[PATCH 02/10] mmc: sdhci-of-k1: enable essential clock infrastructure for SD operation

Iker Pedrosa ikerpedrosam at gmail.com
Mon Mar 2 07:13:23 PST 2026


Ensure SD card pins receive clock signals by enabling pad clock
generation and overriding automatic clock gating. Required for all SD
operation modes.

Signed-off-by: Iker Pedrosa <ikerpedrosam at gmail.com>
---
 drivers/mmc/host/sdhci-of-k1.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-k1.c b/drivers/mmc/host/sdhci-of-k1.c
index 0cc97e23a2f9c7b2f9376318a8a7ebb860571504..b703b78282ed8d89183c816477c149c0a565618a 100644
--- a/drivers/mmc/host/sdhci-of-k1.c
+++ b/drivers/mmc/host/sdhci-of-k1.c
@@ -20,6 +20,13 @@
 #include "sdhci.h"
 #include "sdhci-pltfm.h"
 
+#define SPACEMIT_SDHC_OP_EXT_REG	0x108
+#define  SDHC_OVRRD_CLK_OEN		BIT(11)
+#define  SDHC_FORCE_CLK_ON		BIT(12)
+
+#define SPACEMIT_SDHC_LEGACY_CTRL_REG	0x10C
+#define  SDHC_GEN_PAD_CLK_ON		BIT(6)
+
 #define SPACEMIT_SDHC_MMC_CTRL_REG	0x114
 #define  SDHC_MISC_INT_EN		BIT(1)
 #define  SDHC_MISC_INT			BIT(2)
@@ -100,6 +107,10 @@ static void spacemit_sdhci_reset(struct sdhci_host *host, u8 mask)
 
 	if (!(host->mmc->caps2 & MMC_CAP2_NO_MMC))
 		spacemit_sdhci_setbits(host, SDHC_MMC_CARD_MODE, SPACEMIT_SDHC_MMC_CTRL_REG);
+
+	spacemit_sdhci_setbits(host, SDHC_GEN_PAD_CLK_ON, SPACEMIT_SDHC_LEGACY_CTRL_REG);
+	spacemit_sdhci_setbits(host, SDHC_OVRRD_CLK_OEN | SDHC_FORCE_CLK_ON,
+			       SPACEMIT_SDHC_OP_EXT_REG);
 }
 
 static void spacemit_sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)

-- 
2.53.0




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