diff options
| author | Daniel Drake <dsd@laptop.org> | 2012-11-25 18:01:19 +0000 |
|---|---|---|
| committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2013-04-18 14:01:32 +0200 |
| commit | e892379bb58aed6db12e45d033f99f532055a1b4 (patch) | |
| tree | 5ef1c19b61d899e5fa063d3d6e8a5264a718a1ff /include | |
| parent | 5aca4fabc06a93cfd0c99025fb38e3594a5d048c (diff) | |
mmc: sdhci: add quirk for lack of 1.8v support
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.
Add a quirk so that systems such as this one can override disable
1.8v support, adding support for UHS-I cards (by running them at
3.3v).
This avoids a problem where the system would first try to run the
card at 1.8v, fail, and then not be able to fully reset the card
to retry at the normal 3.3v voltage.
This is more appropriate than using the MISSING_CAPS quirk, which
is intended for cases where the SDHCI controller is actually lying
about its capabilities, and would force us to somehow override both
caps words from another source.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Reviewed-by: Philip Rakity <prakity@nvidia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mmc/sdhci.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index 5ee48390decc..db86304e1c28 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -93,6 +93,8 @@ struct sdhci_host { #define SDHCI_QUIRK_NON_STANDARD_TUNING (1ULL<<33) /* Controller doesn't calculate max_discard_to */ #define SDHCI_QUIRK_NO_CALC_MAX_DISCARD_TO (1ULL<<34) +/* The system physically doesn't support 1.8v, even if the host does */ +#define SDHCI_QUIRK2_NO_1_8_V (1ULL<<35) int irq; /* Device IRQ */ void __iomem *ioaddr; /* Mapped address */ |