mmc: sdhci-msm: Add pm_runtime and system PM support

Provides runtime PM callbacks to enable and disable clock resources
when idle. Also support system PM callbacks to be called during system
suspend and resume.
Reviewed-by: Ritesh Harjani <riteshh@codeaurora.org>
Reviewed-by: Georgi Djakov <georgi.djakov@linaro.org>
Tested-by: Ritesh Harjani <riteshh@codeaurora.org>
Signed-off-by: Pramod Gurav <pramod.gurav@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-msm.c

@@ -18,6 +18,7 @@
 #include <linux/of_device.h>
 #include <linux/delay.h>
 #include <linux/mmc/mmc.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
 #include "sdhci-pltfm.h"
@@ -68,6 +69,7 @@
 #define CMUX_SHIFT_PHASE_SHIFT	24
 #define CMUX_SHIFT_PHASE_MASK	(7 << CMUX_SHIFT_PHASE_SHIFT)
 
+#define MSM_MMC_AUTOSUSPEND_DELAY_MS	50
 struct sdhci_msm_host {
 	struct platform_device *pdev;
 	void __iomem *core_mem;	/* MSM SDCC mapped address */
@@ -659,12 +661,26 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 		goto clk_disable;
 	}
 
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev,
+					 MSM_MMC_AUTOSUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(&pdev->dev);
+
 	ret = sdhci_add_host(host);
 	if (ret)
-		goto clk_disable;
+		goto pm_runtime_disable;
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
 
 	return 0;
 
+pm_runtime_disable:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
 clk_disable:
 	clk_disable_unprepare(msm_host->clk);
 pclk_disable:
@@ -686,6 +702,11 @@ static int sdhci_msm_remove(struct platform_device *pdev)
 		    0xffffffff);
 
 	sdhci_remove_host(host, dead);
+
+	pm_runtime_get_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
+
 	clk_disable_unprepare(msm_host->clk);
 	clk_disable_unprepare(msm_host->pclk);
 	if (!IS_ERR(msm_host->bus_clk))
@@ -694,12 +715,57 @@ static int sdhci_msm_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int sdhci_msm_runtime_suspend(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+
+	clk_disable_unprepare(msm_host->clk);
+	clk_disable_unprepare(msm_host->pclk);
+
+	return 0;
+}
+
+static int sdhci_msm_runtime_resume(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	int ret;
+
+	ret = clk_prepare_enable(msm_host->clk);
+	if (ret) {
+		dev_err(dev, "clk_enable failed for core_clk: %d\n", ret);
+		return ret;
+	}
+	ret = clk_prepare_enable(msm_host->pclk);
+	if (ret) {
+		dev_err(dev, "clk_enable failed for iface_clk: %d\n", ret);
+		clk_disable_unprepare(msm_host->clk);
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops sdhci_msm_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
+			   sdhci_msm_runtime_resume,
+			   NULL)
+};
+
 static struct platform_driver sdhci_msm_driver = {
 	.probe = sdhci_msm_probe,
 	.remove = sdhci_msm_remove,
 	.driver = {
 		   .name = "sdhci_msm",
 		   .of_match_table = sdhci_msm_dt_match,
+		   .pm = &sdhci_msm_pm_ops,
 	},
 };