diff options
| author | Brad Larson <blarson@amd.com> | 2023-04-10 21:45:25 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2023-04-17 12:45:43 +0300 |
| commit | aad53d4ee7569d82cbc8ee14dacf3b8011fe827a (patch) | |
| tree | 9ee5364fbd03919628d5252fb0d30eb7e6563c22 /drivers/mmc | |
| parent | b5dbcf1f1d1a7349ca731c22dda7d429151956ac (diff) | |
| download | linux-aad53d4ee7569d82cbc8ee14dacf3b8011fe827a.tar.xz | |
mmc: sdhci-cadence: Support mmc hardware reset
Add support for mmc hardware reset using a reset-controller
that would need to be enabled in the device tree with
a supporting driver. The default is disabled for all
existing designs.
Signed-off-by: Brad Larson <blarson@amd.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20230410184526.15990-15-blarson@amd.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-cadence.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c index 5d1e9cef74f5..b24aa27da50c 100644 --- a/drivers/mmc/host/sdhci-cadence.c +++ b/drivers/mmc/host/sdhci-cadence.c @@ -12,6 +12,7 @@ #include <linux/mmc/mmc.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/reset.h> #include "sdhci-pltfm.h" @@ -70,6 +71,7 @@ struct sdhci_cdns_priv { spinlock_t wrlock; /* write lock */ bool enhanced_strobe; void (*priv_writel)(struct sdhci_cdns_priv *priv, u32 val, void __iomem *reg); + struct reset_control *rst_hw; unsigned int nr_phy_params; struct sdhci_cdns_phy_param phy_params[]; }; @@ -457,6 +459,22 @@ static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc, SDHCI_CDNS_HRS06_MODE_MMC_HS400); } +static void sdhci_cdns_mmc_hw_reset(struct mmc_host *mmc) +{ + struct sdhci_host *host = mmc_priv(mmc); + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host); + + dev_dbg(mmc_dev(host->mmc), "emmc hardware reset\n"); + + reset_control_assert(priv->rst_hw); + /* For eMMC, minimum is 1us but give it 3us for good measure */ + udelay(3); + + reset_control_deassert(priv->rst_hw); + /* For eMMC, minimum is 200us but give it 300us for good measure */ + usleep_range(300, 1000); +} + static int sdhci_cdns_probe(struct platform_device *pdev) { struct sdhci_host *host; @@ -520,6 +538,15 @@ static int sdhci_cdns_probe(struct platform_device *pdev) if (ret) goto free; + if (host->mmc->caps & MMC_CAP_HW_RESET) { + priv->rst_hw = devm_reset_control_get_optional_exclusive(dev, NULL); + if (IS_ERR(priv->rst_hw)) + return dev_err_probe(mmc_dev(host->mmc), PTR_ERR(priv->rst_hw), + "reset controller error\n"); + if (priv->rst_hw) + host->mmc_host_ops.card_hw_reset = sdhci_cdns_mmc_hw_reset; + } + ret = sdhci_add_host(host); if (ret) goto free; |