mmc: sdhci-esdhc-imx: simplify the auto tuning logic

Clear auto tuning bit when reset tuning, and enable auto tuning
only after tuning done successfully for both standard tuning and
manual tuning.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20221223025022.1893102-2-haibo.chen@nxp.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -430,9 +430,10 @@ static inline void esdhc_wait_for_card_clock_gate_off(struct sdhci_host *host)
 }
 
 /* Enable the auto tuning circuit to check the CMD line and BUS line */
-static inline void usdhc_auto_tuning_mode_sel(struct sdhci_host *host)
+static inline void usdhc_auto_tuning_mode_sel_and_en(struct sdhci_host *host)
 {
 	u32 buswidth, auto_tune_buswidth;
+	u32 reg;
 
 	buswidth = USDHC_GET_BUSWIDTH(readl(host->ioaddr + SDHCI_HOST_CONTROL));
 
@@ -451,6 +452,10 @@ static inline void usdhc_auto_tuning_mode_sel(struct sdhci_host *host)
 	esdhc_clrset_le(host, ESDHC_VEND_SPEC2_AUTO_TUNE_MODE_MASK,
 			auto_tune_buswidth | ESDHC_VEND_SPEC2_AUTO_TUNE_CMD_EN,
 			ESDHC_VEND_SPEC2);
+
+	reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
+	reg |= ESDHC_MIX_CTRL_AUTO_TUNE_EN;
+	writel(reg, host->ioaddr + ESDHC_MIX_CTRL);
 }
 
 static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
@@ -682,14 +687,11 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
 			} else {
 				v &= ~ESDHC_MIX_CTRL_SMPCLK_SEL;
 				m &= ~ESDHC_MIX_CTRL_FBCLK_SEL;
-				m &= ~ESDHC_MIX_CTRL_AUTO_TUNE_EN;
 			}
 
 			if (val & SDHCI_CTRL_EXEC_TUNING) {
 				v |= ESDHC_MIX_CTRL_EXE_TUNE;
 				m |= ESDHC_MIX_CTRL_FBCLK_SEL;
-				m |= ESDHC_MIX_CTRL_AUTO_TUNE_EN;
-				usdhc_auto_tuning_mode_sel(host);
 			} else {
 				v &= ~ESDHC_MIX_CTRL_EXE_TUNE;
 			}
@@ -1023,13 +1025,15 @@ static void esdhc_reset_tuning(struct sdhci_host *host)
 
 	/* Reset the tuning circuit */
 	if (esdhc_is_usdhc(imx_data)) {
+		ctrl = readl(host->ioaddr + ESDHC_MIX_CTRL);
+		ctrl &= ~ESDHC_MIX_CTRL_AUTO_TUNE_EN;
 		if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING) {
-			ctrl = readl(host->ioaddr + ESDHC_MIX_CTRL);
 			ctrl &= ~ESDHC_MIX_CTRL_SMPCLK_SEL;
 			ctrl &= ~ESDHC_MIX_CTRL_FBCLK_SEL;
 			writel(ctrl, host->ioaddr + ESDHC_MIX_CTRL);
 			writel(0, host->ioaddr + ESDHC_TUNE_CTRL_STATUS);
 		} else if (imx_data->socdata->flags & ESDHC_FLAG_STD_TUNING) {
+			writel(ctrl, host->ioaddr + ESDHC_MIX_CTRL);
 			ctrl = readl(host->ioaddr + SDHCI_AUTO_CMD_STATUS);
 			ctrl &= ~ESDHC_MIX_CTRL_SMPCLK_SEL;
 			ctrl &= ~ESDHC_MIX_CTRL_EXE_TUNE;
@@ -1055,6 +1059,7 @@ static void esdhc_reset_tuning(struct sdhci_host *host)
 static int usdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
+	int err;
 
 	/*
 	 * i.MX uSDHC internally already uses a fixed optimized timing for
@@ -1069,7 +1074,12 @@ static int usdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	 * correct delay cell.
 	 */
 	esdhc_reset_tuning(host);
-	return sdhci_execute_tuning(mmc, opcode);
+	err = sdhci_execute_tuning(mmc, opcode);
+	/* If tuning done, enable auto tuning */
+	if (!err && !host->tuning_err)
+		usdhc_auto_tuning_mode_sel_and_en(host);
+
+	return err;
 }
 
 static void esdhc_prepare_tuning(struct sdhci_host *host, u32 val)
@@ -1103,11 +1113,8 @@ static void esdhc_post_tuning(struct sdhci_host *host)
 {
 	u32 reg;
 
-	usdhc_auto_tuning_mode_sel(host);
-
 	reg = readl(host->ioaddr + ESDHC_MIX_CTRL);
 	reg &= ~ESDHC_MIX_CTRL_EXE_TUNE;
-	reg |= ESDHC_MIX_CTRL_AUTO_TUNE_EN;
 	writel(reg, host->ioaddr + ESDHC_MIX_CTRL);
 }