eMMC voltage change not required for 1.8V. 3.3V and 1.8V vcc
are capable of doing DDR. vccq of 1.8v is not required.
Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
Reviewed-by: Arindam Nath <arindam.nath@xxxxxxx>
---
drivers/mmc/core/core.c | 14 ++------------
drivers/mmc/core/core.h | 2 --
drivers/mmc/core/mmc.c | 35 ++++++++++++++++++++++++++++++-----
include/linux/mmc/host.h | 1 +
4 files changed, 33 insertions(+), 19 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 74b4409..f4c5ac2 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -718,22 +718,12 @@ void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
}
/*
- * Change data bus width and DDR mode of a host.
- */
-void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
- unsigned int ddr)
-{
- host->ios.bus_width = width;
- host->ios.ddr = ddr;
- mmc_set_ios(host);
-}
-
-/*
* Change data bus width of a host.
*/
void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
{
- mmc_set_bus_width_ddr(host, width, MMC_SDR_MODE);
+ host->ios.bus_width = width;
+ mmc_set_ios(host);
}
/**
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 3c11e17..51b2f5b 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -38,8 +38,6 @@ void mmc_ungate_clock(struct mmc_host *host);
void mmc_set_ungated(struct mmc_host *host);
void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
-void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
- unsigned int ddr);
u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
int cmd11);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index a2c795e..0433fe6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -20,6 +20,7 @@
#include "core.h"
#include "bus.h"
#include "mmc_ops.h"
+#include "sd_ops.h"
static const unsigned int tran_exp[] = {
10000, 100000, 1000000, 10000000,
@@ -633,10 +634,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
*/
if (mmc_card_highspeed(card)) {
if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_8V)
- && (host->caps & (MMC_CAP_1_8V_DDR)))
+ && ((host->caps & (MMC_CAP_1_8V_DDR |
+ MMC_CAP_UHS_DDR50))
+ == (MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50)))
ddr = MMC_1_8V_DDR_MODE;
else if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_2V)
- && (host->caps & (MMC_CAP_1_2V_DDR)))
+ && ((host->caps & (MMC_CAP_1_2V_DDR |
+ MMC_CAP_UHS_DDR50))
+ == (MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50)))
ddr = MMC_1_2V_DDR_MODE;
}
@@ -670,8 +675,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
ext_csd_bits[idx][0],
0);
if (!err) {
- mmc_set_bus_width_ddr(card->host,
- bus_width, MMC_SDR_MODE);
+ mmc_set_bus_width(card->host, bus_width);
/*
* If controller can't handle bus width test,
* use the highest bus width to maintain
@@ -697,8 +701,29 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
1 << bus_width, ddr);
goto free_card;
} else if (ddr) {
+ /*
+ * eMMC cards can support 3.3V to 1.2V i/o (vccq)
+ * signaling.
+ *
+ * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq.
+ *
+ * 1.8V vccq at 3.3V core voltage (vcc) is not required
+ * in the JEDEC spec for DDR.
+ *
+ * Do not force change in vccq since we are obviously
+ * working and no change to vccq is needed.
+ *
+ * WARNING: eMMC rules are NOT the same as SD DDR
+ */
+ if (ddr == EXT_CSD_CARD_TYPE_DDR_1_2V) {
+ err = mmc_set_signal_voltage(host,
+ MMC_SIGNAL_VOLTAGE_120, 0);
+ if (err)
+ goto err;
+ }
mmc_card_set_ddr_mode(card);
- mmc_set_bus_width_ddr(card->host, bus_width, ddr);
+ mmc_set_timing(card->host, MMC_TIMING_UHS_DDR50);
+ mmc_set_bus_width(card->host, bus_width);
}
}
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 2209e01..dcae3b4 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -66,6 +66,7 @@ struct mmc_ios {
#define MMC_SIGNAL_VOLTAGE_330 0
#define MMC_SIGNAL_VOLTAGE_180 1
+#define MMC_SIGNAL_VOLTAGE_120 2
unsigned char drv_type; /* driver type (A, B, C, D) */
--
1.7.1
--
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