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path: root/drivers/tty/serial/imx.c
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Diffstat (limited to 'drivers/tty/serial/imx.c')
-rw-r--r--drivers/tty/serial/imx.c85
1 files changed, 46 insertions, 39 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 708b9852a575..e14813250616 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -415,13 +415,13 @@ static void imx_uart_stop_tx(struct uart_port *port)
ucr1 = imx_uart_readl(sport, UCR1);
imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
+ ucr4 = imx_uart_readl(sport, UCR4);
usr2 = imx_uart_readl(sport, USR2);
- if (!(usr2 & USR2_TXDC)) {
+ if ((!(usr2 & USR2_TXDC)) && (ucr4 & UCR4_TCEN)) {
/* The shifter is still busy, so retry once TC triggers */
return;
}
- ucr4 = imx_uart_readl(sport, UCR4);
ucr4 &= ~UCR4_TCEN;
imx_uart_writel(sport, ucr4, UCR4);
@@ -462,8 +462,7 @@ static void imx_uart_stop_tx(struct uart_port *port)
}
}
-/* called with port.lock taken and irqs off */
-static void imx_uart_stop_rx(struct uart_port *port)
+static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr1, ucr2, ucr4, uts;
@@ -485,7 +484,7 @@ static void imx_uart_stop_rx(struct uart_port *port)
/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
if (port->rs485.flags & SER_RS485_ENABLED &&
port->rs485.flags & SER_RS485_RTS_ON_SEND &&
- sport->have_rtscts && !sport->have_rtsgpio) {
+ sport->have_rtscts && !sport->have_rtsgpio && loopback) {
uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
uts |= UTS_LOOP;
imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
@@ -498,6 +497,16 @@ static void imx_uart_stop_rx(struct uart_port *port)
}
/* called with port.lock taken and irqs off */
+static void imx_uart_stop_rx(struct uart_port *port)
+{
+ /*
+ * Stop RX and enable loopback in order to make sure RS485 bus
+ * is not blocked. Se comment in imx_uart_probe().
+ */
+ imx_uart_stop_rx_with_loopback_ctrl(port, true);
+}
+
+/* called with port.lock taken and irqs off */
static void imx_uart_enable_ms(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
@@ -682,9 +691,14 @@ static void imx_uart_start_tx(struct uart_port *port)
imx_uart_rts_inactive(sport, &ucr2);
imx_uart_writel(sport, ucr2, UCR2);
+ /*
+ * Since we are about to transmit we can not stop RX
+ * with loopback enabled because that will make our
+ * transmitted data being just looped to RX.
+ */
if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) &&
!port->rs485_rx_during_tx_gpio)
- imx_uart_stop_rx(port);
+ imx_uart_stop_rx_with_loopback_ctrl(port, false);
sport->tx_state = WAIT_AFTER_RTS;
@@ -1336,15 +1350,18 @@ static int imx_uart_dma_init(struct imx_port *sport)
{
struct dma_slave_config slave_config = {};
struct device *dev = sport->port.dev;
+ struct dma_chan *chan;
int ret;
/* Prepare for RX : */
- sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
- if (!sport->dma_chan_rx) {
+ chan = dma_request_chan(dev, "rx");
+ if (IS_ERR(chan)) {
dev_dbg(dev, "cannot get the DMA channel.\n");
- ret = -EINVAL;
+ sport->dma_chan_rx = NULL;
+ ret = PTR_ERR(chan);
goto err;
}
+ sport->dma_chan_rx = chan;
slave_config.direction = DMA_DEV_TO_MEM;
slave_config.src_addr = sport->port.mapbase + URXD0;
@@ -1366,12 +1383,14 @@ static int imx_uart_dma_init(struct imx_port *sport)
sport->rx_ring.buf = sport->rx_buf;
/* Prepare for TX : */
- sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
- if (!sport->dma_chan_tx) {
+ chan = dma_request_chan(dev, "tx");
+ if (IS_ERR(chan)) {
dev_err(dev, "cannot get the TX DMA channel!\n");
- ret = -EINVAL;
+ sport->dma_chan_tx = NULL;
+ ret = PTR_ERR(chan);
goto err;
}
+ sport->dma_chan_tx = chan;
slave_config.direction = DMA_MEM_TO_DEV;
slave_config.dst_addr = sport->port.mapbase + URTX0;
@@ -1943,10 +1962,6 @@ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termio
rs485conf->flags & SER_RS485_RX_DURING_TX)
imx_uart_start_rx(port);
- if (port->rs485_rx_during_tx_gpio)
- gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
- !!(rs485conf->flags & SER_RS485_RX_DURING_TX));
-
return 0;
}
@@ -2210,7 +2225,6 @@ static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
return HRTIMER_NORESTART;
}
-static const struct serial_rs485 imx_no_rs485 = {}; /* No RS485 if no RTS */
static const struct serial_rs485 imx_rs485_supported = {
.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
SER_RS485_RX_DURING_TX,
@@ -2294,8 +2308,6 @@ static int imx_uart_probe(struct platform_device *pdev)
/* RTS is required to control the RS485 transmitter */
if (sport->have_rtscts || sport->have_rtsgpio)
sport->port.rs485_supported = imx_rs485_supported;
- else
- sport->port.rs485_supported = imx_no_rs485;
sport->port.flags = UPF_BOOT_AUTOCONF;
timer_setup(&sport->timer, imx_uart_timeout, 0);
@@ -2322,19 +2334,13 @@ static int imx_uart_probe(struct platform_device *pdev)
/* For register access, we only need to enable the ipg clock. */
ret = clk_prepare_enable(sport->clk_ipg);
if (ret) {
- dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
+ dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
return ret;
}
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))
- dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
+ if (ret)
+ goto err_clk;
/*
* If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
@@ -2414,8 +2420,6 @@ static int imx_uart_probe(struct platform_device *pdev)
imx_uart_writel(sport, ucr3, UCR3);
}
- 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;
@@ -2431,7 +2435,7 @@ static int imx_uart_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "failed to request rx irq: %d\n",
ret);
- return ret;
+ goto err_clk;
}
ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
@@ -2439,7 +2443,7 @@ static int imx_uart_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "failed to request tx irq: %d\n",
ret);
- return ret;
+ goto err_clk;
}
ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
@@ -2447,14 +2451,14 @@ static int imx_uart_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "failed to request rts irq: %d\n",
ret);
- return ret;
+ goto err_clk;
}
} else {
ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
dev_name(&pdev->dev), sport);
if (ret) {
dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
- return ret;
+ goto err_clk;
}
}
@@ -2462,16 +2466,19 @@ static int imx_uart_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, sport);
- return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
+ ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port);
+
+err_clk:
+ clk_disable_unprepare(sport->clk_ipg);
+
+ return ret;
}
-static int imx_uart_remove(struct platform_device *pdev)
+static void imx_uart_remove(struct platform_device *pdev)
{
struct imx_port *sport = platform_get_drvdata(pdev);
uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
-
- return 0;
}
static void imx_uart_restore_context(struct imx_port *sport)
@@ -2640,7 +2647,7 @@ static const struct dev_pm_ops imx_uart_pm_ops = {
static struct platform_driver imx_uart_platform_driver = {
.probe = imx_uart_probe,
- .remove = imx_uart_remove,
+ .remove_new = imx_uart_remove,
.driver = {
.name = "imx-uart",
generated by cgit (git 2.34.1) at 2025-05-30 06:17:25 +0000