mmc: dw_mmc-rockchip: Fix runtime PM support for internal phase support

RK3576 is the first platform to introduce internal phase support, and
subsequent platforms are expected to adopt a similar design. In this
architecture, runtime suspend powers off the attached power domain, which
resets registers, including vendor-specific ones such as SDMMC_TIMING_CON0,
SDMMC_TIMING_CON1, and SDMMC_MISC_CON. These registers must be saved and
restored, a requirement that falls outside the scope of the dw_mmc core.

Fixes: 59903441f5e4 ("mmc: dw_mmc-rockchip: Add internal phase support")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Marco Schirrmeister <mschirrmeister@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index 4e3423a19bdfe10c4639965c6afe5d4f0eb74f7d..ac069d0c42b260670b1b10d6216d1b35f9622f80 100644 (file)
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -36,6 +36,8 @@ struct dw_mci_rockchip_priv_data {
        int                     default_sample_phase;
        int                     num_phases;
        bool                    internal_phase;
+       int                     sample_phase;
+       int                     drv_phase;
 };
 
 /*
@@ -573,9 +575,43 @@ static void dw_mci_rockchip_remove(struct platform_device *pdev)
        dw_mci_pltfm_remove(pdev);
 }
 
+static int dw_mci_rockchip_runtime_suspend(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct dw_mci *host = platform_get_drvdata(pdev);
+       struct dw_mci_rockchip_priv_data *priv = host->priv;
+
+       if (priv->internal_phase) {
+               priv->sample_phase = rockchip_mmc_get_phase(host, true);
+               priv->drv_phase = rockchip_mmc_get_phase(host, false);
+       }
+
+       return dw_mci_runtime_suspend(dev);
+}
+
+static int dw_mci_rockchip_runtime_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct dw_mci *host = platform_get_drvdata(pdev);
+       struct dw_mci_rockchip_priv_data *priv = host->priv;
+       int ret;
+
+       ret = dw_mci_runtime_resume(dev);
+       if (ret)
+               return ret;
+
+       if (priv->internal_phase) {
+               rockchip_mmc_set_phase(host, true, priv->sample_phase);
+               rockchip_mmc_set_phase(host, false, priv->drv_phase);
+               mci_writel(host, MISC_CON, MEM_CLK_AUTOGATE_ENABLE);
+       }
+
+       return ret;
+}
+
 static const struct dev_pm_ops dw_mci_rockchip_dev_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
-       RUNTIME_PM_OPS(dw_mci_runtime_suspend, dw_mci_runtime_resume, NULL)
+       RUNTIME_PM_OPS(dw_mci_rockchip_runtime_suspend, dw_mci_rockchip_runtime_resume, NULL)
 };
 
 static struct platform_driver dw_mci_rockchip_pltfm_driver = {