From 286c4a7dc0cd51fc89f7942f0e59f301a637d814 Mon Sep 17 00:00:00 2001 From: Yangbo Lu Date: Fri, 22 May 2020 11:12:56 +0800 Subject: [PATCH] mmc: sdhci-of-esdhc: exit HS400 properly before setting any speed mode The eSDHC HS400 timing requires many specific registers setting, unlike other speed modes which need to set only host controller 2 register. When driver needs to downgrade HS400 mode to other speed mode, the controller have to exit HS400 timing properly first. This patch is to support the procedure of HS400 exiting at the beginning of esdhc_set_uhs_signaling. Signed-off-by: Yangbo Lu Acked-by: Adrian Hunter Link: https://lore.kernel.org/r/20200522031256.856-1-yangbo.lu@nxp.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-of-esdhc.c | 34 +++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index 5d8dd870bd442..7c73d243dc6ce 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -1135,6 +1135,40 @@ static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode) static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int timing) { + u32 val; + + /* + * There are specific registers setting for HS400 mode. + * Clean all of them if controller is in HS400 mode to + * exit HS400 mode before re-setting any speed mode. + */ + val = sdhci_readl(host, ESDHC_TBCTL); + if (val & ESDHC_HS400_MODE) { + val = sdhci_readl(host, ESDHC_SDTIMNGCTL); + val &= ~ESDHC_FLW_CTL_BG; + sdhci_writel(host, val, ESDHC_SDTIMNGCTL); + + val = sdhci_readl(host, ESDHC_SDCLKCTL); + val &= ~ESDHC_CMD_CLK_CTL; + sdhci_writel(host, val, ESDHC_SDCLKCTL); + + esdhc_clock_enable(host, false); + val = sdhci_readl(host, ESDHC_TBCTL); + val &= ~ESDHC_HS400_MODE; + sdhci_writel(host, val, ESDHC_TBCTL); + esdhc_clock_enable(host, true); + + val = sdhci_readl(host, ESDHC_DLLCFG0); + val &= ~(ESDHC_DLL_ENABLE | ESDHC_DLL_FREQ_SEL); + sdhci_writel(host, val, ESDHC_DLLCFG0); + + val = sdhci_readl(host, ESDHC_TBCTL); + val &= ~ESDHC_HS400_WNDW_ADJUST; + sdhci_writel(host, val, ESDHC_TBCTL); + + esdhc_tuning_block_enable(host, false); + } + if (timing == MMC_TIMING_MMC_HS400) esdhc_tuning_block_enable(host, true); else -- 2.39.5