diff options
| author | Kishon Vijay Abraham I <kishon@ti.com> | 2017-09-21 16:30:02 +0200 |
|---|---|---|
| committer | Jaehoon Chung <jh80.chung@samsung.com> | 2018-01-12 18:11:04 +0900 |
| commit | fb7c3beb5178e5c81a00642e71a4b73427b52429 (patch) | |
| tree | 5b0bce50a8636b9bf6d43e3e8e751746dde16067 /drivers/mmc/mmc.c | |
| parent | 318a7a576bc49aa8b4207e694d3fbd48c663d6ac (diff) | |
mmc: add power cyle support in mmc core
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>
Diffstat (limited to 'drivers/mmc/mmc.c')
| -rw-r--r-- | drivers/mmc/mmc.c | 88 |
1 files changed, 71 insertions, 17 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 1875b31ad1..0ffe7bf417 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 */ |