ARM: 7724/1: mmc: mmci: Support signal voltage switch for UHS cards

Add .start_signal_voltage_switch callback to be able to support UHS cards.
The voltage switch requires the optional vqmmc regulator to exist since
the actual voltage switch will be performed directly on it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a8bbdd1c4314..cb9e562b3571 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1266,6 +1266,39 @@ static int mmci_get_cd(struct mmc_host *mmc)
         return status;
 }
 
+static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+        int ret = 0;
+
+        if (!IS_ERR(mmc->supply.vqmmc)) {
+
+                pm_runtime_get_sync(mmc_dev(mmc));
+
+                switch (ios->signal_voltage) {
+                case MMC_SIGNAL_VOLTAGE_330:
+                        ret = regulator_set_voltage(mmc->supply.vqmmc,
+                                                2700000, 3600000);
+                        break;
+                case MMC_SIGNAL_VOLTAGE_180:
+                        ret = regulator_set_voltage(mmc->supply.vqmmc,
+                                                1700000, 1950000);
+                        break;
+                case MMC_SIGNAL_VOLTAGE_120:
+                        ret = regulator_set_voltage(mmc->supply.vqmmc,
+                                                1100000, 1300000);
+                        break;
+                }
+
+                if (ret)
+                        dev_warn(mmc_dev(mmc), "Voltage switch failed\n");
+
+                pm_runtime_mark_last_busy(mmc_dev(mmc));
+                pm_runtime_put_autosuspend(mmc_dev(mmc));
+        }
+
+        return ret;
+}
+
 static irqreturn_t mmci_cd_irq(int irq, void *dev_id)
 {
         struct mmci_host *host = dev_id;
@@ -1282,6 +1315,7 @@ static const struct mmc_host_ops mmci_ops = {
         .set_ios        = mmci_set_ios,
         .get_ro         = mmci_get_ro,
         .get_cd         = mmci_get_cd,
+        .start_signal_voltage_switch = mmci_sig_volt_switch,
 };
 
 #ifdef CONFIG_OF