From ebc5a1bf4f2afc2f2b348320dcfb45a8c0ac3de5 Mon Sep 17 00:00:00 2001 From: "harish_kandiga@mentor.com" Date: Tue, 10 Apr 2018 12:30:31 +0530 Subject: 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 Reviewed-by: Shawn Lin Signed-off-by: Ulf Hansson --- drivers/mmc/core/card.h | 6 ++++++ drivers/mmc/core/sdio.c | 6 +++++- 2 files changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/mmc/core') diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h index 9c821eedd156..1170feb8f969 100644 --- a/drivers/mmc/core/card.h +++ b/drivers/mmc/core/card.h @@ -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. */ diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index c599a628a387..24b510b743da 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -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; -- cgit v1.2.3