summaryrefslogtreecommitdiff
path: root/drivers/mmc
diff options
context:
space:
mode:
authorRitesh Harjani <riteshh@codeaurora.org>2020-02-07 17:34:28 +0530
committerUlf Hansson <ulf.hansson@linaro.org>2020-03-24 14:35:39 +0100
commit219c02ca1cf65c457f31ec32523a75972019a862 (patch)
treec5411e26de5943f79f1976b0213db6ca588f46d2 /drivers/mmc
parent2a2b821607aea16c9c20f9f4d45096dc860fd33a (diff)
mmc: sdhci-msm: Don't enable PWRSAVE_DLL for certain sdhc hosts
SDHC core with new 14lpp and later tech DLL should not enable PWRSAVE_DLL since such controller's internal gating cannot meet following MCLK requirement: When MCLK is gated OFF, it is not gated for less than 0.5us and MCLK must be switched on for at-least 1us before DATA starts coming. Adding support for this requirement. Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org> Reviewed-by: Can Guo <cang@codeaurora.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/1581077075-26011-1-git-send-email-vbadigan@codeaurora.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-msm.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 3955fa5db43c..53b79ee37fdd 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -977,9 +977,21 @@ static int sdhci_msm_cm_dll_sdc4_calibration(struct sdhci_host *host)
goto out;
}
- config = readl_relaxed(host->ioaddr + msm_offset->core_vendor_spec3);
- config |= CORE_PWRSAVE_DLL;
- writel_relaxed(config, host->ioaddr + msm_offset->core_vendor_spec3);
+ /*
+ * Set CORE_PWRSAVE_DLL bit in CORE_VENDOR_SPEC3.
+ * When MCLK is gated OFF, it is not gated for less than 0.5us
+ * and MCLK must be switched on for at-least 1us before DATA
+ * starts coming. Controllers with 14lpp and later tech DLL cannot
+ * guarantee above requirement. So PWRSAVE_DLL should not be
+ * turned on for host controllers using this DLL.
+ */
+ if (!msm_host->use_14lpp_dll_reset) {
+ config = readl_relaxed(host->ioaddr +
+ msm_offset->core_vendor_spec3);
+ config |= CORE_PWRSAVE_DLL;
+ writel_relaxed(config, host->ioaddr +
+ msm_offset->core_vendor_spec3);
+ }
/*
* Drain writebuffer to ensure above DLL calibration