mmc: Enable signal voltage to be selected from mmc core
Add a new function *mmc_set_signal_voltage* in mmc core
which can be used during mmc initialization to select the
signal voltage. Platform driver should use the set_ios
callback function to select the signal voltage.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 588cfb2..24b5e16 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -30,6 +30,8 @@
SZ_16M / 512, (SZ_16M + SZ_8M) / 512, SZ_32M / 512, SZ_64M / 512,
};
+static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage);
+
#if CONFIG_IS_ENABLED(MMC_TINY)
static struct mmc mmc_static;
struct mmc *find_mmc_device(int dev_num)
@@ -1257,6 +1259,12 @@
uint widths;
};
+static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage)
+{
+ mmc->signal_voltage = signal_voltage;
+ return mmc_set_ios(mmc);
+}
+
static const struct mode_width_tuning sd_modes_by_pref[] = {
{
.mode = SD_HS,
@@ -1964,6 +1972,14 @@
return err;
#endif
mmc->ddr_mode = 0;
+
+ /* First try to set 3.3V. If it fails set to 1.8V */
+ err = mmc_set_signal_voltage(mmc, MMC_SIGNAL_VOLTAGE_330);
+ if (err != 0)
+ err = mmc_set_signal_voltage(mmc, MMC_SIGNAL_VOLTAGE_180);
+ if (err != 0)
+ printf("failed to set signal voltage\n");
+
mmc_set_bus_width(mmc, 1);
mmc_set_clock(mmc, 1);
diff --git a/include/mmc.h b/include/mmc.h
index 3e57887..e524963 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -272,6 +272,13 @@
#define ENHNCD_SUPPORT (0x2)
#define PART_ENH_ATTRIB (0x1f)
+enum mmc_voltage {
+ MMC_SIGNAL_VOLTAGE_000 = 0,
+ MMC_SIGNAL_VOLTAGE_120,
+ MMC_SIGNAL_VOLTAGE_180,
+ MMC_SIGNAL_VOLTAGE_330
+};
+
/* Maximum block size for MMC */
#define MMC_MAX_BLOCK_LEN 512
@@ -457,6 +464,7 @@
int high_capacity;
uint bus_width;
uint clock;
+ enum mmc_voltage signal_voltage;
uint card_caps;
uint ocr;
uint dsr;