Add runtime pm support to manage the lpuart clock.
Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
drivers/tty/serial/fsl_lpuart.c | 60 +++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 474943cb06b2..e678a7aaf7e4 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -19,6 +19,7 @@
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/tty_flip.h>
@@ -235,6 +236,7 @@
/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
#define DMA_RX_TIMEOUT (10)
+#define UART_AUTOSUSPEND_TIMEOUT 3000
#define DRIVER_NAME "fsl-lpuart"
#define DEV_NAME "ttyLP"
@@ -795,6 +797,20 @@ static void lpuart32_start_tx(struct uart_port *port)
}
}
+static void
+lpuart_uart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
+{
+ switch (state) {
+ case UART_PM_STATE_OFF:
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+ break;
+ default:
+ pm_runtime_get_sync(port->dev);
+ break;
+ }
+}
+
/* return TIOCSER_TEMT when transmitter is not busy */
static unsigned int lpuart_tx_empty(struct uart_port *port)
{
@@ -2243,6 +2259,7 @@ static const struct uart_ops lpuart_pops = {
.startup = lpuart_startup,
.shutdown = lpuart_shutdown,
.set_termios = lpuart_set_termios,
+ .pm = lpuart_uart_pm,
.type = lpuart_type,
.request_port = lpuart_request_port,
.release_port = lpuart_release_port,
@@ -2267,6 +2284,7 @@ static const struct uart_ops lpuart32_pops = {
.startup = lpuart32_startup,
.shutdown = lpuart32_shutdown,
.set_termios = lpuart32_set_termios,
+ .pm = lpuart_uart_pm,
.type = lpuart_type,
.request_port = lpuart_request_port,
.release_port = lpuart_release_port,
@@ -2747,6 +2765,11 @@ static int lpuart_probe(struct platform_device *pdev)
handler = lpuart_int;
}
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
ret = lpuart_global_reset(sport);
if (ret)
goto failed_reset;
@@ -2771,6 +2794,9 @@ static int lpuart_probe(struct platform_device *pdev)
failed_attach_port:
failed_get_rs485:
failed_reset:
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
lpuart_disable_clks(sport);
return ret;
}
@@ -2789,9 +2815,30 @@ static int lpuart_remove(struct platform_device *pdev)
if (sport->dma_rx_chan)
dma_release_channel(sport->dma_rx_chan);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
return 0;
}
+static int __maybe_unused lpuart_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+ lpuart_disable_clks(sport);
+
+ return 0;
+};
+
+static int __maybe_unused lpuart_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+ return lpuart_enable_clks(sport);
+};
+
static void serial_lpuart_enable_wakeup(struct lpuart_port *sport, bool on)
{
unsigned int val, baud;
@@ -2937,6 +2984,10 @@ static int __maybe_unused lpuart_suspend(struct device *dev)
sport->dma_tx_in_progress = false;
dmaengine_terminate_all(sport->dma_tx_chan);
}
+ } else if (pm_runtime_active(sport->port.dev)) {
+ lpuart_disable_clks(sport);
+ pm_runtime_disable(sport->port.dev);
+ pm_runtime_set_suspended(sport->port.dev);
}
return 0;
@@ -2971,12 +3022,19 @@ static void lpuart_console_fixup(struct lpuart_port *sport)
static int __maybe_unused lpuart_resume(struct device *dev)
{
struct lpuart_port *sport = dev_get_drvdata(dev);
+ int ret;
if (lpuart_uport_is_active(sport)) {
if (lpuart_is_32(sport))
lpuart32_hw_setup(sport);
else
lpuart_hw_setup(sport);
+ } else if (pm_runtime_active(sport->port.dev)) {
+ ret = lpuart_enable_clks(sport);
+ if (ret)
+ return ret;
+ pm_runtime_set_active(sport->port.dev);
+ pm_runtime_enable(sport->port.dev);
}
lpuart_console_fixup(sport);
@@ -2986,6 +3044,8 @@ static int __maybe_unused lpuart_resume(struct device *dev)
}
static const struct dev_pm_ops lpuart_pm_ops = {
+ SET_RUNTIME_PM_OPS(lpuart_runtime_suspend,
+ lpuart_runtime_resume, NULL)
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(lpuart_suspend_noirq,
lpuart_resume_noirq)
SET_SYSTEM_SLEEP_PM_OPS(lpuart_suspend, lpuart_resume)
--
2.17.1
