This patch adds a quirk to handle broken UHS which
can be used to reduce the SDIO clock rate for some
chips with broken UHS.
Signed-off-by: Harish Jenny K N <harish_kandiga@xxxxxxxxxx>
---
drivers/mmc/core/card.h | 5 +++++
drivers/mmc/core/sdio.c | 19 +++++++++++++++++++
include/linux/mmc/card.h | 2 ++
3 files changed, 26 insertions(+)
diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
index 9c821ee..e6c7dad 100644
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -221,4 +221,9 @@ static inline int mmc_card_broken_hpi(const struct mmc_card *c)
return c->quirks & MMC_QUIRK_BROKEN_HPI;
}
+static inline int mmc_card_broken_uhs(const struct mmc_card *c)
+{
+ return c->quirks & MMC_QUIRK_BROKEN_UHS;
+}
+
#endif
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index c599a62..d3fcc4c 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -444,6 +444,7 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
unsigned int bus_speed, timing;
int err;
unsigned char speed;
+ unsigned char cccr;
/*
* If the host doesn't support any of the UHS-I modes, fallback on
@@ -460,6 +461,24 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
timing = MMC_TIMING_UHS_SDR104;
card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
card->sd_bus_speed = UHS_SDR104_BUS_SPEED;
+
+ err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR,
+ 0, &cccr);
+ if (err)
+ return err;
+
+ if ((cccr & 0x0f) >= SDIO_CCCR_REV_3_00) {
+ if (mmc_host_uhs(card->host) &&
+ mmc_card_broken_uhs(card)) {
+ /*
+ * Reduce the max clock rate to
+ * 150MHz for SD_MODE_UHS_SDR104.
+ */
+ card->sw_caps.uhs_max_dtr =
+ UHS_SDR104_REDUCED_DTR;
+ }
+ }
+
} else if ((card->host->caps & MMC_CAP_UHS_DDR50) &&
(card->sw_caps.sd3_bus_mode & SD_MODE_UHS_DDR50)) {
bus_speed = SDIO_SPEED_DDR50;
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 279b390..daab735 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -152,6 +152,7 @@ struct sd_switch_caps {
unsigned int uhs_max_dtr;
#define HIGH_SPEED_MAX_DTR 50000000
#define UHS_SDR104_MAX_DTR 208000000
+#define UHS_SDR104_REDUCED_DTR 150000000
#define UHS_SDR50_MAX_DTR 100000000
#define UHS_DDR50_MAX_DTR 50000000
#define UHS_SDR25_MAX_DTR UHS_DDR50_MAX_DTR
@@ -268,6 +269,7 @@ struct mmc_card {
#define MMC_QUIRK_BROKEN_IRQ_POLLING (1<<11) /* Polling SDIO_CCCR_INTx could create a fake interrupt */
#define MMC_QUIRK_TRIM_BROKEN (1<<12) /* Skip trim */
#define MMC_QUIRK_BROKEN_HPI (1<<13) /* Disable broken HPI support */
+#define MMC_QUIRK_BROKEN_UHS (1<<14) /* Broken UHS */
bool reenable_cmdq; /* Re-enable Command Queue */
--
1.9.1
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