From mboxrd@z Thu Jan 1 00:00:00 1970 From: mw@semihalf.com (Marcin Wojtas) Date: Tue, 6 Oct 2015 03:22:36 +0200 Subject: [PATCH 2/8] mmc: sdhci-pxav3: disable clock inversion for HS MMC cards In-Reply-To: <1444094562-31165-1-git-send-email-mw@semihalf.com> References: <1444094562-31165-1-git-send-email-mw@semihalf.com> Message-ID: <1444094562-31165-3-git-send-email-mw@semihalf.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Nadav Haklai According to 'FE-2946959' erratum the clock inversion option is needed to support slow frequencies when the card input hold time requirement is high. This setting is not required for high speed MMC and might cause timing violation. Signed-off-by: Nadav Haklai Cc: # v4.2 --- drivers/mmc/host/sdhci-pxav3.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c index 976cddd..89a9e49 100644 --- a/drivers/mmc/host/sdhci-pxav3.c +++ b/drivers/mmc/host/sdhci-pxav3.c @@ -291,6 +291,9 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs) uhs == MMC_TIMING_UHS_DDR50) { reg_val &= ~SDIO3_CONF_CLK_INV; reg_val |= SDIO3_CONF_SD_FB_CLK; + } else if (uhs == MMC_TIMING_MMC_HS) { + reg_val &= ~SDIO3_CONF_CLK_INV; + reg_val &= ~SDIO3_CONF_SD_FB_CLK; } else { reg_val |= SDIO3_CONF_CLK_INV; reg_val &= ~SDIO3_CONF_SD_FB_CLK; -- 1.8.3.1