[PATCH 5/9] serial: 8250_dw: Enable runtime PM

From: Heikki Krogerus
Date: Wed Apr 10 2013 - 10:00:14 EST


This allows ACPI to put the device to D3 when it's not used.

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_dw.c | 61 +++++++++++++++++++++++++++++++------
1 file changed, 52 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 3dedd24..d6aea85 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -27,6 +27,7 @@
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/clk.h>
+#include <linux/pm_runtime.h>

#include "8250.h"

@@ -115,6 +116,18 @@ static int dw8250_handle_irq(struct uart_port *p)
return 0;
}

+static void
+dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
+{
+ if (!state)
+ pm_runtime_get_sync(port->dev);
+
+ serial8250_do_pm(port, state, old);
+
+ if (state)
+ pm_runtime_put_sync_suspend(port->dev);
+}
+
static int dw8250_probe_of(struct uart_port *p)
{
struct device_node *np = p->dev->of_node;
@@ -293,6 +306,7 @@ static int dw8250_probe(struct platform_device *pdev)
uart.port.mapbase = regs->start;
uart.port.irq = irq->start;
uart.port.handle_irq = dw8250_handle_irq;
+ uart.port.pm = dw8250_do_pm;
uart.port.type = PORT_8250;
uart.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
uart.port.dev = &pdev->dev;
@@ -336,6 +350,9 @@ static int dw8250_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, data);

+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
return 0;
}

@@ -343,37 +360,64 @@ static int dw8250_remove(struct platform_device *pdev)
{
struct dw8250_data *data = platform_get_drvdata(pdev);

+ pm_runtime_get_sync(&pdev->dev);
+
serial8250_unregister_port(data->line);

if (!IS_ERR(data->clk))
clk_disable_unprepare(data->clk);

+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+
return 0;
}

#ifdef CONFIG_PM
-static int dw8250_suspend(struct platform_device *pdev, pm_message_t state)
+static int dw8250_suspend(struct device *dev)
{
- struct dw8250_data *data = platform_get_drvdata(pdev);
+ struct dw8250_data *data = dev_get_drvdata(dev);

serial8250_suspend_port(data->line);

return 0;
}

-static int dw8250_resume(struct platform_device *pdev)
+static int dw8250_resume(struct device *dev)
{
- struct dw8250_data *data = platform_get_drvdata(pdev);
+ struct dw8250_data *data = dev_get_drvdata(dev);

serial8250_resume_port(data->line);

return 0;
}
-#else
-#define dw8250_suspend NULL
-#define dw8250_resume NULL
#endif /* CONFIG_PM */

+#ifdef CONFIG_PM_RUNTIME
+static int dw8250_runtime_suspend(struct device *dev)
+{
+ struct dw8250_data *data = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(data->clk);
+
+ return 0;
+}
+
+static int dw8250_runtime_resume(struct device *dev)
+{
+ struct dw8250_data *data = dev_get_drvdata(dev);
+
+ clk_prepare_enable(data->clk);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops dw8250_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
+ SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
+};
+
static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "snps,dw-apb-uart" },
{ /* Sentinel */ }
@@ -391,13 +435,12 @@ static struct platform_driver dw8250_platform_driver = {
.driver = {
.name = "dw-apb-uart",
.owner = THIS_MODULE,
+ .pm = &dw8250_pm_ops,
.of_match_table = dw8250_of_match,
.acpi_match_table = ACPI_PTR(dw8250_acpi_match),
},
.probe = dw8250_probe,
.remove = dw8250_remove,
- .suspend = dw8250_suspend,
- .resume = dw8250_resume,
};

module_platform_driver(dw8250_platform_driver);
--
1.7.10.4

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