[PATCH] serial: of-serial: add PM suspend/resume support
From: Joseph Lo <hidden>
Date: 2014-10-03 07:45:38
Also in:
linux-devicetree, linux-serial, lkml
Hi, This patch might have a potential issue that cause system hard hung immediately when it accesses to registers with no clock. This could happen on many chips that mainline kernel supporting with the setting "no_console_suspend=1" during suspend time. On 09/23/2014 04:34 PM, Jingchang Lu wrote:
quoted hunk ↗ jump to hunk
This adds PM suspend/resume support for the of-serial driver to provide power management support on devices attatched to it. Signed-off-by: Jingchang Lu <redacted> --- drivers/tty/serial/of_serial.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 27981e2..8bc2563 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c@@ -240,6 +240,32 @@ static int of_platform_serial_remove(struct platform_device *ofdev) return 0; } +#ifdef CONFIG_PM_SLEEP +static int of_serial_suspend(struct device *dev) +{ + struct of_serial_info *info = dev_get_drvdata(dev); + + serial8250_suspend_port(info->line); + if (info->clk)
The fix would be something like this. if (info->clk && console_suspend_enabled)
+ clk_disable_unprepare(info->clk);
+
+ return 0;
+}
+
+static int of_serial_resume(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+
+ if (info->clk)Ditto. Thanks, -Joseph
quoted hunk ↗ jump to hunk
+ clk_prepare_enable(info->clk); + + serial8250_resume_port(info->line); + + return 0; +} +#endif +static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume); + /* * A few common types, add more as needed. */@@ -271,6 +297,7 @@ static struct platform_driver of_platform_serial_driver = { .name = "of_serial", .owner = THIS_MODULE, .of_match_table = of_platform_serial_table, + .pm = &of_serial_pm_ops, }, .probe = of_platform_serial_probe, .remove = of_platform_serial_remove,