SDHC MSM controller need 2x clock for MCLK at GCC.
Hence make required changes to have 2x clock for
DDR timing modes.
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-msm.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 853639b..538594c 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -667,21 +667,35 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
- u32 msm_clock = 0;
+ struct mmc_ios curr_ios = host->mmc->ios;
+ u32 msm_clock, ddr_clock;
int rc = 0;
if (!clock)
goto out;
- if (clock != msm_host->clk_rate) {
- msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
+ msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
+ if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
+ (curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
+ (curr_ios.timing == MMC_TIMING_MMC_HS400)) {
+ /*
+ * The SDHC requires internal clock frequency to be double the
+ * actual clock that will be set for DDR mode. The controller
+ * uses the faster clock(100/400MHz) for some of its parts and
+ * send the actual required clock (50/200MHz) to the card.
+ */
+ ddr_clock = clock * 2;
+ msm_clock = sdhci_msm_get_msm_clk_rate(host, ddr_clock);
+ }
+
+ if (msm_clock != msm_host->clk_rate) {
rc = clk_set_rate(msm_host->clk, msm_clock);
if (rc) {
pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n",
mmc_hostname(host->mmc), msm_clock, clock);
goto out;
}
- msm_host->clk_rate = clock;
+ msm_host->clk_rate = msm_clock;
pr_debug("%s: setting clock at rate %lu\n",
mmc_hostname(host->mmc), clk_get_rate(msm_host->clk));
}
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
