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authorKishon Vijay Abraham I <kishon@ti.com>2017-09-21 16:30:00 +0200
committerJaehoon Chung <jh80.chung@samsung.com>2018-01-12 18:11:04 +0900
commitaff5d3c83fb8c294b3c4b97c5b6386306b47f1a0 (patch)
tree77ca6c45a1fe42319577c1e6ca456c6dfab8c925 /drivers/mmc/mmc.c
parent2a4d212f7110712f51ae8af73abbdb0ae2af0814 (diff)
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>
Diffstat (limited to 'drivers/mmc/mmc.c')
-rw-r--r--drivers/mmc/mmc.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 588cfb2b2e..24b5e16a3b 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -30,6 +30,8 @@ static const unsigned int sd_au_size[] = {
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 @@ struct mode_width_tuning {
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 @@ int mmc_start_init(struct mmc *mmc)
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);