diff options
Diffstat (limited to 'drivers/mmc/core/sdio_io.c')
-rw-r--r-- | drivers/mmc/core/sdio_io.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c index f79f0b0caab8..2ba00acf64e6 100644 --- a/drivers/mmc/core/sdio_io.c +++ b/drivers/mmc/core/sdio_io.c @@ -15,6 +15,7 @@ #include "sdio_ops.h" #include "core.h" #include "card.h" +#include "host.h" /** * sdio_claim_host - exclusively claim a bus for a certain SDIO function @@ -734,3 +735,79 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags) return 0; } EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags); + +/** + * sdio_retune_crc_disable - temporarily disable retuning on CRC errors + * @func: SDIO function attached to host + * + * If the SDIO card is known to be in a state where it might produce + * CRC errors on the bus in response to commands (like if we know it is + * transitioning between power states), an SDIO function driver can + * call this function to temporarily disable the SD/MMC core behavior of + * triggering an automatic retuning. + * + * This function should be called while the host is claimed and the host + * should remain claimed until sdio_retune_crc_enable() is called. + * Specifically, the expected sequence of calls is: + * - sdio_claim_host() + * - sdio_retune_crc_disable() + * - some number of calls like sdio_writeb() and sdio_readb() + * - sdio_retune_crc_enable() + * - sdio_release_host() + */ +void sdio_retune_crc_disable(struct sdio_func *func) +{ + func->card->host->retune_crc_disable = true; +} +EXPORT_SYMBOL_GPL(sdio_retune_crc_disable); + +/** + * sdio_retune_crc_enable - re-enable retuning on CRC errors + * @func: SDIO function attached to host + * + * This is the compement to sdio_retune_crc_disable(). + */ +void sdio_retune_crc_enable(struct sdio_func *func) +{ + func->card->host->retune_crc_disable = false; +} +EXPORT_SYMBOL_GPL(sdio_retune_crc_enable); + +/** + * sdio_retune_hold_now - start deferring retuning requests till release + * @func: SDIO function attached to host + * + * This function can be called if it's currently a bad time to do + * a retune of the SDIO card. Retune requests made during this time + * will be held and we'll actually do the retune sometime after the + * release. + * + * This function could be useful if an SDIO card is in a power state + * where it can respond to a small subset of commands that doesn't + * include the retuning command. Care should be taken when using + * this function since (presumably) the retuning request we might be + * deferring was made for a good reason. + * + * This function should be called while the host is claimed. + */ +void sdio_retune_hold_now(struct sdio_func *func) +{ + mmc_retune_hold_now(func->card->host); +} +EXPORT_SYMBOL_GPL(sdio_retune_hold_now); + +/** + * sdio_retune_release - signal that it's OK to retune now + * @func: SDIO function attached to host + * + * This is the complement to sdio_retune_hold_now(). Calling this + * function won't make a retune happen right away but will allow + * them to be scheduled normally. + * + * This function should be called while the host is claimed. + */ +void sdio_retune_release(struct sdio_func *func) +{ + mmc_retune_release(func->card->host); +} +EXPORT_SYMBOL_GPL(sdio_retune_release); |