* [PATCH 2/3] serial-uartlite: Add runtime pm support
2020-12-09 12:18 [PATCH 1/3] serial-uartlite: Disable clocks in the error path Shubhrajyoti Datta
@ 2020-12-09 12:18 ` Shubhrajyoti Datta
2020-12-09 14:33 ` Greg KH
2020-12-09 12:18 ` [PATCH 3/3] serial-uartlite: Remove an un-necessary read of control register Shubhrajyoti Datta
2020-12-09 14:32 ` [PATCH 1/3] serial-uartlite: Disable clocks in the error path Greg KH
2 siblings, 1 reply; 6+ messages in thread
From: Shubhrajyoti Datta @ 2020-12-09 12:18 UTC (permalink / raw)
To: linux-serial; +Cc: git, jacmet, linuxfoundation.org, Shubhrajyoti Datta
Add runtime pm support
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
drivers/tty/serial/uartlite.c | 59 +++++++++++++++++++++++++++++++++++++------
1 file changed, 51 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index ab4954f..92dd528 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -22,6 +22,7 @@
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
+#include <linux/pm_runtime.h>
#define ULITE_NAME "ttyUL"
#define ULITE_MAJOR 204
@@ -54,6 +55,7 @@
#define ULITE_CONTROL_RST_TX 0x01
#define ULITE_CONTROL_RST_RX 0x02
#define ULITE_CONTROL_IE 0x10
+#define UART_AUTOSUSPEND_TIMEOUT 3000
/* Static pointer to console port */
#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
@@ -390,12 +392,16 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
static void ulite_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
- struct uartlite_data *pdata = port->private_data;
+ int ret;
- if (!state)
- clk_enable(pdata->clk);
- else
- clk_disable(pdata->clk);
+ if (!state) {
+ ret = pm_runtime_get_sync(port->dev);
+ if (ret < 0)
+ dev_err(port->dev, "Failed to enable clocks\n");
+ } else {
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+ }
}
#ifdef CONFIG_CONSOLE_POLL
@@ -734,11 +740,37 @@ static int __maybe_unused ulite_resume(struct device *dev)
return 0;
}
+static int __maybe_unused ulite_runtime_suspend(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct uartlite_data *pdata = port->private_data;
+
+ clk_disable(pdata->clk);
+ return 0;
+};
+
+static int __maybe_unused ulite_runtime_resume(struct device *dev)
+{
+ struct uart_port *port = dev_get_drvdata(dev);
+ struct uartlite_data *pdata = port->private_data;
+ int ret;
+
+ ret = clk_enable(pdata->clk);
+ if (ret) {
+ dev_err(dev, "Cannot enable clock.\n");
+ return ret;
+ }
+ return 0;
+}
/* ---------------------------------------------------------------------
* Platform bus binding
*/
-static SIMPLE_DEV_PM_OPS(ulite_pm_ops, ulite_suspend, ulite_resume);
+static const struct dev_pm_ops ulite_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume)
+ SET_RUNTIME_PM_OPS(ulite_runtime_suspend,
+ ulite_runtime_resume, NULL)
+};
#if defined(CONFIG_OF)
/* Match table for of_platform binding */
@@ -803,9 +835,15 @@ static int ulite_probe(struct platform_device *pdev)
}
}
+ 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 = ulite_assign(&pdev->dev, id, res->start, irq, pdata);
- clk_disable(pdata->clk);
+ pm_runtime_mark_last_busy(&pdev->dev);
+ pm_runtime_put_autosuspend(&pdev->dev);
return ret;
@@ -818,9 +856,14 @@ static int ulite_remove(struct platform_device *pdev)
{
struct uart_port *port = dev_get_drvdata(&pdev->dev);
struct uartlite_data *pdata = port->private_data;
+ int rc;
clk_disable_unprepare(pdata->clk);
- return ulite_release(&pdev->dev);
+ rc = ulite_release(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+ return rc;
}
/* work with hotplug and coldplug */
--
2.1.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] serial-uartlite: Remove an un-necessary read of control register
2020-12-09 12:18 [PATCH 1/3] serial-uartlite: Disable clocks in the error path Shubhrajyoti Datta
2020-12-09 12:18 ` [PATCH 2/3] serial-uartlite: Add runtime pm support Shubhrajyoti Datta
@ 2020-12-09 12:18 ` Shubhrajyoti Datta
2020-12-09 14:33 ` Greg KH
2020-12-09 14:32 ` [PATCH 1/3] serial-uartlite: Disable clocks in the error path Greg KH
2 siblings, 1 reply; 6+ messages in thread
From: Shubhrajyoti Datta @ 2020-12-09 12:18 UTC (permalink / raw)
To: linux-serial; +Cc: git, jacmet, linuxfoundation.org, Shubhrajyoti Datta
The control register is a writeonly register that's why reading it
doesn't make any sense.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
drivers/tty/serial/uartlite.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index 92dd528..52c223f 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -296,7 +296,6 @@ static void ulite_shutdown(struct uart_port *port)
struct uartlite_data *pdata = port->private_data;
uart_out32(0, ULITE_CONTROL, port);
- uart_in32(ULITE_CONTROL, port); /* dummy */
free_irq(port->irq, port);
clk_disable(pdata->clk);
}
@@ -367,7 +366,6 @@ static int ulite_request_port(struct uart_port *port)
}
pdata->reg_ops = &uartlite_be;
- ret = uart_in32(ULITE_CONTROL, port);
uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
ret = uart_in32(ULITE_STATUS, port);
/* Endianess detection */
--
2.1.1
^ permalink raw reply related [flat|nested] 6+ messages in thread