[PATCH 2/8] mmc: sdhci-pxav3: disable clock inversion for HS MMC cards

Marcin Wojtas mw at semihalf.com
Mon Oct 5 18:22:36 PDT 2015


From: Nadav Haklai <nadavh at marvell.com>

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 <nadavh at marvell.com>
Cc: <stable at vger.kernel.org> # 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




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