Implement voltage switch callback (shamelessly copied from sunxi mmc
driver). This allow, with the appropriate tuning function, to use
SD ultra high speed modes.
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/mmc/host/meson-gx-mmc.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index e991c9e452ab..de2d7b8a9d97 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -38,6 +38,8 @@
#include <linux/interrupt.h>
#include <linux/bitfield.h>
+#include <linux/delay.h>
+
#define DRIVER_NAME "meson-gx-mmc"
#define SD_EMMC_CLOCK 0x0
@@ -1024,6 +1026,28 @@ static int meson_mmc_card_busy(struct mmc_host *mmc)
return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
}
+static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ /* vqmmc regulator is available */
+ if (!IS_ERR(mmc->supply.vqmmc)) {
+ /*
+ * The usual amlogic setup uses a GPIO to switch from one
+ * regulator to the other. While the voltage ramp up is
+ * pretty fast, care must be taken when switching from 3.3v
+ * to 1.8v. Please make sure the regulator framework is aware
+ * of your own regulator constraints
+ */
+ return mmc_regulator_set_vqmmc(mmc, ios);
+
+ }
+
+ /* no vqmmc regulator, assume fixed regulator at 3/3.3V */
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+ return 0;
+
+ return -EINVAL;
+}
+
static const struct mmc_host_ops meson_mmc_ops = {
.request = meson_mmc_request,
.set_ios = meson_mmc_set_ios,
@@ -1032,6 +1056,7 @@ static const struct mmc_host_ops meson_mmc_ops = {
.post_req = meson_mmc_post_req,
.execute_tuning = meson_mmc_execute_tuning,
.card_busy = meson_mmc_card_busy,
+ .start_signal_voltage_switch = meson_mmc_voltage_switch,
};
static int meson_mmc_probe(struct platform_device *pdev)
--
2.9.4
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