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Subject[PATCH v4 09/11] mmc: sdhci-omap: Add ti,needs-special-reset property
Date
Some omap controllers need software to monitor a 0->1->0 for software
reset. Add a ti,needs-special-reset property to indicate this and use
the special_reset member to indicate when a controller needs this.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
---
drivers/mmc/host/sdhci-omap.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 1f05c8e98d62..34df30edd450 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -107,6 +107,7 @@ struct sdhci_omap_host {
struct pinctrl *pinctrl;
struct pinctrl_state **pinctrl_state;
bool is_tuning;
+ bool special_reset;
};

static void sdhci_omap_start_clock(struct sdhci_omap_host *omap_host);
@@ -779,15 +780,35 @@ static void sdhci_omap_set_uhs_signaling(struct sdhci_host *host,
sdhci_omap_start_clock(omap_host);
}

+#define MMC_TIMEOUT_US 20000 /* 20000 micro Sec */
static void sdhci_omap_reset(struct sdhci_host *host, u8 mask)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+ unsigned long limit = MMC_TIMEOUT_US;
+ unsigned long i = 0;

/* Don't reset data lines during tuning operation */
if (omap_host->is_tuning)
mask &= ~SDHCI_RESET_DATA;

+ if (omap_host->special_reset) {
+ sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
+ while ((!(sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)) &&
+ (i++ < limit))
+ udelay(1);
+ i = 0;
+ while ((sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) &&
+ (i++ < limit))
+ udelay(1);
+
+ if (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)
+ dev_err(mmc_dev(host->mmc),
+ "Timeout waiting on controller reset in %s\n",
+ __func__);
+ return;
+ }
+
sdhci_reset(host, mask);
}

@@ -1107,6 +1128,9 @@ static int sdhci_omap_probe(struct platform_device *pdev)
if (!mmc_can_gpio_ro(mmc))
mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;

+ if (of_find_property(dev->of_node, "ti,needs-special-reset", NULL))
+ omap_host->special_reset = true;
+
pltfm_host->clk = devm_clk_get(dev, "fck");
if (IS_ERR(pltfm_host->clk)) {
ret = PTR_ERR(pltfm_host->clk);
--
2.19.2
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