mmc: core: Add a new quirk for limiting clock rate

This patch adds a quirk to limit clock rate which
can be used to reduce the SDIO clock rate for some
chips with broken UHS.

Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
harish_kandiga@mentor.com 2018-04-10 12:30:31 +05:30 committed by Ulf Hansson
parent d39b1b2abf
commit ebc5a1bf4f
3 changed files with 12 additions and 1 deletions

View file

@ -149,6 +149,12 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
card->quirks &= ~data;
}
static inline void __maybe_unused add_limit_rate_quirk(struct mmc_card *card,
int data)
{
card->quirk_max_rate = data;
}
/*
* Quirk add/remove for MMC products.
*/

View file

@ -444,6 +444,7 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
unsigned int bus_speed, timing;
int err;
unsigned char speed;
unsigned int max_rate;
/*
* If the host doesn't support any of the UHS-I modes, fallback on
@ -500,9 +501,12 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
if (err)
return err;
max_rate = min_not_zero(card->quirk_max_rate,
card->sw_caps.uhs_max_dtr);
if (bus_speed) {
mmc_set_timing(card->host, timing);
mmc_set_clock(card->host, card->sw_caps.uhs_max_dtr);
mmc_set_clock(card->host, max_rate);
}
return 0;

View file

@ -252,6 +252,7 @@ struct mmc_card {
#define MMC_TYPE_SD_COMBO 3 /* SD combo (IO+mem) card */
unsigned int state; /* (our) card state */
unsigned int quirks; /* card quirks */
unsigned int quirk_max_rate; /* max rate set by quirks */
#define MMC_QUIRK_LENIENT_FN0 (1<<0) /* allow SDIO FN0 writes outside of the VS CCCR range */
#define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1) /* use func->cur_blksize */
/* for byte mode */