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| author | Ludovic Barre <ludovic.barre@st.com> | 2020-04-20 19:18:31 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2020-05-28 12:21:00 +0300 |
| commit | 33ba6fec0012e47f4e72bfab922b99327373f210 (patch) | |
| tree | 1597466bd4cc92eeed5bb4a86eb94512386c0d1c /drivers/mmc/host/mmci_stm32_sdmmc.c | |
| parent | 0472f8d3c054a0ff58122fc9d2dbf84f197a284f (diff) | |
| download | linux-33ba6fec0012e47f4e72bfab922b99327373f210.tar.xz | |
mmc: mmci_sdmmc: fix power on issue due to pwr_reg initialization
This patch fix a power-on issue, and avoid to retry the power sequence.
In power off sequence: sdmmc must set pwr_reg in "power-cycle" state
(value 0x2), to prevent the card from being supplied through the signal
lines (all the lines are driven low).
In power on sequence: when the power is stable, sdmmc must set pwr_reg
in "power-off" state (value 0x0) to drive all signal to high before to
set "power-on".
To avoid writing the same value to the power register several times, this
register is cached by the pwr_reg variable. At probe pwr_reg is initialized
to 0 by kzalloc of mmc_alloc_host.
Like pwr_reg value is 0 at probing, the power on sequence fail because
the "power-off" state is not writes (value 0x0) and the lines
remain drive to low.
This patch initializes "pwr_reg" variable with power register value.
This it done in sdmmc variant init to not disturb default mmci behavior.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Link: https://lore.kernel.org/r/20200420161831.5043-1-ludovic.barre@st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/host/mmci_stm32_sdmmc.c')
| -rw-r--r-- | drivers/mmc/host/mmci_stm32_sdmmc.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c index d33e62bd6153..14f99d8aa3f0 100644 --- a/drivers/mmc/host/mmci_stm32_sdmmc.c +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c @@ -519,6 +519,7 @@ void sdmmc_variant_init(struct mmci_host *host) struct sdmmc_dlyb *dlyb; host->ops = &sdmmc_variant_ops; + host->pwr_reg = readl_relaxed(host->base + MMCIPOWER); base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL); if (IS_ERR(base_dlyb)) |