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mmc: core: Add capability to avoid 3.3V signaling

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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>
This commit is contained in:
Kyle Roeschley 2018-04-13 16:54:57 -05:00 committed by Ulf Hansson
parent 1d6efe08c8
commit 247cfe5355
4 changed files with 25 additions and 0 deletions
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8
drivers/mmc/core/mmc.c
View File

@ -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;

8
drivers/mmc/core/sd.c
View File

@ -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;

8
drivers/mmc/core/sdio.c
View File

@ -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;

1
include/linux/mmc/host.h
View File

@ -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 */