clocksource: sh_cmt: Runtime PM support
Magnus Damm [Mon, 25 Apr 2011 13:36:10 +0000 (22:36 +0900)]
Add Runtime PM support to the CMT driver.

The hardware device is enabled as long as the clocksource
or the clockevent portion of the driver is used.

Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/clocksource/sh_cmt.c

index dc7c033..036e586 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/clk.h>
+#include <linux/pm_runtime.h>
 #include <linux/irq.h>
 #include <linux/err.h>
 #include <linux/clocksource.h>
@@ -152,10 +153,12 @@ static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate)
 {
        int ret;
 
-       /* enable clock */
+       /* wake up device and enable clock */
+       pm_runtime_get_sync(&p->pdev->dev);
        ret = clk_enable(p->clk);
        if (ret) {
                dev_err(&p->pdev->dev, "cannot enable clock\n");
+               pm_runtime_put_sync(&p->pdev->dev);
                return ret;
        }
 
@@ -187,8 +190,9 @@ static void sh_cmt_disable(struct sh_cmt_priv *p)
        /* disable interrupts in CMT block */
        sh_cmt_write(p, CMCSR, 0);
 
-       /* stop clock */
+       /* stop clock and mark device as idle */
        clk_disable(p->clk);
+       pm_runtime_put_sync(&p->pdev->dev);
 }
 
 /* private flags */
@@ -660,6 +664,7 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev)
 
        if (p) {
                dev_info(&pdev->dev, "kept as earlytimer\n");
+               pm_runtime_enable(&pdev->dev);
                return 0;
        }
 
@@ -674,6 +679,9 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev)
                kfree(p);
                platform_set_drvdata(pdev, NULL);
        }
+
+       if (!is_early_platform_device(pdev))
+               pm_runtime_enable(&pdev->dev);
        return ret;
 }