| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sebastian Andrzej Siewior | 5096 | 77.93% | 10 | 21.28% |
| Vignesh R | 368 | 5.63% | 8 | 17.02% |
| Sekhar Nori | 361 | 5.52% | 5 | 10.64% |
| Peter Hurley | 274 | 4.19% | 10 | 21.28% |
| John Ogness | 199 | 3.04% | 1 | 2.13% |
| Matwey V. Kornilov | 120 | 1.84% | 1 | 2.13% |
| Tony Lindgren | 75 | 1.15% | 3 | 6.38% |
| Doug Anderson | 17 | 0.26% | 1 | 2.13% |
| Andy Shevchenko | 12 | 0.18% | 2 | 4.26% |
| Nishanth Menon | 7 | 0.11% | 1 | 2.13% |
| Rafael J. Wysocki | 4 | 0.06% | 1 | 2.13% |
| Yegor Yefremov | 2 | 0.03% | 1 | 2.13% |
| Ed Blake | 2 | 0.03% | 1 | 2.13% |
| Rolf Evers-Fischer | 1 | 0.02% | 1 | 2.13% |
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 2.13% |
| Total | 6539 | 47 |
// SPDX-License-Identifier: GPL-2.0 /* * 8250-core based driver for the OMAP internal UART * * based on omap-serial.c, Copyright (C) 2010 Texas Instruments. * * Copyright (C) 2014 Sebastian Andrzej Siewior * */ #if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include <linux/clk.h> #include <linux/device.h> #include <linux/io.h> #include <linux/module.h> #include <linux/serial_8250.h> #include <linux/serial_reg.h> #include <linux/tty_flip.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_gpio.h> #include <linux/of_irq.h> #include <linux/delay.h> #include <linux/pm_runtime.h> #include <linux/console.h> #include <linux/pm_qos.h> #include <linux/pm_wakeirq.h> #include <linux/dma-mapping.h> #include "8250.h" #define DEFAULT_CLK_SPEED 48000000 #define UART_ERRATA_i202_MDR1_ACCESS (1 << 0) #define OMAP_UART_WER_HAS_TX_WAKEUP (1 << 1) #define OMAP_DMA_TX_KICK (1 << 2) /* * See Advisory 21 in AM437x errata SPRZ408B, updated April 2015. * The same errata is applicable to AM335x and DRA7x processors too. */ #define UART_ERRATA_CLOCK_DISABLE (1 << 3) #define OMAP_UART_FCR_RX_TRIG 6 #define OMAP_UART_FCR_TX_TRIG 4 /* SCR register bitmasks */ #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK (1 << 7) #define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK (1 << 6) #define OMAP_UART_SCR_TX_EMPTY (1 << 3) #define OMAP_UART_SCR_DMAMODE_MASK (3 << 1) #define OMAP_UART_SCR_DMAMODE_1 (1 << 1) #define OMAP_UART_SCR_DMAMODE_CTL (1 << 0) /* MVR register bitmasks */ #define OMAP_UART_MVR_SCHEME_SHIFT 30 #define OMAP_UART_LEGACY_MVR_MAJ_MASK 0xf0 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT 4 #define OMAP_UART_LEGACY_MVR_MIN_MASK 0x0f #define OMAP_UART_MVR_MAJ_MASK 0x700 #define OMAP_UART_MVR_MAJ_SHIFT 8 #define OMAP_UART_MVR_MIN_MASK 0x3f /* SYSC register bitmasks */ #define OMAP_UART_SYSC_SOFTRESET (1 << 1) /* SYSS register bitmasks */ #define OMAP_UART_SYSS_RESETDONE (1 << 0) #define UART_TI752_TLR_TX 0 #define UART_TI752_TLR_RX 4 #define TRIGGER_TLR_MASK(x) ((x & 0x3c) >> 2) #define TRIGGER_FCR_MASK(x) (x & 3) /* Enable XON/XOFF flow control on output */ #define OMAP_UART_SW_TX 0x08 /* Enable XON/XOFF flow control on input */ #define OMAP_UART_SW_RX 0x02 #define OMAP_UART_WER_MOD_WKUP 0x7f #define OMAP_UART_TX_WAKEUP_EN (1 << 7) #define TX_TRIGGER 1 #define RX_TRIGGER 48 #define OMAP_UART_TCR_RESTORE(x) ((x / 4) << 4) #define OMAP_UART_TCR_HALT(x) ((x / 4) << 0) #define UART_BUILD_REVISION(x, y) (((x) << 8) | (y)) #define OMAP_UART_REV_46 0x0406 #define OMAP_UART_REV_52 0x0502 #define OMAP_UART_REV_63 0x0603 struct omap8250_priv { int line; u8 habit; u8 mdr1; u8 efr; u8 scr; u8 wer; u8 xon; u8 xoff; u8 delayed_restore; u16 quot; bool is_suspending; int wakeirq; int wakeups_enabled; u32 latency; u32 calc_latency; struct pm_qos_request pm_qos_request; struct work_struct qos_work; struct uart_8250_dma omap8250_dma; spinlock_t rx_dma_lock; bool rx_dma_broken; bool throttled; }; #ifdef CONFIG_SERIAL_8250_DMA static void omap_8250_rx_dma_flush(struct uart_8250_port *p); #else static inline void omap_8250_rx_dma_flush(struct uart_8250_port *p) { } #endif static u32 uart_read(struct uart_8250_port *up, u32 reg) { return readl(up->port.membase + (reg << up->port.regshift)); } static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = up->port.private_data; u8 lcr; serial8250_do_set_mctrl(port, mctrl); /* * Turn off autoRTS if RTS is lowered and restore autoRTS setting * if RTS is raised */ lcr = serial_in(up, UART_LCR); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS)) priv->efr |= UART_EFR_RTS; else priv->efr &= ~UART_EFR_RTS; serial_out(up, UART_EFR, priv->efr); serial_out(up, UART_LCR, lcr); } /* * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460) * The access to uart register after MDR1 Access * causes UART to corrupt data. * * Need a delay = * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS) * give 10 times as much */ static void omap_8250_mdr1_errataset(struct uart_8250_port *up, struct omap8250_priv *priv) { u8 timeout = 255; u8 old_mdr1; old_mdr1 = serial_in(up, UART_OMAP_MDR1); if (old_mdr1 == priv->mdr1) return; serial_out(up, UART_OMAP_MDR1, priv->mdr1); udelay(2); serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); /* * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and * TX_FIFO_E bit is 1. */ while (UART_LSR_THRE != (serial_in(up, UART_LSR) & (UART_LSR_THRE | UART_LSR_DR))) { timeout--; if (!timeout) { /* Should *never* happen. we warn and carry on */ dev_crit(up->port.dev, "Errata i202: timedout %x\n", serial_in(up, UART_LSR)); break; } udelay(1); } } static void omap_8250_get_divisor(struct uart_port *port, unsigned int baud, struct omap8250_priv *priv) { unsigned int uartclk = port->uartclk; unsigned int div_13, div_16; unsigned int abs_d13, abs_d16; /* * Old custom speed handling. */ if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) { priv->quot = port->custom_divisor & UART_DIV_MAX; /* * I assume that nobody is using this. But hey, if somebody * would like to specify the divisor _and_ the mode then the * driver is ready and waiting for it. */ if (port->custom_divisor & (1 << 16)) priv->mdr1 = UART_OMAP_MDR1_13X_MODE; else priv->mdr1 = UART_OMAP_MDR1_16X_MODE; return; } div_13 = DIV_ROUND_CLOSEST(uartclk, 13 * baud); div_16 = DIV_ROUND_CLOSEST(uartclk, 16 * baud); if (!div_13) div_13 = 1; if (!div_16) div_16 = 1; abs_d13 = abs(baud - uartclk / 13 / div_13); abs_d16 = abs(baud - uartclk / 16 / div_16); if (abs_d13 >= abs_d16) { priv->mdr1 = UART_OMAP_MDR1_16X_MODE; priv->quot = div_16; } else { priv->mdr1 = UART_OMAP_MDR1_13X_MODE; priv->quot = div_13; } } static void omap8250_update_scr(struct uart_8250_port *up, struct omap8250_priv *priv) { u8 old_scr; old_scr = serial_in(up, UART_OMAP_SCR); if (old_scr == priv->scr) return; /* * The manual recommends not to enable the DMA mode selector in the SCR * (instead of the FCR) register _and_ selecting the DMA mode as one * register write because this may lead to malfunction. */ if (priv->scr & OMAP_UART_SCR_DMAMODE_MASK) serial_out(up, UART_OMAP_SCR, priv->scr & ~OMAP_UART_SCR_DMAMODE_MASK); serial_out(up, UART_OMAP_SCR, priv->scr); } static void omap8250_update_mdr1(struct uart_8250_port *up, struct omap8250_priv *priv) { if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS) omap_8250_mdr1_errataset(up, priv); else serial_out(up, UART_OMAP_MDR1, priv->mdr1); } static void omap8250_restore_regs(struct uart_8250_port *up) { struct omap8250_priv *priv = up->port.private_data; struct uart_8250_dma *dma = up->dma; if (dma && dma->tx_running) { /* * TCSANOW requests the change to occur immediately however if * we have a TX-DMA operation in progress then it has been * observed that it might stall and never complete. Therefore we * delay DMA completes to prevent this hang from happen. */ priv->delayed_restore = 1; return; } serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, UART_EFR_ECB); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); serial8250_out_MCR(up, UART_MCR_TCRTLR); serial_out(up, UART_FCR, up->fcr); omap8250_update_scr(up, priv); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_RESTORE(16) | OMAP_UART_TCR_HALT(52)); serial_out(up, UART_TI752_TLR, TRIGGER_TLR_MASK(TX_TRIGGER) << UART_TI752_TLR_TX | TRIGGER_TLR_MASK(RX_TRIGGER) << UART_TI752_TLR_RX); serial_out(up, UART_LCR, 0); /* drop TCR + TLR access, we setup XON/XOFF later */ serial8250_out_MCR(up, up->mcr); serial_out(up, UART_IER, up->ier); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_dl_write(up, priv->quot); serial_out(up, UART_EFR, priv->efr); /* Configure flow control */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_XON1, priv->xon); serial_out(up, UART_XOFF1, priv->xoff); serial_out(up, UART_LCR, up->lcr); omap8250_update_mdr1(up, priv); up->port.ops->set_mctrl(&up->port, up->port.mctrl); } /* * OMAP can use "CLK / (16 or 13) / div" for baud rate. And then we have have * some differences in how we want to handle flow control. */ static void omap_8250_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = up->port.private_data; unsigned char cval = 0; unsigned int baud; switch (termios->c_cflag & CSIZE) { case CS5: cval = UART_LCR_WLEN5; break; case CS6: cval = UART_LCR_WLEN6; break; case CS7: cval = UART_LCR_WLEN7; break; default: case CS8: cval = UART_LCR_WLEN8; break; } if (termios->c_cflag & CSTOPB) cval |= UART_LCR_STOP; if (termios->c_cflag & PARENB) cval |= UART_LCR_PARITY; if (!(termios->c_cflag & PARODD)) cval |= UART_LCR_EPAR; if (termios->c_cflag & CMSPAR) cval |= UART_LCR_SPAR; /* * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / UART_DIV_MAX, port->uartclk / 13); omap_8250_get_divisor(port, baud, priv); /* * Ok, we're now changing the port state. Do it with * interrupts disabled. */ pm_runtime_get_sync(port->dev); spin_lock_irq(&port->lock); /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; if (termios->c_iflag & INPCK) up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE; if (termios->c_iflag & (IGNBRK | PARMRK)) up->port.read_status_mask |= UART_LSR_BI; /* * Characters to ignore */ up->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; if (termios->c_iflag & IGNBRK) { up->port.ignore_status_mask |= UART_LSR_BI; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) up->port.ignore_status_mask |= UART_LSR_OE; } /* * ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) up->port.ignore_status_mask |= UART_LSR_DR; /* * Modem status interrupts */ up->ier &= ~UART_IER_MSI; if (UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; up->lcr = cval; /* Up to here it was mostly serial8250_do_set_termios() */ /* * We enable TRIG_GRANU for RX and TX and additionally we set * SCR_TX_EMPTY bit. The result is the following: * - RX_TRIGGER amount of bytes in the FIFO will cause an interrupt. * - less than RX_TRIGGER number of bytes will also cause an interrupt * once the UART decides that there no new bytes arriving. * - Once THRE is enabled, the interrupt will be fired once the FIFO is * empty - the trigger level is ignored here. * * Once DMA is enabled: * - UART will assert the TX DMA line once there is room for TX_TRIGGER * bytes in the TX FIFO. On each assert the DMA engine will move * TX_TRIGGER bytes into the FIFO. * - UART will assert the RX DMA line once there are RX_TRIGGER bytes in * the FIFO and move RX_TRIGGER bytes. * This is because threshold and trigger values are the same. */ up->fcr = UART_FCR_ENABLE_FIFO; up->fcr |= TRIGGER_FCR_MASK(TX_TRIGGER) << OMAP_UART_FCR_TX_TRIG; up->fcr |= TRIGGER_FCR_MASK(RX_TRIGGER) << OMAP_UART_FCR_RX_TRIG; priv->scr = OMAP_UART_SCR_RX_TRIG_GRANU1_MASK | OMAP_UART_SCR_TX_EMPTY | OMAP_UART_SCR_TX_TRIG_GRANU1_MASK; if (up->dma) priv->scr |= OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL; priv->xon = termios->c_cc[VSTART]; priv->xoff = termios->c_cc[VSTOP]; priv->efr = 0; up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF); if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) { /* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */ up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; priv->efr |= UART_EFR_CTS; } else if (up->port.flags & UPF_SOFT_FLOW) { /* * OMAP rx s/w flow control is borked; the transmitter remains * stuck off even if rx flow control is subsequently disabled */ /* * IXOFF Flag: * Enable XON/XOFF flow control on output. * Transmit XON1, XOFF1 */ if (termios->c_iflag & IXOFF) { up->port.status |= UPSTAT_AUTOXOFF; priv->efr |= OMAP_UART_SW_TX; } } omap8250_restore_regs(up); spin_unlock_irq(&up->port.lock); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); /* calculate wakeup latency constraint */ priv->calc_latency = USEC_PER_SEC * 64 * 8 / baud; priv->latency = priv->calc_latency; schedule_work(&priv->qos_work); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); } /* same as 8250 except that we may have extra flow bits set in EFR */ static void omap_8250_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct uart_8250_port *up = up_to_u8250p(port); u8 efr; pm_runtime_get_sync(port->dev); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); efr = serial_in(up, UART_EFR); serial_out(up, UART_EFR, efr | UART_EFR_ECB); serial_out(up, UART_LCR, 0); serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, efr); serial_out(up, UART_LCR, 0); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); } static void omap_serial_fill_features_erratas(struct uart_8250_port *up, struct omap8250_priv *priv) { u32 mvr, scheme; u16 revision, major, minor; mvr = uart_read(up, UART_OMAP_MVER); /* Check revision register scheme */ scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT; switch (scheme) { case 0: /* Legacy Scheme: OMAP2/3 */ /* MINOR_REV[0:4], MAJOR_REV[4:7] */ major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >> OMAP_UART_LEGACY_MVR_MAJ_SHIFT; minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK); break; case 1: /* New Scheme: OMAP4+ */ /* MINOR_REV[0:5], MAJOR_REV[8:10] */ major = (mvr & OMAP_UART_MVR_MAJ_MASK) >> OMAP_UART_MVR_MAJ_SHIFT; minor = (mvr & OMAP_UART_MVR_MIN_MASK); break; default: dev_warn(up->port.dev, "Unknown revision, defaulting to highest\n"); /* highest possible revision */ major = 0xff; minor = 0xff; } /* normalize revision for the driver */ revision = UART_BUILD_REVISION(major, minor); switch (revision) { case OMAP_UART_REV_46: priv->habit |= UART_ERRATA_i202_MDR1_ACCESS; break; case OMAP_UART_REV_52: priv->habit |= UART_ERRATA_i202_MDR1_ACCESS | OMAP_UART_WER_HAS_TX_WAKEUP; break; case OMAP_UART_REV_63: priv->habit |= UART_ERRATA_i202_MDR1_ACCESS | OMAP_UART_WER_HAS_TX_WAKEUP; break; default: break; } } static void omap8250_uart_qos_work(struct work_struct *work) { struct omap8250_priv *priv; priv = container_of(work, struct omap8250_priv, qos_work); pm_qos_update_request(&priv->pm_qos_request, priv->latency); } #ifdef CONFIG_SERIAL_8250_DMA static int omap_8250_dma_handle_irq(struct uart_port *port); #endif static irqreturn_t omap8250_irq(int irq, void *dev_id) { struct uart_port *port = dev_id; struct uart_8250_port *up = up_to_u8250p(port); unsigned int iir; int ret; #ifdef CONFIG_SERIAL_8250_DMA if (up->dma) { ret = omap_8250_dma_handle_irq(port); return IRQ_RETVAL(ret); } #endif serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); serial8250_rpm_put(up); return IRQ_RETVAL(ret); } static int omap_8250_startup(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data; int ret; if (priv->wakeirq) { ret = dev_pm_set_dedicated_wake_irq(port->dev, priv->wakeirq); if (ret) return ret; } pm_runtime_get_sync(port->dev); up->mcr = 0; serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_out(up, UART_LCR, UART_LCR_WLEN8); up->lsr_saved_flags = 0; up->msr_saved_flags = 0; /* Disable DMA for console UART */ if (uart_console(port)) up->dma = NULL; if (up->dma) { ret = serial8250_request_dma(up); if (ret) { dev_warn_ratelimited(port->dev, "failed to request DMA\n"); up->dma = NULL; } } ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED, dev_name(port->dev), port); if (ret < 0) goto err; up->ier = UART_IER_RLSI | UART_IER_RDI; serial_out(up, UART_IER, up->ier); #ifdef CONFIG_PM up->capabilities |= UART_CAP_RPM; #endif /* Enable module level wake up */ priv->wer = OMAP_UART_WER_MOD_WKUP; if (priv->habit & OMAP_UART_WER_HAS_TX_WAKEUP) priv->wer |= OMAP_UART_TX_WAKEUP_EN; serial_out(up, UART_OMAP_WER, priv->wer); if (up->dma) up->dma->rx_dma(up); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); return 0; err: pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); dev_pm_clear_wake_irq(port->dev); return ret; } static void omap_8250_shutdown(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data; flush_work(&priv->qos_work); if (up->dma) omap_8250_rx_dma_flush(up); pm_runtime_get_sync(port->dev); serial_out(up, UART_OMAP_WER, 0); up->ier = 0; serial_out(up, UART_IER, 0); if (up->dma) serial8250_release_dma(up); /* * Disable break condition and FIFOs */ if (up->lcr & UART_LCR_SBC) serial_out(up, UART_LCR, up->lcr & ~UART_LCR_SBC); serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); free_irq(port->irq, port); dev_pm_clear_wake_irq(port->dev); } static void omap_8250_throttle(struct uart_port *port) { struct omap8250_priv *priv = port->private_data; struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; pm_runtime_get_sync(port->dev); spin_lock_irqsave(&port->lock, flags); up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); serial_out(up, UART_IER, up->ier); priv->throttled = true; spin_unlock_irqrestore(&port->lock, flags); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); } static int omap_8250_rs485_config(struct uart_port *port, struct serial_rs485 *rs485) { struct uart_8250_port *up = up_to_u8250p(port); /* Clamp the delays to [0, 100ms] */ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U); rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U); port->rs485 = *rs485; /* * Both serial8250_em485_init and serial8250_em485_destroy * are idempotent */ if (rs485->flags & SER_RS485_ENABLED) { int ret = serial8250_em485_init(up); if (ret) { rs485->flags &= ~SER_RS485_ENABLED; port->rs485.flags &= ~SER_RS485_ENABLED; } return ret; } serial8250_em485_destroy(up); return 0; } static void omap_8250_unthrottle(struct uart_port *port) { struct omap8250_priv *priv = port->private_data; struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; pm_runtime_get_sync(port->dev); spin_lock_irqsave(&port->lock, flags); priv->throttled = false; if (up->dma) up->dma->rx_dma(up); up->ier |= UART_IER_RLSI | UART_IER_RDI; serial_out(up, UART_IER, up->ier); spin_unlock_irqrestore(&port->lock, flags); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); } #ifdef CONFIG_SERIAL_8250_DMA static int omap_8250_rx_dma(struct uart_8250_port *p); static void __dma_rx_do_complete(struct uart_8250_port *p) { struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; struct tty_port *tty_port = &p->port.state->port; struct dma_tx_state state; int count; unsigned long flags; int ret; spin_lock_irqsave(&priv->rx_dma_lock, flags); if (!dma->rx_running) goto unlock; dma->rx_running = 0; dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); count = dma->rx_size - state.residue; ret = tty_insert_flip_string(tty_port, dma->rx_buf, count); p->port.icount.rx += ret; p->port.icount.buf_overrun += count - ret; unlock: spin_unlock_irqrestore(&priv->rx_dma_lock, flags); tty_flip_buffer_push(tty_port); } static void __dma_rx_complete(void *param) { struct uart_8250_port *p = param; struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; struct dma_tx_state state; unsigned long flags; spin_lock_irqsave(&p->port.lock, flags); /* * If the tx status is not DMA_COMPLETE, then this is a delayed * completion callback. A previous RX timeout flush would have * already pushed the data, so exit. */ if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) != DMA_COMPLETE) { spin_unlock_irqrestore(&p->port.lock, flags); return; } __dma_rx_do_complete(p); if (!priv->throttled) omap_8250_rx_dma(p); spin_unlock_irqrestore(&p->port.lock, flags); } static void omap_8250_rx_dma_flush(struct uart_8250_port *p) { struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; struct dma_tx_state state; unsigned long flags; int ret; spin_lock_irqsave(&priv->rx_dma_lock, flags); if (!dma->rx_running) { spin_unlock_irqrestore(&priv->rx_dma_lock, flags); return; } ret = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); if (ret == DMA_IN_PROGRESS) { ret = dmaengine_pause(dma->rxchan); if (WARN_ON_ONCE(ret)) priv->rx_dma_broken = true; } spin_unlock_irqrestore(&priv->rx_dma_lock, flags); __dma_rx_do_complete(p); dmaengine_terminate_all(dma->rxchan); } static int omap_8250_rx_dma(struct uart_8250_port *p) { struct omap8250_priv *priv = p->port.private_data; struct uart_8250_dma *dma = p->dma; int err = 0; struct dma_async_tx_descriptor *desc; unsigned long flags; if (priv->rx_dma_broken) return -EINVAL; spin_lock_irqsave(&priv->rx_dma_lock, flags); if (dma->rx_running) goto out; desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { err = -EBUSY; goto out; } dma->rx_running = 1; desc->callback = __dma_rx_complete; desc->callback_param = p; dma->rx_cookie = dmaengine_submit(desc); dma_async_issue_pending(dma->rxchan); out: spin_unlock_irqrestore(&priv->rx_dma_lock, flags); return err; } static int omap_8250_tx_dma(struct uart_8250_port *p); static void omap_8250_dma_tx_complete(void *param) { struct uart_8250_port *p = param; struct uart_8250_dma *dma = p->dma; struct circ_buf *xmit = &p->port.state->xmit; unsigned long flags; bool en_thri = false; struct omap8250_priv *priv = p->port.private_data; dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); spin_lock_irqsave(&p->port.lock, flags); dma->tx_running = 0; xmit->tail += dma->tx_size; xmit->tail &= UART_XMIT_SIZE - 1; p->port.icount.tx += dma->tx_size; if (priv->delayed_restore) { priv->delayed_restore = 0; omap8250_restore_regs(p); } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&p->port); if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) { int ret; ret = omap_8250_tx_dma(p); if (ret) en_thri = true; } else if (p->capabilities & UART_CAP_RPM) { en_thri = true; } if (en_thri) { dma->tx_err = 1; p->ier |= UART_IER_THRI; serial_port_out(&p->port, UART_IER, p->ier); } spin_unlock_irqrestore(&p->port.lock, flags); } static int omap_8250_tx_dma(struct uart_8250_port *p) { struct uart_8250_dma *dma = p->dma; struct omap8250_priv *priv = p->port.private_data; struct circ_buf *xmit = &p->port.state->xmit; struct dma_async_tx_descriptor *desc; unsigned int skip_byte = 0; int ret; if (dma->tx_running) return 0; if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) { /* * Even if no data, we need to return an error for the two cases * below so serial8250_tx_chars() is invoked and properly clears * THRI and/or runtime suspend. */ if (dma->tx_err || p->capabilities & UART_CAP_RPM) { ret = -EBUSY; goto err; } if (p->ier & UART_IER_THRI) { p->ier &= ~UART_IER_THRI; serial_out(p, UART_IER, p->ier); } return 0; } dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); if (priv->habit & OMAP_DMA_TX_KICK) { u8 tx_lvl; /* * We need to put the first byte into the FIFO in order to start * the DMA transfer. For transfers smaller than four bytes we * don't bother doing DMA at all. It seem not matter if there * are still bytes in the FIFO from the last transfer (in case * we got here directly from omap_8250_dma_tx_complete()). Bytes * leaving the FIFO seem not to trigger the DMA transfer. It is * really the byte that we put into the FIFO. * If the FIFO is already full then we most likely got here from * omap_8250_dma_tx_complete(). And this means the DMA engine * just completed its work. We don't have to wait the complete * 86us at 115200,8n1 but around 60us (not to mention lower * baudrates). So in that case we take the interrupt and try * again with an empty FIFO. */ tx_lvl = serial_in(p, UART_OMAP_TX_LVL); if (tx_lvl == p->tx_loadsz) { ret = -EBUSY; goto err; } if (dma->tx_size < 4) { ret = -EINVAL; goto err; } skip_byte = 1; } desc = dmaengine_prep_slave_single(dma->txchan, dma->tx_addr + xmit->tail + skip_byte, dma->tx_size - skip_byte, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { ret = -EBUSY; goto err; } dma->tx_running = 1; desc->callback = omap_8250_dma_tx_complete; desc->callback_param = p; dma->tx_cookie = dmaengine_submit(desc); dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); dma_async_issue_pending(dma->txchan); if (dma->tx_err) dma->tx_err = 0; if (p->ier & UART_IER_THRI) { p->ier &= ~UART_IER_THRI; serial_out(p, UART_IER, p->ier); } if (skip_byte) serial_out(p, UART_TX, xmit->buf[xmit->tail]); return 0; err: dma->tx_err = 1; return ret; } static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { case UART_IIR_RLSI: case UART_IIR_RX_TIMEOUT: case UART_IIR_RDI: omap_8250_rx_dma_flush(up); return true; } return omap_8250_rx_dma(up); } /* * This is mostly serial8250_handle_irq(). We have a slightly different DMA * hoook for RX/TX and need different logic for them in the ISR. Therefore we * use the default routine in the non-DMA case and this one for with DMA. */ static int omap_8250_dma_handle_irq(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char status; unsigned long flags; u8 iir; serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); if (iir & UART_IIR_NO_INT) { serial8250_rpm_put(up); return 0; } spin_lock_irqsave(&port->lock, flags); status = serial_port_in(port, UART_LSR); if (status & (UART_LSR_DR | UART_LSR_BI)) { if (handle_rx_dma(up, iir)) { status = serial8250_rx_chars(up, status); omap_8250_rx_dma(up); } } serial8250_modem_status(up); if (status & UART_LSR_THRE && up->dma->tx_err) { if (uart_tx_stopped(&up->port) || uart_circ_empty(&up->port.state->xmit)) { up->dma->tx_err = 0; serial8250_tx_chars(up); } else { /* * try again due to an earlier failer which * might have been resolved by now. */ if (omap_8250_tx_dma(up)) serial8250_tx_chars(up); } } uart_unlock_and_check_sysrq(port, flags); serial8250_rpm_put(up); return 1; } static bool the_no_dma_filter_fn(struct dma_chan *chan, void *param) { return false; } #else static inline int omap_8250_rx_dma(struct uart_8250_port *p) { return -EINVAL; } #endif static int omap8250_no_handle_irq(struct uart_port *port) { /* IRQ has not been requested but handling irq? */ WARN_ONCE(1, "Unexpected irq handling before port startup\n"); return 0; } static const u8 omap4_habit = UART_ERRATA_CLOCK_DISABLE; static const u8 am3352_habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE; static const u8 dra742_habit = UART_ERRATA_CLOCK_DISABLE; static const struct of_device_id omap8250_dt_ids[] = { { .compatible = "ti,am654-uart" }, { .compatible = "ti,omap2-uart" }, { .compatible = "ti,omap3-uart" }, { .compatible = "ti,omap4-uart", .data = &omap4_habit, }, { .compatible = "ti,am3352-uart", .data = &am3352_habit, }, { .compatible = "ti,am4372-uart", .data = &am3352_habit, }, { .compatible = "ti,dra742-uart", .data = &dra742_habit, }, {}, }; MODULE_DEVICE_TABLE(of, omap8250_dt_ids); static int omap8250_probe(struct platform_device *pdev) { struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); struct device_node *np = pdev->dev.of_node; struct omap8250_priv *priv; struct uart_8250_port up; int ret; void __iomem *membase; const struct of_device_id *id; if (!regs || !irq) { dev_err(&pdev->dev, "missing registers or irq\n"); return -EINVAL; } priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; membase = devm_ioremap_nocache(&pdev->dev, regs->start, resource_size(regs)); if (!membase) return -ENODEV; memset(&up, 0, sizeof(up)); up.port.dev = &pdev->dev; up.port.mapbase = regs->start; up.port.membase = membase; up.port.irq = irq->start; /* * It claims to be 16C750 compatible however it is a little different. * It has EFR and has no FCR7_64byte bit. The AFE (which it claims to * have) is enabled via EFR instead of MCR. The type is set here 8250 * just to get things going. UNKNOWN does not work for a few reasons and * we don't need our own type since we don't use 8250's set_termios() * or pm callback. */ up.port.type = PORT_8250; up.port.iotype = UPIO_MEM; up.port.flags = UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_SOFT_FLOW | UPF_HARD_FLOW; up.port.private_data = priv; up.port.regshift = 2; up.port.fifosize = 64; up.tx_loadsz = 64; up.capabilities = UART_CAP_FIFO; #ifdef CONFIG_PM /* * Runtime PM is mostly transparent. However to do it right we need to a * TX empty interrupt before we can put the device to auto idle. So if * PM is not enabled we don't add that flag and can spare that one extra * interrupt in the TX path. */ up.capabilities |= UART_CAP_RPM; #endif up.port.set_termios = omap_8250_set_termios; up.port.set_mctrl = omap8250_set_mctrl; up.port.pm = omap_8250_pm; up.port.startup = omap_8250_startup; up.port.shutdown = omap_8250_shutdown; up.port.throttle = omap_8250_throttle; up.port.unthrottle = omap_8250_unthrottle; up.port.rs485_config = omap_8250_rs485_config; ret = of_alias_get_id(np, "serial"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias\n"); return ret; } up.port.line = ret; if (of_property_read_u32(np, "clock-frequency", &up.port.uartclk)) { struct clk *clk; clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(clk)) { if (PTR_ERR(clk) == -EPROBE_DEFER) return -EPROBE_DEFER; } else { up.port.uartclk = clk_get_rate(clk); } } priv->wakeirq = irq_of_parse_and_map(np, 1); id = of_match_device(of_match_ptr(omap8250_dt_ids), &pdev->dev); if (id && id->data) priv->habit |= *(u8 *)id->data; if (!up.port.uartclk) { up.port.uartclk = DEFAULT_CLK_SPEED; dev_warn(&pdev->dev, "No clock speed specified: using default: %d\n", DEFAULT_CLK_SPEED); } priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; priv->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; pm_qos_add_request(&priv->pm_qos_request, PM_QOS_CPU_DMA_LATENCY, priv->latency); INIT_WORK(&priv->qos_work, omap8250_uart_qos_work); spin_lock_init(&priv->rx_dma_lock); device_init_wakeup(&pdev->dev, true); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, -1); pm_runtime_irq_safe(&pdev->dev); pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); omap_serial_fill_features_erratas(&up, priv); up.port.handle_irq = omap8250_no_handle_irq; #ifdef CONFIG_SERIAL_8250_DMA /* * Oh DMA support. If there are no DMA properties in the DT then * we will fall back to a generic DMA channel which does not * really work here. To ensure that we do not get a generic DMA * channel assigned, we have the the_no_dma_filter_fn() here. * To avoid "failed to request DMA" messages we check for DMA * properties in DT. */ ret = of_property_count_strings(np, "dma-names"); if (ret == 2) { up.dma = &priv->omap8250_dma; priv->omap8250_dma.fn = the_no_dma_filter_fn; priv->omap8250_dma.tx_dma = omap_8250_tx_dma; priv->omap8250_dma.rx_dma = omap_8250_rx_dma; priv->omap8250_dma.rx_size = RX_TRIGGER; priv->omap8250_dma.rxconf.src_maxburst = RX_TRIGGER; priv->omap8250_dma.txconf.dst_maxburst = TX_TRIGGER; } #endif ret = serial8250_register_8250_port(&up); if (ret < 0) { dev_err(&pdev->dev, "unable to register 8250 port\n"); goto err; } priv->line = ret; platform_set_drvdata(pdev, priv); pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); return 0; err: pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); return ret; } static int omap8250_remove(struct platform_device *pdev) { struct omap8250_priv *priv = platform_get_drvdata(pdev); pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); serial8250_unregister_port(priv->line); pm_qos_remove_request(&priv->pm_qos_request); device_init_wakeup(&pdev->dev, false); return 0; } #ifdef CONFIG_PM_SLEEP static int omap8250_prepare(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); if (!priv) return 0; priv->is_suspending = true; return 0; } static void omap8250_complete(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); if (!priv) return; priv->is_suspending = false; } static int omap8250_suspend(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); struct uart_8250_port *up = serial8250_get_port(priv->line); serial8250_suspend_port(priv->line); pm_runtime_get_sync(dev); if (!device_may_wakeup(dev)) priv->wer = 0; serial_out(up, UART_OMAP_WER, priv->wer); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); flush_work(&priv->qos_work); return 0; } static int omap8250_resume(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); serial8250_resume_port(priv->line); return 0; } #else #define omap8250_prepare NULL #define omap8250_complete NULL #endif #ifdef CONFIG_PM static int omap8250_lost_context(struct uart_8250_port *up) { u32 val; val = serial_in(up, UART_OMAP_SCR); /* * If we lose context, then SCR is set to its reset value of zero. * After set_termios() we set bit 3 of SCR (TX_EMPTY_CTL_IT) to 1, * among other bits, to never set the register back to zero again. */ if (!val) return 1; return 0; } /* TODO: in future, this should happen via API in drivers/reset/ */ static int omap8250_soft_reset(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); struct uart_8250_port *up = serial8250_get_port(priv->line); int timeout = 100; int sysc; int syss; /* * At least on omap4, unused uarts may not idle after reset without * a basic scr dma configuration even with no dma in use. The * module clkctrl status bits will be 1 instead of 3 blocking idle * for the whole clockdomain. The softreset below will clear scr, * and we restore it on resume so this is safe to do on all SoCs * needing omap8250_soft_reset() quirk. Do it in two writes as * recommended in the comment for omap8250_update_scr(). */ serial_out(up, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1); serial_out(up, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL); sysc = serial_in(up, UART_OMAP_SYSC); /* softreset the UART */ sysc |= OMAP_UART_SYSC_SOFTRESET; serial_out(up, UART_OMAP_SYSC, sysc); /* By experiments, 1us enough for reset complete on AM335x */ do { udelay(1); syss = serial_in(up, UART_OMAP_SYSS); } while (--timeout && !(syss & OMAP_UART_SYSS_RESETDONE)); if (!timeout) { dev_err(dev, "timed out waiting for reset done\n"); return -ETIMEDOUT; } return 0; } static int omap8250_runtime_suspend(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); struct uart_8250_port *up; /* In case runtime-pm tries this before we are setup */ if (!priv) return 0; up = serial8250_get_port(priv->line); /* * When using 'no_console_suspend', the console UART must not be * suspended. Since driver suspend is managed by runtime suspend, * preventing runtime suspend (by returning error) will keep device * active during suspend. */ if (priv->is_suspending && !console_suspend_enabled) { if (uart_console(&up->port)) return -EBUSY; } if (priv->habit & UART_ERRATA_CLOCK_DISABLE) { int ret; ret = omap8250_soft_reset(dev); if (ret) return ret; /* Restore to UART mode after reset (for wakeup) */ omap8250_update_mdr1(up, priv); /* Restore wakeup enable register */ serial_out(up, UART_OMAP_WER, priv->wer); } if (up->dma && up->dma->rxchan) omap_8250_rx_dma_flush(up); priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; schedule_work(&priv->qos_work); return 0; } static int omap8250_runtime_resume(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); struct uart_8250_port *up; /* In case runtime-pm tries this before we are setup */ if (!priv) return 0; up = serial8250_get_port(priv->line); if (omap8250_lost_context(up)) omap8250_restore_regs(up); if (up->dma && up->dma->rxchan) omap_8250_rx_dma(up); priv->latency = priv->calc_latency; schedule_work(&priv->qos_work); return 0; } #endif #ifdef CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP static int __init omap8250_console_fixup(void) { char *omap_str; char *options; u8 idx; if (strstr(boot_command_line, "console=ttyS")) /* user set a ttyS based name for the console */ return 0; omap_str = strstr(boot_command_line, "console=ttyO"); if (!omap_str) /* user did not set ttyO based console, so we don't care */ return 0; omap_str += 12; if ('0' <= *omap_str && *omap_str <= '9') idx = *omap_str - '0'; else return 0; omap_str++; if (omap_str[0] == ',') { omap_str++; options = omap_str; } else { options = NULL; } add_preferred_console("ttyS", idx, options); pr_err("WARNING: Your 'console=ttyO%d' has been replaced by 'ttyS%d'\n", idx, idx); pr_err("This ensures that you still see kernel messages. Please\n"); pr_err("update your kernel commandline.\n"); return 0; } console_initcall(omap8250_console_fixup); #endif static const struct dev_pm_ops omap8250_dev_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume) SET_RUNTIME_PM_OPS(omap8250_runtime_suspend, omap8250_runtime_resume, NULL) .prepare = omap8250_prepare, .complete = omap8250_complete, }; static struct platform_driver omap8250_platform_driver = { .driver = { .name = "omap8250", .pm = &omap8250_dev_pm_ops, .of_match_table = omap8250_dt_ids, }, .probe = omap8250_probe, .remove = omap8250_remove, }; module_platform_driver(omap8250_platform_driver); MODULE_AUTHOR("Sebastian Andrzej Siewior"); MODULE_DESCRIPTION("OMAP 8250 Driver"); MODULE_LICENSE("GPL v2");
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