summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/8250/8250_omap.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/tty/serial/8250/8250_omap.c1748
1 files changed, 1748 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
new file mode 100644
index 000000000..25765ebb7
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -0,0 +1,1748 @@
+// 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 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)
+
+/* 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 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));
+}
+
+static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val)
+{
+ writel(val, 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);
+
+ 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);
+
+ if (up->port.rs485.flags & SER_RS485_ENABLED)
+ 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,
+ 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(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);
+ 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)
+{
+ 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 uart_port *port = dev_id;
+ struct omap8250_priv *priv = port->private_data;
+ struct uart_8250_port *up = up_to_u8250p(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;
+ 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 (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 && !(priv->habit & UART_HAS_EFR2))
+ 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);
+ if (priv->habit & UART_HAS_EFR2)
+ serial_out(up, UART_OMAP_EFR2, 0x0);
+
+ 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;
+ 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);
+
+ 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);
+}
+
+#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, reg);
+ }
+
+ 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;
+
+ 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;
+
+ 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, reg);
+ }
+
+ 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;
+ 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 unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up,
+ u8 iir, unsigned char 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,
+ unsigned char status)
+{
+ /*
+ * 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;
+ 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 IRQ_HANDLED;
+ }
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ status = serial_port_in(port, UART_LSR);
+
+ if ((iir & 0x3f) != UART_IIR_THRI) {
+ 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, 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 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,
+};
+
+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 = serial8250_em485_config;
+ 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;
+
+ priv->wakeirq = irq_of_parse_and_map(np, 1);
+
+ 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;
+
+ up.dma = &priv->omap8250_dma;
+ up.dma->fn = the_no_dma_filter_fn;
+ up.dma->tx_dma = omap_8250_tx_dma;
+ up.dma->rx_dma = omap_8250_rx_dma;
+ if (pdata)
+ dma_params = pdata->dma_params;
+
+ if (dma_params) {
+ up.dma->rx_size = dma_params->rx_size;
+ up.dma->rxconf.src_maxburst = dma_params->rx_trigger;
+ up.dma->txconf.dst_maxburst = dma_params->tx_trigger;
+ priv->rx_trigger = dma_params->rx_trigger;
+ priv->tx_trigger = dma_params->tx_trigger;
+ } else {
+ up.dma->rx_size = RX_TRIGGER;
+ up.dma->rxconf.src_maxburst = RX_TRIGGER;
+ up.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;
+ 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);
+ int err;
+
+ err = pm_runtime_resume_and_get(&pdev->dev);
+ if (err)
+ dev_err(&pdev->dev, "Failed to resume hardware\n");
+
+ 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;
+}
+
+#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);
+ int err = 0;
+
+ 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);
+ if (uart_console(&up->port) && console_suspend_enabled)
+ 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);
+ struct uart_8250_port *up = serial8250_get_port(priv->line);
+ int err;
+
+ if (uart_console(&up->port) && console_suspend_enabled) {
+ 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;
+}
+#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);
+ 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);
+
+ 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))
+ omap8250_restore_regs(up);
+
+ if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2))
+ 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");