ARM: SAMSUNG: Add suspend/resume support for S3C PWM driver

Reset period_ns and duty_ns values in suspend handler to avoid skip of
configuration if same values passed to pwm_config;
Restore invertion bit in resume handler.

Without this patch PWM works incorrectly after resume from suspend.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/pwm.c b/arch/arm/plat-samsung/pwm.c
index ef019f27b67d..f2d11390d01c 100644
--- a/arch/arm/plat-samsung/pwm.c
+++ b/arch/arm/plat-samsung/pwm.c
@@ -379,6 +379,39 @@ static int __devexit s3c_pwm_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_PM
+static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct pwm_device *pwm = platform_get_drvdata(pdev);
+
+        /* No one preserve these values during suspend so reset them
+         * Otherwise driver leaves PWM unconfigured if same values
+         * passed to pwm_config
+         */
+        pwm->period_ns = 0;
+        pwm->duty_ns = 0;
+
+        return 0;
+}
+
+static int s3c_pwm_resume(struct platform_device *pdev)
+{
+        struct pwm_device *pwm = platform_get_drvdata(pdev);
+        unsigned long tcon;
+
+        /* Restore invertion */
+        tcon = __raw_readl(S3C2410_TCON);
+        tcon |= pwm_tcon_invert(pwm);
+        __raw_writel(tcon, S3C2410_TCON);
+
+        return 0;
+}
+
+#else
+#define s3c_pwm_suspend NULL
+#define s3c_pwm_resume NULL
+#endif
+
 static struct platform_driver s3c_pwm_driver = {
         .driver         = {
                 .name   = "s3c24xx-pwm",
@@ -386,6 +419,8 @@ static struct platform_driver s3c_pwm_driver = {
         },
         .probe          = s3c_pwm_probe,
         .remove         = __devexit_p(s3c_pwm_remove),
+        .suspend        = s3c_pwm_suspend,
+        .resume         = s3c_pwm_resume,
 };
 
 static int __init pwm_init(void)