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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.c62
1 files changed, 40 insertions, 22 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 91f3a1a5cb7f..4e853570ea80 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -316,7 +316,7 @@ static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
* differ from the value that was last written. As it only
* clears after being set, reread conditionally.
*/
- if (sport->ucr2 & UCR2_SRST)
+ if (!(sport->ucr2 & UCR2_SRST))
sport->ucr2 = readl(sport->port.membase + offset);
return sport->ucr2;
break;
@@ -1291,18 +1291,13 @@ static void imx_uart_enable_dma(struct imx_port *sport)
static void imx_uart_disable_dma(struct imx_port *sport)
{
- u32 ucr1, ucr2;
+ u32 ucr1;
/* clear UCR1 */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
imx_uart_writel(sport, ucr1, UCR1);
- /* clear UCR2 */
- ucr2 = imx_uart_readl(sport, UCR2);
- ucr2 &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
- imx_uart_writel(sport, ucr2, UCR2);
-
imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
sport->dma_is_enabled = 0;
@@ -1427,13 +1422,21 @@ static void imx_uart_shutdown(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
- u32 ucr1, ucr2;
+ u32 ucr1, ucr2, ucr4;
if (sport->dma_is_enabled) {
- sport->dma_is_rxing = 0;
- sport->dma_is_txing = 0;
dmaengine_terminate_sync(sport->dma_chan_tx);
+ if (sport->dma_is_txing) {
+ dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+ sport->dma_tx_nents, DMA_TO_DEVICE);
+ sport->dma_is_txing = 0;
+ }
dmaengine_terminate_sync(sport->dma_chan_rx);
+ if (sport->dma_is_rxing) {
+ dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
+ 1, DMA_FROM_DEVICE);
+ sport->dma_is_rxing = 0;
+ }
spin_lock_irqsave(&sport->port.lock, flags);
imx_uart_stop_tx(port);
@@ -1449,6 +1452,10 @@ static void imx_uart_shutdown(struct uart_port *port)
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);
/*
@@ -1833,6 +1840,11 @@ static int imx_uart_rs485_config(struct uart_port *port,
rs485conf->flags &= ~SER_RS485_ENABLED;
if (rs485conf->flags & SER_RS485_ENABLED) {
+ /* Enable receiver if low-active RTS signal is requested */
+ if (sport->have_rtscts && !sport->have_rtsgpio &&
+ !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
+ rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
/* disable transmitter */
ucr2 = imx_uart_readl(sport, UCR2);
if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
@@ -2265,6 +2277,18 @@ static int imx_uart_probe(struct platform_device *pdev)
(!sport->have_rtscts && !sport->have_rtsgpio))
dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
+ /*
+ * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
+ * signal cannot be set low during transmission in case the
+ * receiver is off (limitation of the i.MX UART IP).
+ */
+ if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+ sport->have_rtscts && !sport->have_rtsgpio &&
+ (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
+ !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
+ 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 */
@@ -2408,8 +2432,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
static int imx_uart_suspend_noirq(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
imx_uart_save_context(sport);
@@ -2420,8 +2443,7 @@ static int imx_uart_suspend_noirq(struct device *dev)
static int imx_uart_resume_noirq(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
int ret;
ret = clk_enable(sport->clk_ipg);
@@ -2435,8 +2457,7 @@ static int imx_uart_resume_noirq(struct device *dev)
static int imx_uart_suspend(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
int ret;
uart_suspend_port(&imx_uart_uart_driver, &sport->port);
@@ -2454,8 +2475,7 @@ static int imx_uart_suspend(struct device *dev)
static int imx_uart_resume(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
/* disable wakeup from i.MX UART */
imx_uart_enable_wakeup(sport, false);
@@ -2470,8 +2490,7 @@ static int imx_uart_resume(struct device *dev)
static int imx_uart_freeze(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
uart_suspend_port(&imx_uart_uart_driver, &sport->port);
@@ -2480,8 +2499,7 @@ static int imx_uart_freeze(struct device *dev)
static int imx_uart_thaw(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct imx_port *sport = platform_get_drvdata(pdev);
+ struct imx_port *sport = dev_get_drvdata(dev);
uart_resume_port(&imx_uart_uart_driver, &sport->port);