mmc: sdhci-cadence: add suspend / resume support

Currently, the probe function initializes the PHY, but PHY settings
are lost during the sleep state.  Restore the PHY registers when
resuming.

To facilitate this, split sdhci_cdns_phy_init() into the DT parse
part and PHY update part so that the latter can be invoked from the
resume hook.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index 19d5698244b596a3642cac81a674d6c5e857ad72..3dca3b3c6436bd04e4729d90dc6b832915c714d7 100644 (file)
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -67,9 +67,16 @@
  */
 #define SDHCI_CDNS_MAX_TUNING_LOOP     40
 
+struct sdhci_cdns_phy_param {
+       u8 addr;
+       u8 data;
+};
+
 struct sdhci_cdns_priv {
        void __iomem *hrs_addr;
        bool enhanced_strobe;
+       unsigned int nr_phy_params;
+       struct sdhci_cdns_phy_param phy_params[0];
 };
 
 struct sdhci_cdns_phy_cfg {
@@ -115,9 +122,22 @@ static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
        return 0;
 }
 
-static int sdhci_cdns_phy_init(struct device_node *np,
-                              struct sdhci_cdns_priv *priv)
+static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
 {
+       unsigned int count = 0;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
+               if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
+                       count++;
+
+       return count;
+}
+
+static void sdhci_cdns_phy_param_parse(struct device_node *np,
+                                      struct sdhci_cdns_priv *priv)
+{
+       struct sdhci_cdns_phy_param *p = priv->phy_params;
        u32 val;
        int ret, i;
 
@@ -127,9 +147,19 @@ static int sdhci_cdns_phy_init(struct device_node *np,
                if (ret)
                        continue;
 
-               ret = sdhci_cdns_write_phy_reg(priv,
-                                              sdhci_cdns_phy_cfgs[i].addr,
-                                              val);
+               p->addr = sdhci_cdns_phy_cfgs[i].addr;
+               p->data = val;
+               p++;
+       }
+}
+
+static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
+{
+       int ret, i;
+
+       for (i = 0; i < priv->nr_phy_params; i++) {
+               ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
+                                              priv->phy_params[i].data);
                if (ret)
                        return ret;
        }
@@ -302,6 +332,8 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        struct sdhci_pltfm_host *pltfm_host;
        struct sdhci_cdns_priv *priv;
        struct clk *clk;
+       size_t priv_size;
+       unsigned int nr_phy_params;
        int ret;
        struct device *dev = &pdev->dev;
 
@@ -313,7 +345,9 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, sizeof(*priv));
+       nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
+       priv_size = sizeof(*priv) + sizeof(priv->phy_params[0]) * nr_phy_params;
+       host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, priv_size);
        if (IS_ERR(host)) {
                ret = PTR_ERR(host);
                goto disable_clk;
@@ -322,7 +356,8 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        pltfm_host = sdhci_priv(host);
        pltfm_host->clk = clk;
 
-       priv = sdhci_cdns_priv(host);
+       priv = sdhci_pltfm_priv(pltfm_host);
+       priv->nr_phy_params = nr_phy_params;
        priv->hrs_addr = host->ioaddr;
        priv->enhanced_strobe = false;
        host->ioaddr += SDHCI_CDNS_SRS_BASE;
@@ -336,7 +371,9 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        if (ret)
                goto free;
 
-       ret = sdhci_cdns_phy_init(dev->of_node, priv);
+       sdhci_cdns_phy_param_parse(dev->of_node, priv);
+
+       ret = sdhci_cdns_phy_init(priv);
        if (ret)
                goto free;
 
@@ -353,6 +390,57 @@ disable_clk:
        return ret;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int sdhci_cdns_suspend(struct device *dev)
+{
+       struct sdhci_host *host = dev_get_drvdata(dev);
+       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+       int ret;
+
+       if (host->tuning_mode != SDHCI_TUNING_MODE_3)
+               mmc_retune_needed(host->mmc);
+
+       ret = sdhci_suspend_host(host);
+       if (ret)
+               return ret;
+
+       clk_disable_unprepare(pltfm_host->clk);
+
+       return 0;
+}
+
+static int sdhci_cdns_resume(struct device *dev)
+{
+       struct sdhci_host *host = dev_get_drvdata(dev);
+       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+       struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
+       int ret;
+
+       ret = clk_prepare_enable(pltfm_host->clk);
+       if (ret)
+               return ret;
+
+       ret = sdhci_cdns_phy_init(priv);
+       if (ret)
+               goto disable_clk;
+
+       ret = sdhci_resume_host(host);
+       if (ret)
+               goto disable_clk;
+
+       return 0;
+
+disable_clk:
+       clk_disable_unprepare(pltfm_host->clk);
+
+       return ret;
+}
+#endif
+
+static const struct dev_pm_ops sdhci_cdns_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(sdhci_cdns_suspend, sdhci_cdns_resume)
+};
+
 static const struct of_device_id sdhci_cdns_match[] = {
        { .compatible = "socionext,uniphier-sd4hc" },
        { .compatible = "cdns,sd4hc" },
@@ -363,7 +451,7 @@ MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
 static struct platform_driver sdhci_cdns_driver = {
        .driver = {
                .name = "sdhci-cdns",
-               .pm = &sdhci_pltfm_pmops,
+               .pm = &sdhci_cdns_pm_ops,
                .of_match_table = sdhci_cdns_match,
        },
        .probe = sdhci_cdns_probe,