=<name>,0x<addr>,<options> * * console=<name>,0x<addr>,<options> * * is also accepted; the returned @iotype will be %UPIO_MEM. * * Returns: 0 on success or -%EINVAL on failure */ int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, char **options) { if (strncmp(p, "mmio,", 5) == 0) { *iotype = UPIO_MEM; p += 5; } else if (strncmp(p, "mmio16,", 7) == 0) { *iotype = UPIO_MEM16; p += 7; } else if (strncmp(p, "mmio32,", 7) == 0) { *iotype = UPIO_MEM32; p += 7; } else if (strncmp(p, "mmio32be,", 9) == 0) { *iotype = UPIO_MEM32BE; p += 9; } else if (strncmp(p, "mmio32native,", 13) == 0) { *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ? UPIO_MEM32BE : UPIO_MEM32; p += 13; } else if (strncmp(p, "io,", 3) == 0) { *iotype = UPIO_PORT; p += 3; } else if (strncmp(p, "0x", 2) == 0) { *iotype = UPIO_MEM; } else { return -EINVAL; } /* * Before you replace it with kstrtoull(), think about options separator * (',') it will not tolerate */ *addr = simple_strtoull(p, NULL, 0); p = strchr(p, ','); if (p) p++; *options = p; return 0; } EXPORT_SYMBOL_GPL(uart_parse_earlycon); /** * uart_parse_options - Parse serial port baud/parity/bits/flow control. * @options: pointer to option string * @baud: pointer to an 'int' variable for the baud rate. * @parity: pointer to an 'int' variable for the parity. * @bits: pointer to an 'int' variable for the number of data bits. * @flow: pointer to an 'int' variable for the flow control character. * * uart_parse_options() decodes a string containing the serial console * options. The format of the string is <baud><parity><bits><flow>, * eg: 115200n8r */ void uart_parse_options(const char *options, int *baud, int *parity, int *bits, int *flow) { const char *s = options; *baud = simple_strtoul(s, NULL, 10); while (*s >= '0' && *s <= '9') s++; if (*s) *parity = *s++; if (*s) *bits = *s++ - '0'; if (*s) *flow = *s; } EXPORT_SYMBOL_GPL(uart_parse_options); /** * uart_set_options - setup the serial console parameters * @port: pointer to the serial ports uart_port structure * @co: console pointer * @baud: baud rate * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) * @bits: number of data bits * @flow: flow control character - 'r' (rts) */ int uart_set_options(struct uart_port *port, struct console *co, int baud, int parity, int bits, int flow) { struct ktermios termios; static struct ktermios dummy; /* * Ensure that the serial-console lock is initialised early. * * Note that the console-enabled check is needed because of kgdboc, * which can end up calling uart_set_options() for an already enabled * console via tty_find_polling_driver() and uart_poll_init(). */ if (!uart_console_enabled(port) && !port->console_reinit) uart_port_spin_lock_init(port); memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag |= CREAD | HUPCL | CLOCAL; tty_termios_encode_baud_rate(&termios, baud, baud); if (bits == 7) termios.c_cflag |= CS7; else termios.c_cflag |= CS8; switch (parity) { case 'o': case 'O': termios.c_cflag |= PARODD; fallthrough; case 'e': case 'E': termios.c_cflag |= PARENB; break; } if (flow == 'r') termios.c_cflag |= CRTSCTS; /* * some uarts on other side don't support no flow control. * So we set * DTR in host uart to make them happy */ port->mctrl |= TIOCM_DTR; port->ops->set_termios(port, &termios, &dummy); /* * Allow the setting of the UART parameters with a NULL console * too: */ if (co) { co->cflag = termios.c_cflag; co->ispeed = termios.c_ispeed; co->ospeed = termios.c_ospeed; } return 0; } EXPORT_SYMBOL_GPL(uart_set_options); #endif /* CONFIG_SERIAL_CORE_CONSOLE */ /** * uart_change_pm - set power state of the port * * @state: port descriptor * @pm_state: new state * * Locking: port->mutex has to be held */ static void uart_change_pm(struct uart_state *state, enum uart_pm_state pm_state) { struct uart_port *port = uart_port_check(state); if (state->pm_state != pm_state) { if (port && port->ops->pm) port->ops->pm(port, pm_state, state->pm_state); state->pm_state = pm_state; } } struct uart_match { struct uart_port *port; struct uart_driver *driver; }; static int serial_match_port(struct device *dev, void *data) { struct uart_match *match = data; struct tty_driver *tty_drv = match->driver->tty_driver; dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + match->port->line; return dev->devt == devt; /* Actually, only one tty per port */ } int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state = drv->state + uport->line; struct tty_port *port = &state->port; struct device *tty_dev; struct uart_match match = {uport, drv}; mutex_lock(&port->mutex); tty_dev = device_find_child(uport->dev, &match, serial_match_port); if (tty_dev && device_may_wakeup(tty_dev)) { enable_irq_wake(uport->irq); put_device(tty_dev); mutex_unlock(&port->mutex); return 0; } put_device(tty_dev); /* * Nothing to do if the console is not suspending * except stop_rx to prevent any asynchronous data * over RX line. However ensure that we will be * able to Re-start_rx later. */ if (!console_suspend_enabled && uart_console(uport)) { if (uport->ops->start_rx) uport->ops->stop_rx(uport); goto unlock; } uport->suspended = 1; if (tty_port_initialized(port)) { const struct uart_ops *ops = uport->ops; int tries; unsigned int mctrl; tty_port_set_suspended(port, 1); tty_port_set_initialized(port, 0); spin_lock_irq(&uport->lock); ops->stop_tx(uport); ops->set_mctrl(uport, 0); /* save mctrl so it can be restored on resume */ mctrl = uport->mctrl; uport->mctrl = 0; ops->stop_rx(uport); spin_unlock_irq(&uport->lock); /* * Wait for the transmitter to empty. */ for (tries = 3; !ops->tx_empty(uport) && tries; tries--) msleep(10); if (!tries) dev_err(uport->dev, "%s: Unable to drain transmitter\n", uport->name); ops->shutdown(uport); uport->mctrl = mctrl; } /* * Disable the console device before suspending. */ if (uart_console(uport)) console_stop(uport->cons); uart_change_pm(state, UART_PM_STATE_OFF); unlock: mutex_unlock(&port->mutex); return 0; } EXPORT_SYMBOL(uart_suspend_port); int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state = drv->state + uport->line; struct tty_port *port = &state->port; struct device *tty_dev; struct uart_match match = {uport, drv}; struct ktermios termios; mutex_lock(&port->mutex); tty_dev = device_find_child(uport->dev, &match, serial_match_port); if (!uport->suspended && device_may_wakeup(tty_dev)) { if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq)))) disable_irq_wake(uport->irq); put_device(tty_dev); mutex_unlock(&port->mutex); return 0; } put_device(tty_dev); uport->suspended = 0; /* * Re-enable the console device after suspending. */ if (uart_console(uport)) { /* * First try to use the console cflag setting. */ memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag = uport->cons->cflag; termios.c_ispeed = uport->cons->ispeed; termios.c_ospeed = uport->cons->ospeed; /* * If that's unset, use the tty termios setting. */ if (port->tty && termios.c_cflag == 0) termios = port->tty->termios; if (console_suspend_enabled) uart_change_pm(state, UART_PM_STATE_ON); uport->ops->set_termios(uport, &termios, NULL); if (!console_suspend_enabled && uport->ops->start_rx) uport->ops->start_rx(uport); if (console_suspend_enabled) console_start(uport->cons); } if (tty_port_suspended(port)) { const struct uart_ops *ops = uport->ops; int ret; uart_change_pm(state, UART_PM_STATE_ON); spin_lock_irq(&uport->lock); ops->set_mctrl(uport, 0); spin_unlock_irq(&uport->lock); if (console_suspend_enabled || !uart_console(uport)) { /* Protected by port mutex for now */ struct tty_struct *tty = port->tty; ret = ops->startup(uport); if (ret == 0) { if (tty) uart_change_speed(tty, state, NULL); spin_lock_irq(&uport->lock); ops->set_mctrl(uport, uport->mctrl); ops->start_tx(uport); spin_unlock_irq(&uport->lock); tty_port_set_initialized(port, 1); } else { /* * Failed to resume - maybe hardware went away? * Clear the "initialized" flag so we won't try * to call the low level drivers shutdown method. */ uart_shutdown(tty, state); } } tty_port_set_suspended(port, 0); } mutex_unlock(&port->mutex); return 0; } EXPORT_SYMBOL(uart_resume_port); static inline void uart_report_port(struct uart_driver *drv, struct uart_port *port) { char address[64]; switch (port->iotype) { case UPIO_PORT: snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase); break; case UPIO_HUB6: snprintf(address, sizeof(address), "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); break; case UPIO_MEM: case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: case UPIO_TSI: snprintf(address, sizeof(address), "MMIO 0x%llx", (unsigned long long)port->mapbase); break; default: strlcpy(address, "*unknown*", sizeof(address)); break; } pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n", port->dev ? dev_name(port->dev) : "", port->dev ? ": " : "", port->name, address, port->irq, port->uartclk / 16, uart_type(port)); /* The magic multiplier feature is a bit obscure, so report it too. */ if (port->flags & UPF_MAGIC_MULTIPLIER) pr_info("%s%s%s extra baud rates supported: %d, %d", port->dev ? dev_name(port->dev) : "", port->dev ? ": " : "", port->name, port->uartclk / 8, port->uartclk / 4); } static void uart_configure_port(struct uart_driver *drv, struct uart_state *state, struct uart_port *port) { unsigned int flags; /* * If there isn't a port here, don't do anything further. */ if (!port->iobase && !port->mapbase && !port->membase) return; /* * Now do the auto configuration stuff. Note that config_port * is expected to claim the resources and map the port for us. */ flags = 0; if (port->flags & UPF_AUTO_IRQ) flags |= UART_CONFIG_IRQ; if (port->flags & UPF_BOOT_AUTOCONF) { if (!(port->flags & UPF_FIXED_TYPE)) { port->type = PORT_UNKNOWN; flags |= UART_CONFIG_TYPE; } port->ops->config_port(port, flags); } if (port->type != PORT_UNKNOWN) { unsigned long flags; uart_report_port(drv, port); /* Power up port for set_mctrl() */ uart_change_pm(state, UART_PM_STATE_ON); /* * Ensure that the modem control lines are de-activated. * keep the DTR setting that is set in uart_set_options() * We probably don't need a spinlock around this, but */ spin_lock_irqsave(&port->lock, flags); port->mctrl &= TIOCM_DTR; if (port->rs485.flags & SER_RS485_ENABLED && !(port->rs485.flags & SER_RS485_RTS_AFTER_SEND)) port->mctrl |= TIOCM_RTS; port->ops->set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); /* * If this driver supports console, and it hasn't been * successfully registered yet, try to re-register it. * It may be that the port was not available. */ if (port->cons && !(port->cons->flags & CON_ENABLED)) register_console(port->cons); /* * Power down all ports by default, except the * console if we have one. */ if (!uart_console(port)) uart_change_pm(state, UART_PM_STATE_OFF); } } #ifdef CONFIG_CONSOLE_POLL static int uart_poll_init(struct tty_driver *driver, int line, char *options) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; struct tty_port *tport; struct uart_port *port; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int ret = 0; tport = &state->port; mutex_lock(&tport->mutex); port = uart_port_check(state); if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) { ret = -1; goto out; } if (port->ops->poll_init) { /* * We don't set initialized as we only initialized the hw, * e.g. state->xmit is still uninitialized. */ if (!tty_port_initialized(tport)) ret = port->ops->poll_init(port); } if (!ret && options) { uart_parse_options(options, &baud, &parity, &bits, &flow); ret = uart_set_options(port, NULL, baud, parity, bits, flow); } out: mutex_unlock(&tport->mutex); return ret; } static int uart_poll_get_char(struct tty_driver *driver, int line) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; struct uart_port *port; int ret = -1; port = uart_port_ref(state); if (port) { ret = port->ops->poll_get_char(port); uart_port_deref(port); } return ret; } static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; struct uart_port *port; port = uart_port_ref(state); if (!port) return; if (ch == '\n') port->ops->poll_put_char(port, '\r'); port->ops->poll_put_char(port, ch); uart_port_deref(port); } #endif static const struct tty_operations uart_ops = { .install = uart_install, .open = uart_open, .close = uart_close, .write = uart_write, .put_char = uart_put_char, .flush_chars = uart_flush_chars, .write_room = uart_write_room, .chars_in_buffer= uart_chars_in_buffer, .flush_buffer = uart_flush_buffer, .ioctl = uart_ioctl, .throttle = uart_throttle, .unthrottle = uart_unthrottle, .send_xchar = uart_send_xchar, .set_termios = uart_set_termios, .set_ldisc = uart_set_ldisc, .stop = uart_stop, .start = uart_start, .hangup = uart_hangup, .break_ctl = uart_break_ctl, .wait_until_sent= uart_wait_until_sent, #ifdef CONFIG_PROC_FS .proc_show = uart_proc_show, #endif .tiocmget = uart_tiocmget, .tiocmset = uart_tiocmset, .set_serial = uart_set_info_user, .get_serial = uart_get_info_user, .get_icount = uart_get_icount, #ifdef CONFIG_CONSOLE_POLL .poll_init = uart_poll_init, .poll_get_char = uart_poll_get_char, .poll_put_char = uart_poll_put_char, #endif }; static const struct tty_port_operations uart_port_ops = { .carrier_raised = uart_carrier_raised, .dtr_rts = uart_dtr_rts, .activate = uart_port_activate, .shutdown = uart_tty_port_shutdown, }; /** * uart_register_driver - register a driver with the uart core layer * @drv: low level driver structure * * Register a uart driver with the core driver. We in turn register with the * tty layer, and initialise the core driver per-port state. * * We have a proc file in /proc/tty/driver which is named after the normal * driver. * * @drv->port should be %NULL, and the per-port structures should be registered * using uart_add_one_port() after this call has succeeded. * * Locking: none, Interrupts: enabled */ int uart_register_driver(struct uart_driver *drv) { struct tty_driver *normal; int i, retval = -ENOMEM; BUG_ON(drv->state); /* * Maybe we should be using a slab cache for this, especially if * we have a large number of ports to handle. */ drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL); if (!drv->state) goto out; normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); if (IS_ERR(normal)) { retval = PTR_ERR(normal); goto out_kfree; } drv->tty_driver = normal; normal->driver_name = drv->driver_name; normal->name = drv->dev_name; normal->major = drv->major; normal->minor_start = drv->minor; normal->type = TTY_DRIVER_TYPE_SERIAL; normal->subtype = SERIAL_TYPE_NORMAL; normal->init_termios = tty_std_termios; normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; normal->driver_state = drv; tty_set_operations(normal, &uart_ops); /* * Initialise the UART state(s). */ for (i = 0; i < drv->nr; i++) { struct uart_state *state = drv->state + i; struct tty_port *port = &state->port; tty_port_init(port); port->ops = &uart_port_ops; } retval = tty_register_driver(normal); if (retval >= 0) return retval; for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); tty_driver_kref_put(normal); out_kfree: kfree(drv->state); out: return retval; } EXPORT_SYMBOL(uart_register_driver); /** * uart_unregister_driver - remove a driver from the uart core layer * @drv: low level driver structure * * Remove all references to a driver from the core driver. The low level * driver must have removed all its ports via the uart_remove_one_port() if it * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.) * * Locking: none, Interrupts: enabled */ void uart_unregister_driver(struct uart_driver *drv) { struct tty_driver *p = drv->tty_driver; unsigned int i; tty_unregister_driver(p); tty_driver_kref_put(p); for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); kfree(drv->state); drv->state = NULL; drv->tty_driver = NULL; } EXPORT_SYMBOL(uart_unregister_driver); struct tty_driver *uart_console_device(struct console *co, int *index) { struct uart_driver *p = co->data; *index = co->index; return p->tty_driver; } EXPORT_SYMBOL_GPL(uart_console_device); static ssize_t uartclk_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.baud_base * 16); } static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.type); } static ssize_t line_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.line); } static ssize_t port_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); unsigned long ioaddr; uart_get_info(port, &tmp); ioaddr = tmp.port; if (HIGH_BITS_OFFSET) ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; return sprintf(buf, "0x%lX\n", ioaddr); } static ssize_t irq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.irq); } static ssize_t flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "0x%X\n", tmp.flags); } static ssize_t xmit_fifo_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.xmit_fifo_size); } static ssize_t close_delay_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.close_delay); } static ssize_t closing_wait_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.closing_wait); } static ssize_t custom_divisor_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.custom_divisor); } static ssize_t io_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.io_type); } static ssize_t iomem_base_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base); } static ssize_t iomem_reg_shift_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); return sprintf(buf, "%d\n", tmp.iomem_reg_shift); } static ssize_t console_show(struct device *dev, struct device_attribute *attr, char *buf) { struct tty_port *port = dev_get_drvdata(dev); struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; bool console = false; mutex_lock(&port->mutex); uport = uart_port_check(state); if (uport) console = uart_console_enabled(uport); mutex_unlock(&port->mutex); return sprintf(buf, "%c\n", console ? 'Y' : 'N'); } static ssize_t console_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct tty_port *port = dev_get_drvdata(dev); struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport; bool oldconsole, newconsole; int ret; ret = kstrtobool(buf, &newconsole); if (ret) return ret; mutex_lock(&port->mutex); uport = uart_port_check(state); if (uport) { oldconsole = uart_console_enabled(uport); if (oldconsole && !newconsole) { ret = unregister_console(uport->cons); } else if (!oldconsole && newconsole) { if (uart_console(uport)) { uport->console_reinit = 1; register_console(uport->cons); } else { ret = -ENOENT; } } } else { ret = -ENXIO; } mutex_unlock(&port->mutex); return ret < 0 ? ret : count; } static DEVICE_ATTR_RO(uartclk); static DEVICE_ATTR_RO(type); static DEVICE_ATTR_RO(line); static DEVICE_ATTR_RO(port); static DEVICE_ATTR_RO(irq); static DEVICE_ATTR_RO(flags); static DEVICE_ATTR_RO(xmit_fifo_size); static DEVICE_ATTR_RO(close_delay); static DEVICE_ATTR_RO(closing_wait); static DEVICE_ATTR_RO(custom_divisor); static DEVICE_ATTR_RO(io_type); static DEVICE_ATTR_RO(iomem_base); static DEVICE_ATTR_RO(iomem_reg_shift); static DEVICE_ATTR_RW(console); static struct attribute *tty_dev_attrs[] = { &dev_attr_uartclk.attr, &dev_attr_type.attr, &dev_attr_line.attr, &dev_attr_port.attr, &dev_attr_irq.attr, &dev_attr_flags.attr, &dev_attr_xmit_fifo_size.attr, &dev_attr_close_delay.attr, &dev_attr_closing_wait.attr, &dev_attr_custom_divisor.attr, &dev_attr_io_type.attr, &dev_attr_iomem_base.attr, &dev_attr_iomem_reg_shift.attr, &dev_attr_console.attr, NULL }; static const struct attribute_group tty_dev_attr_group = { .attrs = tty_dev_attrs, }; /** * uart_add_one_port - attach a driver-defined port structure * @drv: pointer to the uart low level driver structure for this port * @uport: uart port structure to use for this port. * * Context: task context, might sleep * * This allows the driver @drv to register its own uart_port structure with the * core driver. The main purpose is to allow the low level uart drivers to * expand uart_port, rather than having yet more levels of structures. */ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state; struct tty_port *port; int ret = 0; struct device *tty_dev; int num_groups; if (uport->line >= drv->nr) return -EINVAL; state = drv->state + uport->line; port = &state->port; mutex_lock(&port_mutex); mutex_lock(&port->mutex); if (state->uart_port) { ret = -EINVAL; goto out; } /* Link the port to the driver state table and vice versa */ atomic_set(&state->refcount, 1); init_waitqueue_head(&state->remove_wait); state->uart_port = uport; uport->state = state; state->pm_state = UART_PM_STATE_UNDEFINED; uport->cons = drv->cons; uport->minor = drv->tty_driver->minor_start + uport->line; uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name, drv->tty_driver->name_base + uport->line); if (!uport->name) { ret = -ENOMEM; goto out; } /* * If this port is in use as a console then the spinlock is already * initialised. */ if (!uart_console_enabled(uport)) uart_port_spin_lock_init(uport); if (uport->cons && uport->dev) of_console_check(uport->dev->of_node, uport->cons->name, uport->line); tty_port_link_device(port, drv->tty_driver, uport->line); uart_configure_port(drv, state, uport); port->console = uart_console(uport); num_groups = 2; if (uport->attr_group) num_groups++; uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), GFP_KERNEL); if (!uport->tty_groups) { ret = -ENOMEM; goto out; } uport->tty_groups[0] = &tty_dev_attr_group; if (uport->attr_group) uport->tty_groups[1] = uport->attr_group; /* * Register the port whether it's detected or not. This allows * setserial to be used to alter this port's parameters. */ tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver, uport->line, uport->dev, port, uport->tty_groups); if (!IS_ERR(tty_dev)) { device_set_wakeup_capable(tty_dev, 1); } else { dev_err(uport->dev, "Cannot register tty device on line %d\n", uport->line); } /* * Ensure UPF_DEAD is not set. */ uport->flags &= ~UPF_DEAD; out: mutex_unlock(&port->mutex); mutex_unlock(&port_mutex); return ret; } EXPORT_SYMBOL(uart_add_one_port); /** * uart_remove_one_port - detach a driver defined port structure * @drv: pointer to the uart low level driver structure for this port * @uport: uart port structure for this port * * Context: task context, might sleep * * This unhooks (and hangs up) the specified port structure from the core * driver. No further calls will be made to the low-level code for this port. */ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state = drv->state + uport->line; struct tty_port *port = &state->port; struct uart_port *uart_port; struct tty_struct *tty; int ret = 0; mutex_lock(&port_mutex); /* * Mark the port "dead" - this prevents any opens from * succeeding while we shut down the port. */ mutex_lock(&port->mutex); uart_port = uart_port_check(state); if (uart_port != uport) dev_alert(uport->dev, "Removing wrong port: %p != %p\n", uart_port, uport); if (!uart_port) { mutex_unlock(&port->mutex); ret = -EINVAL; goto out; } uport->flags |= UPF_DEAD; mutex_unlock(&port->mutex); /* * Remove the devices from the tty layer */ tty_port_unregister_device(port, drv->tty_driver, uport->line); tty = tty_port_tty_get(port); if (tty) { tty_vhangup(port->tty); tty_kref_put(tty); } /* * If the port is used as a console, unregister it */ if (uart_console(uport)) unregister_console(uport->cons); /* * Free the port IO and memory resources, if any. */ if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); kfree(uport->tty_groups); kfree(uport->name); /* * Indicate that there isn't a port here anymore. */ uport->type = PORT_UNKNOWN; mutex_lock(&port->mutex); WARN_ON(atomic_dec_return(&state->refcount) < 0); wait_event(state->remove_wait, !atomic_read(&state->refcount)); state->uart_port = NULL; mutex_unlock(&port->mutex); out: mutex_unlock(&port_mutex); return ret; } EXPORT_SYMBOL(uart_remove_one_port); /** * uart_match_port - are the two ports equivalent? * @port1: first port * @port2: second port * * This utility function can be used to determine whether two uart_port * structures describe the same port. */ bool uart_match_port(const struct uart_port *port1, const struct uart_port *port2) { if (port1->iotype != port2->iotype) return false; switch (port1->iotype) { case UPIO_PORT: return port1->iobase == port2->iobase; case UPIO_HUB6: return port1->iobase == port2->iobase && port1->hub6 == port2->hub6; case UPIO_MEM: case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: case UPIO_TSI: return port1->mapbase == port2->mapbase; } return false; } EXPORT_SYMBOL(uart_match_port); /** * uart_handle_dcd_change - handle a change of carrier detect state * @uport: uart_port structure for the open port * @status: new carrier detect status, nonzero if active * * Caller must hold uport->lock. */ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) { struct tty_port *port = &uport->state->port; struct tty_struct *tty = port->tty; struct tty_ldisc *ld; lockdep_assert_held_once(&uport->lock); if (tty) { ld = tty_ldisc_ref(tty); if (ld) { if (ld->ops->dcd_change) ld->ops->dcd_change(tty, status); tty_ldisc_deref(ld); } } uport->icount.dcd++; if (uart_dcd_enabled(uport)) { if (status) wake_up_interruptible(&port->open_wait); else if (tty) tty_hangup(tty); } } EXPORT_SYMBOL_GPL(uart_handle_dcd_change); /** * uart_handle_cts_change - handle a change of clear-to-send state * @uport: uart_port structure for the open port * @status: new clear to send status, nonzero if active * * Caller must hold uport->lock. */ void uart_handle_cts_change(struct uart_port *uport, unsigned int status) { lockdep_assert_held_once(&uport->lock); uport->icount.cts++; if (uart_softcts_mode(uport)) { if (uport->hw_stopped) { if (status) { uport->hw_stopped = 0; uport->ops->start_tx(uport); uart_write_wakeup(uport); } } else { if (!status) { uport->hw_stopped = 1; uport->ops->stop_tx(uport); } } } } EXPORT_SYMBOL_GPL(uart_handle_cts_change); /** * uart_insert_char - push a char to the uart layer * * User is responsible to call tty_flip_buffer_push when they are done with * insertion. * * @port: corresponding port * @status: state of the serial port RX buffer (LSR for 8250) * @overrun: mask of overrun bits in @status * @ch: character to push * @flag: flag for the character (see TTY_NORMAL and friends) */ void uart_insert_char(struct uart_port *port, unsigned int status, unsigned int overrun, unsigned int ch, unsigned int flag) { struct tty_port *tport = &port->state->port; if ((status & port->ignore_status_mask & ~overrun) == 0) if (tty_insert_flip_char(tport, ch, flag) == 0) ++port->icount.buf_overrun; /* * Overrun is special. Since it's reported immediately, * it doesn't affect the current character. */ if (status & ~port->ignore_status_mask & overrun) if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0) ++port->icount.buf_overrun; } EXPORT_SYMBOL_GPL(uart_insert_char); #ifdef CONFIG_MAGIC_SYSRQ_SERIAL static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; static void uart_sysrq_on(struct work_struct *w) { int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); sysrq_toggle_support(1); pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n", sysrq_toggle_seq_len, sysrq_toggle_seq); } static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on); /** * uart_try_toggle_sysrq - Enables SysRq from serial line * @port: uart_port structure where char(s) after BREAK met * @ch: new character in the sequence after received BREAK * * Enables magic SysRq when the required sequence is met on port * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE). * * Returns: %false if @ch is out of enabling sequence and should be * handled some other way, %true if @ch was consumed. */ bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch) { int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); if (!sysrq_toggle_seq_len) return false; BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX); if (sysrq_toggle_seq[port->sysrq_seq] != ch) { port->sysrq_seq = 0; return false; } if (++port->sysrq_seq < sysrq_toggle_seq_len) { port->sysrq = jiffies + SYSRQ_TIMEOUT; return true; } schedule_work(&sysrq_enable_work); port->sysrq = 0; return true; } EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq); #endif /** * uart_get_rs485_mode() - retrieve rs485 properties for given uart * @port: uart device's target port * * This function implements the device tree binding described in * Documentation/devicetree/bindings/serial/rs485.txt. */ int uart_get_rs485_mode(struct uart_port *port) { struct serial_rs485 *rs485conf = &port->rs485; struct device *dev = port->dev; u32 rs485_delay[2]; int ret; ret = device_property_read_u32_array(dev, "rs485-rts-delay", rs485_delay, 2); if (!ret) { rs485conf->delay_rts_before_send = rs485_delay[0]; rs485conf->delay_rts_after_send = rs485_delay[1]; } else { rs485conf->delay_rts_before_send = 0; rs485conf->delay_rts_after_send = 0; } uart_sanitize_serial_rs485_delays(port, rs485conf); /* * Clear full-duplex and enabled flags, set RTS polarity to active high * to get to a defined state with the following properties: */ rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | SER_RS485_TERMINATE_BUS | SER_RS485_RTS_AFTER_SEND); rs485conf->flags |= SER_RS485_RTS_ON_SEND; if (device_property_read_bool(dev, "rs485-rx-during-tx")) rs485conf->flags |= SER_RS485_RX_DURING_TX; if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time")) rs485conf->flags |= SER_RS485_ENABLED; if (device_property_read_bool(dev, "rs485-rts-active-low")) { rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; } /* * Disabling termination by default is the safe choice: Else if many * bus participants enable it, no communication is possible at all. * Works fine for short cables and users may enable for longer cables. */ port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term", GPIOD_OUT_LOW); if (IS_ERR(port->rs485_term_gpio)) { ret = PTR_ERR(port->rs485_term_gpio); port->rs485_term_gpio = NULL; return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n"); } if (port->rs485_term_gpio) port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS; return 0; } EXPORT_SYMBOL_GPL(uart_get_rs485_mode); /* Compile-time assertions for serial_rs485 layout */ static_assert(offsetof(struct serial_rs485, padding) == (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32))); static_assert(offsetof(struct serial_rs485, padding1) == offsetof(struct serial_rs485, padding[1])); static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) == sizeof(struct serial_rs485)); MODULE_DESCRIPTION("Serial driver core"); MODULE_LICENSE("GPL");
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