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| author | yangbo lu <yangbo.lu@nxp.com> | 2017-09-21 16:43:31 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2017-10-30 11:40:09 +0100 |
| commit | dd3f6983b4a468efca9e8caa0e2b4aa20946d801 (patch) | |
| tree | e5767b670d684dcea6f8e6ce0958b1e281c13381 | |
| parent | cdaba732ff2fde83685bce889eddc70964404381 (diff) | |
| download | linux-dd3f6983b4a468efca9e8caa0e2b4aa20946d801.tar.bz2 | |
mmc: sdhci-of-esdhc: disable SD clock for clock value 0
SD clock should be disabled for clock value 0. It's not
right to just return. This may cause failure of signal
voltage switching.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/host/sdhci-of-esdhc.c | 58 |
1 files changed, 30 insertions, 28 deletions
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index d96a057a7db8..1f424374bbbb 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -458,6 +458,33 @@ static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host) return clock / 256 / 16; } +static void esdhc_clock_enable(struct sdhci_host *host, bool enable) +{ + u32 val; + ktime_t timeout; + + val = sdhci_readl(host, ESDHC_SYSTEM_CONTROL); + + if (enable) + val |= ESDHC_CLOCK_SDCLKEN; + else + val &= ~ESDHC_CLOCK_SDCLKEN; + + sdhci_writel(host, val, ESDHC_SYSTEM_CONTROL); + + /* Wait max 20 ms */ + timeout = ktime_add_ms(ktime_get(), 20); + val = ESDHC_CLOCK_STABLE; + while (!(sdhci_readl(host, ESDHC_PRSSTAT) & val)) { + if (ktime_after(ktime_get(), timeout)) { + pr_err("%s: Internal clock never stabilised.\n", + mmc_hostname(host->mmc)); + break; + } + udelay(10); + } +} + static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); @@ -469,8 +496,10 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) host->mmc->actual_clock = 0; - if (clock == 0) + if (clock == 0) { + esdhc_clock_enable(host, false); return; + } /* Workaround to start pre_div at 2 for VNN < VENDOR_V_23 */ if (esdhc->vendor_ver < VENDOR_V_23) @@ -558,33 +587,6 @@ static void esdhc_pltfm_set_bus_width(struct sdhci_host *host, int width) sdhci_writel(host, ctrl, ESDHC_PROCTL); } -static void esdhc_clock_enable(struct sdhci_host *host, bool enable) -{ - u32 val; - ktime_t timeout; - - val = sdhci_readl(host, ESDHC_SYSTEM_CONTROL); - - if (enable) - val |= ESDHC_CLOCK_SDCLKEN; - else - val &= ~ESDHC_CLOCK_SDCLKEN; - - sdhci_writel(host, val, ESDHC_SYSTEM_CONTROL); - - /* Wait max 20 ms */ - timeout = ktime_add_ms(ktime_get(), 20); - val = ESDHC_CLOCK_STABLE; - while (!(sdhci_readl(host, ESDHC_PRSSTAT) & val)) { - if (ktime_after(ktime_get(), timeout)) { - pr_err("%s: Internal clock never stabilised.\n", - mmc_hostname(host->mmc)); - break; - } - udelay(10); - } -} - static void esdhc_reset(struct sdhci_host *host, u8 mask) { sdhci_reset(host, mask); |