mmc/sd specification requires vdd to be disabled for 1 ms and then enabled again during power cycle. Add a function in mmc core to perform power cycle and set the io signal to it's initial state.
Signed-off-by: Kishon Vijay Abraham I kishon@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com --- drivers/mmc/mmc.c | 50 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 41 insertions(+), 9 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index d40a22b..032260b 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -30,6 +30,7 @@ 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); +static void mmc_power_cycle(struct mmc *mmc);
#if CONFIG_IS_ENABLED(MMC_TINY) static struct mmc mmc_static; @@ -1915,6 +1916,45 @@ static int mmc_power_init(struct mmc *mmc) return 0; }
+static void mmc_set_initial_state(struct mmc *mmc) +{ + int err; + + /* 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); + mmc_select_mode(mmc, MMC_LEGACY); +} + +static void mmc_power_up(struct mmc *mmc) +{ + mmc_set_initial_state(mmc); + mmc_set_vdd(mmc, true); + udelay(10000); +} + +static void mmc_power_off(struct mmc *mmc) +{ + mmc_set_vdd(mmc, false); +} + +static void mmc_power_cycle(struct mmc *mmc) +{ + mmc_power_off(mmc); + /* + * SD spec recommends at least 1ms of delay. Let's wait for 2ms + * to be on the safer side. + */ + udelay(2000); + mmc_power_up(mmc); +} + int mmc_start_init(struct mmc *mmc) { bool no_card; @@ -1952,16 +1992,8 @@ int mmc_start_init(struct mmc *mmc) return err; #endif mmc->ddr_mode = 0; - mmc_set_vdd(mmc, true); - /* 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); + mmc_power_cycle(mmc);
/* Reset the Card */ err = mmc_go_idle(mmc);