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| author | Yangbo Lu <yangbo.lu@freescale.com> | 2015-08-11 05:53:34 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2015-08-27 15:50:49 +0300 |
| commit | 77bd2f6f6c65b4ad259394d416855ed561f21e8f (patch) | |
| tree | 1ebaf54fa3e5cb0fccdfc54545dc5f2da8417af7 /drivers/mmc | |
| parent | d31911b9374a76560d2c8ea4aa6ce5781621e81d (diff) | |
| download | linux-77bd2f6f6c65b4ad259394d416855ed561f21e8f.tar.xz | |
mmc: sdhci-of-esdhc: add workaround for pre divider initial value
For eSDHC(version < 2.3), the pre divider only could divide base clock
by 2 at least. Add workaround for this to avoid unexpected issue.
Signed-off-by: Yangbo Lu <yangbo.lu@freescale.com>
Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Fixes: bd455029d01c ("mmc: sdhci-of-esdhc: Pre divider starts at 1")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-esdhc.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index 797be7549a15..653f335bef15 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -208,6 +208,12 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) if (clock == 0) return; + /* Workaround to start pre_div at 2 for VNN < VENDOR_V_23 */ + temp = esdhc_readw(host, SDHCI_HOST_VERSION); + temp = (temp & SDHCI_VENDOR_VER_MASK) >> SDHCI_VENDOR_VER_SHIFT; + if (temp < VENDOR_V_23) + pre_div = 2; + /* Workaround to reduce the clock frequency for p1010 esdhc */ if (of_find_compatible_node(NULL, NULL, "fsl,p1010-esdhc")) { if (clock > 20000000) |