| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Elen Song | 3031 | 23.85% | 7 | 4.79% |
| Andrew Victor | 2088 | 16.43% | 6 | 4.11% |
| Nicolas Ferre | 1448 | 11.40% | 11 | 7.53% |
| Cyrille Pitchen | 1231 | 9.69% | 10 | 6.85% |
| Chip Coldwell | 889 | 7.00% | 1 | 0.68% |
| Remy Bohmer | 753 | 5.93% | 2 | 1.37% |
| Richard Genoud | 529 | 4.16% | 10 | 6.85% |
| Håvard Skinnemoen | 460 | 3.62% | 19 | 13.01% |
| Claudio Scordino | 391 | 3.08% | 3 | 2.05% |
| Alexandre Belloni | 348 | 2.74% | 7 | 4.79% |
| Boris Brezillon | 273 | 2.15% | 2 | 1.37% |
| Romain Izard | 179 | 1.41% | 3 | 2.05% |
| Ludovic Desroches | 166 | 1.31% | 4 | 2.74% |
| Peter Hurley | 105 | 0.83% | 5 | 3.42% |
| Uwe Kleine-König | 99 | 0.78% | 4 | 2.74% |
| Radu Pirea | 77 | 0.61% | 1 | 0.68% |
| Albin Tonnerre | 75 | 0.59% | 2 | 1.37% |
| Anti Sullin | 59 | 0.46% | 1 | 0.68% |
| Leilei Zhao | 47 | 0.37% | 6 | 4.11% |
| Jaeden Amero | 46 | 0.36% | 1 | 0.68% |
| David Brownell | 41 | 0.32% | 1 | 0.68% |
| Viktar Palstsiuk | 40 | 0.31% | 1 | 0.68% |
| Bernhard Roth | 36 | 0.28% | 1 | 0.68% |
| Ricardo Ribalda Delgado | 34 | 0.27% | 2 | 1.37% |
| Marc Pignat | 30 | 0.24% | 1 | 0.68% |
| Marek Roszko | 29 | 0.23% | 2 | 1.37% |
| Kees Cook | 25 | 0.20% | 2 | 1.37% |
| Russell King | 19 | 0.15% | 1 | 0.68% |
| Linus Walleij | 18 | 0.14% | 1 | 0.68% |
| Mark Deneen | 17 | 0.13% | 1 | 0.68% |
| Michael Trimarchi | 17 | 0.13% | 1 | 0.68% |
| Siftar, Gabe | 12 | 0.09% | 1 | 0.68% |
| Atsushi Nemoto | 10 | 0.08% | 1 | 0.68% |
| Geliang Tang | 9 | 0.07% | 1 | 0.68% |
| Pawel Wieczorkiewicz | 8 | 0.06% | 1 | 0.68% |
| Alexey Y. Starikovskiy | 7 | 0.06% | 1 | 0.68% |
| Sascha Hauer | 7 | 0.06% | 1 | 0.68% |
| Itai Levi | 6 | 0.05% | 1 | 0.68% |
| Sebastian Andrzej Siewior | 6 | 0.05% | 1 | 0.68% |
| Jiri Slaby | 5 | 0.04% | 2 | 1.37% |
| Alan Cox | 5 | 0.04% | 2 | 1.37% |
| Julia Lawall | 5 | 0.04% | 2 | 1.37% |
| Andre Przywara | 4 | 0.03% | 1 | 0.68% |
| Wolfram Sang | 4 | 0.03% | 1 | 0.68% |
| Vinod Koul | 3 | 0.02% | 1 | 0.68% |
| Jonas Danielsson | 3 | 0.02% | 1 | 0.68% |
| Lukas Wunner | 2 | 0.02% | 1 | 0.68% |
| Maxime Ripard | 2 | 0.02% | 1 | 0.68% |
| Peter Ma | 2 | 0.02% | 1 | 0.68% |
| Greg Kroah-Hartman | 2 | 0.02% | 2 | 1.37% |
| Paul Gortmaker | 1 | 0.01% | 1 | 0.68% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.68% |
| Jean-Christophe Plagniol-Villard | 1 | 0.01% | 1 | 0.68% |
| Andy Shevchenko | 1 | 0.01% | 1 | 0.68% |
| Total | 12706 | 146 |
// SPDX-License-Identifier: GPL-2.0+ /* * Driver for Atmel AT91 Serial ports * Copyright (C) 2003 Rick Bronson * * Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd. * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * DMA support added by Chip Coldwell. */ #include <linux/tty.h> #include <linux/ioport.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/serial.h> #include <linux/clk.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/tty_flip.h> #include <linux/platform_device.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_gpio.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/atmel_pdc.h> #include <linux/uaccess.h> #include <linux/platform_data/atmel.h> #include <linux/timer.h> #include <linux/gpio.h> #include <linux/gpio/consumer.h> #include <linux/err.h> #include <linux/irq.h> #include <linux/suspend.h> #include <linux/mm.h> #include <asm/div64.h> #include <asm/io.h> #include <asm/ioctls.h> #define PDC_BUFFER_SIZE 512 /* Revisit: We should calculate this based on the actual port settings */ #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */ /* The minium number of data FIFOs should be able to contain */ #define ATMEL_MIN_FIFO_SIZE 8 /* * These two offsets are substracted from the RX FIFO size to define the RTS * high and low thresholds */ #define ATMEL_RTS_HIGH_OFFSET 16 #define ATMEL_RTS_LOW_OFFSET 20 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include <linux/serial_core.h> #include "serial_mctrl_gpio.h" #include "atmel_serial.h" static void atmel_start_rx(struct uart_port *port); static void atmel_stop_rx(struct uart_port *port); #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we * should coexist with the 8250 driver, such as if we have an external 16C550 * UART. */ #define SERIAL_ATMEL_MAJOR 204 #define MINOR_START 154 #define ATMEL_DEVICENAME "ttyAT" #else /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port * name, but it is legally reserved for the 8250 driver. */ #define SERIAL_ATMEL_MAJOR TTY_MAJOR #define MINOR_START 64 #define ATMEL_DEVICENAME "ttyS" #endif #define ATMEL_ISR_PASS_LIMIT 256 struct atmel_dma_buffer { unsigned char *buf; dma_addr_t dma_addr; unsigned int dma_size; unsigned int ofs; }; struct atmel_uart_char { u16 status; u16 ch; }; /* * Be careful, the real size of the ring buffer is * sizeof(atmel_uart_char) * ATMEL_SERIAL_RINGSIZE. It means that ring buffer * can contain up to 1024 characters in PIO mode and up to 4096 characters in * DMA mode. */ #define ATMEL_SERIAL_RINGSIZE 1024 /* * at91: 6 USARTs and one DBGU port (SAM9260) * samx7: 3 USARTs and 5 UARTs */ #define ATMEL_MAX_UART 8 /* * We wrap our port structure around the generic uart_port. */ struct atmel_uart_port { struct uart_port uart; /* uart */ struct clk *clk; /* uart clock */ int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */ u32 backup_imr; /* IMR saved during suspend */ int break_active; /* break being received */ bool use_dma_rx; /* enable DMA receiver */ bool use_pdc_rx; /* enable PDC receiver */ short pdc_rx_idx; /* current PDC RX buffer */ struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */ bool use_dma_tx; /* enable DMA transmitter */ bool use_pdc_tx; /* enable PDC transmitter */ struct atmel_dma_buffer pdc_tx; /* PDC transmitter */ spinlock_t lock_tx; /* port lock */ spinlock_t lock_rx; /* port lock */ struct dma_chan *chan_tx; struct dma_chan *chan_rx; struct dma_async_tx_descriptor *desc_tx; struct dma_async_tx_descriptor *desc_rx; dma_cookie_t cookie_tx; dma_cookie_t cookie_rx; struct scatterlist sg_tx; struct scatterlist sg_rx; struct tasklet_struct tasklet_rx; struct tasklet_struct tasklet_tx; atomic_t tasklet_shutdown; unsigned int irq_status_prev; unsigned int tx_len; struct circ_buf rx_ring; struct mctrl_gpios *gpios; u32 backup_mode; /* MR saved during iso7816 operations */ u32 backup_brgr; /* BRGR saved during iso7816 operations */ unsigned int tx_done_mask; u32 fifo_size; u32 rts_high; u32 rts_low; bool ms_irq_enabled; u32 rtor; /* address of receiver timeout register if it exists */ bool has_frac_baudrate; bool has_hw_timer; struct timer_list uart_timer; bool tx_stopped; bool suspended; unsigned int pending; unsigned int pending_status; spinlock_t lock_suspended; /* ISO7816 */ unsigned int fidi_min; unsigned int fidi_max; #ifdef CONFIG_PM struct { u32 cr; u32 mr; u32 imr; u32 brgr; u32 rtor; u32 ttgr; u32 fmr; u32 fimr; } cache; #endif int (*prepare_rx)(struct uart_port *port); int (*prepare_tx)(struct uart_port *port); void (*schedule_rx)(struct uart_port *port); void (*schedule_tx)(struct uart_port *port); void (*release_rx)(struct uart_port *port); void (*release_tx)(struct uart_port *port); }; static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART); #ifdef SUPPORT_SYSRQ static struct console atmel_console; #endif #if defined(CONFIG_OF) static const struct of_device_id atmel_serial_dt_ids[] = { { .compatible = "atmel,at91rm9200-usart-serial" }, { /* sentinel */ } }; #endif static inline struct atmel_uart_port * to_atmel_uart_port(struct uart_port *uart) { return container_of(uart, struct atmel_uart_port, uart); } static inline u32 atmel_uart_readl(struct uart_port *port, u32 reg) { return __raw_readl(port->membase + reg); } static inline void atmel_uart_writel(struct uart_port *port, u32 reg, u32 value) { __raw_writel(value, port->membase + reg); } static inline u8 atmel_uart_read_char(struct uart_port *port) { return __raw_readb(port->membase + ATMEL_US_RHR); } static inline void atmel_uart_write_char(struct uart_port *port, u8 value) { __raw_writeb(value, port->membase + ATMEL_US_THR); } #ifdef CONFIG_SERIAL_ATMEL_PDC static bool atmel_use_pdc_rx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); return atmel_port->use_pdc_rx; } static bool atmel_use_pdc_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); return atmel_port->use_pdc_tx; } #else static bool atmel_use_pdc_rx(struct uart_port *port) { return false; } static bool atmel_use_pdc_tx(struct uart_port *port) { return false; } #endif static bool atmel_use_dma_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); return atmel_port->use_dma_tx; } static bool atmel_use_dma_rx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); return atmel_port->use_dma_rx; } static bool atmel_use_fifo(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); return atmel_port->fifo_size; } static void atmel_tasklet_schedule(struct atmel_uart_port *atmel_port, struct tasklet_struct *t) { if (!atomic_read(&atmel_port->tasklet_shutdown)) tasklet_schedule(t); } static unsigned int atmel_get_lines_status(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, ret = 0; status = atmel_uart_readl(port, ATMEL_US_CSR); mctrl_gpio_get(atmel_port->gpios, &ret); if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))) { if (ret & TIOCM_CTS) status &= ~ATMEL_US_CTS; else status |= ATMEL_US_CTS; } if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR))) { if (ret & TIOCM_DSR) status &= ~ATMEL_US_DSR; else status |= ATMEL_US_DSR; } if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI))) { if (ret & TIOCM_RI) status &= ~ATMEL_US_RI; else status |= ATMEL_US_RI; } if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD))) { if (ret & TIOCM_CD) status &= ~ATMEL_US_DCD; else status |= ATMEL_US_DCD; } return status; } /* Enable or disable the rs485 support */ static int atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int mode; /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); mode = atmel_uart_readl(port, ATMEL_US_MR); /* Resetting serial mode to RS232 (0x0) */ mode &= ~ATMEL_US_USMODE; port->rs485 = *rs485conf; if (rs485conf->flags & SER_RS485_ENABLED) { dev_dbg(port->dev, "Setting UART to RS485\n"); atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; atmel_uart_writel(port, ATMEL_US_TTGR, rs485conf->delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else { dev_dbg(port->dev, "Setting UART to RS232\n"); if (atmel_use_pdc_tx(port)) atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; else atmel_port->tx_done_mask = ATMEL_US_TXRDY; } atmel_uart_writel(port, ATMEL_US_MR, mode); /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); return 0; } static unsigned int atmel_calc_cd(struct uart_port *port, struct serial_iso7816 *iso7816conf) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int cd; u64 mck_rate; mck_rate = (u64)clk_get_rate(atmel_port->clk); do_div(mck_rate, iso7816conf->clk); cd = mck_rate; return cd; } static unsigned int atmel_calc_fidi(struct uart_port *port, struct serial_iso7816 *iso7816conf) { u64 fidi = 0; if (iso7816conf->sc_fi && iso7816conf->sc_di) { fidi = (u64)iso7816conf->sc_fi; do_div(fidi, iso7816conf->sc_di); } return (u32)fidi; } /* Enable or disable the iso7816 support */ /* Called with interrupts disabled */ static int atmel_config_iso7816(struct uart_port *port, struct serial_iso7816 *iso7816conf) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int mode; unsigned int cd, fidi; int ret = 0; /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); mode = atmel_uart_readl(port, ATMEL_US_MR); if (iso7816conf->flags & SER_ISO7816_ENABLED) { mode &= ~ATMEL_US_USMODE; if (iso7816conf->tg > 255) { dev_err(port->dev, "ISO7816: Timeguard exceeding 255\n"); memset(iso7816conf, 0, sizeof(struct serial_iso7816)); ret = -EINVAL; goto err_out; } if ((iso7816conf->flags & SER_ISO7816_T_PARAM) == SER_ISO7816_T(0)) { mode |= ATMEL_US_USMODE_ISO7816_T0 | ATMEL_US_DSNACK; } else if ((iso7816conf->flags & SER_ISO7816_T_PARAM) == SER_ISO7816_T(1)) { mode |= ATMEL_US_USMODE_ISO7816_T1 | ATMEL_US_INACK; } else { dev_err(port->dev, "ISO7816: Type not supported\n"); memset(iso7816conf, 0, sizeof(struct serial_iso7816)); ret = -EINVAL; goto err_out; } mode &= ~(ATMEL_US_USCLKS | ATMEL_US_NBSTOP | ATMEL_US_PAR); /* select mck clock, and output */ mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO; /* set parity for normal/inverse mode + max iterations */ mode |= ATMEL_US_PAR_EVEN | ATMEL_US_NBSTOP_1 | ATMEL_US_MAX_ITER(3); cd = atmel_calc_cd(port, iso7816conf); fidi = atmel_calc_fidi(port, iso7816conf); if (fidi == 0) { dev_warn(port->dev, "ISO7816 fidi = 0, Generator generates no signal\n"); } else if (fidi < atmel_port->fidi_min || fidi > atmel_port->fidi_max) { dev_err(port->dev, "ISO7816 fidi = %u, value not supported\n", fidi); memset(iso7816conf, 0, sizeof(struct serial_iso7816)); ret = -EINVAL; goto err_out; } if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) { /* port not yet in iso7816 mode: store configuration */ atmel_port->backup_mode = atmel_uart_readl(port, ATMEL_US_MR); atmel_port->backup_brgr = atmel_uart_readl(port, ATMEL_US_BRGR); } atmel_uart_writel(port, ATMEL_US_TTGR, iso7816conf->tg); atmel_uart_writel(port, ATMEL_US_BRGR, cd); atmel_uart_writel(port, ATMEL_US_FIDI, fidi); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXEN); atmel_port->tx_done_mask = ATMEL_US_TXEMPTY | ATMEL_US_NACK | ATMEL_US_ITERATION; } else { dev_dbg(port->dev, "Setting UART back to RS232\n"); /* back to last RS232 settings */ mode = atmel_port->backup_mode; memset(iso7816conf, 0, sizeof(struct serial_iso7816)); atmel_uart_writel(port, ATMEL_US_TTGR, 0); atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->backup_brgr); atmel_uart_writel(port, ATMEL_US_FIDI, 0x174); if (atmel_use_pdc_tx(port)) atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; else atmel_port->tx_done_mask = ATMEL_US_TXRDY; } port->iso7816 = *iso7816conf; atmel_uart_writel(port, ATMEL_US_MR, mode); err_out: /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); return ret; } /* * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. */ static u_int atmel_tx_empty(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_port->tx_stopped) return TIOCSER_TEMT; return (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0; } /* * Set state of the modem control output lines */ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int control = 0; unsigned int mode = atmel_uart_readl(port, ATMEL_US_MR); unsigned int rts_paused, rts_ready; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* override mode to RS485 if needed, otherwise keep the current mode */ if (port->rs485.flags & SER_RS485_ENABLED) { atmel_uart_writel(port, ATMEL_US_TTGR, port->rs485.delay_rts_after_send); mode &= ~ATMEL_US_USMODE; mode |= ATMEL_US_USMODE_RS485; } /* set the RTS line state according to the mode */ if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { /* force RTS line to high level */ rts_paused = ATMEL_US_RTSEN; /* give the control of the RTS line back to the hardware */ rts_ready = ATMEL_US_RTSDIS; } else { /* force RTS line to high level */ rts_paused = ATMEL_US_RTSDIS; /* force RTS line to low level */ rts_ready = ATMEL_US_RTSEN; } if (mctrl & TIOCM_RTS) control |= rts_ready; else control |= rts_paused; if (mctrl & TIOCM_DTR) control |= ATMEL_US_DTREN; else control |= ATMEL_US_DTRDIS; atmel_uart_writel(port, ATMEL_US_CR, control); mctrl_gpio_set(atmel_port->gpios, mctrl); /* Local loopback mode? */ mode &= ~ATMEL_US_CHMODE; if (mctrl & TIOCM_LOOP) mode |= ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; atmel_uart_writel(port, ATMEL_US_MR, mode); } /* * Get state of the modem control input lines */ static u_int atmel_get_mctrl(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int ret = 0, status; status = atmel_uart_readl(port, ATMEL_US_CSR); /* * The control signals are active low. */ if (!(status & ATMEL_US_DCD)) ret |= TIOCM_CD; if (!(status & ATMEL_US_CTS)) ret |= TIOCM_CTS; if (!(status & ATMEL_US_DSR)) ret |= TIOCM_DSR; if (!(status & ATMEL_US_RI)) ret |= TIOCM_RI; return mctrl_gpio_get(atmel_port->gpios, &ret); } /* * Stop transmitting. */ static void atmel_stop_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_pdc_tx(port)) { /* disable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS); } /* * Disable the transmitter. * This is mandatory when DMA is used, otherwise the DMA buffer * is fully transmitted. */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS); atmel_port->tx_stopped = true; /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); if (((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) || port->iso7816.flags & SER_ISO7816_ENABLED) atmel_start_rx(port); } /* * Start transmitting. */ static void atmel_start_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN)) /* The transmitter is already running. Yes, we really need this.*/ return; if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) if (((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) || port->iso7816.flags & SER_ISO7816_ENABLED) atmel_stop_rx(port); if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); /* re-enable the transmitter */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); atmel_port->tx_stopped = false; } /* * start receiving - port is in process of being opened. */ static void atmel_start_rx(struct uart_port *port) { /* reset status and receiver */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RXEN); if (atmel_use_pdc_rx(port)) { /* enable PDC controller */ atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask); atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN); } else { atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_RXRDY); } } /* * Stop receiving - port is in process of being closed. */ static void atmel_stop_rx(struct uart_port *port) { atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RXDIS); if (atmel_use_pdc_rx(port)) { /* disable PDC receive */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS); atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask); } else { atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXRDY); } } /* * Enable modem status interrupts */ static void atmel_enable_ms(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); uint32_t ier = 0; /* * Interrupt should not be enabled twice */ if (atmel_port->ms_irq_enabled) return; atmel_port->ms_irq_enabled = true; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) ier |= ATMEL_US_CTSIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR)) ier |= ATMEL_US_DSRIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI)) ier |= ATMEL_US_RIIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD)) ier |= ATMEL_US_DCDIC; atmel_uart_writel(port, ATMEL_US_IER, ier); mctrl_gpio_enable_ms(atmel_port->gpios); } /* * Disable modem status interrupts */ static void atmel_disable_ms(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); uint32_t idr = 0; /* * Interrupt should not be disabled twice */ if (!atmel_port->ms_irq_enabled) return; atmel_port->ms_irq_enabled = false; mctrl_gpio_disable_ms(atmel_port->gpios); if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) idr |= ATMEL_US_CTSIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR)) idr |= ATMEL_US_DSRIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI)) idr |= ATMEL_US_RIIC; if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD)) idr |= ATMEL_US_DCDIC; atmel_uart_writel(port, ATMEL_US_IDR, idr); } /* * Control the transmission of a break signal */ static void atmel_break_ctl(struct uart_port *port, int break_state) { if (break_state != 0) /* start break */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTBRK); else /* stop break */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STPBRK); } /* * Stores the incoming character in the ring buffer */ static void atmel_buffer_rx_char(struct uart_port *port, unsigned int status, unsigned int ch) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct circ_buf *ring = &atmel_port->rx_ring; struct atmel_uart_char *c; if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE)) /* Buffer overflow, ignore char */ return; c = &((struct atmel_uart_char *)ring->buf)[ring->head]; c->status = status; c->ch = ch; /* Make sure the character is stored before we update head. */ smp_wmb(); ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1); } /* * Deal with parity, framing and overrun errors. */ static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status) { /* clear error */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA); if (status & ATMEL_US_RXBRK) { /* ignore side-effect */ status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME); port->icount.brk++; } if (status & ATMEL_US_PARE) port->icount.parity++; if (status & ATMEL_US_FRAME) port->icount.frame++; if (status & ATMEL_US_OVRE) port->icount.overrun++; } /* * Characters received (called from interrupt handler) */ static void atmel_rx_chars(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, ch; status = atmel_uart_readl(port, ATMEL_US_CSR); while (status & ATMEL_US_RXRDY) { ch = atmel_uart_read_char(port); /* * note that the error handling code is * out of the main execution path */ if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME | ATMEL_US_OVRE | ATMEL_US_RXBRK) || atmel_port->break_active)) { /* clear error */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA); if (status & ATMEL_US_RXBRK && !atmel_port->break_active) { atmel_port->break_active = 1; atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_RXBRK); } else { /* * This is either the end-of-break * condition or we've received at * least one character without RXBRK * being set. In both cases, the next * RXBRK will indicate start-of-break. */ atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXBRK); status &= ~ATMEL_US_RXBRK; atmel_port->break_active = 0; } } atmel_buffer_rx_char(port, status, ch); status = atmel_uart_readl(port, ATMEL_US_CSR); } atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx); } /* * Transmit characters (called from tasklet with TXRDY interrupt * disabled) */ static void atmel_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (port->x_char && (atmel_uart_readl(port, ATMEL_US_CSR) & atmel_port->tx_done_mask)) { atmel_uart_write_char(port, port->x_char); port->icount.tx++; port->x_char = 0; } if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; while (atmel_uart_readl(port, ATMEL_US_CSR) & atmel_port->tx_done_mask) { atmel_uart_write_char(port, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (uart_circ_empty(xmit)) break; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (!uart_circ_empty(xmit)) /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } static void atmel_complete_tx_dma(void *arg) { struct atmel_uart_port *atmel_port = arg; struct uart_port *port = &atmel_port->uart; struct circ_buf *xmit = &port->state->xmit; struct dma_chan *chan = atmel_port->chan_tx; unsigned long flags; spin_lock_irqsave(&port->lock, flags); if (chan) dmaengine_terminate_all(chan); xmit->tail += atmel_port->tx_len; xmit->tail &= UART_XMIT_SIZE - 1; port->icount.tx += atmel_port->tx_len; spin_lock_irq(&atmel_port->lock_tx); async_tx_ack(atmel_port->desc_tx); atmel_port->cookie_tx = -EINVAL; atmel_port->desc_tx = NULL; spin_unlock_irq(&atmel_port->lock_tx); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); /* * xmit is a circular buffer so, if we have just send data from * xmit->tail to the end of xmit->buf, now we have to transmit the * remaining data from the beginning of xmit->buf to xmit->head. */ if (!uart_circ_empty(xmit)) atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); else if (((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) || port->iso7816.flags & SER_ISO7816_ENABLED) { /* DMA done, stop TX, start RX for RS485 */ atmel_start_rx(port); } spin_unlock_irqrestore(&port->lock, flags); } static void atmel_release_tx_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct dma_chan *chan = atmel_port->chan_tx; if (chan) { dmaengine_terminate_all(chan); dma_release_channel(chan); dma_unmap_sg(port->dev, &atmel_port->sg_tx, 1, DMA_TO_DEVICE); } atmel_port->desc_tx = NULL; atmel_port->chan_tx = NULL; atmel_port->cookie_tx = -EINVAL; } /* * Called from tasklet with TXRDY interrupt is disabled. */ static void atmel_tx_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct circ_buf *xmit = &port->state->xmit; struct dma_chan *chan = atmel_port->chan_tx; struct dma_async_tx_descriptor *desc; struct scatterlist sgl[2], *sg, *sg_tx = &atmel_port->sg_tx; unsigned int tx_len, part1_len, part2_len, sg_len; dma_addr_t phys_addr; /* Make sure we have an idle channel */ if (atmel_port->desc_tx != NULL) return; if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) { /* * DMA is idle now. * Port xmit buffer is already mapped, * and it is one page... Just adjust * offsets and lengths. Since it is a circular buffer, * we have to transmit till the end, and then the rest. * Take the port lock to get a * consistent xmit buffer state. */ tx_len = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); if (atmel_port->fifo_size) { /* multi data mode */ part1_len = (tx_len & ~0x3); /* DWORD access */ part2_len = (tx_len & 0x3); /* BYTE access */ } else { /* single data (legacy) mode */ part1_len = 0; part2_len = tx_len; /* BYTE access only */ } sg_init_table(sgl, 2); sg_len = 0; phys_addr = sg_dma_address(sg_tx) + xmit->tail; if (part1_len) { sg = &sgl[sg_len++]; sg_dma_address(sg) = phys_addr; sg_dma_len(sg) = part1_len; phys_addr += part1_len; } if (part2_len) { sg = &sgl[sg_len++]; sg_dma_address(sg) = phys_addr; sg_dma_len(sg) = part2_len; } /* * save tx_len so atmel_complete_tx_dma() will increase * xmit->tail correctly */ atmel_port->tx_len = tx_len; desc = dmaengine_prep_slave_sg(chan, sgl, sg_len, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { dev_err(port->dev, "Failed to send via dma!\n"); return; } dma_sync_sg_for_device(port->dev, sg_tx, 1, DMA_TO_DEVICE); atmel_port->desc_tx = desc; desc->callback = atmel_complete_tx_dma; desc->callback_param = atmel_port; atmel_port->cookie_tx = dmaengine_submit(desc); } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); } static int atmel_prepare_tx_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct device *mfd_dev = port->dev->parent; dma_cap_mask_t mask; struct dma_slave_config config; int ret, nent; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); atmel_port->chan_tx = dma_request_slave_channel(mfd_dev, "tx"); if (atmel_port->chan_tx == NULL) goto chan_err; dev_info(port->dev, "using %s for tx DMA transfers\n", dma_chan_name(atmel_port->chan_tx)); spin_lock_init(&atmel_port->lock_tx); sg_init_table(&atmel_port->sg_tx, 1); /* UART circular tx buffer is an aligned page. */ BUG_ON(!PAGE_ALIGNED(port->state->xmit.buf)); sg_set_page(&atmel_port->sg_tx, virt_to_page(port->state->xmit.buf), UART_XMIT_SIZE, offset_in_page(port->state->xmit.buf)); nent = dma_map_sg(port->dev, &atmel_port->sg_tx, 1, DMA_TO_DEVICE); if (!nent) { dev_dbg(port->dev, "need to release resource of dma\n"); goto chan_err; } else { dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__, sg_dma_len(&atmel_port->sg_tx), port->state->xmit.buf, &sg_dma_address(&atmel_port->sg_tx)); } /* Configure the slave DMA */ memset(&config, 0, sizeof(config)); config.direction = DMA_MEM_TO_DEV; config.dst_addr_width = (atmel_port->fifo_size) ? DMA_SLAVE_BUSWIDTH_4_BYTES : DMA_SLAVE_BUSWIDTH_1_BYTE; config.dst_addr = port->mapbase + ATMEL_US_THR; config.dst_maxburst = 1; ret = dmaengine_slave_config(atmel_port->chan_tx, &config); if (ret) { dev_err(port->dev, "DMA tx slave configuration failed\n"); goto chan_err; } return 0; chan_err: dev_err(port->dev, "TX channel not available, switch to pio\n"); atmel_port->use_dma_tx = 0; if (atmel_port->chan_tx) atmel_release_tx_dma(port); return -EINVAL; } static void atmel_complete_rx_dma(void *arg) { struct uart_port *port = arg; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx); } static void atmel_release_rx_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct dma_chan *chan = atmel_port->chan_rx; if (chan) { dmaengine_terminate_all(chan); dma_release_channel(chan); dma_unmap_sg(port->dev, &atmel_port->sg_rx, 1, DMA_FROM_DEVICE); } atmel_port->desc_rx = NULL; atmel_port->chan_rx = NULL; atmel_port->cookie_rx = -EINVAL; } static void atmel_rx_from_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct tty_port *tport = &port->state->port; struct circ_buf *ring = &atmel_port->rx_ring; struct dma_chan *chan = atmel_port->chan_rx; struct dma_tx_state state; enum dma_status dmastat; size_t count; /* Reset the UART timeout early so that we don't miss one */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO); dmastat = dmaengine_tx_status(chan, atmel_port->cookie_rx, &state); /* Restart a new tasklet if DMA status is error */ if (dmastat == DMA_ERROR) { dev_dbg(port->dev, "Get residue error, restart tasklet\n"); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT); atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx); return; } /* CPU claims ownership of RX DMA buffer */ dma_sync_sg_for_cpu(port->dev, &atmel_port->sg_rx, 1, DMA_FROM_DEVICE); /* * ring->head points to the end of data already written by the DMA. * ring->tail points to the beginning of data to be read by the * framework. * The current transfer size should not be larger than the dma buffer * length. */ ring->head = sg_dma_len(&atmel_port->sg_rx) - state.residue; BUG_ON(ring->head > sg_dma_len(&atmel_port->sg_rx)); /* * At this point ring->head may point to the first byte right after the * last byte of the dma buffer: * 0 <= ring->head <= sg_dma_len(&atmel_port->sg_rx) * * However ring->tail must always points inside the dma buffer: * 0 <= ring->tail <= sg_dma_len(&atmel_port->sg_rx) - 1 * * Since we use a ring buffer, we have to handle the case * where head is lower than tail. In such a case, we first read from * tail to the end of the buffer then reset tail. */ if (ring->head < ring->tail) { count = sg_dma_len(&atmel_port->sg_rx) - ring->tail; tty_insert_flip_string(tport, ring->buf + ring->tail, count); ring->tail = 0; port->icount.rx += count; } /* Finally we read data from tail to head */ if (ring->tail < ring->head) { count = ring->head - ring->tail; tty_insert_flip_string(tport, ring->buf + ring->tail, count); /* Wrap ring->head if needed */ if (ring->head >= sg_dma_len(&atmel_port->sg_rx)) ring->head = 0; ring->tail = ring->head; port->icount.rx += count; } /* USART retreives ownership of RX DMA buffer */ dma_sync_sg_for_device(port->dev, &atmel_port->sg_rx, 1, DMA_FROM_DEVICE); /* * Drop the lock here since it might end up calling * uart_start(), which takes the lock. */ spin_unlock(&port->lock); tty_flip_buffer_push(tport); spin_lock(&port->lock); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT); } static int atmel_prepare_rx_dma(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct device *mfd_dev = port->dev->parent; struct dma_async_tx_descriptor *desc; dma_cap_mask_t mask; struct dma_slave_config config; struct circ_buf *ring; int ret, nent; ring = &atmel_port->rx_ring; dma_cap_zero(mask); dma_cap_set(DMA_CYCLIC, mask); atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx"); if (atmel_port->chan_rx == NULL) goto chan_err; dev_info(port->dev, "using %s for rx DMA transfers\n", dma_chan_name(atmel_port->chan_rx)); spin_lock_init(&atmel_port->lock_rx); sg_init_table(&atmel_port->sg_rx, 1); /* UART circular rx buffer is an aligned page. */ BUG_ON(!PAGE_ALIGNED(ring->buf)); sg_set_page(&atmel_port->sg_rx, virt_to_page(ring->buf), sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE, offset_in_page(ring->buf)); nent = dma_map_sg(port->dev, &atmel_port->sg_rx, 1, DMA_FROM_DEVICE); if (!nent) { dev_dbg(port->dev, "need to release resource of dma\n"); goto chan_err; } else { dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__, sg_dma_len(&atmel_port->sg_rx), ring->buf, &sg_dma_address(&atmel_port->sg_rx)); } /* Configure the slave DMA */ memset(&config, 0, sizeof(config)); config.direction = DMA_DEV_TO_MEM; config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; config.src_addr = port->mapbase + ATMEL_US_RHR; config.src_maxburst = 1; ret = dmaengine_slave_config(atmel_port->chan_rx, &config); if (ret) { dev_err(port->dev, "DMA rx slave configuration failed\n"); goto chan_err; } /* * Prepare a cyclic dma transfer, assign 2 descriptors, * each one is half ring buffer size */ desc = dmaengine_prep_dma_cyclic(atmel_port->chan_rx, sg_dma_address(&atmel_port->sg_rx), sg_dma_len(&atmel_port->sg_rx), sg_dma_len(&atmel_port->sg_rx)/2, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); desc->callback = atmel_complete_rx_dma; desc->callback_param = port; atmel_port->desc_rx = desc; atmel_port->cookie_rx = dmaengine_submit(desc); return 0; chan_err: dev_err(port->dev, "RX channel not available, switch to pio\n"); atmel_port->use_dma_rx = 0; if (atmel_port->chan_rx) atmel_release_rx_dma(port); return -EINVAL; } static void atmel_uart_timer_callback(struct timer_list *t) { struct atmel_uart_port *atmel_port = from_timer(atmel_port, t, uart_timer); struct uart_port *port = &atmel_port->uart; if (!atomic_read(&atmel_port->tasklet_shutdown)) { tasklet_schedule(&atmel_port->tasklet_rx); mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port)); } } /* * receive interrupt handler. */ static void atmel_handle_receive(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_pdc_rx(port)) { /* * PDC receive. Just schedule the tasklet and let it * figure out the details. * * TODO: We're not handling error flags correctly at * the moment. */ if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) { atmel_uart_writel(port, ATMEL_US_IDR, (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)); atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx); } if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE | ATMEL_US_FRAME | ATMEL_US_PARE)) atmel_pdc_rxerr(port, pending); } if (atmel_use_dma_rx(port)) { if (pending & ATMEL_US_TIMEOUT) { atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_TIMEOUT); atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx); } } /* Interrupt receive */ if (pending & ATMEL_US_RXRDY) atmel_rx_chars(port); else if (pending & ATMEL_US_RXBRK) { /* * End of break detected. If it came along with a * character, atmel_rx_chars will handle it. */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA); atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXBRK); atmel_port->break_active = 0; } } /* * transmit interrupt handler. (Transmit is IRQF_NODELAY safe) */ static void atmel_handle_transmit(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (pending & atmel_port->tx_done_mask) { /* Either PDC or interrupt transmission */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); } } /* * status flags interrupt handler. */ static void atmel_handle_status(struct uart_port *port, unsigned int pending, unsigned int status) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status_change; if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC)) { status_change = status ^ atmel_port->irq_status_prev; atmel_port->irq_status_prev = status; if (status_change & (ATMEL_US_RI | ATMEL_US_DSR | ATMEL_US_DCD | ATMEL_US_CTS)) { /* TODO: All reads to CSR will clear these interrupts! */ if (status_change & ATMEL_US_RI) port->icount.rng++; if (status_change & ATMEL_US_DSR) port->icount.dsr++; if (status_change & ATMEL_US_DCD) uart_handle_dcd_change(port, !(status & ATMEL_US_DCD)); if (status_change & ATMEL_US_CTS) uart_handle_cts_change(port, !(status & ATMEL_US_CTS)); wake_up_interruptible(&port->state->port.delta_msr_wait); } } if (pending & (ATMEL_US_NACK | ATMEL_US_ITERATION)) dev_dbg(port->dev, "ISO7816 ERROR (0x%08x)\n", pending); } /* * Interrupt handler */ static irqreturn_t atmel_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, pending, mask, pass_counter = 0; spin_lock(&atmel_port->lock_suspended); do { status = atmel_get_lines_status(port); mask = atmel_uart_readl(port, ATMEL_US_IMR); pending = status & mask; if (!pending) break; if (atmel_port->suspended) { atmel_port->pending |= pending; atmel_port->pending_status = status; atmel_uart_writel(port, ATMEL_US_IDR, mask); pm_system_wakeup(); break; } atmel_handle_receive(port, pending); atmel_handle_status(port, pending, status); atmel_handle_transmit(port, pending); } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT); spin_unlock(&atmel_port->lock_suspended); return pass_counter ? IRQ_HANDLED : IRQ_NONE; } static void atmel_release_tx_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx; dma_unmap_single(port->dev, pdc->dma_addr, pdc->dma_size, DMA_TO_DEVICE); } /* * Called from tasklet with ENDTX and TXBUFE interrupts disabled. */ static void atmel_tx_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct circ_buf *xmit = &port->state->xmit; struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx; int count; /* nothing left to transmit? */ if (atmel_uart_readl(port, ATMEL_PDC_TCR)) return; xmit->tail += pdc->ofs; xmit->tail &= UART_XMIT_SIZE - 1; port->icount.tx += pdc->ofs; pdc->ofs = 0; /* more to transmit - setup next transfer */ /* disable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS); if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) { dma_sync_single_for_device(port->dev, pdc->dma_addr, pdc->dma_size, DMA_TO_DEVICE); count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); pdc->ofs = count; atmel_uart_writel(port, ATMEL_PDC_TPR, pdc->dma_addr + xmit->tail); atmel_uart_writel(port, ATMEL_PDC_TCR, count); /* re-enable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } else { if (((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) || port->iso7816.flags & SER_ISO7816_ENABLED) { /* DMA done, stop TX, start RX for RS485 */ atmel_start_rx(port); } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); } static int atmel_prepare_tx_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx; struct circ_buf *xmit = &port->state->xmit; pdc->buf = xmit->buf; pdc->dma_addr = dma_map_single(port->dev, pdc->buf, UART_XMIT_SIZE, DMA_TO_DEVICE); pdc->dma_size = UART_XMIT_SIZE; pdc->ofs = 0; return 0; } static void atmel_rx_from_ring(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct circ_buf *ring = &atmel_port->rx_ring; unsigned int flg; unsigned int status; while (ring->head != ring->tail) { struct atmel_uart_char c; /* Make sure c is loaded after head. */ smp_rmb(); c = ((struct atmel_uart_char *)ring->buf)[ring->tail]; ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1); port->icount.rx++; status = c.status; flg = TTY_NORMAL; /* * note that the error handling code is * out of the main execution path */ if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME | ATMEL_US_OVRE | ATMEL_US_RXBRK))) { if (status & ATMEL_US_RXBRK) { /* ignore side-effect */ status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME); port->icount.brk++; if (uart_handle_break(port)) continue; } if (status & ATMEL_US_PARE) port->icount.parity++; if (status & ATMEL_US_FRAME) port->icount.frame++; if (status & ATMEL_US_OVRE) port->icount.overrun++; status &= port->read_status_mask; if (status & ATMEL_US_RXBRK) flg = TTY_BREAK; else if (status & ATMEL_US_PARE) flg = TTY_PARITY; else if (status & ATMEL_US_FRAME) flg = TTY_FRAME; } if (uart_handle_sysrq_char(port, c.ch)) continue; uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg); } /* * Drop the lock here since it might end up calling * uart_start(), which takes the lock. */ spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); spin_lock(&port->lock); } static void atmel_release_rx_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int i; for (i = 0; i < 2; i++) { struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i]; dma_unmap_single(port->dev, pdc->dma_addr, pdc->dma_size, DMA_FROM_DEVICE); kfree(pdc->buf); } } static void atmel_rx_from_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct tty_port *tport = &port->state->port; struct atmel_dma_buffer *pdc; int rx_idx = atmel_port->pdc_rx_idx; unsigned int head; unsigned int tail; unsigned int count; do { /* Reset the UART timeout early so that we don't miss one */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO); pdc = &atmel_port->pdc_rx[rx_idx]; head = atmel_uart_readl(port, ATMEL_PDC_RPR) - pdc->dma_addr; tail = pdc->ofs; /* If the PDC has switched buffers, RPR won't contain * any address within the current buffer. Since head * is unsigned, we just need a one-way comparison to * find out. * * In this case, we just need to consume the entire * buffer and resubmit it for DMA. This will clear the * ENDRX bit as well, so that we can safely re-enable * all interrupts below. */ head = min(head, pdc->dma_size); if (likely(head != tail)) { dma_sync_single_for_cpu(port->dev, pdc->dma_addr, pdc->dma_size, DMA_FROM_DEVICE); /* * head will only wrap around when we recycle * the DMA buffer, and when that happens, we * explicitly set tail to 0. So head will * always be greater than tail. */ count = head - tail; tty_insert_flip_string(tport, pdc->buf + pdc->ofs, count); dma_sync_single_for_device(port->dev, pdc->dma_addr, pdc->dma_size, DMA_FROM_DEVICE); port->icount.rx += count; pdc->ofs = head; } /* * If the current buffer is full, we need to check if * the next one contains any additional data. */ if (head >= pdc->dma_size) { pdc->ofs = 0; atmel_uart_writel(port, ATMEL_PDC_RNPR, pdc->dma_addr); atmel_uart_writel(port, ATMEL_PDC_RNCR, pdc->dma_size); rx_idx = !rx_idx; atmel_port->pdc_rx_idx = rx_idx; } } while (head >= pdc->dma_size); /* * Drop the lock here since it might end up calling * uart_start(), which takes the lock. */ spin_unlock(&port->lock); tty_flip_buffer_push(tport); spin_lock(&port->lock); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); } static int atmel_prepare_rx_pdc(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int i; for (i = 0; i < 2; i++) { struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i]; pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL); if (pdc->buf == NULL) { if (i != 0) { dma_unmap_single(port->dev, atmel_port->pdc_rx[0].dma_addr, PDC_BUFFER_SIZE, DMA_FROM_DEVICE); kfree(atmel_port->pdc_rx[0].buf); } atmel_port->use_pdc_rx = 0; return -ENOMEM; } pdc->dma_addr = dma_map_single(port->dev, pdc->buf, PDC_BUFFER_SIZE, DMA_FROM_DEVICE); pdc->dma_size = PDC_BUFFER_SIZE; pdc->ofs = 0; } atmel_port->pdc_rx_idx = 0; atmel_uart_writel(port, ATMEL_PDC_RPR, atmel_port->pdc_rx[0].dma_addr); atmel_uart_writel(port, ATMEL_PDC_RCR, PDC_BUFFER_SIZE); atmel_uart_writel(port, ATMEL_PDC_RNPR, atmel_port->pdc_rx[1].dma_addr); atmel_uart_writel(port, ATMEL_PDC_RNCR, PDC_BUFFER_SIZE); return 0; } /* * tasklet handling tty stuff outside the interrupt handler. */ static void atmel_tasklet_rx_func(unsigned long data) { struct uart_port *port = (struct uart_port *)data; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* The interrupt handler does not take the lock */ spin_lock(&port->lock); atmel_port->schedule_rx(port); spin_unlock(&port->lock); } static void atmel_tasklet_tx_func(unsigned long data) { struct uart_port *port = (struct uart_port *)data; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* The interrupt handler does not take the lock */ spin_lock(&port->lock); atmel_port->schedule_tx(port); spin_unlock(&port->lock); } static void atmel_init_property(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; /* DMA/PDC usage specification */ if (of_property_read_bool(np, "atmel,use-dma-rx")) { if (of_property_read_bool(np, "dmas")) { atmel_port->use_dma_rx = true; atmel_port->use_pdc_rx = false; } else { atmel_port->use_dma_rx = false; atmel_port->use_pdc_rx = true; } } else { atmel_port->use_dma_rx = false; atmel_port->use_pdc_rx = false; } if (of_property_read_bool(np, "atmel,use-dma-tx")) { if (of_property_read_bool(np, "dmas")) { atmel_port->use_dma_tx = true; atmel_port->use_pdc_tx = false; } else { atmel_port->use_dma_tx = false; atmel_port->use_pdc_tx = true; } } else { atmel_port->use_dma_tx = false; atmel_port->use_pdc_tx = false; } } static void atmel_set_ops(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_dma_rx(port)) { atmel_port->prepare_rx = &atmel_prepare_rx_dma; atmel_port->schedule_rx = &atmel_rx_from_dma; atmel_port->release_rx = &atmel_release_rx_dma; } else if (atmel_use_pdc_rx(port)) { atmel_port->prepare_rx = &atmel_prepare_rx_pdc; atmel_port->schedule_rx = &atmel_rx_from_pdc; atmel_port->release_rx = &atmel_release_rx_pdc; } else { atmel_port->prepare_rx = NULL; atmel_port->schedule_rx = &atmel_rx_from_ring; atmel_port->release_rx = NULL; } if (atmel_use_dma_tx(port)) { atmel_port->prepare_tx = &atmel_prepare_tx_dma; atmel_port->schedule_tx = &atmel_tx_dma; atmel_port->release_tx = &atmel_release_tx_dma; } else if (atmel_use_pdc_tx(port)) { atmel_port->prepare_tx = &atmel_prepare_tx_pdc; atmel_port->schedule_tx = &atmel_tx_pdc; atmel_port->release_tx = &atmel_release_tx_pdc; } else { atmel_port->prepare_tx = NULL; atmel_port->schedule_tx = &atmel_tx_chars; atmel_port->release_tx = NULL; } } /* * Get ip name usart or uart */ static void atmel_get_ip_name(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int name = atmel_uart_readl(port, ATMEL_US_NAME); u32 version; u32 usart, dbgu_uart, new_uart; /* ASCII decoding for IP version */ usart = 0x55534152; /* USAR(T) */ dbgu_uart = 0x44424755; /* DBGU */ new_uart = 0x55415254; /* UART */ /* * Only USART devices from at91sam9260 SOC implement fractional * baudrate. It is available for all asynchronous modes, with the * following restriction: the sampling clock's duty cycle is not * constant. */ atmel_port->has_frac_baudrate = false; atmel_port->has_hw_timer = false; if (name == new_uart) { dev_dbg(port->dev, "Uart with hw timer"); atmel_port->has_hw_timer = true; atmel_port->rtor = ATMEL_UA_RTOR; } else if (name == usart) { dev_dbg(port->dev, "Usart\n"); atmel_port->has_frac_baudrate = true; atmel_port->has_hw_timer = true; atmel_port->rtor = ATMEL_US_RTOR; version = atmel_uart_readl(port, ATMEL_US_VERSION); switch (version) { case 0x814: /* sama5d2 */ /* fall through */ case 0x701: /* sama5d4 */ atmel_port->fidi_min = 3; atmel_port->fidi_max = 65535; break; case 0x502: /* sam9x5, sama5d3 */ atmel_port->fidi_min = 3; atmel_port->fidi_max = 2047; break; default: atmel_port->fidi_min = 1; atmel_port->fidi_max = 2047; } } else if (name == dbgu_uart) { dev_dbg(port->dev, "Dbgu or uart without hw timer\n"); } else { /* fallback for older SoCs: use version field */ version = atmel_uart_readl(port, ATMEL_US_VERSION); switch (version) { case 0x302: case 0x10213: case 0x10302: dev_dbg(port->dev, "This version is usart\n"); atmel_port->has_frac_baudrate = true; atmel_port->has_hw_timer = true; atmel_port->rtor = ATMEL_US_RTOR; break; case 0x203: case 0x10202: dev_dbg(port->dev, "This version is uart\n"); break; default: dev_err(port->dev, "Not supported ip name nor version, set to uart\n"); } } } /* * Perform initialization and enable port for reception */ static int atmel_startup(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int retval; /* * Ensure that no interrupts are enabled otherwise when * request_irq() is called we could get stuck trying to * handle an unexpected interrupt */ atmel_uart_writel(port, ATMEL_US_IDR, -1); atmel_port->ms_irq_enabled = false; /* * Allocate the IRQ */ retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED | IRQF_COND_SUSPEND, dev_name(&pdev->dev), port); if (retval) { dev_err(port->dev, "atmel_startup - Can't get irq\n"); return retval; } atomic_set(&atmel_port->tasklet_shutdown, 0); tasklet_init(&atmel_port->tasklet_rx, atmel_tasklet_rx_func, (unsigned long)port); tasklet_init(&atmel_port->tasklet_tx, atmel_tasklet_tx_func, (unsigned long)port); /* * Initialize DMA (if necessary) */ atmel_init_property(atmel_port, pdev); atmel_set_ops(port); if (atmel_port->prepare_rx) { retval = atmel_port->prepare_rx(port); if (retval < 0) atmel_set_ops(port); } if (atmel_port->prepare_tx) { retval = atmel_port->prepare_tx(port); if (retval < 0) atmel_set_ops(port); } /* * Enable FIFO when available */ if (atmel_port->fifo_size) { unsigned int txrdym = ATMEL_US_ONE_DATA; unsigned int rxrdym = ATMEL_US_ONE_DATA; unsigned int fmr; atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_FIFOEN | ATMEL_US_RXFCLR | ATMEL_US_TXFLCLR); if (atmel_use_dma_tx(port)) txrdym = ATMEL_US_FOUR_DATA; fmr = ATMEL_US_TXRDYM(txrdym) | ATMEL_US_RXRDYM(rxrdym); if (atmel_port->rts_high && atmel_port->rts_low) fmr |= ATMEL_US_FRTSC | ATMEL_US_RXFTHRES(atmel_port->rts_high) | ATMEL_US_RXFTHRES2(atmel_port->rts_low); atmel_uart_writel(port, ATMEL_US_FMR, fmr); } /* Save current CSR for comparison in atmel_tasklet_func() */ atmel_port->irq_status_prev = atmel_get_lines_status(port); /* * Finally, enable the serial port */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); /* enable xmit & rcvr */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); atmel_port->tx_stopped = false; timer_setup(&atmel_port->uart_timer, atmel_uart_timer_callback, 0); if (atmel_use_pdc_rx(port)) { /* set UART timeout */ if (!atmel_port->has_hw_timer) { mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port)); /* set USART timeout */ } else { atmel_uart_writel(port, atmel_port->rtor, PDC_RX_TIMEOUT); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); } /* enable PDC controller */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN); } else if (atmel_use_dma_rx(port)) { /* set UART timeout */ if (!atmel_port->has_hw_timer) { mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port)); /* set USART timeout */ } else { atmel_uart_writel(port, atmel_port->rtor, PDC_RX_TIMEOUT); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_STTTO); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT); } } else { /* enable receive only */ atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_RXRDY); } return 0; } /* * Flush any TX data submitted for DMA. Called when the TX circular * buffer is reset. */ static void atmel_flush_buffer(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_pdc_tx(port)) { atmel_uart_writel(port, ATMEL_PDC_TCR, 0); atmel_port->pdc_tx.ofs = 0; } /* * in uart_flush_buffer(), the xmit circular buffer has just * been cleared, so we have to reset tx_len accordingly. */ atmel_port->tx_len = 0; } /* * Disable the port */ static void atmel_shutdown(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Disable modem control lines interrupts */ atmel_disable_ms(port); /* Disable interrupts at device level */ atmel_uart_writel(port, ATMEL_US_IDR, -1); /* Prevent spurious interrupts from scheduling the tasklet */ atomic_inc(&atmel_port->tasklet_shutdown); /* * Prevent any tasklets being scheduled during * cleanup */ del_timer_sync(&atmel_port->uart_timer); /* Make sure that no interrupt is on the fly */ synchronize_irq(port->irq); /* * Clear out any scheduled tasklets before * we destroy the buffers */ tasklet_kill(&atmel_port->tasklet_rx); tasklet_kill(&atmel_port->tasklet_tx); /* * Ensure everything is stopped and * disable port and break condition. */ atmel_stop_rx(port); atmel_stop_tx(port); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA); /* * Shut-down the DMA. */ if (atmel_port->release_rx) atmel_port->release_rx(port); if (atmel_port->release_tx) atmel_port->release_tx(port); /* * Reset ring buffer pointers */ atmel_port->rx_ring.head = 0; atmel_port->rx_ring.tail = 0; /* * Free the interrupts */ free_irq(port->irq, port); atmel_flush_buffer(port); } /* * Power / Clock management. */ static void atmel_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); switch (state) { case 0: /* * Enable the peripheral clock for this serial port. * This is called on uart_open() or a resume event. */ clk_prepare_enable(atmel_port->clk); /* re-enable interrupts if we disabled some on suspend */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->backup_imr); break; case 3: /* Back up the interrupt mask and disable all interrupts */ atmel_port->backup_imr = atmel_uart_readl(port, ATMEL_US_IMR); atmel_uart_writel(port, ATMEL_US_IDR, -1); /* * Disable the peripheral clock for this serial port. * This is called on uart_close() or a suspend event. */ clk_disable_unprepare(atmel_port->clk); break; default: dev_err(port->dev, "atmel_serial: unknown pm %d\n", state); } } /* * Change the port parameters */ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned long flags; unsigned int old_mode, mode, imr, quot, baud, div, cd, fp = 0; /* save the current mode register */ mode = old_mode = atmel_uart_readl(port, ATMEL_US_MR); /* reset the mode, clock divisor, parity, stop bits and data size */ mode &= ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR | ATMEL_US_USMODE); baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16); /* byte size */ switch (termios->c_cflag & CSIZE) { case CS5: mode |= ATMEL_US_CHRL_5; break; case CS6: mode |= ATMEL_US_CHRL_6; break; case CS7: mode |= ATMEL_US_CHRL_7; break; default: mode |= ATMEL_US_CHRL_8; break; } /* stop bits */ if (termios->c_cflag & CSTOPB) mode |= ATMEL_US_NBSTOP_2; /* parity */ if (termios->c_cflag & PARENB) { /* Mark or Space parity */ if (termios->c_cflag & CMSPAR) { if (termios->c_cflag & PARODD) mode |= ATMEL_US_PAR_MARK; else mode |= ATMEL_US_PAR_SPACE; } else if (termios->c_cflag & PARODD) mode |= ATMEL_US_PAR_ODD; else mode |= ATMEL_US_PAR_EVEN; } else mode |= ATMEL_US_PAR_NONE; spin_lock_irqsave(&port->lock, flags); port->read_status_mask = ATMEL_US_OVRE; if (termios->c_iflag & INPCK) port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE); if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= ATMEL_US_RXBRK; if (atmel_use_pdc_rx(port)) /* need to enable error interrupts */ atmel_uart_writel(port, ATMEL_US_IER, port->read_status_mask); /* * Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE); if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= ATMEL_US_RXBRK; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= ATMEL_US_OVRE; } /* TODO: Ignore all characters if CREAD is set.*/ /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); /* * save/disable interrupts. The tty layer will ensure that the * transmitter is empty if requested by the caller, so there's * no need to wait for it here. */ imr = atmel_uart_readl(port, ATMEL_US_IMR); atmel_uart_writel(port, ATMEL_US_IDR, -1); /* disable receiver and transmitter */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS); atmel_port->tx_stopped = true; /* mode */ if (port->rs485.flags & SER_RS485_ENABLED) { atmel_uart_writel(port, ATMEL_US_TTGR, port->rs485.delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else if (port->iso7816.flags & SER_ISO7816_ENABLED) { atmel_uart_writel(port, ATMEL_US_TTGR, port->iso7816.tg); /* select mck clock, and output */ mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO; /* set max iterations */ mode |= ATMEL_US_MAX_ITER(3); if ((port->iso7816.flags & SER_ISO7816_T_PARAM) == SER_ISO7816_T(0)) mode |= ATMEL_US_USMODE_ISO7816_T0; else mode |= ATMEL_US_USMODE_ISO7816_T1; } else if (termios->c_cflag & CRTSCTS) { /* RS232 with hardware handshake (RTS/CTS) */ if (atmel_use_fifo(port) && !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { /* * with ATMEL_US_USMODE_HWHS set, the controller will * be able to drive the RTS pin high/low when the RX * FIFO is above RXFTHRES/below RXFTHRES2. * It will also disable the transmitter when the CTS * pin is high. * This mode is not activated if CTS pin is a GPIO * because in this case, the transmitter is always * disabled (there must be an internal pull-up * responsible for this behaviour). * If the RTS pin is a GPIO, the controller won't be * able to drive it according to the FIFO thresholds, * but it will be handled by the driver. */ mode |= ATMEL_US_USMODE_HWHS; } else { /* * For platforms without FIFO, the flow control is * handled by the driver. */ mode |= ATMEL_US_USMODE_NORMAL; } } else { /* RS232 without hadware handshake */ mode |= ATMEL_US_USMODE_NORMAL; } /* set the mode, clock divisor, parity, stop bits and data size */ atmel_uart_writel(port, ATMEL_US_MR, mode); /* * when switching the mode, set the RTS line state according to the * new mode, otherwise keep the former state */ if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { unsigned int rts_state; if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { /* let the hardware control the RTS line */ rts_state = ATMEL_US_RTSDIS; } else { /* force RTS line to low level */ rts_state = ATMEL_US_RTSEN; } atmel_uart_writel(port, ATMEL_US_CR, rts_state); } /* * Set the baud rate: * Fractional baudrate allows to setup output frequency more * accurately. This feature is enabled only when using normal mode. * baudrate = selected clock / (8 * (2 - OVER) * (CD + FP / 8)) * Currently, OVER is always set to 0 so we get * baudrate = selected clock / (16 * (CD + FP / 8)) * then * 8 CD + FP = selected clock / (2 * baudrate) */ if (atmel_port->has_frac_baudrate) { div = DIV_ROUND_CLOSEST(port->uartclk, baud * 2); cd = div >> 3; fp = div & ATMEL_US_FP_MASK; } else { cd = uart_get_divisor(port, baud); } if (cd > 65535) { /* BRGR is 16-bit, so switch to slower clock */ cd /= 8; mode |= ATMEL_US_USCLKS_MCK_DIV8; } quot = cd | fp << ATMEL_US_FP_OFFSET; if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) atmel_uart_writel(port, ATMEL_US_BRGR, quot); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); atmel_port->tx_stopped = false; /* restore interrupts */ atmel_uart_writel(port, ATMEL_US_IER, imr); /* CTS flow-control and modem-status interrupts */ if (UART_ENABLE_MS(port, termios->c_cflag)) atmel_enable_ms(port); else atmel_disable_ms(port); spin_unlock_irqrestore(&port->lock, flags); } static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios) { if (termios->c_line == N_PPS) { port->flags |= UPF_HARDPPS_CD; spin_lock_irq(&port->lock); atmel_enable_ms(port); spin_unlock_irq(&port->lock); } else { port->flags &= ~UPF_HARDPPS_CD; if (!UART_ENABLE_MS(port, termios->c_cflag)) { spin_lock_irq(&port->lock); atmel_disable_ms(port); spin_unlock_irq(&port->lock); } } } /* * Return string describing the specified port */ static const char *atmel_type(struct uart_port *port) { return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL; } /* * Release the memory region(s) being used by 'port'. */ static void atmel_release_port(struct uart_port *port) { struct platform_device *mpdev = to_platform_device(port->dev->parent); int size = resource_size(mpdev->resource); release_mem_region(port->mapbase, size); if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } } /* * Request the memory region(s) being used by 'port'. */ static int atmel_request_port(struct uart_port *port) { struct platform_device *mpdev = to_platform_device(port->dev->parent); int size = resource_size(mpdev->resource); if (!request_mem_region(port->mapbase, size, "atmel_serial")) return -EBUSY; if (port->flags & UPF_IOREMAP) { port->membase = ioremap(port->mapbase, size); if (port->membase == NULL) { release_mem_region(port->mapbase, size); return -ENOMEM; } } return 0; } /* * Configure/autoconfigure the port. */ static void atmel_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_ATMEL; atmel_request_port(port); } } /* * Verify the new serial_struct (for TIOCSSERIAL). */ static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL) ret = -EINVAL; if (port->irq != ser->irq) ret = -EINVAL; if (ser->io_type != SERIAL_IO_MEM) ret = -EINVAL; if (port->uartclk / 16 != ser->baud_base) ret = -EINVAL; if (port->mapbase != (unsigned long)ser->iomem_base) ret = -EINVAL; if (port->iobase != ser->port) ret = -EINVAL; if (ser->hub6 != 0) ret = -EINVAL; return ret; } #ifdef CONFIG_CONSOLE_POLL static int atmel_poll_get_char(struct uart_port *port) { while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_RXRDY)) cpu_relax(); return atmel_uart_read_char(port); } static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) { while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY)) cpu_relax(); atmel_uart_write_char(port, ch); } #endif static const struct uart_ops atmel_pops = { .tx_empty = atmel_tx_empty, .set_mctrl = atmel_set_mctrl, .get_mctrl = atmel_get_mctrl, .stop_tx = atmel_stop_tx, .start_tx = atmel_start_tx, .stop_rx = atmel_stop_rx, .enable_ms = atmel_enable_ms, .break_ctl = atmel_break_ctl, .startup = atmel_startup, .shutdown = atmel_shutdown, .flush_buffer = atmel_flush_buffer, .set_termios = atmel_set_termios, .set_ldisc = atmel_set_ldisc, .type = atmel_type, .release_port = atmel_release_port, .request_port = atmel_request_port, .config_port = atmel_config_port, .verify_port = atmel_verify_port, .pm = atmel_serial_pm, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = atmel_poll_get_char, .poll_put_char = atmel_poll_put_char, #endif }; /* * Configure the port from the platform device resource info. */ static int atmel_init_port(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { int ret; struct uart_port *port = &atmel_port->uart; struct platform_device *mpdev = to_platform_device(pdev->dev.parent); atmel_init_property(atmel_port, pdev); atmel_set_ops(port); uart_get_rs485_mode(&mpdev->dev, &port->rs485); port->iotype = UPIO_MEM; port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP; port->ops = &atmel_pops; port->fifosize = 1; port->dev = &pdev->dev; port->mapbase = mpdev->resource[0].start; port->irq = mpdev->resource[1].start; port->rs485_config = atmel_config_rs485; port->iso7816_config = atmel_config_iso7816; port->membase = NULL; memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring)); /* for console, the clock could already be configured */ if (!atmel_port->clk) { atmel_port->clk = clk_get(&mpdev->dev, "usart"); if (IS_ERR(atmel_port->clk)) { ret = PTR_ERR(atmel_port->clk); atmel_port->clk = NULL; return ret; } ret = clk_prepare_enable(atmel_port->clk); if (ret) { clk_put(atmel_port->clk); atmel_port->clk = NULL; return ret; } port->uartclk = clk_get_rate(atmel_port->clk); clk_disable_unprepare(atmel_port->clk); /* only enable clock when USART is in use */ } /* * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or * ENDTX|TXBUFE */ if (port->rs485.flags & SER_RS485_ENABLED || port->iso7816.flags & SER_ISO7816_ENABLED) atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; else if (atmel_use_pdc_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; } else { atmel_port->tx_done_mask = ATMEL_US_TXRDY; } return 0; } #ifdef CONFIG_SERIAL_ATMEL_CONSOLE static void atmel_console_putchar(struct uart_port *port, int ch) { while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY)) cpu_relax(); atmel_uart_write_char(port, ch); } /* * Interrupts are disabled on entering */ static void atmel_console_write(struct console *co, const char *s, u_int count) { struct uart_port *port = &atmel_ports[co->index].uart; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, imr; unsigned int pdc_tx; /* * First, save IMR and then disable interrupts */ imr = atmel_uart_readl(port, ATMEL_US_IMR); atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_RXRDY | atmel_port->tx_done_mask); /* Store PDC transmit status and disable it */ pdc_tx = atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN; atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS); /* Make sure that tx path is actually able to send characters */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); atmel_port->tx_stopped = false; uart_console_write(port, s, count, atmel_console_putchar); /* * Finally, wait for transmitter to become empty * and restore IMR */ do { status = atmel_uart_readl(port, ATMEL_US_CSR); } while (!(status & ATMEL_US_TXRDY)); /* Restore PDC transmit status */ if (pdc_tx) atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); /* set interrupts back the way they were */ atmel_uart_writel(port, ATMEL_US_IER, imr); } /* * If the port was already initialised (eg, by a boot loader), * try to determine the current setup. */ static void __init atmel_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { unsigned int mr, quot; /* * If the baud rate generator isn't running, the port wasn't * initialized by the boot loader. */ quot = atmel_uart_readl(port, ATMEL_US_BRGR) & ATMEL_US_CD; if (!quot) return; mr = atmel_uart_readl(port, ATMEL_US_MR) & ATMEL_US_CHRL; if (mr == ATMEL_US_CHRL_8) *bits = 8; else *bits = 7; mr = atmel_uart_readl(port, ATMEL_US_MR) & ATMEL_US_PAR; if (mr == ATMEL_US_PAR_EVEN) *parity = 'e'; else if (mr == ATMEL_US_PAR_ODD) *parity = 'o'; /* * The serial core only rounds down when matching this to a * supported baud rate. Make sure we don't end up slightly * lower than one of those, as it would make us fall through * to a much lower baud rate than we really want. */ *baud = port->uartclk / (16 * (quot - 1)); } static int __init atmel_console_setup(struct console *co, char *options) { int ret; struct uart_port *port = &atmel_ports[co->index].uart; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (port->membase == NULL) { /* Port not initialized yet - delay setup */ return -ENODEV; } ret = clk_prepare_enable(atmel_ports[co->index].clk); if (ret) return ret; atmel_uart_writel(port, ATMEL_US_IDR, -1); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); atmel_port->tx_stopped = false; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else atmel_console_get_options(port, &baud, &parity, &bits); return uart_set_options(port, co, baud, parity, bits, flow); } static struct uart_driver atmel_uart; static struct console atmel_console = { .name = ATMEL_DEVICENAME, .write = atmel_console_write, .device = uart_console_device, .setup = atmel_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &atmel_uart, }; #define ATMEL_CONSOLE_DEVICE (&atmel_console) static inline bool atmel_is_console_port(struct uart_port *port) { return port->cons && port->cons->index == port->line; } #else #define ATMEL_CONSOLE_DEVICE NULL static inline bool atmel_is_console_port(struct uart_port *port) { return false; } #endif static struct uart_driver atmel_uart = { .owner = THIS_MODULE, .driver_name = "atmel_serial", .dev_name = ATMEL_DEVICENAME, .major = SERIAL_ATMEL_MAJOR, .minor = MINOR_START, .nr = ATMEL_MAX_UART, .cons = ATMEL_CONSOLE_DEVICE, }; #ifdef CONFIG_PM static bool atmel_serial_clk_will_stop(void) { #ifdef CONFIG_ARCH_AT91 return at91_suspend_entering_slow_clock(); #else return false; #endif } static int atmel_serial_suspend(struct platform_device *pdev, pm_message_t state) { struct uart_port *port = platform_get_drvdata(pdev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_is_console_port(port) && console_suspend_enabled) { /* Drain the TX shifter */ while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY)) cpu_relax(); } if (atmel_is_console_port(port) && !console_suspend_enabled) { /* Cache register values as we won't get a full shutdown/startup * cycle */ atmel_port->cache.mr = atmel_uart_readl(port, ATMEL_US_MR); atmel_port->cache.imr = atmel_uart_readl(port, ATMEL_US_IMR); atmel_port->cache.brgr = atmel_uart_readl(port, ATMEL_US_BRGR); atmel_port->cache.rtor = atmel_uart_readl(port, atmel_port->rtor); atmel_port->cache.ttgr = atmel_uart_readl(port, ATMEL_US_TTGR); atmel_port->cache.fmr = atmel_uart_readl(port, ATMEL_US_FMR); atmel_port->cache.fimr = atmel_uart_readl(port, ATMEL_US_FIMR); } /* we can not wake up if we're running on slow clock */ atmel_port->may_wakeup = device_may_wakeup(&pdev->dev); if (atmel_serial_clk_will_stop()) { unsigned long flags; spin_lock_irqsave(&atmel_port->lock_suspended, flags); atmel_port->suspended = true; spin_unlock_irqrestore(&atmel_port->lock_suspended, flags); device_set_wakeup_enable(&pdev->dev, 0); } uart_suspend_port(&atmel_uart, port); return 0; } static int atmel_serial_resume(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned long flags; if (atmel_is_console_port(port) && !console_suspend_enabled) { atmel_uart_writel(port, ATMEL_US_MR, atmel_port->cache.mr); atmel_uart_writel(port, ATMEL_US_IER, atmel_port->cache.imr); atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->cache.brgr); atmel_uart_writel(port, atmel_port->rtor, atmel_port->cache.rtor); atmel_uart_writel(port, ATMEL_US_TTGR, atmel_port->cache.ttgr); if (atmel_port->fifo_size) { atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_FIFOEN | ATMEL_US_RXFCLR | ATMEL_US_TXFLCLR); atmel_uart_writel(port, ATMEL_US_FMR, atmel_port->cache.fmr); atmel_uart_writel(port, ATMEL_US_FIER, atmel_port->cache.fimr); } atmel_start_rx(port); } spin_lock_irqsave(&atmel_port->lock_suspended, flags); if (atmel_port->pending) { atmel_handle_receive(port, atmel_port->pending); atmel_handle_status(port, atmel_port->pending, atmel_port->pending_status); atmel_handle_transmit(port, atmel_port->pending); atmel_port->pending = 0; } atmel_port->suspended = false; spin_unlock_irqrestore(&atmel_port->lock_suspended, flags); uart_resume_port(&atmel_uart, port); device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup); return 0; } #else #define atmel_serial_suspend NULL #define atmel_serial_resume NULL #endif static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { atmel_port->fifo_size = 0; atmel_port->rts_low = 0; atmel_port->rts_high = 0; if (of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size", &atmel_port->fifo_size)) return; if (!atmel_port->fifo_size) return; if (atmel_port->fifo_size < ATMEL_MIN_FIFO_SIZE) { atmel_port->fifo_size = 0; dev_err(&pdev->dev, "Invalid FIFO size\n"); return; } /* * 0 <= rts_low <= rts_high <= fifo_size * Once their CTS line asserted by the remote peer, some x86 UARTs tend * to flush their internal TX FIFO, commonly up to 16 data, before * actually stopping to send new data. So we try to set the RTS High * Threshold to a reasonably high value respecting this 16 data * empirical rule when possible. */ atmel_port->rts_high = max_t(int, atmel_port->fifo_size >> 1, atmel_port->fifo_size - ATMEL_RTS_HIGH_OFFSET); atmel_port->rts_low = max_t(int, atmel_port->fifo_size >> 2, atmel_port->fifo_size - ATMEL_RTS_LOW_OFFSET); dev_info(&pdev->dev, "Using FIFO (%u data)\n", atmel_port->fifo_size); dev_dbg(&pdev->dev, "RTS High Threshold : %2u data\n", atmel_port->rts_high); dev_dbg(&pdev->dev, "RTS Low Threshold : %2u data\n", atmel_port->rts_low); } static int atmel_serial_probe(struct platform_device *pdev) { struct atmel_uart_port *atmel_port; struct device_node *np = pdev->dev.parent->of_node; void *data; int ret = -ENODEV; bool rs485_enabled; BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1)); /* * In device tree there is no node with "atmel,at91rm9200-usart-serial" * as compatible string. This driver is probed by at91-usart mfd driver * which is just a wrapper over the atmel_serial driver and * spi-at91-usart driver. All attributes needed by this driver are * found in of_node of parent. */ pdev->dev.of_node = np; ret = of_alias_get_id(np, "serial"); if (ret < 0) /* port id not found in platform data nor device-tree aliases: * auto-enumerate it */ ret = find_first_zero_bit(atmel_ports_in_use, ATMEL_MAX_UART); if (ret >= ATMEL_MAX_UART) { ret = -ENODEV; goto err; } if (test_and_set_bit(ret, atmel_ports_in_use)) { /* port already in use */ ret = -EBUSY; goto err; } atmel_port = &atmel_ports[ret]; atmel_port->backup_imr = 0; atmel_port->uart.line = ret; atmel_serial_probe_fifos(atmel_port, pdev); atomic_set(&atmel_port->tasklet_shutdown, 0); spin_lock_init(&atmel_port->lock_suspended); ret = atmel_init_port(atmel_port, pdev); if (ret) goto err_clear_bit; atmel_port->gpios = mctrl_gpio_init(&atmel_port->uart, 0); if (IS_ERR(atmel_port->gpios)) { ret = PTR_ERR(atmel_port->gpios); goto err_clear_bit; } if (!atmel_use_pdc_rx(&atmel_port->uart)) { ret = -ENOMEM; data = kmalloc_array(ATMEL_SERIAL_RINGSIZE, sizeof(struct atmel_uart_char), GFP_KERNEL); if (!data) goto err_alloc_ring; atmel_port->rx_ring.buf = data; } rs485_enabled = atmel_port->uart.rs485.flags & SER_RS485_ENABLED; ret = uart_add_one_port(&atmel_uart, &atmel_port->uart); if (ret) goto err_add_port; #ifdef CONFIG_SERIAL_ATMEL_CONSOLE if (atmel_is_console_port(&atmel_port->uart) && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) { /* * The serial core enabled the clock for us, so undo * the clk_prepare_enable() in atmel_console_setup() */ clk_disable_unprepare(atmel_port->clk); } #endif device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, atmel_port); /* * The peripheral clock has been disabled by atmel_init_port(): * enable it before accessing I/O registers */ clk_prepare_enable(atmel_port->clk); if (rs485_enabled) { atmel_uart_writel(&atmel_port->uart, ATMEL_US_MR, ATMEL_US_USMODE_NORMAL); atmel_uart_writel(&atmel_port->uart, ATMEL_US_CR, ATMEL_US_RTSEN); } /* * Get port name of usart or uart */ atmel_get_ip_name(&atmel_port->uart); /* * The peripheral clock can now safely be disabled till the port * is used */ clk_disable_unprepare(atmel_port->clk); return 0; err_add_port: kfree(atmel_port->rx_ring.buf); atmel_port->rx_ring.buf = NULL; err_alloc_ring: if (!atmel_is_console_port(&atmel_port->uart)) { clk_put(atmel_port->clk); atmel_port->clk = NULL; } err_clear_bit: clear_bit(atmel_port->uart.line, atmel_ports_in_use); err: return ret; } /* * Even if the driver is not modular, it makes sense to be able to * unbind a device: there can be many bound devices, and there are * situations where dynamic binding and unbinding can be useful. * * For example, a connected device can require a specific firmware update * protocol that needs bitbanging on IO lines, but use the regular serial * port in the normal case. */ static int atmel_serial_remove(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int ret = 0; tasklet_kill(&atmel_port->tasklet_rx); tasklet_kill(&atmel_port->tasklet_tx); device_init_wakeup(&pdev->dev, 0); ret = uart_remove_one_port(&atmel_uart, port); kfree(atmel_port->rx_ring.buf); /* "port" is allocated statically, so we shouldn't free it */ clear_bit(port->line, atmel_ports_in_use); clk_put(atmel_port->clk); atmel_port->clk = NULL; pdev->dev.of_node = NULL; return ret; } static struct platform_driver atmel_serial_driver = { .probe = atmel_serial_probe, .remove = atmel_serial_remove, .suspend = atmel_serial_suspend, .resume = atmel_serial_resume, .driver = { .name = "atmel_usart_serial", .of_match_table = of_match_ptr(atmel_serial_dt_ids), }, }; static int __init atmel_serial_init(void) { int ret; ret = uart_register_driver(&atmel_uart); if (ret) return ret; ret = platform_driver_register(&atmel_serial_driver); if (ret) uart_unregister_driver(&atmel_uart); return ret; } device_initcall(atmel_serial_init);
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