On 15/05/2017 05:28, Simon Glass wrote:
Hi Jen-Jacques,
On 12 May 2017 at 12:16, Jean-Jacques Hiblot <[email protected]> wrote:
From: Kishon Vijay Abraham I <[email protected]>
Add a new function *mmc_set_signal_voltage* in mmc core
which can be used during mmc initialization to select the
signal voltage. Platform driver should use the set_ios
callback function to select the signal voltage.
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
---
drivers/mmc/mmc.c | 15 +++++++++++++++
include/mmc.h | 5 +++++
2 files changed, 20 insertions(+)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 2ae6f1c..10af81d 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -29,6 +29,7 @@ static const unsigned int sd_au_size[] = {
SZ_4M / 512, SZ_8M / 512, (SZ_8M + SZ_4M) / 512,
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);
#if CONFIG_IS_ENABLED(MMC_TINY)
static struct mmc mmc_static;
@@ -1247,6 +1248,12 @@ struct mode_width_tuning {
uint widths;
};
+static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage)
+{
+ mmc->signal_voltage = signal_voltage;
+ return mmc_set_ios(mmc);
+}
+
static const struct mode_width_tuning sd_modes_by_pref[] = {
{
.mode = SD_HS,
@@ -1935,6 +1942,14 @@ int mmc_start_init(struct mmc *mmc)
return err;
#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");
Return error?
Maybe we should. I don't know.
Setting signal voltage is optional (at least for most modes), some
platforms don't support it. So I wouldn't exit on this kind of error.
Those 2 calls to mmc_set_signal_voltage() are here merely to turn on
regulators before doing the card init. If setting voltage is required
and fails, the init process won't go very far.
+
mmc_set_bus_width(mmc, 1);
mmc_set_clock(mmc, 1);
diff --git a/include/mmc.h b/include/mmc.h
index 9f20eb4..89cb26c 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -266,6 +266,10 @@
#define ENHNCD_SUPPORT (0x2)
#define PART_ENH_ATTRIB (0x1f)
+#define MMC_SIGNAL_VOLTAGE_330 1
+#define MMC_SIGNAL_VOLTAGE_180 2
+#define MMC_SIGNAL_VOLTAGE_120 3
+
/* Maximum block size for MMC */
#define MMC_MAX_BLOCK_LEN 512
@@ -452,6 +456,7 @@ struct mmc {
int high_capacity;
uint bus_width;
uint clock;
+ uint signal_voltage;
Comment. What does this value mean? What units is it? Millivolts or
something else?
it's more an enum than a value with a physical meaning (like mV). I'll
change this in the next version to be a real enum.
uint card_caps;
uint ocr;
uint dsr;
--
1.9.1
Regards,
Simon
_______________________________________________
U-Boot mailing list
[email protected]
https://lists.denx.de/listinfo/u-boot
