diff options
| author | Kyle Roeschley <kyle.roeschley@ni.com> | 2018-04-13 16:54:57 -0500 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2018-05-02 15:08:44 +0200 |
| commit | 247cfe53557524a94dd1001d19e5aa50bd5aca81 (patch) | |
| tree | 73c891362517c86cc25e5fc85b1ee48188a1a6aa /drivers/mmc/core/sd.c | |
| parent | 1d6efe08c80d84b1f39845707288ffd4df239c3b (diff) | |
| download | linux-247cfe53557524a94dd1001d19e5aa50bd5aca81.tar.gz linux-247cfe53557524a94dd1001d19e5aa50bd5aca81.tar.bz2 linux-247cfe53557524a94dd1001d19e5aa50bd5aca81.zip | |
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>
Diffstat (limited to 'drivers/mmc/core/sd.c')
| -rw-r--r-- | drivers/mmc/core/sd.c | 8 |
1 files changed, 8 insertions, 0 deletions
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; |