From: Kyle Roeschley <kyle.roeschley@xxxxxx>
Some SD host controllers cannot handle extended use of 3.3V signaling.
To accommodate these controllers, add a capability that requires us to
negotiate the voltage down from 3.3V during card initialization.
Signed-off-by: Kyle Roeschley <kyle.roeschley@xxxxxx>
Signed-off-by: Jennifer Dahm <jennifer.dahm@xxxxxx>
---
drivers/mmc/core/mmc.c | 8 ++++++++
drivers/mmc/core/sd.c | 8 ++++++++
drivers/mmc/core/sdio.c | 8 ++++++++
include/linux/mmc/host.h | 1 +
4 files changed, 25 insertions(+)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 6f8ebd6..915b58f 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1830,6 +1830,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
}
}
+ if (host->caps2 & MMC_CAP2_AVOID_3_3V &&
+ host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ pr_err("%s: Host failed to negotiate down from 3.3V\n",
+ mmc_hostname(host));
+ err = -EINVAL;
+ goto free_card;
+ }
+
if (!oldcard)
host->card = card;
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index baf3d5d..7f87a53 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1058,6 +1058,14 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
}
}
+
+ if (host->caps2 & MMC_CAP2_AVOID_3_3V &&
+ host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ pr_err("%s: Host failed to negotiate down from 3.3V\n",
+ mmc_hostname(host));
+ err = -EINVAL;
+ goto free_card;
+ }
done:
host->card = card;
return 0;
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index c599a62..9b5a0a5 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -788,6 +788,14 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
if (err)
goto remove;
}
+
+ if (host->caps2 & MMC_CAP2_AVOID_3_3V &&
+ host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ pr_err("%s: Host failed to negotiate down from 3.3V\n",
+ mmc_hostname(host));
+ err = -EINVAL;
+ goto remove;
+ }
finish:
if (!oldcard)
host->card = card;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 8514623..7c6eaf6 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -354,6 +354,7 @@ struct mmc_host {
#define MMC_CAP2_NO_MMC (1 << 22) /* Do not send (e)MMC commands during initialization */
#define MMC_CAP2_CQE (1 << 23) /* Has eMMC command queue engine */
#define MMC_CAP2_CQE_DCMD (1 << 24) /* CQE can issue a direct command */
+#define MMC_CAP2_AVOID_3_3V (1 << 25) /* Host must negotiate down from 3.3V */
int fixed_drv_type; /* fixed driver type for non-removable media */
--
2.7.4
--
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