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| author |   Helmut Grohne <h.grohne@intenta.de> | 2018-06-20 13:33:00 +0200 |
|---|---|---|
| committer |   Ulf Hansson <ulf.hansson@linaro.org> | 2018-07-16 11:21:45 +0200 |
| commit | 3f2c7d5d158d7df430b5763674be9e0b834dfd6f (patch) | |
| tree | cf64451cd5c72025e5d388d2c63af2e0537d8479 /drivers/mmc | |
| parent | dt-bindings: mmc: broken clock stable indicator on arasan controllers (diff) | |
| download | linux-dev-3f2c7d5d158d7df430b5763674be9e0b834dfd6f.tar.xz linux-dev-3f2c7d5d158d7df430b5763674be9e0b834dfd6f.zip | |
mmc: sdhci-of-arasan: Add quirk for unstable clocks
Some controllers immediately report SDHCI_CLOCK_INT_STABLE after
enabling the clock even when the clock is not stable. When used in
conjunction with older/slower cards, this can result in:
mmc0: error -84 whilst initialising SD card
When the stable reporting is known to be broken, we simply wait for the
maximum stabilization period.
Signed-off-by: Helmut Grohne <h.grohne@intenta.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-arasan.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index e3332a522a5d..a40bcc27f187 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -102,6 +102,9 @@ struct sdhci_arasan_data { /* Controller does not have CD wired and will not function normally without */ #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST BIT(0) +/* Controller immediately reports SDHCI_CLOCK_INT_STABLE after enabling the + * internal clock even when the clock isn't stable */ +#define SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE BIT(1) }; static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = { @@ -207,6 +210,16 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) sdhci_set_clock(host, clock); + if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE) + /* + * Some controllers immediately report SDHCI_CLOCK_INT_STABLE + * after enabling the clock even though the clock is not + * stable. Trying to use a clock without waiting here results + * in EILSEQ while detecting some older/slower cards. The + * chosen delay is the maximum delay from sdhci_set_clock. + */ + msleep(20); + if (ctrl_phy) { phy_power_on(sdhci_arasan->phy); sdhci_arasan->is_phy_on = true; @@ -758,6 +771,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev) if (of_property_read_bool(np, "xlnx,fails-without-test-cd")) sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_FORCE_CDTEST; + if (of_property_read_bool(np, "xlnx,int-clock-stable-broken")) + sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE; + pltfm_host->clk = clk_xin; if (of_device_is_compatible(pdev->dev.of_node, |