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mmc: add power cyle support in mmc core

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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>
This commit is contained in:
Kishon Vijay Abraham I 2017-09-21 16:30:02 +02:00 committed by Jaehoon Chung
parent 318a7a576b
commit fb7c3beb51
1 changed files with 72 additions and 18 deletions
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90
drivers/mmc/mmc.c
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@ -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;
@ -1920,14 +1921,6 @@ static int mmc_power_init(struct mmc *mmc)
&mmc->vqmmc_supply);
if (ret)
debug("%s: No vqmmc supply\n", mmc->dev->name);
if (mmc->vmmc_supply) {
ret = regulator_set_enable(mmc->vmmc_supply, true);
if (ret) {
puts("Error enabling VMMC supply\n");
return ret;
}
}
#endif
#else /* !CONFIG_DM_MMC */
/*
@ -1939,6 +1932,72 @@ static int mmc_power_init(struct mmc *mmc)
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) {
int ret = regulator_set_enable(mmc->vmmc_supply, true);
if (ret) {
puts("Error enabling VMMC supply\n");
return ret;
}
}
#endif
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 */