mmc: sdhci-of-at91: add PM support

Add runtime PM support and use runtime_force_suspend|resume() for system
PM.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 73 insertions, 2 deletions

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 06d0b50dfe71..7e7d8f0c9438 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -21,6 +21,8 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
 
 #include "sdhci-pltfm.h"
 
@@ -51,6 +53,60 @@ static const struct of_device_id sdhci_at91_dt_match[] = {
         {}
 };
 
+#ifdef CONFIG_PM
+static int sdhci_at91_runtime_suspend(struct device *dev)
+{
+        struct sdhci_host *host = dev_get_drvdata(dev);
+        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+        struct sdhci_at91_priv *priv = pltfm_host->priv;
+        int ret;
+
+        ret = sdhci_runtime_suspend_host(host);
+
+        clk_disable_unprepare(priv->gck);
+        clk_disable_unprepare(priv->hclock);
+        clk_disable_unprepare(priv->mainck);
+
+        return ret;
+}
+
+static int sdhci_at91_runtime_resume(struct device *dev)
+{
+        struct sdhci_host *host = dev_get_drvdata(dev);
+        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+        struct sdhci_at91_priv *priv = pltfm_host->priv;
+        int ret;
+
+        ret = clk_prepare_enable(priv->mainck);
+        if (ret) {
+                dev_err(dev, "can't enable mainck\n");
+                return ret;
+        }
+
+        ret = clk_prepare_enable(priv->hclock);
+        if (ret) {
+                dev_err(dev, "can't enable hclock\n");
+                return ret;
+        }
+
+        ret = clk_prepare_enable(priv->gck);
+        if (ret) {
+                dev_err(dev, "can't enable gck\n");
+                return ret;
+        }
+
+        return sdhci_runtime_resume_host(host);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
+        SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+                                pm_runtime_force_resume)
+        SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
+                           sdhci_at91_runtime_resume,
+                           NULL)
+};
+
 static int sdhci_at91_probe(struct platform_device *pdev)
 {
         const struct of_device_id       *match;
@@ -144,12 +200,23 @@ static int sdhci_at91_probe(struct platform_device *pdev)
 
         sdhci_get_of_property(pdev);
 
+        pm_runtime_get_noresume(&pdev->dev);
+        pm_runtime_set_active(&pdev->dev);
+        pm_runtime_enable(&pdev->dev);
+        pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
+        pm_runtime_use_autosuspend(&pdev->dev);
+
         ret = sdhci_add_host(host);
         if (ret)
-                goto clocks_disable_unprepare;
+                goto pm_runtime_disable;
+
+        pm_runtime_put_autosuspend(&pdev->dev);
 
         return 0;
 
+pm_runtime_disable:
+        pm_runtime_disable(&pdev->dev);
+        pm_runtime_set_suspended(&pdev->dev);
 clocks_disable_unprepare:
         clk_disable_unprepare(priv->gck);
         clk_disable_unprepare(priv->mainck);
@@ -165,6 +232,10 @@ static int sdhci_at91_remove(struct platform_device *pdev)
         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
         struct sdhci_at91_priv  *priv = pltfm_host->priv;
 
+        pm_runtime_get_sync(&pdev->dev);
+        pm_runtime_disable(&pdev->dev);
+        pm_runtime_put_noidle(&pdev->dev);
+
         sdhci_pltfm_unregister(pdev);
 
         clk_disable_unprepare(priv->gck);
@@ -178,7 +249,7 @@ static struct platform_driver sdhci_at91_driver = {
         .driver         = {
                 .name   = "sdhci-at91",
                 .of_match_table = sdhci_at91_dt_match,
-                .pm     = SDHCI_PLTFM_PMOPS,
+                .pm     = &sdhci_at91_dev_pm_ops,
         },
         .probe          = sdhci_at91_probe,
         .remove         = sdhci_at91_remove,