| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sebastian Andrzej Siewior | 4882 | 62.14% | 10 | 9.62% |
| Vignesh R | 1172 | 14.92% | 16 | 15.38% |
| Tony Lindgren | 517 | 6.58% | 11 | 10.58% |
| Lukas Wunner | 311 | 3.96% | 6 | 5.77% |
| John Ogness | 294 | 3.74% | 5 | 4.81% |
| Sekhar Nori | 241 | 3.07% | 5 | 4.81% |
| Peter Hurley | 163 | 2.07% | 9 | 8.65% |
| Andy Shevchenko | 58 | 0.74% | 5 | 4.81% |
| Adam Ford | 25 | 0.32% | 1 | 0.96% |
| Yegor Yefremov | 20 | 0.25% | 2 | 1.92% |
| Paul Gortmaker | 18 | 0.23% | 1 | 0.96% |
| Peter Ujfalusi | 17 | 0.22% | 2 | 1.92% |
| Russell King | 14 | 0.18% | 3 | 2.88% |
| Sudhakar Mamillapalli | 13 | 0.17% | 1 | 0.96% |
| Heikki Krogerus | 13 | 0.17% | 2 | 1.92% |
| Dmitry Safonov | 13 | 0.17% | 1 | 0.96% |
| Arnd Bergmann | 11 | 0.14% | 1 | 0.96% |
| Rafael J. Wysocki | 10 | 0.13% | 3 | 2.88% |
| Matthias Schiffer | 8 | 0.10% | 1 | 0.96% |
| Jiri Slaby | 8 | 0.10% | 1 | 0.96% |
| Matwey V. Kornilov | 8 | 0.10% | 1 | 0.96% |
| Nishanth Menon | 7 | 0.09% | 2 | 1.92% |
| Magnus Damm | 6 | 0.08% | 1 | 0.96% |
| Ilpo Järvinen | 5 | 0.06% | 2 | 1.92% |
| Sean Young | 4 | 0.05% | 1 | 0.96% |
| Uwe Kleine-König | 4 | 0.05% | 1 | 0.96% |
| Dan Carpenter | 3 | 0.04% | 1 | 0.96% |
| Christoph Hellwig | 3 | 0.04% | 2 | 1.92% |
| Ed Blake | 2 | 0.03% | 1 | 0.96% |
| Fabian Godehardt | 1 | 0.01% | 1 | 0.96% |
| Colin Ian King | 1 | 0.01% | 1 | 0.96% |
| Greg Kroah-Hartman | 1 | 0.01% | 1 | 0.96% |
| Johan Hovold | 1 | 0.01% | 1 | 0.96% |
| Rolf Evers-Fischer | 1 | 0.01% | 1 | 0.96% |
| Doug Anderson | 1 | 0.01% | 1 | 0.96% |
| Total | 7856 | 104 |
// 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 * */ #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 <linux/sys_soc.h> #include "8250.h" #define DEFAULT_CLK_SPEED 48000000 #define OMAP_UART_REGSHIFT 2 #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 UART_HAS_EFR2 BIT(4) #define UART_HAS_RHR_IT_DIS BIT(5) #define UART_RX_TIMEOUT_QUIRK BIT(6) #define UART_HAS_NATIVE_RS485 BIT(7) #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 /* Interrupt Enable Register 2 */ #define UART_OMAP_IER2 0x1B #define UART_OMAP_IER2_RHR_IT_DIS BIT(2) /* Mode Definition Register 3 */ #define UART_OMAP_MDR3 0x20 #define UART_OMAP_MDR3_DIR_POL BIT(3) #define UART_OMAP_MDR3_DIR_EN BIT(4) /* Enhanced features register 2 */ #define UART_OMAP_EFR2 0x23 #define UART_OMAP_EFR2_TIMEOUT_BEHAVE BIT(6) /* RX FIFO occupancy indicator */ #define UART_OMAP_RX_LVL 0x19 struct omap8250_priv { void __iomem *membase; int line; u8 habit; u8 mdr1; u8 mdr3; u8 efr; u8 scr; u8 wer; u8 xon; u8 xoff; u8 delayed_restore; u16 quot; u8 tx_trigger; u8 rx_trigger; 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; }; struct omap8250_dma_params { u32 rx_size; u8 rx_trigger; u8 tx_trigger; }; struct omap8250_platdata { struct omap8250_dma_params *dma_params; u8 habit; }; #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 omap8250_priv *priv, u32 reg) { return readl(priv->membase + (reg << OMAP_UART_REGSHIFT)); } /* * Called on runtime PM resume path from omap8250_restore_regs(), and * omap8250_set_mctrl(). */ 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); if (!mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS)) { /* * 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); } } static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { int err; err = pm_runtime_resume_and_get(port->dev); if (err) return; __omap8250_set_mctrl(port, mctrl); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); } /* * 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) { 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); } 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; u8 mcr = serial8250_in_MCR(up); /* Port locked to synchronize UART_IER access against the console. */ lockdep_assert_held_once(&up->port.lock); 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, mcr | 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(priv->tx_trigger) << UART_TI752_TLR_TX | TRIGGER_TLR_MASK(priv->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, 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); __omap8250_set_mctrl(&up->port, up->port.mctrl); serial_out(up, UART_OMAP_MDR3, priv->mdr3); if (up->port.rs485.flags & SER_RS485_ENABLED && up->port.rs485_config == serial8250_em485_config) serial8250_em485_stop_tx(up); } /* * 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, const 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; cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag)); 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(priv->tx_trigger) << OMAP_UART_FCR_TX_TRIG; up->fcr |= TRIGGER_FCR_MASK(priv->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 && !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS) && !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_CTS)) { /* 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); /* Synchronize UART_IER access against the console. */ spin_lock_irq(&port->lock); 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); spin_unlock_irq(&port->lock); 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) { static const struct soc_device_attribute k3_soc_devices[] = { { .family = "AM65X", }, { .family = "J721E", .revision = "SR1.0" }, { /* sentinel */ } }; u32 mvr, scheme; u16 revision, major, minor; mvr = uart_read(priv, 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; } /* * AM65x SR1.0, AM65x SR2.0 and J721e SR1.0 don't * don't have RHR_IT_DIS bit in IER2 register. So drop to flag * to enable errata workaround. */ if (soc_device_match(k3_soc_devices)) priv->habit &= ~UART_HAS_RHR_IT_DIS; } static void omap8250_uart_qos_work(struct work_struct *work) { struct omap8250_priv *priv; priv = container_of(work, struct omap8250_priv, qos_work); cpu_latency_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 omap8250_priv *priv = dev_id; struct uart_8250_port *up = serial8250_get_port(priv->line); struct uart_port *port = &up->port; unsigned int iir, lsr; 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); lsr = serial_port_in(port, UART_LSR); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); /* * On K3 SoCs, it is observed that RX TIMEOUT is signalled after * FIFO has been drained, in which case a dummy read of RX FIFO * is required to clear RX TIMEOUT condition. */ if (priv->habit & UART_RX_TIMEOUT_QUIRK && (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT && serial_port_in(port, UART_OMAP_RX_LVL) == 0) { serial_port_in(port, UART_RX); } /* Stop processing interrupts on input overrun */ if ((lsr & UART_LSR_OE) && up->overrun_backoff_time_ms > 0) { unsigned long delay; /* Synchronize UART_IER access against the console. */ spin_lock(&port->lock); up->ier = port->serial_in(port, UART_IER); if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) { port->ops->stop_rx(port); } else { /* Keep restarting the timer until * the input overrun subsides. */ cancel_delayed_work(&up->overrun_backoff); } spin_unlock(&port->lock); delay = msecs_to_jiffies(up->overrun_backoff_time_ms); schedule_delayed_work(&up->overrun_backoff, delay); } 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; struct uart_8250_dma *dma = &priv->omap8250_dma; 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); 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 (dma->fn && !uart_console(port)) { up->dma = &priv->omap8250_dma; ret = serial8250_request_dma(up); if (ret) { dev_warn_ratelimited(port->dev, "failed to request DMA\n"); up->dma = NULL; } } else { up->dma = NULL; } /* Synchronize UART_IER access against the console. */ spin_lock_irq(&port->lock); up->ier = UART_IER_RLSI | UART_IER_RDI; serial_out(up, UART_IER, up->ier); spin_unlock_irq(&port->lock); #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 && !(priv->habit & UART_HAS_EFR2)) { spin_lock_irq(&port->lock); up->dma->rx_dma(up); spin_unlock_irq(&port->lock); } enable_irq(up->port.irq); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); return 0; } 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); if (priv->habit & UART_HAS_EFR2) serial_out(up, UART_OMAP_EFR2, 0x0); /* Synchronize UART_IER access against the console. */ spin_lock_irq(&port->lock); up->ier = 0; serial_out(up, UART_IER, 0); spin_unlock_irq(&port->lock); disable_irq_nosync(up->port.irq); dev_pm_clear_wake_irq(port->dev); serial8250_release_dma(up); up->dma = NULL; /* * 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); } static void omap_8250_throttle(struct uart_port *port) { struct omap8250_priv *priv = port->private_data; unsigned long flags; pm_runtime_get_sync(port->dev); spin_lock_irqsave(&port->lock, flags); port->ops->stop_rx(port); priv->throttled = true; spin_unlock_irqrestore(&port->lock, flags); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); } 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); /* Synchronize UART_IER access against the console. */ 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; port->read_status_mask |= UART_LSR_DR; 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); } static int omap8250_rs485_config(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485) { struct omap8250_priv *priv = port->private_data; struct uart_8250_port *up = up_to_u8250p(port); u32 fixed_delay_rts_before_send = 0; u32 fixed_delay_rts_after_send = 0; unsigned int baud; /* * There is a fixed delay of 3 bit clock cycles after the TX shift * register is going empty to allow time for the stop bit to transition * through the transceiver before direction is changed to receive. * * Additionally there appears to be a 1 bit clock delay between writing * to the THR register and transmission of the start bit, per page 8783 * of the AM65 TRM: https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf */ if (priv->quot) { if (priv->mdr1 == UART_OMAP_MDR1_16X_MODE) baud = port->uartclk / (16 * priv->quot); else baud = port->uartclk / (13 * priv->quot); fixed_delay_rts_after_send = 3 * MSEC_PER_SEC / baud; fixed_delay_rts_before_send = 1 * MSEC_PER_SEC / baud; } /* * Fall back to RS485 software emulation if the UART is missing * hardware support, if the device tree specifies an mctrl_gpio * (indicates that RTS is unavailable due to a pinmux conflict) * or if the requested delays exceed the fixed hardware delays. */ if (!(priv->habit & UART_HAS_NATIVE_RS485) || mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS) || rs485->delay_rts_after_send > fixed_delay_rts_after_send || rs485->delay_rts_before_send > fixed_delay_rts_before_send) { priv->mdr3 &= ~UART_OMAP_MDR3_DIR_EN; serial_out(up, UART_OMAP_MDR3, priv->mdr3); port->rs485_config = serial8250_em485_config; return serial8250_em485_config(port, termios, rs485); } rs485->delay_rts_after_send = fixed_delay_rts_after_send; rs485->delay_rts_before_send = fixed_delay_rts_before_send; if (rs485->flags & SER_RS485_ENABLED) priv->mdr3 |= UART_OMAP_MDR3_DIR_EN; else priv->mdr3 &= ~UART_OMAP_MDR3_DIR_EN; /* * Retain same polarity semantics as RS485 software emulation, * i.e. SER_RS485_RTS_ON_SEND means driving RTS low on send. */ if (rs485->flags & SER_RS485_RTS_ON_SEND) priv->mdr3 &= ~UART_OMAP_MDR3_DIR_POL; else priv->mdr3 |= UART_OMAP_MDR3_DIR_POL; serial_out(up, UART_OMAP_MDR3, priv->mdr3); return 0; } #ifdef CONFIG_SERIAL_8250_DMA static int omap_8250_rx_dma(struct uart_8250_port *p); /* Must be called while priv->rx_dma_lock is held */ static void __dma_rx_do_complete(struct uart_8250_port *p) { struct uart_8250_dma *dma = p->dma; struct tty_port *tty_port = &p->port.state->port; struct omap8250_priv *priv = p->port.private_data; struct dma_chan *rxchan = dma->rxchan; dma_cookie_t cookie; struct dma_tx_state state; int count; int ret; u32 reg; if (!dma->rx_running) goto out; cookie = dma->rx_cookie; dma->rx_running = 0; /* Re-enable RX FIFO interrupt now that transfer is complete */ if (priv->habit & UART_HAS_RHR_IT_DIS) { reg = serial_in(p, UART_OMAP_IER2); reg &= ~UART_OMAP_IER2_RHR_IT_DIS; serial_out(p, UART_OMAP_IER2, UART_OMAP_IER2_RHR_IT_DIS); } dmaengine_tx_status(rxchan, cookie, &state); count = dma->rx_size - state.residue + state.in_flight_bytes; if (count < dma->rx_size) { dmaengine_terminate_async(rxchan); /* * Poll for teardown to complete which guarantees in * flight data is drained. */ if (state.in_flight_bytes) { int poll_count = 25; while (dmaengine_tx_status(rxchan, cookie, NULL) && poll_count--) cpu_relax(); if (poll_count == -1) dev_err(p->port.dev, "teardown incomplete\n"); } } if (!count) goto out; ret = tty_insert_flip_string(tty_port, dma->rx_buf, count); p->port.icount.rx += ret; p->port.icount.buf_overrun += count - ret; out: 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; /* Synchronize UART_IER access against the console. */ 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) { p->ier |= UART_IER_RLSI | UART_IER_RDI; serial_out(p, UART_IER, p->ier); if (!(priv->habit & UART_HAS_EFR2)) 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; } __dma_rx_do_complete(p); spin_unlock_irqrestore(&priv->rx_dma_lock, flags); } 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; u32 reg; /* Port locked to synchronize UART_IER access against the console. */ lockdep_assert_held_once(&p->port.lock); if (priv->rx_dma_broken) return -EINVAL; spin_lock_irqsave(&priv->rx_dma_lock, flags); if (dma->rx_running) { enum dma_status state; state = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, NULL); if (state == DMA_COMPLETE) { /* * Disable RX interrupts to allow RX DMA completion * callback to run. */ p->ier &= ~(UART_IER_RLSI | UART_IER_RDI); serial_out(p, UART_IER, p->ier); } 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); /* * Disable RX FIFO interrupt while RX DMA is enabled, else * spurious interrupt may be raised when data is in the RX FIFO * but is yet to be drained by DMA. */ if (priv->habit & UART_HAS_RHR_IT_DIS) { reg = serial_in(p, UART_OMAP_IER2); reg |= UART_OMAP_IER2_RHR_IT_DIS; serial_out(p, UART_OMAP_IER2, UART_OMAP_IER2_RHR_IT_DIS); } 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; uart_xmit_advance(&p->port, 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; serial8250_set_THRI(p); } 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; } serial8250_clear_THRI(p); 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; serial8250_clear_THRI(p); 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); } static u16 omap_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, u16 status) { if ((status & (UART_LSR_DR | UART_LSR_BI)) && (iir & UART_IIR_RDI)) { if (handle_rx_dma(up, iir)) { status = serial8250_rx_chars(up, status); omap_8250_rx_dma(up); } } return status; } static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, u16 status) { /* Port locked to synchronize UART_IER access against the console. */ lockdep_assert_held_once(&up->port.lock); /* * Queue a new transfer if FIFO has data. */ if ((status & (UART_LSR_DR | UART_LSR_BI)) && (up->ier & UART_IER_RDI)) { omap_8250_rx_dma(up); serial_out(up, UART_OMAP_EFR2, UART_OMAP_EFR2_TIMEOUT_BEHAVE); } else if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) { /* * Disable RX timeout, read IIR to clear * current timeout condition, clear EFR2 to * periodic timeouts, re-enable interrupts. */ up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); serial_out(up, UART_IER, up->ier); omap_8250_rx_dma_flush(up); serial_in(up, UART_IIR); serial_out(up, UART_OMAP_EFR2, 0x0); up->ier |= UART_IER_RLSI | UART_IER_RDI; serial_out(up, UART_IER, up->ier); } } /* * 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); struct omap8250_priv *priv = up->port.private_data; u16 status; u8 iir; serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); if (iir & UART_IIR_NO_INT) { serial8250_rpm_put(up); return IRQ_HANDLED; } spin_lock(&port->lock); status = serial_port_in(port, UART_LSR); if (priv->habit & UART_HAS_EFR2) am654_8250_handle_rx_dma(up, iir, status); else status = omap_8250_handle_rx_dma(up, iir, status); 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); 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 struct omap8250_dma_params am654_dma = { .rx_size = SZ_2K, .rx_trigger = 1, .tx_trigger = TX_TRIGGER, }; static struct omap8250_dma_params am33xx_dma = { .rx_size = RX_TRIGGER, .rx_trigger = RX_TRIGGER, .tx_trigger = TX_TRIGGER, }; static struct omap8250_platdata am654_platdata = { .dma_params = &am654_dma, .habit = UART_HAS_EFR2 | UART_HAS_RHR_IT_DIS | UART_RX_TIMEOUT_QUIRK | UART_HAS_NATIVE_RS485, }; static struct omap8250_platdata am33xx_platdata = { .dma_params = &am33xx_dma, .habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE, }; static struct omap8250_platdata omap4_platdata = { .dma_params = &am33xx_dma, .habit = UART_ERRATA_CLOCK_DISABLE, }; static const struct of_device_id omap8250_dt_ids[] = { { .compatible = "ti,am654-uart", .data = &am654_platdata, }, { .compatible = "ti,omap2-uart" }, { .compatible = "ti,omap3-uart" }, { .compatible = "ti,omap4-uart", .data = &omap4_platdata, }, { .compatible = "ti,am3352-uart", .data = &am33xx_platdata, }, { .compatible = "ti,am4372-uart", .data = &am33xx_platdata, }, { .compatible = "ti,dra742-uart", .data = &omap4_platdata, }, {}, }; MODULE_DEVICE_TABLE(of, omap8250_dt_ids); static int omap8250_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct omap8250_priv *priv; const struct omap8250_platdata *pdata; struct uart_8250_port up; struct resource *regs; void __iomem *membase; int irq, ret; irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) { dev_err(&pdev->dev, "missing registers\n"); return -EINVAL; } priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; membase = devm_ioremap(&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; /* * 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 = OMAP_UART_REGSHIFT; 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 = omap8250_rs485_config; /* same rs485_supported for software emulation and native RS485 */ up.port.rs485_supported = serial8250_em485_supported; up.rs485_start_tx = serial8250_em485_start_tx; up.rs485_stop_tx = serial8250_em485_stop_tx; up.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); 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); } } if (of_property_read_u32(np, "overrun-throttle-ms", &up.overrun_backoff_time_ms) != 0) up.overrun_backoff_time_ms = 0; pdata = of_device_get_match_data(&pdev->dev); if (pdata) priv->habit |= pdata->habit; 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->membase = membase; priv->line = -ENODEV; priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; priv->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; cpu_latency_qos_add_request(&priv->pm_qos_request, priv->latency); INIT_WORK(&priv->qos_work, omap8250_uart_qos_work); spin_lock_init(&priv->rx_dma_lock); platform_set_drvdata(pdev, priv); device_init_wakeup(&pdev->dev, true); pm_runtime_enable(&pdev->dev); pm_runtime_use_autosuspend(&pdev->dev); /* * Disable runtime PM until autosuspend delay unless specifically * enabled by the user via sysfs. This is the historic way to * prevent an unsafe default policy with lossy characters on wake-up. * For serdev devices this is not needed, the policy can be managed by * the serdev driver. */ if (!of_get_available_child_count(pdev->dev.of_node)) pm_runtime_set_autosuspend_delay(&pdev->dev, -1); pm_runtime_irq_safe(&pdev->dev); pm_runtime_get_sync(&pdev->dev); omap_serial_fill_features_erratas(&up, priv); up.port.handle_irq = omap8250_no_handle_irq; priv->rx_trigger = RX_TRIGGER; priv->tx_trigger = TX_TRIGGER; #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) { struct omap8250_dma_params *dma_params = NULL; struct uart_8250_dma *dma = &priv->omap8250_dma; dma->fn = the_no_dma_filter_fn; dma->tx_dma = omap_8250_tx_dma; dma->rx_dma = omap_8250_rx_dma; if (pdata) dma_params = pdata->dma_params; if (dma_params) { dma->rx_size = dma_params->rx_size; dma->rxconf.src_maxburst = dma_params->rx_trigger; dma->txconf.dst_maxburst = dma_params->tx_trigger; priv->rx_trigger = dma_params->rx_trigger; priv->tx_trigger = dma_params->tx_trigger; } else { dma->rx_size = RX_TRIGGER; dma->rxconf.src_maxburst = RX_TRIGGER; dma->txconf.dst_maxburst = TX_TRIGGER; } } #endif irq_set_status_flags(irq, IRQ_NOAUTOEN); ret = devm_request_irq(&pdev->dev, irq, omap8250_irq, 0, dev_name(&pdev->dev), priv); if (ret < 0) return ret; priv->wakeirq = irq_of_parse_and_map(np, 1); ret = serial8250_register_8250_port(&up); if (ret < 0) { dev_err(&pdev->dev, "unable to register 8250 port\n"); goto err; } priv->line = ret; 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); flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); cpu_latency_qos_remove_request(&priv->pm_qos_request); return ret; } static int omap8250_remove(struct platform_device *pdev) { struct omap8250_priv *priv = platform_get_drvdata(pdev); struct uart_8250_port *up; int err; err = pm_runtime_resume_and_get(&pdev->dev); if (err) return err; up = serial8250_get_port(priv->line); omap_8250_shutdown(&up->port); serial8250_unregister_port(priv->line); priv->line = -ENODEV; pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); cpu_latency_qos_remove_request(&priv->pm_qos_request); device_init_wakeup(&pdev->dev, false); return 0; } 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); int err; serial8250_suspend_port(priv->line); err = pm_runtime_resume_and_get(dev); if (err) return err; if (!device_may_wakeup(dev)) priv->wer = 0; serial_out(up, UART_OMAP_WER, priv->wer); err = pm_runtime_force_suspend(dev); flush_work(&priv->qos_work); return err; } static int omap8250_resume(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); int err; err = pm_runtime_force_resume(dev); if (err) return err; serial8250_resume_port(priv->line); /* Paired with pm_runtime_resume_and_get() in omap8250_suspend() */ pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); return 0; } 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; } static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val) { writel(val, priv->membase + (reg << OMAP_UART_REGSHIFT)); } /* 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); 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(). */ uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1); uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL); sysc = uart_read(priv, UART_OMAP_SYSC); /* softreset the UART */ sysc |= OMAP_UART_SYSC_SOFTRESET; uart_write(priv, UART_OMAP_SYSC, sysc); /* By experiments, 1us enough for reset complete on AM335x */ do { udelay(1); syss = uart_read(priv, 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 = NULL; if (priv->line >= 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 (up && uart_console(&up->port)) return -EBUSY; } if (priv->habit & UART_ERRATA_CLOCK_DISABLE) { int ret; ret = omap8250_soft_reset(dev); if (ret) return ret; if (up) { /* 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 && up->dma && up->dma->rxchan) omap_8250_rx_dma_flush(up); priv->latency = PM_QOS_CPU_LATENCY_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 = NULL; if (priv->line >= 0) up = serial8250_get_port(priv->line); if (up && omap8250_lost_context(up)) { spin_lock_irq(&up->port.lock); omap8250_restore_regs(up); spin_unlock_irq(&up->port.lock); } if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) { spin_lock_irq(&up->port.lock); omap_8250_rx_dma(up); spin_unlock_irq(&up->port.lock); } priv->latency = priv->calc_latency; schedule_work(&priv->qos_work); return 0; } #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 = { SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume) RUNTIME_PM_OPS(omap8250_runtime_suspend, omap8250_runtime_resume, NULL) .prepare = pm_sleep_ptr(omap8250_prepare), .complete = pm_sleep_ptr(omap8250_complete), }; static struct platform_driver omap8250_platform_driver = { .driver = { .name = "omap8250", .pm = pm_ptr(&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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