From: Kishon Vijay Abraham I kishon@ti.com
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 | 88 ++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 71 insertions(+), 17 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index fd93691..65a3d8e 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -31,6 +31,7 @@ static const unsigned int sd_au_size[] = { };
static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage); +static int mmc_power_cycle(struct mmc *mmc);
#if CONFIG_IS_ENABLED(MMC_TINY) static struct mmc mmc_static; @@ -1920,25 +1921,83 @@ static int mmc_power_init(struct mmc *mmc) &mmc->vqmmc_supply); if (ret) debug("%s: No vqmmc supply\n", mmc->dev->name); +#endif +#else /* !CONFIG_DM_MMC */ + /* + * Driver model should use a regulator, as above, rather than calling + * out to board code. + */ + board_mmc_power_init(); +#endif + return 0; +} + +/* + * put the host in the initial state: + * - turn on Vdd (card power supply) + * - configure the bus width and clock to minimal values + */ +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("mmc: failed to set signal voltage\n"); + + mmc_select_mode(mmc, MMC_LEGACY); + mmc_set_bus_width(mmc, 1); + mmc_set_clock(mmc, 0); +}
+static int mmc_power_on(struct mmc *mmc) +{ +#if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(DM_REGULATOR) if (mmc->vmmc_supply) { - ret = regulator_set_enable(mmc->vmmc_supply, true); + int ret = regulator_set_enable(mmc->vmmc_supply, true); + if (ret) { puts("Error enabling VMMC supply\n"); return ret; } } #endif -#else /* !CONFIG_DM_MMC */ - /* - * Driver model should use a regulator, as above, rather than calling - * out to board code. - */ - board_mmc_power_init(); + return 0; +} + +static int mmc_power_off(struct mmc *mmc) +{ +#if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(DM_REGULATOR) + if (mmc->vmmc_supply) { + int ret = regulator_set_enable(mmc->vmmc_supply, false); + + if (ret) { + puts("Error disabling VMMC supply\n"); + return ret; + } + } #endif return 0; }
+static int mmc_power_cycle(struct mmc *mmc) +{ + int ret; + + ret = mmc_power_off(mmc); + if (ret) + return ret; + /* + * SD spec recommends at least 1ms of delay. Let's wait for 2ms + * to be on the safer side. + */ + udelay(2000); + return mmc_power_on(mmc); +} + int mmc_start_init(struct mmc *mmc) { bool no_card; @@ -1967,6 +2026,10 @@ int mmc_start_init(struct mmc *mmc) if (err) return err;
+ err = mmc_power_on(mmc); + if (err) + return err; + #if CONFIG_IS_ENABLED(DM_MMC) /* The device has already been probed ready for use */ #else @@ -1977,16 +2040,7 @@ int mmc_start_init(struct mmc *mmc) #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); - + mmc_set_initial_state(mmc); mmc_send_init_stream(mmc);
/* Reset the Card */