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authorAdrian Hunter <adrian.hunter@intel.com>2017-09-25 11:29:04 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2017-10-30 11:45:57 +0100
commit6a11fc47f175c8d87018e89cb58e2d36c66534cb (patch)
tree99e66a5bc89c10e724bb463ac37873f0455ff13e /drivers/mmc/core
parent3f496afb6fb361b282f37968ff7d3d80b0f1b5cb (diff)
downloadop-kernel-dev-6a11fc47f175c8d87018e89cb58e2d36c66534cb.zip
op-kernel-dev-6a11fc47f175c8d87018e89cb58e2d36c66534cb.tar.gz
mmc: sd: Fix signal voltage when there is no power cycle
Some boards have SD card connectors where the power rail cannot be switched off by the driver. However there are various circumstances when a card might be re-initialized, such as after system resume, warm re-boot, or error handling. However, a UHS card will continue to use 1.8V signaling unless it is power cycled. If the card has not been power cycled, it may still be using 1.8V signaling. According to the SD spec., the Bus Speed Mode (function group 1) bits 2 to 4 are zero if the card is initialized at 3.3V signal level. Thus they can be used to determine if the card has already switched to 1.8V signaling. Detect that situation and try to initialize a UHS-I (1.8V) transfer mode. Tested with the following cards: Transcend 4GB High Speed Kingston 64GB SDR104 Lexar by Micron HIGH-PERFORMANCE 300x 16GB DDR50 SanDisk Ultra 8GB DDR50 Transcend Ultimate 600x 16GB SDR104 Transcend Premium 300x 64GB SDR104 Lexar by Micron Professional 1000x 32GB UHS-II SDR104 SanDisk Extreme Pro 16GB SDR104 Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Zhoujie Wu <zjwu@marvell.com> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/sd.c47
1 files changed, 45 insertions, 2 deletions
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 2036b2b..45bf78f 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -908,6 +908,18 @@ unsigned mmc_sd_get_max_clock(struct mmc_card *card)
return max_dtr;
}
+static bool mmc_sd_card_using_v18(struct mmc_card *card)
+{
+ /*
+ * According to the SD spec., the Bus Speed Mode (function group 1) bits
+ * 2 to 4 are zero if the card is initialized at 3.3V signal level. Thus
+ * they can be used to determine if the card has already switched to
+ * 1.8V signaling.
+ */
+ return card->sw_caps.sd3_bus_mode &
+ (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50);
+}
+
/*
* Handle the detection and initialisation of a card.
*
@@ -921,9 +933,10 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
int err;
u32 cid[4];
u32 rocr = 0;
+ bool v18_fixup_failed = false;
WARN_ON(!host->claimed);
-
+retry:
err = mmc_sd_get_cid(host, ocr, cid, &rocr);
if (err)
return err;
@@ -989,6 +1002,36 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
if (err)
goto free_card;
+ /*
+ * If the card has not been power cycled, it may still be using 1.8V
+ * signaling. Detect that situation and try to initialize a UHS-I (1.8V)
+ * transfer mode.
+ */
+ if (!v18_fixup_failed && !mmc_host_is_spi(host) && mmc_host_uhs(host) &&
+ mmc_sd_card_using_v18(card) &&
+ host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
+ /*
+ * Re-read switch information in case it has changed since
+ * oldcard was initialized.
+ */
+ if (oldcard) {
+ err = mmc_read_switch(card);
+ if (err)
+ goto free_card;
+ }
+ if (mmc_sd_card_using_v18(card)) {
+ if (mmc_host_set_uhs_voltage(host) ||
+ mmc_sd_init_uhs_card(card)) {
+ v18_fixup_failed = true;
+ mmc_power_cycle(host, ocr);
+ if (!oldcard)
+ mmc_remove_card(card);
+ goto retry;
+ }
+ goto done;
+ }
+ }
+
/* Initialization sequence for UHS-I cards */
if (rocr & SD_ROCR_S18A) {
err = mmc_sd_init_uhs_card(card);
@@ -1021,7 +1064,7 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
}
}
-
+done:
host->card = card;
return 0;
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