On 15/05/2017 05:28, Simon Glass wrote:
Hi,
On 12 May 2017 at 12:16, Jean-Jacques Hiblot jjhiblot@ti.com wrote:
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)
Function comment
OK
+{
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);Eek. Please add a comment as to why
This is to let the Vdd time to settle. I'll remove this for the next version. If a delay is required by the platform it can be handled by the host driver.
+}
+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");Return error? Also please add some mmc: to your message.
mmc_set_bus_width(mmc, 1);mmc_set_clock(mmc, 1);
mmc_power_cycle(mmc); /* Reset the Card */ err = mmc_go_idle(mmc);-- 1.9.1
Regards, Simon