From 70d2c9940e54ada6bf9e1e538c958f13ccc97c38 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sun, 5 Nov 2023 23:42:45 +0100 Subject: [PATCH] mmc: renesas-sdhi: Disable clock after tuning reset when possible Currently the renesas_sdhi_reset_tuning() unconditionally leaves SDHI clock enabled after the tuning reset. This is not always necessary. After the driver performed tuning reset at the end of probe function, or in the unlikely case that tuning failed during regular operation, the SDHI clock can be disabled after the tuning reset. The following set_ios call would reconfigure the clock as needed. In case of regular set_ios call which requires a tuning reset, keep the clock enabled or disabled according to the mmc->clk_disable state. With this in place, the controllers which have not been accessed via block subsystem after boot are left in quiescent state. However, if an MMC device is used e.g. for environment storage, that controller would be accessed during the environment load and left active, including its clock which would still be generated. This is due to the design of the MMC subsystem, which does not deinit a controller after it was started once, the controller is only deinited in case of mmc rescan, or before OS boot. Signed-off-by: Marek Vasut Reviewed-by: Jaehoon Chung Reviewed-by: Paul Barker Tested-by: Paul Barker Reviewed-by: Yoshihiro Shimoda Tested-by: Thuan Nguyen Hong --- drivers/mmc/renesas-sdhi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/renesas-sdhi.c b/drivers/mmc/renesas-sdhi.c index 8cd501c5f7..97aaf1e4ec 100644 --- a/drivers/mmc/renesas-sdhi.c +++ b/drivers/mmc/renesas-sdhi.c @@ -318,7 +318,7 @@ static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv) RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK; } -static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv) +static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv, bool clk_disable) { u32 reg; @@ -350,6 +350,12 @@ static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv) reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL); reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN; tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL); + + if (clk_disable) { + reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL); + reg &= ~TMIO_SD_CLKCTL_SCLKEN; + tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL); + } } static int renesas_sdhi_hs400(struct udevice *dev) @@ -629,7 +635,7 @@ int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode) out: if (ret < 0) { dev_warn(dev, "Tuning procedure failed\n"); - renesas_sdhi_reset_tuning(priv); + renesas_sdhi_reset_tuning(priv, true); } return ret; @@ -668,7 +674,7 @@ static int renesas_sdhi_set_ios(struct udevice *dev) (mmc->selected_mode != UHS_SDR104) && (mmc->selected_mode != MMC_HS_200) && (mmc->selected_mode != MMC_HS_400)) { - renesas_sdhi_reset_tuning(priv); + renesas_sdhi_reset_tuning(priv, mmc->clk_disable); } #endif @@ -1095,7 +1101,7 @@ static int renesas_sdhi_probe(struct udevice *dev) CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \ CONFIG_IS_ENABLED(MMC_HS400_SUPPORT) if (priv->caps & TMIO_SD_CAP_RCAR_UHS) - renesas_sdhi_reset_tuning(priv); + renesas_sdhi_reset_tuning(priv, true); #endif return 0; -- 2.39.5