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Subject[PATCH v2] mmc: sdhci-omap: Add Support for Suspend/Resume
Date
Add power management ops which save and restore the driver context and
facilitate a system suspend and resume.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
---
v2:
1. Save and restore only those registers which are not written to by
core
2. Use force_suspend()/resume() APIs instead of runtime_resume()/suspend()
as the driver has no runtime PM support.
drivers/mmc/host/sdhci-omap.c | 57 +++++++++++++++++++++++++++++++++++
1 file changed, 57 insertions(+)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 882053151a47..989133ec74d6 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -108,6 +108,11 @@ struct sdhci_omap_host {
struct pinctrl *pinctrl;
struct pinctrl_state **pinctrl_state;
bool is_tuning;
+ /* Omap specific context save */
+ u32 con;
+ u32 hctl;
+ u32 sysctl;
+ u32 capa;
};

static void sdhci_omap_start_clock(struct sdhci_omap_host *omap_host);
@@ -1232,12 +1237,64 @@ static int sdhci_omap_remove(struct platform_device *pdev)

return 0;
}
+#ifdef CONFIG_PM_SLEEP
+static void sdhci_omap_context_save(struct sdhci_omap_host *omap_host)
+{
+ omap_host->con = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
+ omap_host->hctl = sdhci_omap_readl(omap_host, SDHCI_OMAP_HCTL);
+ omap_host->capa = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
+}
+
+static void sdhci_omap_context_restore(struct sdhci_omap_host *omap_host)
+{
+ sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, omap_host->con);
+ sdhci_omap_writel(omap_host, SDHCI_OMAP_HCTL, omap_host->hctl);
+ sdhci_omap_writel(omap_host, SDHCI_OMAP_CAPA, omap_host->capa);
+}
+
+static int __maybe_unused sdhci_omap_suspend(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+
+ sdhci_suspend_host(host);
+
+ sdhci_omap_context_save(omap_host);
+
+ pinctrl_pm_select_idle_state(dev);
+
+ pm_runtime_force_suspend(dev);
+
+ return 0;
+}
+
+static int __maybe_unused sdhci_omap_resume(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+
+ pm_runtime_force_resume(dev);
+
+ pinctrl_pm_select_default_state(dev);
+
+ sdhci_omap_context_restore(omap_host);
+
+ sdhci_resume_host(host);
+
+ return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(sdhci_omap_dev_pm_ops, sdhci_omap_suspend,
+ sdhci_omap_resume);

static struct platform_driver sdhci_omap_driver = {
.probe = sdhci_omap_probe,
.remove = sdhci_omap_remove,
.driver = {
.name = "sdhci-omap",
+ .pm = &sdhci_omap_dev_pm_ops,
.of_match_table = omap_sdhci_match,
},
};
--
2.19.2
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