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sd: Enable eMMC cache

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Use cache on eMMC

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>
This commit is contained in:
Declan Snyder 2022-09-12 10:09:11 -05:00 • committed by Carles Cufí
commit bb41f7dc9d
1 changed files with 37 additions and 0 deletions
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37
subsys/sd/mmc.c
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@ -46,6 +46,9 @@
#define MMC_SWITCH_PWR_CLASS_ARG \
(0xFC000000 & (0U << 26)) + (0x03000000 & (0b11 << 24)) + (0x00FF0000 & (187U << 16)) + \
(0x0000FF00 & (0U << 8)) + (0x000000F7 & (0U << 3)) + (0x00000000 & (3U << 0))
#define MMC_SWITCH_CACHE_ON_ARG \
(0xFC000000 & (0U << 26)) + (0x03000000 & (0b11 << 24)) + (0x00FF0000 & (33U << 16)) + \
(0x0000FF00 & (1U << 8)) + (0x000000F7 & (0U << 3)) + (0x00000000 & (3U << 0))
LOG_MODULE_DECLARE(sd, CONFIG_SD_LOG_LEVEL);
@ -89,6 +92,9 @@ static int mmc_set_bus_width(struct sd_card *card);
/* Sets card to the fastest timing mode (using CMD6) and SDHC to max frequency */
static int mmc_set_timing(struct sd_card *card, struct mmc_ext_csd *card_ext_csd);
/* Enable cache for emmc if applicable */
static int mmc_set_cache(struct sd_card *card, struct mmc_ext_csd *card_ext_csd);
/*
* Initialize MMC card for use with subsystem
*/
@ -187,6 +193,12 @@ int mmc_card_init(struct sd_card *card)
return ret;
}
/* Turn on cache if it exists */
ret = mmc_set_cache(card, &card_ext_csd);
if (ret) {
return ret;
}
return 0;
}
@ -603,4 +615,29 @@ static inline void mmc_decode_ext_csd(struct mmc_ext_csd *ext, uint8_t *raw)
ext->power_class = (raw[187] & 0x0F);
ext->mmc_driver_strengths = raw[197U];
ext->pwr_class_200MHZ_VCCQ195 = raw[237U];
ext->cache_size =
(raw[252] << 24U) + (raw[251] << 16U) + (raw[250] << 8U) + (raw[249] << 0U);
}
static int mmc_set_cache(struct sd_card *card, struct mmc_ext_csd *card_ext_csd)
{
int ret = 0;
struct sdhc_command cmd = {0};
/* If there is no cache, don't use cache */
if (card_ext_csd->cache_size == 0) {
return 0;
}
/* CMD6 to write to EXT CSD to turn on cache */
cmd.opcode = SD_SWITCH;
cmd.arg = MMC_SWITCH_CACHE_ON_ARG;
cmd.response_type = SD_RSP_TYPE_R1b;
cmd.timeout_ms = CONFIG_SD_CMD_TIMEOUT;
ret = sdhc_request(card->sdhc, &cmd, NULL);
if (ret) {
LOG_DBG("Error turning on card cache: %d", ret);
return ret;
}
ret = sdmmc_wait_ready(card);
return ret;
}