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| author | Daniel Drake <dsd@laptop.org> | 2012-11-25 13:02:54 -0500 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-12-06 13:55:05 -0500 |
| commit | 8ed765aac31b473e1881986d9fe2b6386f49f933 (patch) | |
| tree | 98c4a32d712ab6cab9e0b6258e19c3ade6b57f48 | |
| parent | 6a66180a252f5856fc25de69c6313831f343f50f (diff) | |
| download | op-kernel-dev-8ed765aac31b473e1881986d9fe2b6386f49f933.zip op-kernel-dev-8ed765aac31b473e1881986d9fe2b6386f49f933.tar.gz | |
mmc: dt: add no-1-8-v device tree flag
The OLPC XO-1.75 laptop includes a SDHCI controller which is 1.8v
capable, and it truthfully reports so in its capabilities. This
alternate voltage is used for driving new "UHS-I" SD cards at their
full speed.
However, what the controller doesn't know is that the motherboard
physically doesn't have a 1.8v supply available, so attempting to
switch to the 1.8v level will result in a situation that cannot be
recovered from without physically replugging the SD card.
Add a device tree flag that can be used on systems like these,
and hook it up to the equivalent SDHCI quirk.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Reviewed-by: Philip Rakity <prakity@nvidia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
| -rw-r--r-- | Documentation/devicetree/bindings/mmc/mmc.txt | 2 | ||||
| -rw-r--r-- | drivers/mmc/host/sdhci-pltfm.c | 3 |
2 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index b96e510..a591c67 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -21,6 +21,8 @@ Optional properties: - cd-inverted: when present, polarity on the cd gpio line is inverted - wp-inverted: when present, polarity on the wp gpio line is inverted - max-frequency: maximum operating clock frequency +- no-1-8-v: when present, denotes that 1.8v card voltage is not supported on + this system, even if the controller claims it is. Optional SDIO properties: - keep-power-in-suspend: Preserves card power during a suspend/resume cycle diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c index c6c3b12..d4283ef5 100644 --- a/drivers/mmc/host/sdhci-pltfm.c +++ b/drivers/mmc/host/sdhci-pltfm.c @@ -78,6 +78,9 @@ void sdhci_get_of_property(struct platform_device *pdev) if (of_get_property(np, "broken-cd", NULL)) host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; + if (of_get_property(np, "no-1-8-v", NULL)) + host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; + if (of_device_is_compatible(np, "fsl,p2020-rev1-esdhc")) host->quirks |= SDHCI_QUIRK_BROKEN_DMA; |
