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authorKyle Roeschley <kyle.roeschley@ni.com>2018-04-13 16:54:57 -0500
committerUlf Hansson <ulf.hansson@linaro.org>2018-05-02 15:08:44 +0200
commit247cfe53557524a94dd1001d19e5aa50bd5aca81 (patch)
tree73c891362517c86cc25e5fc85b1ee48188a1a6aa
parent1d6efe08c80d84b1f39845707288ffd4df239c3b (diff)
downloadlinux-247cfe53557524a94dd1001d19e5aa50bd5aca81.tar.bz2
mmc: core: Add capability to avoid 3.3V signaling
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@ni.com> Signed-off-by: Jennifer Dahm <jennifer.dahm@ni.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
-rw-r--r--drivers/mmc/core/mmc.c8
-rw-r--r--drivers/mmc/core/sd.c8
-rw-r--r--drivers/mmc/core/sdio.c8
-rw-r--r--include/linux/mmc/host.h1
4 files changed, 25 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 6f8ebd6caa4c..915b58f9bfc5 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 baf3d5da4ccb..7f87a5354f9f 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1058,6 +1058,14 @@ retry:
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 24b510b743da..87e53a721a10 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -792,6 +792,14 @@ try_again:
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 85146235231e..7c6eaf63f5ce 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 */