mmc: mediatek: Use data tune for CMD line tune

If we don't select a set of better parameters for our emmc host,
It may easily occur CMD response CRC error. And also it may cause
cannot boot up issue.

Fot getting a set of better parameters, our emmc host supports
data tune mechanism.Therefore, our emmc driver also should change
to use data tune for CMD line.

Because our emmc host use the different clock source to sample the
CMD signal between HS200 and HS400 mode, the parameters are also
different between these two modes.
Separate cmd internal delay for HS200/HS400 mode.

This change can fix "System can not boot up" issue.
Signed-off-by: Yong Mao <yong.mao@mediatek.com>
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -76,6 +76,7 @@
 #define MSDC_PATCH_BIT1  0xb4
 #define MSDC_PAD_TUNE    0xec
 #define PAD_DS_TUNE      0x188
+#define PAD_CMD_TUNE     0x18c
 #define EMMC50_CFG0      0x208
 
 /*--------------------------------------------------------------------------*/
@@ -211,13 +212,18 @@
 #define MSDC_PATCH_BIT_SPCPUSH    (0x1 << 29)	/* RW */
 #define MSDC_PATCH_BIT_DECRCTMO   (0x1 << 30)	/* RW */
 
+#define MSDC_PAD_TUNE_DATWRDLY	  (0x1f <<  0)	/* RW */
 #define MSDC_PAD_TUNE_DATRRDLY	  (0x1f <<  8)	/* RW */
 #define MSDC_PAD_TUNE_CMDRDLY	  (0x1f << 16)  /* RW */
+#define MSDC_PAD_TUNE_CMDRRDLY	  (0x1f << 22)	/* RW */
+#define MSDC_PAD_TUNE_CLKTDLY	  (0x1f << 27)  /* RW */
 
 #define PAD_DS_TUNE_DLY1	  (0x1f << 2)   /* RW */
 #define PAD_DS_TUNE_DLY2	  (0x1f << 7)   /* RW */
 #define PAD_DS_TUNE_DLY3	  (0x1f << 12)  /* RW */
 
+#define PAD_CMD_TUNE_RX_DLY3	  (0x1f << 1)  /* RW */
+
 #define EMMC50_CFG_PADCMD_LATCHCK (0x1 << 0)   /* RW */
 #define EMMC50_CFG_CRCSTS_EDGE    (0x1 << 3)   /* RW */
 #define EMMC50_CFG_CFCSTS_SEL     (0x1 << 4)   /* RW */
@@ -285,12 +291,14 @@ struct msdc_save_para {
 	u32 patch_bit0;
 	u32 patch_bit1;
 	u32 pad_ds_tune;
+	u32 pad_cmd_tune;
 	u32 emmc50_cfg0;
 };
 
 struct msdc_tune_para {
 	u32 iocon;
 	u32 pad_tune;
+	u32 pad_cmd_tune;
 };
 
 struct msdc_delay_phase {
@@ -332,6 +340,10 @@ struct msdc_host {
 	unsigned char timing;
 	bool vqmmc_enabled;
 	u32 hs400_ds_delay;
+	u32 hs200_cmd_int_delay; /* cmd internal delay for HS200/SDR104 */
+	u32 hs400_cmd_int_delay; /* cmd internal delay for HS400 */
+	bool hs400_cmd_resp_sel_rising;
+				 /* cmd response sample selection for HS400 */
 	bool hs400_mode;	/* current eMMC will run at hs400 mode */
 	struct msdc_save_para save_para; /* used when gate HCLK */
 	struct msdc_tune_para def_tune_para; /* default tune setting */
@@ -601,8 +613,14 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
 	} else {
 		writel(host->saved_tune_para.iocon, host->base + MSDC_IOCON);
 		writel(host->saved_tune_para.pad_tune, host->base + MSDC_PAD_TUNE);
+		writel(host->saved_tune_para.pad_cmd_tune,
+		       host->base + PAD_CMD_TUNE);
 	}
 
+	if (timing == MMC_TIMING_MMC_HS400)
+		sdr_set_field(host->base + PAD_CMD_TUNE,
+			      MSDC_PAD_TUNE_CMDRRDLY,
+			      host->hs400_cmd_int_delay);
 	dev_dbg(host->dev, "sclk: %d, timing: %d\n", host->sclk, timing);
 }
 
@@ -1303,7 +1321,7 @@ static struct msdc_delay_phase get_best_delay(struct msdc_host *host, u32 delay)
 			len_final = len;
 		}
 		start += len ? len : 1;
-		if (len >= 8 && start_final < 4)
+		if (len >= 12 && start_final < 4)
 			break;
 	}
 
@@ -1326,36 +1344,67 @@ static int msdc_tune_response(struct mmc_host *mmc, u32 opcode)
 	struct msdc_host *host = mmc_priv(mmc);
 	u32 rise_delay = 0, fall_delay = 0;
 	struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,};
+	struct msdc_delay_phase internal_delay_phase;
 	u8 final_delay, final_maxlen;
+	u32 internal_delay = 0;
 	int cmd_err;
-	int i;
+	int i, j;
+
+	if (mmc->ios.timing == MMC_TIMING_MMC_HS200 ||
+	    mmc->ios.timing == MMC_TIMING_UHS_SDR104)
+		sdr_set_field(host->base + MSDC_PAD_TUNE,
+			      MSDC_PAD_TUNE_CMDRRDLY,
+			      host->hs200_cmd_int_delay);
 
 	sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
 	for (i = 0 ; i < PAD_DELAY_MAX; i++) {
 		sdr_set_field(host->base + MSDC_PAD_TUNE,
 			      MSDC_PAD_TUNE_CMDRDLY, i);
-		mmc_send_tuning(mmc, opcode, &cmd_err);
-		if (!cmd_err)
-			rise_delay |= (1 << i);
+		/*
+		 * Using the same parameters, it may sometimes pass the test,
+		 * but sometimes it may fail. To make sure the parameters are
+		 * more stable, we test each set of parameters 3 times.
+		 */
+		for (j = 0; j < 3; j++) {
+			mmc_send_tuning(mmc, opcode, &cmd_err);
+			if (!cmd_err) {
+				rise_delay |= (1 << i);
+			} else {
+				rise_delay &= ~(1 << i);
+				break;
+			}
+		}
 	}
 	final_rise_delay = get_best_delay(host, rise_delay);
 	/* if rising edge has enough margin, then do not scan falling edge */
-	if (final_rise_delay.maxlen >= 10 ||
-	    (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4))
+	if (final_rise_delay.maxlen >= 12 && final_rise_delay.start < 4)
 		goto skip_fall;
 
 	sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
 	for (i = 0; i < PAD_DELAY_MAX; i++) {
 		sdr_set_field(host->base + MSDC_PAD_TUNE,
 			      MSDC_PAD_TUNE_CMDRDLY, i);
-		mmc_send_tuning(mmc, opcode, &cmd_err);
-		if (!cmd_err)
-			fall_delay |= (1 << i);
+		/*
+		 * Using the same parameters, it may sometimes pass the test,
+		 * but sometimes it may fail. To make sure the parameters are
+		 * more stable, we test each set of parameters 3 times.
+		 */
+		for (j = 0; j < 3; j++) {
+			mmc_send_tuning(mmc, opcode, &cmd_err);
+			if (!cmd_err) {
+				fall_delay |= (1 << i);
+			} else {
+				fall_delay &= ~(1 << i);
+				break;
+			}
+		}
 	}
 	final_fall_delay = get_best_delay(host, fall_delay);
 
 skip_fall:
 	final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
+	if (final_fall_delay.maxlen >= 12 && final_fall_delay.start < 4)
+		final_maxlen = final_fall_delay.maxlen;
 	if (final_maxlen == final_rise_delay.maxlen) {
 		sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
 		sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY,
@@ -1367,7 +1416,71 @@ static int msdc_tune_response(struct mmc_host *mmc, u32 opcode)
 			      final_fall_delay.final_phase);
 		final_delay = final_fall_delay.final_phase;
 	}
+	if (host->hs200_cmd_int_delay)
+		goto skip_internal;
+
+	for (i = 0; i < PAD_DELAY_MAX; i++) {
+		sdr_set_field(host->base + MSDC_PAD_TUNE,
+			      MSDC_PAD_TUNE_CMDRRDLY, i);
+		mmc_send_tuning(mmc, opcode, &cmd_err);
+		if (!cmd_err)
+			internal_delay |= (1 << i);
+	}
+	dev_dbg(host->dev, "Final internal delay: 0x%x\n", internal_delay);
+	internal_delay_phase = get_best_delay(host, internal_delay);
+	sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRRDLY,
+		      internal_delay_phase.final_phase);
+skip_internal:
+	dev_dbg(host->dev, "Final cmd pad delay: %x\n", final_delay);
+	return final_delay == 0xff ? -EIO : 0;
+}
+
+static int hs400_tune_response(struct mmc_host *mmc, u32 opcode)
+{
+	struct msdc_host *host = mmc_priv(mmc);
+	u32 cmd_delay = 0;
+	struct msdc_delay_phase final_cmd_delay = { 0,};
+	u8 final_delay;
+	int cmd_err;
+	int i, j;
+
+	/* select EMMC50 PAD CMD tune */
+	sdr_set_bits(host->base + PAD_CMD_TUNE, BIT(0));
+
+	if (mmc->ios.timing == MMC_TIMING_MMC_HS200 ||
+	    mmc->ios.timing == MMC_TIMING_UHS_SDR104)
+		sdr_set_field(host->base + MSDC_PAD_TUNE,
+			      MSDC_PAD_TUNE_CMDRRDLY,
+			      host->hs200_cmd_int_delay);
+
+	if (host->hs400_cmd_resp_sel_rising)
+		sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
+	else
+		sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
+	for (i = 0 ; i < PAD_DELAY_MAX; i++) {
+		sdr_set_field(host->base + PAD_CMD_TUNE,
+			      PAD_CMD_TUNE_RX_DLY3, i);
+		/*
+		 * Using the same parameters, it may sometimes pass the test,
+		 * but sometimes it may fail. To make sure the parameters are
+		 * more stable, we test each set of parameters 3 times.
+		 */
+		for (j = 0; j < 3; j++) {
+			mmc_send_tuning(mmc, opcode, &cmd_err);
+			if (!cmd_err) {
+				cmd_delay |= (1 << i);
+			} else {
+				cmd_delay &= ~(1 << i);
+				break;
+			}
+		}
+	}
+	final_cmd_delay = get_best_delay(host, cmd_delay);
+	sdr_set_field(host->base + PAD_CMD_TUNE, PAD_CMD_TUNE_RX_DLY3,
+		      final_cmd_delay.final_phase);
+	final_delay = final_cmd_delay.final_phase;
 
+	dev_dbg(host->dev, "Final cmd pad delay: %x\n", final_delay);
 	return final_delay == 0xff ? -EIO : 0;
 }
 
@@ -1390,7 +1503,7 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode)
 	}
 	final_rise_delay = get_best_delay(host, rise_delay);
 	/* if rising edge has enough margin, then do not scan falling edge */
-	if (final_rise_delay.maxlen >= 10 ||
+	if (final_rise_delay.maxlen >= 12 ||
 	    (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4))
 		goto skip_fall;
 
@@ -1423,6 +1536,7 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode)
 		final_delay = final_fall_delay.final_phase;
 	}
 
+	dev_dbg(host->dev, "Final data pad delay: %x\n", final_delay);
 	return final_delay == 0xff ? -EIO : 0;
 }
 
@@ -1431,7 +1545,10 @@ static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	struct msdc_host *host = mmc_priv(mmc);
 	int ret;
 
-	ret = msdc_tune_response(mmc, opcode);
+	if (host->hs400_mode)
+		ret = hs400_tune_response(mmc, opcode);
+	else
+		ret = msdc_tune_response(mmc, opcode);
 	if (ret == -EIO) {
 		dev_err(host->dev, "Tune response fail!\n");
 		return ret;
@@ -1444,6 +1561,7 @@ static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 
 	host->saved_tune_para.iocon = readl(host->base + MSDC_IOCON);
 	host->saved_tune_para.pad_tune = readl(host->base + MSDC_PAD_TUNE);
+	host->saved_tune_para.pad_cmd_tune = readl(host->base + PAD_CMD_TUNE);
 	return ret;
 }
 
@@ -1478,6 +1596,25 @@ static struct mmc_host_ops mt_msdc_ops = {
 	.hw_reset = msdc_hw_reset,
 };
 
+static void msdc_of_property_parse(struct platform_device *pdev,
+				   struct msdc_host *host)
+{
+	of_property_read_u32(pdev->dev.of_node, "hs400-ds-delay",
+			     &host->hs400_ds_delay);
+
+	of_property_read_u32(pdev->dev.of_node, "mediatek,hs200-cmd-int-delay",
+			     &host->hs200_cmd_int_delay);
+
+	of_property_read_u32(pdev->dev.of_node, "mediatek,hs400-cmd-int-delay",
+			     &host->hs400_cmd_int_delay);
+
+	if (of_property_read_bool(pdev->dev.of_node,
+				  "mediatek,hs400-cmd-resp-sel-rising"))
+		host->hs400_cmd_resp_sel_rising = true;
+	else
+		host->hs400_cmd_resp_sel_rising = false;
+}
+
 static int msdc_drv_probe(struct platform_device *pdev)
 {
 	struct mmc_host *mmc;
@@ -1549,10 +1686,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
 		goto host_free;
 	}
 
-	if (!of_property_read_u32(pdev->dev.of_node, "hs400-ds-delay",
-				  &host->hs400_ds_delay))
-		dev_dbg(&pdev->dev, "hs400-ds-delay: %x\n",
-			host->hs400_ds_delay);
+	msdc_of_property_parse(pdev, host);
 
 	host->dev = &pdev->dev;
 	host->mmc = mmc;
@@ -1664,6 +1798,7 @@ static void msdc_save_reg(struct msdc_host *host)
 	host->save_para.patch_bit0 = readl(host->base + MSDC_PATCH_BIT);
 	host->save_para.patch_bit1 = readl(host->base + MSDC_PATCH_BIT1);
 	host->save_para.pad_ds_tune = readl(host->base + PAD_DS_TUNE);
+	host->save_para.pad_cmd_tune = readl(host->base + PAD_CMD_TUNE);
 	host->save_para.emmc50_cfg0 = readl(host->base + EMMC50_CFG0);
 }
 
@@ -1676,6 +1811,7 @@ static void msdc_restore_reg(struct msdc_host *host)
 	writel(host->save_para.patch_bit0, host->base + MSDC_PATCH_BIT);
 	writel(host->save_para.patch_bit1, host->base + MSDC_PATCH_BIT1);
 	writel(host->save_para.pad_ds_tune, host->base + PAD_DS_TUNE);
+	writel(host->save_para.pad_cmd_tune, host->base + PAD_CMD_TUNE);
 	writel(host->save_para.emmc50_cfg0, host->base + EMMC50_CFG0);
 }