[PATCH v2] mmc: sdhci-xenon: add runtime pm support and reimplement standby

[Zhoujie Wu <zjwu@marvell.com>]

Enable runtime pm support for xenon controller, which uses 50ms
auto runtime suspend by default.
Reimplement system standby based on runtime pm API.
Introduce restore_needed to restore the Xenon specific registers
when resume.

Signed-off-by: Zhoujie Wu <zjwu@marvell.com>
---
v2: Combined two previous patches(runtime pm support and reimplement standby)
to one according to the suggestion from Adrian.

 drivers/mmc/host/sdhci-xenon.c | 76 ++++++++++++++++++++++++++++++++----------
 drivers/mmc/host/sdhci-xenon.h |  1 +
 2 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
index 306ffaf..f97a78e 100644
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -18,6 +18,8 @@
 #include <linux/ktime.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
 
 #include "sdhci-pltfm.h"
 #include "sdhci-xenon.h"
@@ -506,13 +508,24 @@ static int xenon_probe(struct platform_device *pdev)
 	if (err)
 		goto err_clk;
 
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_suspend_ignore_children(&pdev->dev, 1);
+
 	err = sdhci_add_host(host);
 	if (err)
 		goto remove_sdhc;
 
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	return 0;
 
 remove_sdhc:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_put_noidle(&pdev->dev);
 	xenon_sdhc_unprepare(host);
 err_clk:
 	clk_disable_unprepare(pltfm_host->clk);
@@ -542,40 +555,69 @@ static int xenon_suspend(struct device *dev)
 {
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
-	ret = sdhci_suspend_host(host);
-	if (ret)
-		return ret;
+	ret = pm_runtime_force_suspend(dev);
 
-	clk_disable_unprepare(pltfm_host->clk);
+	priv->restore_needed = true;
 	return ret;
 }
+#endif
 
-static int xenon_resume(struct device *dev)
+#ifdef CONFIG_PM
+static int xenon_runtime_suspend(struct device *dev)
 {
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
-	ret = clk_prepare_enable(pltfm_host->clk);
-	if (ret)
-		return ret;
+	ret = sdhci_runtime_suspend_host(host);
+
+	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
+		mmc_retune_needed(host->mmc);
 
+	clk_disable_unprepare(pltfm_host->clk);
 	/*
-	 * If SoCs power off the entire Xenon, registers setting will
-	 * be lost.
-	 * Re-configure Xenon specific register to enable current SDHC
+	 * Need to update the priv->clock here, or when runtime resume
+	 * back, phy don't aware the clock change and won't adjust phy
+	 * which will cause cmd err
 	 */
-	ret = xenon_sdhc_prepare(host);
-	if (ret)
+	priv->clock = 0;
+	return ret;
+}
+
+static int xenon_runtime_resume(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	int ret;
+
+	ret = clk_prepare_enable(pltfm_host->clk);
+	if (ret) {
+		dev_err(dev, "can't enable mainck\n");
 		return ret;
+	}
+
+	if (priv->restore_needed) {
+		xenon_sdhc_prepare(host);
+		priv->restore_needed = false;
+	}
 
-	return sdhci_resume_host(host);
+	return sdhci_runtime_resume_host(host);
 }
-#endif
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops sdhci_xenon_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(xenon_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(xenon_runtime_suspend,
+			   xenon_runtime_resume,
+			   NULL)
+};
 
-static SIMPLE_DEV_PM_OPS(xenon_pmops, xenon_suspend, xenon_resume);
 
 static const struct of_device_id sdhci_xenon_dt_ids[] = {
 	{ .compatible = "marvell,armada-ap806-sdhci",},
@@ -589,7 +631,7 @@ static int xenon_resume(struct device *dev)
 	.driver	= {
 		.name	= "xenon-sdhci",
 		.of_match_table = sdhci_xenon_dt_ids,
-		.pm = &xenon_pmops,
+		.pm = &sdhci_xenon_dev_pm_ops,
 	},
 	.probe	= xenon_probe,
 	.remove	= xenon_remove,
diff --git a/drivers/mmc/host/sdhci-xenon.h b/drivers/mmc/host/sdhci-xenon.h
index 01937f1..2bc0510 100644
--- a/drivers/mmc/host/sdhci-xenon.h
+++ b/drivers/mmc/host/sdhci-xenon.h
@@ -91,6 +91,7 @@ struct xenon_priv {
 	 */
 	void		*phy_params;
 	struct xenon_emmc_phy_regs *emmc_phy_regs;
+	bool restore_needed;
 };
 
 int xenon_phy_adj(struct sdhci_host *host, struct mmc_ios *ios);
-- 
1.9.1