summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorRitesh Harjani <riteshh@codeaurora.org>2016-07-19 17:52:25 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2016-07-25 10:35:02 +0200
commitee3206748952046e90cf0dcdcffdbb94839289b4 (patch)
treeaa0cf00151eedd4c9dc6fc194d11a68fa618d106 /drivers
parent9718f84b85396e090ca42fafa730410d286d61e3 (diff)
mmc: sdhci-msm: Add set_uhs_signaling() implementation
To allow UHS mode to work properly, we need to implement a Qualcomm specific set_uhs_signaling() callback function. This function differs from the sdhci_set_uhs_signaling() in that we need check the clock rate and enable UHS timing only if the frequency is above 100MHz. This patch resolves the mmc_select_hs200 timeouts noticed after merging commit a5c1f3e55c99 ("mmc: mmc: do not use CMD13 to get status after speed mode switch") mmc0: mmc_select_hs200 failed, error -110 mmc0: error -110 whilst initialising MMC card mmc0: Reset 0x1 never completed. sdhci: =========== REGISTER DUMP (mmc0)=========== sdhci: Sys addr: 0x00000000 | Version: 0x00002e02 sdhci: Blk size: 0x00004000 | Blk cnt: 0x00000000 sdhci: Argument: 0x00000000 | Trn mode: 0x00000000 sdhci: Present: 0x01f80000 | Host ctl: 0x00000000 sdhci: Power: 0x00000000 | Blk gap: 0x00000000 sdhci: Wake-up: 0x00000000 | Clock: 0x00000003 sdhci: Timeout: 0x00000000 | Int stat: 0x00000000 sdhci: Int enab: 0x00000000 | Sig enab: 0x00000000 sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000 sdhci: Caps: 0x322dc8b2 | Caps_1: 0x00008007 sdhci: Cmd: 0x00000000 | Max curr: 0x00000000 sdhci: Host ctl2: 0x00000000 sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x0000000000000000 sdhci: =========================================== Fixes: a5c1f3e55c99 ("mmc: mmc: do not use CMD13 to get status after...") Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/host/sdhci-msm.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index cc4274a023fd..1f59f0008930 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -410,6 +410,52 @@ retry:
return rc;
}
+static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
+ unsigned int uhs)
+{
+ struct mmc_host *mmc = host->mmc;
+ u16 ctrl_2;
+
+ ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ /* Select Bus Speed Mode for host */
+ ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
+ switch (uhs) {
+ case MMC_TIMING_UHS_SDR12:
+ ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
+ break;
+ case MMC_TIMING_UHS_SDR25:
+ ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
+ break;
+ case MMC_TIMING_UHS_SDR50:
+ ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
+ break;
+ case MMC_TIMING_MMC_HS200:
+ case MMC_TIMING_UHS_SDR104:
+ ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
+ break;
+ case MMC_TIMING_UHS_DDR50:
+ case MMC_TIMING_MMC_DDR52:
+ ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
+ break;
+ }
+
+ /*
+ * When clock frequency is less than 100MHz, the feedback clock must be
+ * provided and DLL must not be used so that tuning can be skipped. To
+ * provide feedback clock, the mode selection can be any value less
+ * than 3'b011 in bits [2:0] of HOST CONTROL2 register.
+ */
+ if (host->clock <= 100000000 &&
+ (uhs == MMC_TIMING_MMC_HS400 ||
+ uhs == MMC_TIMING_MMC_HS200 ||
+ uhs == MMC_TIMING_UHS_SDR104))
+ ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
+
+ dev_dbg(mmc_dev(mmc), "%s: clock=%u uhs=%u ctrl_2=0x%x\n",
+ mmc_hostname(host->mmc), host->clock, uhs, ctrl_2);
+ sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+}
+
static const struct of_device_id sdhci_msm_dt_match[] = {
{ .compatible = "qcom,sdhci-msm-v4" },
{},
@@ -422,7 +468,7 @@ static const struct sdhci_ops sdhci_msm_ops = {
.reset = sdhci_reset,
.set_clock = sdhci_set_clock,
.set_bus_width = sdhci_set_bus_width,
- .set_uhs_signaling = sdhci_set_uhs_signaling,
+ .set_uhs_signaling = sdhci_msm_set_uhs_signaling,
};
static const struct sdhci_pltfm_data sdhci_msm_pdata = {