mmc: sdhci-pci: Fix voltage switch for some Intel host controllers

commit 6ae033689d7b1a419def78e8e990b0eab8bb6419 upstream.

Some Intel host controllers (e.g. CNP) use an ACPI device-specific method
to ensure correct voltage switching. Fix voltage switch for those, by
adding a call to the DSM.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index e1721ac37919b619cbd02389ea1ad7fc6723643d..ba8a0f58fe0815041d09517414956f9d95ad9acc 100644 (file)
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -393,6 +393,7 @@ static const struct sdhci_pci_fixes sdhci_intel_pch_sdio = {
 
 enum {
        INTEL_DSM_FNS           =  0,
+       INTEL_DSM_V18_SWITCH    =  3,
        INTEL_DSM_DRV_STRENGTH  =  9,
        INTEL_DSM_D3_RETUNE     = 10,
 };
@@ -558,6 +559,19 @@ static void intel_hs400_enhanced_strobe(struct mmc_host *mmc,
        sdhci_writel(host, val, INTEL_HS400_ES_REG);
 }
 
+static void sdhci_intel_voltage_switch(struct sdhci_host *host)
+{
+       struct sdhci_pci_slot *slot = sdhci_priv(host);
+       struct intel_host *intel_host = sdhci_pci_priv(slot);
+       struct device *dev = &slot->chip->pdev->dev;
+       u32 result = 0;
+       int err;
+
+       err = intel_dsm(intel_host, dev, INTEL_DSM_V18_SWITCH, &result);
+       pr_debug("%s: %s DSM error %d result %u\n",
+                mmc_hostname(host->mmc), __func__, err, result);
+}
+
 static const struct sdhci_ops sdhci_intel_byt_ops = {
        .set_clock              = sdhci_set_clock,
        .set_power              = sdhci_intel_set_power,
@@ -566,6 +580,7 @@ static const struct sdhci_ops sdhci_intel_byt_ops = {
        .reset                  = sdhci_reset,
        .set_uhs_signaling      = sdhci_set_uhs_signaling,
        .hw_reset               = sdhci_pci_hw_reset,
+       .voltage_switch         = sdhci_intel_voltage_switch,
 };
 
 static void byt_read_dsm(struct sdhci_pci_slot *slot)