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

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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>

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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

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5

drivers/mmc/host/mmci.h

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13

drivers/mmc/host/mmci_stm32_sdmmc.c

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