From: cmachida curtis.machida@intel.com
According to the SD Host Controller Simplified Specification v4.20, the multiplier value M is one more than the Clock Multiplier field.
Copied code from Linux project. drivers/mmc/host/sdhci.c line 4405
Signed-off-by: cmachida curtis.machida@intel.com ---
drivers/mmc/sdhci.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c index 0178ed8a11..a8476ec4e9 100644 --- a/drivers/mmc/sdhci.c +++ b/drivers/mmc/sdhci.c @@ -929,6 +929,15 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host, debug("%s, caps_1: 0x%x\n", __func__, caps_1); host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT; + + /* + * In case the value in Clock Multiplier is 0, then programmable + * clock mode is not supported, otherwise the actual clock + * multiplier is one more than the value of Clock Multiplier + * in the Capabilities Register. + */ + if (host->clk_mul) + host->clk_mul += 1; }
if (host->max_clk == 0) {