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Subject[PATCH v5 10/10] mmc: sdhci-omap: Add special reset capability
Date
Some omap controllers need software to monitor a 0->1->0 for software
reset. Add a SDHCI_OMAP_SPECIAL_RESET flag to indicate this.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/host/sdhci-omap.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 5433c9e6ac10..882053151a47 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -86,6 +86,7 @@

/* sdhci-omap controller flags */
#define SDHCI_OMAP_REQUIRE_IODELAY BIT(0)
+#define SDHCI_OMAP_SPECIAL_RESET BIT(1)

struct sdhci_omap_data {
u32 offset;
@@ -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->flags & SDHCI_OMAP_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);
}

@@ -900,10 +921,12 @@ static const struct sdhci_omap_data k2g_data = {

static const struct sdhci_omap_data am335_data = {
.offset = 0x200,
+ .flags = SDHCI_OMAP_SPECIAL_RESET,
};

static const struct sdhci_omap_data am437_data = {
.offset = 0x200,
+ .flags = SDHCI_OMAP_SPECIAL_RESET,
};

static const struct sdhci_omap_data dra7_data = {
--
2.19.2
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