mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

We want SDIO drivers to be able to temporarily stop retuning when the
driver knows that the SDIO card is not in a state where retuning will
work (maybe because the card is asleep).  We'll move the relevant
functions to a place where drivers can call them.

Cc: stable@vger.kernel.org #v4.18+
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Douglas Anderson 2019-06-17 10:56:52 -07:00 committed by Ulf Hansson
parent 2de0b42da2
commit b4c9f938d5
2 changed files with 43 additions and 0 deletions

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@ -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
@ -771,3 +772,42 @@ 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);

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@ -170,4 +170,7 @@ extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
extern void sdio_retune_crc_disable(struct sdio_func *func);
extern void sdio_retune_crc_enable(struct sdio_func *func);
extern void sdio_retune_hold_now(struct sdio_func *func);
extern void sdio_retune_release(struct sdio_func *func);
#endif /* LINUX_MMC_SDIO_FUNC_H */