mmc: Change mode when switching to a boot partition
Boot partitions do not support HS200. Changing to a lower performance mode
is required to access them.
mmc_select_mode_and_width() and sd_select_mode_and_width() are modified to
make it easier to call them outside of the initialization context.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index dbd9594..6278d1f 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -32,6 +32,7 @@
static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage);
static int mmc_power_cycle(struct mmc *mmc);
+static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps);
#if CONFIG_IS_ENABLED(MMC_TINY)
static struct mmc mmc_static;
@@ -792,10 +793,38 @@
return 0;
}
+static int mmc_boot_part_access_chk(struct mmc *mmc, unsigned int part_num)
+{
+ int forbidden = 0;
+ bool change = false;
+
+ if (part_num & PART_ACCESS_MASK)
+ forbidden = MMC_CAP(MMC_HS_200);
+
+ if (MMC_CAP(mmc->selected_mode) & forbidden) {
+ debug("selected mode (%s) is forbidden for part %d\n",
+ mmc_mode_name(mmc->selected_mode), part_num);
+ change = true;
+ } else if (mmc->selected_mode != mmc->best_mode) {
+ debug("selected mode is not optimal\n");
+ change = true;
+ }
+
+ if (change)
+ return mmc_select_mode_and_width(mmc,
+ mmc->card_caps & ~forbidden);
+
+ return 0;
+}
+
int mmc_switch_part(struct mmc *mmc, unsigned int part_num)
{
int ret;
+ ret = mmc_boot_part_access_chk(mmc, part_num);
+ if (ret)
+ return ret;
+
ret = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF,
(mmc->part_config & ~PART_ACCESS_MASK)
| (part_num & PART_ACCESS_MASK));
@@ -1438,7 +1467,7 @@
mwt++) \
if (caps & MMC_CAP(mwt->mode))
-static int sd_select_mode_and_width(struct mmc *mmc)
+static int sd_select_mode_and_width(struct mmc *mmc, uint card_caps)
{
int err;
uint widths[] = {MMC_MODE_4BIT, MMC_MODE_1BIT};
@@ -1447,11 +1476,8 @@
uint caps;
- err = sd_get_capabilities(mmc);
- if (err)
- return err;
/* Restrict card's capabilities by what the host can do */
- caps = mmc->card_caps & (mmc->host_caps | MMC_MODE_1BIT);
+ caps = card_caps & (mmc->host_caps | MMC_MODE_1BIT);
if (!uhs_en)
caps &= ~UHS_CAPS;
@@ -1588,18 +1614,14 @@
ecbv++) \
if ((ddr == ecbv->is_ddr) && (caps & ecbv->cap))
-static int mmc_select_mode_and_width(struct mmc *mmc)
+static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps)
{
int err;
const struct mode_width_tuning *mwt;
const struct ext_csd_bus_width *ecbw;
- err = mmc_get_capabilities(mmc);
- if (err)
- return err;
-
/* Restrict card's capabilities by what the host can do */
- mmc->card_caps &= (mmc->host_caps | MMC_MODE_1BIT);
+ card_caps &= (mmc->host_caps | MMC_MODE_1BIT);
/* Only version 4 of MMC supports wider bus widths */
if (mmc->version < MMC_VERSION_4)
@@ -1610,8 +1632,10 @@
return -ENOTSUPP;
}
- for_each_mmc_mode_by_pref(mmc->card_caps, mwt) {
- for_each_supported_width(mmc->card_caps & mwt->widths,
+ mmc_set_clock(mmc, mmc->legacy_speed, false);
+
+ for_each_mmc_mode_by_pref(card_caps, mwt) {
+ for_each_supported_width(card_caps & mwt->widths,
mmc_is_mode_ddr(mwt->mode), ecbw) {
debug("trying mode %s width %d (at %d MHz)\n",
mmc_mode_name(mwt->mode),
@@ -2006,14 +2030,22 @@
if (err)
return err;
- if (IS_SD(mmc))
- err = sd_select_mode_and_width(mmc);
- else
- err = mmc_select_mode_and_width(mmc);
+ if (IS_SD(mmc)) {
+ err = sd_get_capabilities(mmc);
+ if (err)
+ return err;
+ err = sd_select_mode_and_width(mmc, mmc->card_caps);
+ } else {
+ err = mmc_get_capabilities(mmc);
+ if (err)
+ return err;
+ mmc_select_mode_and_width(mmc, mmc->card_caps);
+ }
if (err)
return err;
+ mmc->best_mode = mmc->selected_mode;
/* Fix the block length for DDR mode */
if (mmc->ddr_mode) {
diff --git a/include/mmc.h b/include/mmc.h
index 59ea363..a8901bf 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -585,7 +585,12 @@
#endif
#endif
u8 *ext_csd;
- enum bus_mode selected_mode;
+ enum bus_mode selected_mode; /* mode currently used */
+ enum bus_mode best_mode; /* best mode is the supported mode with the
+ * highest bandwidth. It may not always be the
+ * operating mode due to limitations when
+ * accessing the boot partitions
+ */
};
struct mmc_hwpart_conf {