From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/drivers/tty/serial/imx.c | 523 +++++++++++++++++++++++++++++++++++----------------------
1 files changed, 320 insertions(+), 203 deletions(-)
diff --git a/kernel/drivers/tty/serial/imx.c b/kernel/drivers/tty/serial/imx.c
index 7a6e26b..164597e 100644
--- a/kernel/drivers/tty/serial/imx.c
+++ b/kernel/drivers/tty/serial/imx.c
@@ -8,10 +8,6 @@
* Copyright (C) 2004 Pengutronix
*/
-#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
@@ -24,6 +20,8 @@
#include <linux/serial.h>
#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/rational.h>
#include <linux/slab.h>
#include <linux/of.h>
@@ -191,6 +189,13 @@
enum imx_uart_type devtype;
};
+enum imx_tx_state {
+ OFF,
+ WAIT_AFTER_RTS,
+ SEND,
+ WAIT_AFTER_SEND,
+};
+
struct imx_port {
struct uart_port port;
struct timer_list timer;
@@ -198,6 +203,8 @@
unsigned int have_rtscts:1;
unsigned int have_rtsgpio:1;
unsigned int dte_mode:1;
+ unsigned int inverted_tx:1;
+ unsigned int inverted_rx:1;
struct clk *clk_ipg;
struct clk *clk_per;
const struct imx_uart_data *devdata;
@@ -225,6 +232,10 @@
unsigned int dma_tx_nents;
unsigned int saved_reg[10];
bool context_saved;
+
+ enum imx_tx_state tx_state;
+ struct hrtimer trigger_start_tx;
+ struct hrtimer trigger_stop_tx;
};
struct imx_port_ucrs {
@@ -362,7 +373,7 @@
/*
* Save and restore functions for UCR1, UCR2 and UCR3 registers
*/
-#if defined(CONFIG_SERIAL_IMX_CONSOLE)
+#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
static void imx_uart_ucrs_save(struct imx_port *sport,
struct imx_port_ucrs *ucr)
{
@@ -387,8 +398,7 @@
{
*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
- sport->port.mctrl |= TIOCM_RTS;
- mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+ mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
}
/* called with port.lock taken and irqs caller dependent */
@@ -397,14 +407,16 @@
*ucr2 &= ~UCR2_CTSC;
*ucr2 |= UCR2_CTS;
- sport->port.mctrl &= ~TIOCM_RTS;
- mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+ mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
}
-/* called with port.lock taken and irqs caller dependent */
-static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
+static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
{
- *ucr2 |= UCR2_CTSC;
+ long sec = msec / MSEC_PER_SEC;
+ long nsec = (msec % MSEC_PER_SEC) * 1000000;
+ ktime_t t = ktime_set(sec, nsec);
+
+ hrtimer_start(hrt, t, HRTIMER_MODE_REL);
}
/* called with port.lock taken and irqs off */
@@ -434,7 +446,10 @@
static void imx_uart_stop_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
- u32 ucr1;
+ u32 ucr1, ucr4, usr2;
+
+ if (sport->tx_state == OFF)
+ return;
/*
* We are maybe in the SMP context, so if the DMA TX thread is running
@@ -444,23 +459,46 @@
return;
ucr1 = imx_uart_readl(sport, UCR1);
- imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
+ imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
- /* in rs485 mode disable transmitter if shifter is empty */
- if (port->rs485.flags & SER_RS485_ENABLED &&
- imx_uart_readl(sport, USR2) & USR2_TXDC) {
- u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
- if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
- imx_uart_rts_active(sport, &ucr2);
- else
- imx_uart_rts_inactive(sport, &ucr2);
- imx_uart_writel(sport, ucr2, UCR2);
+ usr2 = imx_uart_readl(sport, USR2);
+ if (!(usr2 & USR2_TXDC)) {
+ /* The shifter is still busy, so retry once TC triggers */
+ return;
+ }
- imx_uart_start_rx(port);
+ ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 &= ~UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
- ucr4 = imx_uart_readl(sport, UCR4);
- ucr4 &= ~UCR4_TCEN;
- imx_uart_writel(sport, ucr4, UCR4);
+ /* in rs485 mode disable transmitter */
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ if (sport->tx_state == SEND) {
+ sport->tx_state = WAIT_AFTER_SEND;
+ start_hrtimer_ms(&sport->trigger_stop_tx,
+ port->rs485.delay_rts_after_send);
+ return;
+ }
+
+ if (sport->tx_state == WAIT_AFTER_RTS ||
+ sport->tx_state == WAIT_AFTER_SEND) {
+ u32 ucr2;
+
+ hrtimer_try_to_cancel(&sport->trigger_start_tx);
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ imx_uart_start_rx(port);
+
+ sport->tx_state = OFF;
+ }
+ } else {
+ sport->tx_state = OFF;
}
}
@@ -468,18 +506,21 @@
static void imx_uart_stop_rx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
- u32 ucr1, ucr2;
+ u32 ucr1, ucr2, ucr4;
ucr1 = imx_uart_readl(sport, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
+ ucr4 = imx_uart_readl(sport, UCR4);
if (sport->dma_is_enabled) {
ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
} else {
ucr1 &= ~UCR1_RRDYEN;
ucr2 &= ~UCR2_ATEN;
+ ucr4 &= ~UCR4_OREN;
}
imx_uart_writel(sport, ucr1, UCR1);
+ imx_uart_writel(sport, ucr4, UCR4);
ucr2 &= ~UCR2_RXEN;
imx_uart_writel(sport, ucr2, UCR2);
@@ -522,7 +563,7 @@
* and the TX IRQ is disabled.
**/
ucr1 = imx_uart_readl(sport, UCR1);
- ucr1 &= ~UCR1_TXMPTYEN;
+ ucr1 &= ~UCR1_TRDYEN;
if (sport->dma_is_txing) {
ucr1 |= UCR1_TXDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
@@ -658,33 +699,55 @@
if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
return;
+ /*
+ * We cannot simply do nothing here if sport->tx_state == SEND already
+ * because UCR1_TXMPTYEN might already have been cleared in
+ * imx_uart_stop_tx(), but tx_state is still SEND.
+ */
+
if (port->rs485.flags & SER_RS485_ENABLED) {
- u32 ucr2;
+ if (sport->tx_state == OFF) {
+ u32 ucr2 = imx_uart_readl(sport, UCR2);
+ if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ imx_uart_writel(sport, ucr2, UCR2);
- ucr2 = imx_uart_readl(sport, UCR2);
- if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
- imx_uart_rts_active(sport, &ucr2);
- else
- imx_uart_rts_inactive(sport, &ucr2);
- imx_uart_writel(sport, ucr2, UCR2);
+ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+ imx_uart_stop_rx(port);
- if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
- imx_uart_stop_rx(port);
-
- /*
- * Enable transmitter and shifter empty irq only if DMA is off.
- * In the DMA case this is done in the tx-callback.
- */
- if (!sport->dma_is_enabled) {
- u32 ucr4 = imx_uart_readl(sport, UCR4);
- ucr4 |= UCR4_TCEN;
- imx_uart_writel(sport, ucr4, UCR4);
+ sport->tx_state = WAIT_AFTER_RTS;
+ start_hrtimer_ms(&sport->trigger_start_tx,
+ port->rs485.delay_rts_before_send);
+ return;
}
+
+ if (sport->tx_state == WAIT_AFTER_SEND
+ || sport->tx_state == WAIT_AFTER_RTS) {
+
+ hrtimer_try_to_cancel(&sport->trigger_stop_tx);
+
+ /*
+ * Enable transmitter and shifter empty irq only if DMA
+ * is off. In the DMA case this is done in the
+ * tx-callback.
+ */
+ if (!sport->dma_is_enabled) {
+ u32 ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 |= UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+ }
+
+ sport->tx_state = SEND;
+ }
+ } else {
+ sport->tx_state = SEND;
}
if (!sport->dma_is_enabled) {
ucr1 = imx_uart_readl(sport, UCR1);
- imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
+ imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
}
if (sport->dma_is_enabled) {
@@ -693,7 +756,7 @@
* disable TX DMA to let TX interrupt to send X-char */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~UCR1_TXDMAEN;
- ucr1 |= UCR1_TXMPTYEN;
+ ucr1 |= UCR1_TRDYEN;
imx_uart_writel(sport, ucr1, UCR1);
return;
}
@@ -705,42 +768,48 @@
}
}
-static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
u32 usr1;
- unsigned long flags;
-
- spin_lock_irqsave(&sport->port.lock, flags);
imx_uart_writel(sport, USR1_RTSD, USR1);
usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
uart_handle_cts_change(&sport->port, !!usr1);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
- spin_unlock_irqrestore(&sport->port.lock, flags);
return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ irqreturn_t ret;
+
+ spin_lock(&sport->port.lock);
+
+ ret = __imx_uart_rtsint(irq, dev_id);
+
+ spin_unlock(&sport->port.lock);
+
+ return ret;
}
static irqreturn_t imx_uart_txint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
- unsigned long flags;
- spin_lock_irqsave(&sport->port.lock, flags);
+ spin_lock(&sport->port.lock);
imx_uart_transmit_buffer(sport);
- spin_unlock_irqrestore(&sport->port.lock, flags);
+ spin_unlock(&sport->port.lock);
return IRQ_HANDLED;
}
-static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int rx, flg, ignored = 0;
struct tty_port *port = &sport->port.state->port;
- unsigned long flags;
-
- spin_lock_irqsave(&sport->port.lock, flags);
while (imx_uart_readl(sport, USR2) & USR2_RDR) {
u32 usr2;
@@ -787,9 +856,7 @@
if (rx & URXD_OVRRUN)
flg = TTY_OVERRUN;
-#ifdef SUPPORT_SYSRQ
sport->port.sysrq = 0;
-#endif
}
if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
@@ -800,9 +867,23 @@
}
out:
- spin_unlock_irqrestore(&sport->port.lock, flags);
tty_flip_buffer_push(port);
+
return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ irqreturn_t ret;
+
+ spin_lock(&sport->port.lock);
+
+ ret = __imx_uart_rxint(irq, dev_id);
+
+ spin_unlock(&sport->port.lock);
+
+ return ret;
}
static void imx_uart_clear_rx_errors(struct imx_port *sport);
@@ -862,6 +943,14 @@
struct imx_port *sport = dev_id;
unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
irqreturn_t ret = IRQ_NONE;
+ unsigned long flags = 0;
+
+ /*
+ * IRQs might not be disabled upon entering this interrupt handler,
+ * e.g. when interrupt handlers are forced to be threaded. To support
+ * this scenario as well, disable IRQs when acquiring the spinlock.
+ */
+ spin_lock_irqsave(&sport->port.lock, flags);
usr1 = imx_uart_readl(sport, USR1);
usr2 = imx_uart_readl(sport, USR2);
@@ -882,7 +971,7 @@
usr1 &= ~USR1_RRDY;
if ((ucr2 & UCR2_ATEN) == 0)
usr1 &= ~USR1_AGTIM;
- if ((ucr1 & UCR1_TXMPTYEN) == 0)
+ if ((ucr1 & UCR1_TRDYEN) == 0)
usr1 &= ~USR1_TRDY;
if ((ucr4 & UCR4_TCEN) == 0)
usr2 &= ~USR2_TXDC;
@@ -896,29 +985,27 @@
usr2 &= ~USR2_ORE;
if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
- imx_uart_rxint(irq, dev_id);
+ imx_uart_writel(sport, USR1_AGTIM, USR1);
+
+ __imx_uart_rxint(irq, dev_id);
ret = IRQ_HANDLED;
}
if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
- imx_uart_txint(irq, dev_id);
+ imx_uart_transmit_buffer(sport);
ret = IRQ_HANDLED;
}
if (usr1 & USR1_DTRD) {
- unsigned long flags;
-
imx_uart_writel(sport, USR1_DTRD, USR1);
- spin_lock_irqsave(&sport->port.lock, flags);
imx_uart_mctrl_check(sport);
- spin_unlock_irqrestore(&sport->port.lock, flags);
ret = IRQ_HANDLED;
}
if (usr1 & USR1_RTSD) {
- imx_uart_rtsint(irq, dev_id);
+ __imx_uart_rtsint(irq, dev_id);
ret = IRQ_HANDLED;
}
@@ -932,6 +1019,8 @@
imx_uart_writel(sport, USR2_ORE, USR2);
ret = IRQ_HANDLED;
}
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
return ret;
}
@@ -973,10 +1062,22 @@
if (!(port->rs485.flags & SER_RS485_ENABLED)) {
u32 ucr2;
+ /*
+ * Turn off autoRTS if RTS is lowered and restore autoRTS
+ * setting if RTS is raised.
+ */
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
- if (mctrl & TIOCM_RTS)
- ucr2 |= UCR2_CTS | UCR2_CTSC;
+ if (mctrl & TIOCM_RTS) {
+ ucr2 |= UCR2_CTS;
+ /*
+ * UCR2_IRTS is unset if and only if the port is
+ * configured for CRTSCTS, so we use inverted UCR2_IRTS
+ * to get the state to restore to.
+ */
+ if (!(ucr2 & UCR2_IRTS))
+ ucr2 |= UCR2_CTSC;
+ }
imx_uart_writel(sport, ucr2, UCR2);
}
@@ -1031,8 +1132,6 @@
mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
}
}
-
-#define RX_BUF_SIZE (PAGE_SIZE)
/*
* There are two kinds of RX DMA interrupts(such as in the MX6Q):
@@ -1116,7 +1215,8 @@
}
/* RX DMA buffer periods */
-#define RX_DMA_PERIODS 4
+#define RX_DMA_PERIODS 16
+#define RX_BUF_SIZE (RX_DMA_PERIODS * PAGE_SIZE / 4)
static int imx_uart_start_rx_dma(struct imx_port *sport)
{
@@ -1172,7 +1272,6 @@
sport->port.icount.buf_overrun++;
tty_flip_buffer_push(port);
} else {
- dev_err(sport->port.dev, "DMA transaction error.\n");
if (usr1 & USR1_FRAMERR) {
sport->port.icount.frame++;
imx_uart_writel(sport, USR1_FRAMERR, USR1);
@@ -1316,7 +1415,7 @@
int retval, i;
unsigned long flags;
int dma_is_inited = 0;
- u32 ucr1, ucr2, ucr4;
+ u32 ucr1, ucr2, ucr3, ucr4;
retval = clk_prepare_enable(sport->clk_per);
if (retval)
@@ -1368,10 +1467,28 @@
imx_uart_writel(sport, ucr1, UCR1);
- ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
- if (!sport->dma_is_enabled)
+ ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
+ if (!dma_is_inited)
ucr4 |= UCR4_OREN;
+ if (sport->inverted_rx)
+ ucr4 |= UCR4_INVR;
imx_uart_writel(sport, ucr4, UCR4);
+
+ ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
+ /*
+ * configure tx polarity before enabling tx
+ */
+ if (sport->inverted_tx)
+ ucr3 |= UCR3_INVT;
+
+ if (!imx_uart_is_imx1(sport)) {
+ ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
+
+ if (sport->dte_mode)
+ /* disable broken interrupts */
+ ucr3 &= ~(UCR3_RI | UCR3_DCD);
+ }
+ imx_uart_writel(sport, ucr3, UCR3);
ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
ucr2 |= (UCR2_RXEN | UCR2_TXEN);
@@ -1384,20 +1501,6 @@
if (!imx_uart_is_imx1(sport))
ucr2 &= ~UCR2_RTSEN;
imx_uart_writel(sport, ucr2, UCR2);
-
- if (!imx_uart_is_imx1(sport)) {
- u32 ucr3;
-
- ucr3 = imx_uart_readl(sport, UCR3);
-
- ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
-
- if (sport->dte_mode)
- /* disable broken interrupts */
- ucr3 &= ~(UCR3_RI | UCR3_DCD);
-
- imx_uart_writel(sport, ucr3, UCR3);
- }
/*
* Enable modem status interrupts
@@ -1456,10 +1559,6 @@
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
imx_uart_writel(sport, ucr2, UCR2);
-
- ucr4 = imx_uart_readl(sport, UCR4);
- ucr4 &= ~UCR4_OREN;
- imx_uart_writel(sport, ucr4, UCR4);
spin_unlock_irqrestore(&sport->port.lock, flags);
/*
@@ -1472,10 +1571,15 @@
*/
spin_lock_irqsave(&sport->port.lock, flags);
- ucr1 = imx_uart_readl(sport, UCR1);
- ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
imx_uart_writel(sport, ucr1, UCR1);
+
+ ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 &= ~UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+
spin_unlock_irqrestore(&sport->port.lock, flags);
clk_disable_unprepare(sport->clk_per);
@@ -1540,11 +1644,11 @@
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
- u32 ucr2, old_ucr1, old_ucr2, ufcr;
+ u32 ucr2, old_ucr2, ufcr;
unsigned int baud, quot;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
unsigned long div;
- unsigned long num, denom;
+ unsigned long num, denom, old_ubir, old_ubmr;
uint64_t tdiv64;
/*
@@ -1567,41 +1671,42 @@
spin_lock_irqsave(&sport->port.lock, flags);
+ /*
+ * Read current UCR2 and save it for future use, then clear all the bits
+ * except those we will or may need to preserve.
+ */
+ old_ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
+
+ ucr2 |= UCR2_SRST | UCR2_IRTS;
if ((termios->c_cflag & CSIZE) == CS8)
- ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
- else
- ucr2 = UCR2_SRST | UCR2_IRTS;
+ ucr2 |= UCR2_WS;
- if (termios->c_cflag & CRTSCTS) {
- if (sport->have_rtscts) {
- ucr2 &= ~UCR2_IRTS;
+ if (!sport->have_rtscts)
+ termios->c_cflag &= ~CRTSCTS;
- if (port->rs485.flags & SER_RS485_ENABLED) {
- /*
- * RTS is mandatory for rs485 operation, so keep
- * it under manual control and keep transmitter
- * disabled.
- */
- if (port->rs485.flags &
- SER_RS485_RTS_AFTER_SEND)
- imx_uart_rts_active(sport, &ucr2);
- else
- imx_uart_rts_inactive(sport, &ucr2);
- } else {
- imx_uart_rts_auto(sport, &ucr2);
- }
- } else {
- termios->c_cflag &= ~CRTSCTS;
- }
- } else if (port->rs485.flags & SER_RS485_ENABLED) {
- /* disable transmitter */
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ /*
+ * RTS is mandatory for rs485 operation, so keep
+ * it under manual control and keep transmitter
+ * disabled.
+ */
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
imx_uart_rts_active(sport, &ucr2);
else
imx_uart_rts_inactive(sport, &ucr2);
+
+ } else if (termios->c_cflag & CRTSCTS) {
+ /*
+ * Only let receiver control RTS output if we were not requested
+ * to have RTS inactive (which then should take precedence).
+ */
+ if (ucr2 & UCR2_CTS)
+ ucr2 |= UCR2_CTSC;
}
-
+ if (termios->c_cflag & CRTSCTS)
+ ucr2 &= ~UCR2_IRTS;
if (termios->c_cflag & CSTOPB)
ucr2 |= UCR2_STPB;
if (termios->c_cflag & PARENB) {
@@ -1640,23 +1745,6 @@
*/
uart_update_timeout(port, termios->c_cflag, baud);
- /*
- * disable interrupts and drain transmitter
- */
- old_ucr1 = imx_uart_readl(sport, UCR1);
- imx_uart_writel(sport,
- old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
- UCR1);
- old_ucr2 = imx_uart_readl(sport, UCR2);
- imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
-
- while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
- barrier();
-
- /* then, disable everything */
- imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
- old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
-
/* custom-baudrate handling */
div = sport->port.uartclk / (baud * 16);
if (baud == 38400 && quot != div)
@@ -1684,17 +1772,27 @@
ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
imx_uart_writel(sport, ufcr, UFCR);
- imx_uart_writel(sport, num, UBIR);
- imx_uart_writel(sport, denom, UBMR);
+ /*
+ * Two registers below should always be written both and in this
+ * particular order. One consequence is that we need to check if any of
+ * them changes and then update both. We do need the check for change
+ * as even writing the same values seem to "restart"
+ * transmission/receiving logic in the hardware, that leads to data
+ * breakage even when rate doesn't in fact change. E.g., user switches
+ * RTS/CTS handshake and suddenly gets broken bytes.
+ */
+ old_ubir = imx_uart_readl(sport, UBIR);
+ old_ubmr = imx_uart_readl(sport, UBMR);
+ if (old_ubir != num || old_ubmr != denom) {
+ imx_uart_writel(sport, num, UBIR);
+ imx_uart_writel(sport, denom, UBMR);
+ }
if (!imx_uart_is_imx1(sport))
imx_uart_writel(sport, sport->port.uartclk / div / 1000,
IMX21_ONEMS);
- imx_uart_writel(sport, old_ucr1, UCR1);
-
- /* set the parity, stop bits and data size */
- imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
+ imx_uart_writel(sport, ucr2, UCR2);
if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
imx_uart_enable_ms(&sport->port);
@@ -1782,7 +1880,7 @@
ucr1 |= IMX1_UCR1_UARTCLKEN;
ucr1 |= UCR1_UARTEN;
- ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
+ ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
ucr2 |= UCR2_RXEN;
ucr2 &= ~UCR2_ATEN;
@@ -1834,10 +1932,6 @@
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr2;
-
- /* unimplemented */
- rs485conf->delay_rts_before_send = 0;
- rs485conf->delay_rts_after_send = 0;
/* RTS is required to control the transmitter */
if (!sport->have_rtscts && !sport->have_rtsgpio)
@@ -1893,7 +1987,7 @@
static struct imx_port *imx_uart_ports[UART_NR];
-#ifdef CONFIG_SERIAL_IMX_CONSOLE
+#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
static void imx_uart_console_putchar(struct uart_port *port, int ch)
{
struct imx_port *sport = (struct imx_port *)port;
@@ -1932,7 +2026,7 @@
if (imx_uart_is_imx1(sport))
ucr1 |= IMX1_UCR1_UARTCLKEN;
ucr1 |= UCR1_UARTEN;
- ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
+ ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
imx_uart_writel(sport, ucr1, UCR1);
@@ -1956,7 +2050,7 @@
* If the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
-static void __init
+static void
imx_uart_console_get_options(struct imx_port *sport, int *baud,
int *parity, int *bits)
{
@@ -2010,12 +2104,12 @@
}
if (*baud != baud_raw)
- pr_info("Console IMX rounded baud rate from %d to %d\n",
+ dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
baud_raw, *baud);
}
}
-static int __init
+static int
imx_uart_console_setup(struct console *co, char *options)
{
struct imx_port *sport;
@@ -2076,39 +2170,6 @@
#define IMX_CONSOLE &imx_uart_console
-#ifdef CONFIG_OF
-static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
-{
- struct imx_port *sport = (struct imx_port *)port;
-
- while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
- cpu_relax();
-
- imx_uart_writel(sport, ch, URTX0);
-}
-
-static void imx_uart_console_early_write(struct console *con, const char *s,
- unsigned count)
-{
- struct earlycon_device *dev = con->data;
-
- uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
-}
-
-static int __init
-imx_console_early_setup(struct earlycon_device *dev, const char *opt)
-{
- if (!dev->port.membase)
- return -ENODEV;
-
- dev->con->write = imx_uart_console_early_write;
-
- return 0;
-}
-OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
-OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
-#endif
-
#else
#define IMX_CONSOLE NULL
#endif
@@ -2156,6 +2217,12 @@
if (of_get_property(np, "rts-gpios", NULL))
sport->have_rtsgpio = 1;
+ if (of_get_property(np, "fsl,inverted-tx", NULL))
+ sport->inverted_tx = 1;
+
+ if (of_get_property(np, "fsl,inverted-rx", NULL))
+ sport->inverted_rx = 1;
+
return 0;
}
#else
@@ -2179,6 +2246,32 @@
if (pdata->flags & IMXUART_HAVE_RTSCTS)
sport->have_rtscts = 1;
+}
+
+static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
+{
+ struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ if (sport->tx_state == WAIT_AFTER_RTS)
+ imx_uart_start_tx(&sport->port);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ return HRTIMER_NORESTART;
+}
+
+static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
+{
+ struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ if (sport->tx_state == WAIT_AFTER_SEND)
+ imx_uart_stop_tx(&sport->port);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ return HRTIMER_NORESTART;
}
static int imx_uart_probe(struct platform_device *pdev)
@@ -2212,8 +2305,10 @@
return PTR_ERR(base);
rxirq = platform_get_irq(pdev, 0);
- txirq = platform_get_irq(pdev, 1);
- rtsirq = platform_get_irq(pdev, 2);
+ if (rxirq < 0)
+ return rxirq;
+ txirq = platform_get_irq_optional(pdev, 1);
+ rtsirq = platform_get_irq_optional(pdev, 2);
sport->port.dev = &pdev->dev;
sport->port.mapbase = res->start;
@@ -2222,6 +2317,7 @@
sport->port.iotype = UPIO_MEM;
sport->port.irq = rxirq;
sport->port.fifosize = 32;
+ sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE);
sport->port.ops = &imx_uart_pops;
sport->port.rs485_config = imx_uart_rs485_config;
sport->port.flags = UPF_BOOT_AUTOCONF;
@@ -2261,7 +2357,11 @@
sport->ucr4 = readl(sport->port.membase + UCR4);
sport->ufcr = readl(sport->port.membase + UFCR);
- uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
+ ret = uart_get_rs485_mode(&sport->port);
+ if (ret) {
+ clk_disable_unprepare(sport->clk_ipg);
+ return ret;
+ }
if (sport->port.rs485.flags & SER_RS485_ENABLED &&
(!sport->have_rtscts && !sport->have_rtsgpio))
@@ -2279,12 +2379,9 @@
dev_err(&pdev->dev,
"low-active RTS not possible when receiver is off, enabling receiver\n");
- imx_uart_rs485_config(&sport->port, &sport->port.rs485);
-
/* Disable interrupts before requesting them */
ucr1 = imx_uart_readl(sport, UCR1);
- ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
- UCR1_TXMPTYEN | UCR1_RTSDEN);
+ ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN);
imx_uart_writel(sport, ucr1, UCR1);
if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
@@ -2319,6 +2416,11 @@
}
clk_disable_unprepare(sport->clk_ipg);
+
+ hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ sport->trigger_start_tx.function = imx_trigger_start_tx;
+ sport->trigger_stop_tx.function = imx_trigger_stop_tx;
/*
* Allocate the IRQ(s) i.MX1 has three interrupts whereas later
@@ -2373,8 +2475,13 @@
static void imx_uart_restore_context(struct imx_port *sport)
{
- if (!sport->context_saved)
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ if (!sport->context_saved) {
+ spin_unlock_irqrestore(&sport->port.lock, flags);
return;
+ }
imx_uart_writel(sport, sport->saved_reg[4], UFCR);
imx_uart_writel(sport, sport->saved_reg[5], UESC);
@@ -2387,11 +2494,15 @@
imx_uart_writel(sport, sport->saved_reg[2], UCR3);
imx_uart_writel(sport, sport->saved_reg[3], UCR4);
sport->context_saved = false;
+ spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void imx_uart_save_context(struct imx_port *sport)
{
+ unsigned long flags;
+
/* Save necessary regs */
+ spin_lock_irqsave(&sport->port.lock, flags);
sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
@@ -2403,6 +2514,7 @@
sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
sport->context_saved = true;
+ spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
@@ -2436,6 +2548,8 @@
clk_disable(sport->clk_ipg);
+ pinctrl_pm_select_sleep_state(dev);
+
return 0;
}
@@ -2443,6 +2557,8 @@
{
struct imx_port *sport = dev_get_drvdata(dev);
int ret;
+
+ pinctrl_pm_select_default_state(dev);
ret = clk_enable(sport->clk_ipg);
if (ret)
@@ -2510,6 +2626,7 @@
.suspend_noirq = imx_uart_suspend_noirq,
.resume_noirq = imx_uart_resume_noirq,
.freeze_noirq = imx_uart_suspend_noirq,
+ .thaw_noirq = imx_uart_resume_noirq,
.restore_noirq = imx_uart_resume_noirq,
.suspend = imx_uart_suspend,
.resume = imx_uart_resume,
--
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