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authorLudovic Barre <ludovic.barre@st.com>2020-04-20 19:18:31 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2020-05-28 12:21:00 +0300
commit33ba6fec0012e47f4e72bfab922b99327373f210 (patch)
tree1597466bd4cc92eeed5bb4a86eb94512386c0d1c /drivers/mmc/host/mmci_stm32_sdmmc.c
parent0472f8d3c054a0ff58122fc9d2dbf84f197a284f (diff)
downloadlinux-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.c1
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))