github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-27 08:33:17 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mmc: mmci: stm32: manage block gap hardware flow control

Browse Source 
In stm32 sdmmc variant revision v3.0, a block gap hardware flow control
should be used with bus speed modes SDR104 and HS200.
It is enabled by writing a non-null value to the new added register
MMCI_STM32_FIFOTHRR.
The threshold will be 2^(N-1) bytes, so we can use the ffs() function to
compute the value N to be written to the register. The threshold used
should be the data block size, but must not be bigger than the FIFO size.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Link: https://lore.kernel.org/r/20230619115120.64474-5-yann.gautier@foss.st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Yann Gautier 2023-06-19 13:51:18 +02:00 committed by Ulf Hansson
parent ea9ca04119
commit 27bdc37c39
2 changed files with 18 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/mmc/host/mmci.h
View File

@ -218,6 +218,11 @@
#define MCI_STM32_BUSYD0ENDMASK BIT(21)
#define MMCIMASK1 0x040
/* STM32 sdmmc data FIFO threshold register */
#define MMCI_STM32_FIFOTHRR 0x044
#define MMCI_STM32_THR_MASK GENMASK(3, 0)
#define MMCIFIFOCNT 0x048
#define MMCIFIFO 0x080 /* to 0x0bc */

13
drivers/mmc/host/mmci_stm32_sdmmc.c
View File

@ -361,6 +361,19 @@ static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
datactrl = mmci_dctrl_blksz(host);
if (host->hw_revision >= 3) {
u32 thr = 0;
if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
host->mmc->ios.timing == MMC_TIMING_MMC_HS200) {
thr = ffs(min_t(unsigned int, host->data->blksz,
host->variant->fifosize));
thr = min_t(u32, thr, MMCI_STM32_THR_MASK);
}
writel_relaxed(thr, host->base + MMCI_STM32_FIFOTHRR);
}
if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
host->data->blocks == 1)
datactrl |= MCI_DPSM_STM32_MODE_SDIO;