mmc: sdhci-of-dwcmshc: add support for rk3588

Add support for RK3588's DWCMSHC controller, which is used for
providing the rootfs on the RK3588 evaluation board.
Signed-off-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
[port from vendor BSP]
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20220504213251.264819-12-sebastian.reichel@collabora.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-of-dwcmshc.c

@@ -31,6 +31,7 @@
 /* Offset inside the  vendor area 1 */
 #define DWCMSHC_HOST_CTRL3		0x8
 #define DWCMSHC_EMMC_CONTROL		0x2c
+#define DWCMSHC_CARD_IS_EMMC		BIT(0)
 #define DWCMSHC_ENHANCED_STROBE		BIT(8)
 #define DWCMSHC_EMMC_ATCTRL		0x40
 
@@ -39,7 +40,7 @@
 #define DWCMSHC_EMMC_DLL_RXCLK		0x804
 #define DWCMSHC_EMMC_DLL_TXCLK		0x808
 #define DWCMSHC_EMMC_DLL_STRBIN		0x80c
-#define DLL_STRBIN_TAPNUM_FROM_SW	BIT(24)
+#define DECMSHC_EMMC_DLL_CMDOUT		0x810
 #define DWCMSHC_EMMC_DLL_STATUS0	0x840
 #define DWCMSHC_EMMC_DLL_START		BIT(0)
 #define DWCMSHC_EMMC_DLL_LOCKED		BIT(8)
@@ -48,11 +49,21 @@
 #define DWCMSHC_EMMC_DLL_START_POINT	16
 #define DWCMSHC_EMMC_DLL_INC		8
 #define DWCMSHC_EMMC_DLL_DLYENA		BIT(27)
-#define DLL_TXCLK_TAPNUM_DEFAULT	0x8
-#define DLL_STRBIN_TAPNUM_DEFAULT	0x8
+#define DLL_TXCLK_TAPNUM_DEFAULT	0x10
+#define DLL_TXCLK_TAPNUM_90_DEGREES	0xA
 #define DLL_TXCLK_TAPNUM_FROM_SW	BIT(24)
+#define DLL_STRBIN_TAPNUM_DEFAULT	0x8
+#define DLL_STRBIN_TAPNUM_FROM_SW	BIT(24)
+#define DLL_STRBIN_DELAY_NUM_SEL	BIT(26)
+#define DLL_STRBIN_DELAY_NUM_OFFSET	16
+#define DLL_STRBIN_DELAY_NUM_DEFAULT	0x16
 #define DLL_RXCLK_NO_INVERTER		1
 #define DLL_RXCLK_INVERTER		0
+#define DLL_CMDOUT_TAPNUM_90_DEGREES	0x8
+#define DLL_CMDOUT_TAPNUM_FROM_SW	BIT(24)
+#define DLL_CMDOUT_SRC_CLK_NEG		BIT(28)
+#define DLL_CMDOUT_EN_SRC_CLK_NEG	BIT(29)
+
 #define DLL_LOCK_WO_TMOUT(x) \
 	((((x) & DWCMSHC_EMMC_DLL_LOCKED) == DWCMSHC_EMMC_DLL_LOCKED) && \
 	(((x) & DWCMSHC_EMMC_DLL_TIMEOUT) == 0))
@@ -61,10 +72,16 @@
 #define BOUNDARY_OK(addr, len) \
 	((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
 
+enum dwcmshc_rk_type {
+	DWCMSHC_RK3568,
+	DWCMSHC_RK3588,
+};
+
 struct rk35xx_priv {
 	/* Rockchip specified optional clocks */
 	struct clk_bulk_data rockchip_clks[RK35xx_MAX_CLKS];
 	struct reset_control *reset;
+	enum dwcmshc_rk_type devtype;
 	u8 txclk_tapnum;
 };
 
@@ -133,7 +150,9 @@ static void dwcmshc_request(struct mmc_host *mmc, struct mmc_request *mrq)
 static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
 				      unsigned int timing)
 {
-	u16 ctrl_2;
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	u16 ctrl, ctrl_2;
 
 	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 	/* Select Bus Speed Mode for host */
@@ -151,8 +170,15 @@ static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
 	else if ((timing == MMC_TIMING_UHS_DDR50) ||
 		 (timing == MMC_TIMING_MMC_DDR52))
 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
-	else if (timing == MMC_TIMING_MMC_HS400)
+	else if (timing == MMC_TIMING_MMC_HS400) {
+		/* set CARD_IS_EMMC bit to enable Data Strobe for HS400 */
+		ctrl = sdhci_readw(host, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
+		ctrl |= DWCMSHC_CARD_IS_EMMC;
+		sdhci_writew(host, ctrl, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
+
 		ctrl_2 |= DWCMSHC_CTRL_HS400;
+	}
+
 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
 }
 
@@ -185,17 +211,11 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
 
 	host->mmc->actual_clock = 0;
 
-	/*
-	 * DO NOT TOUCH THIS SETTING. RX clk inverter unit is enabled
-	 * by default, but it shouldn't be enabled. We should anyway
-	 * disable it before issuing any cmds.
-	 */
-	extra = DWCMSHC_EMMC_DLL_DLYENA |
-		DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL;
-	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_RXCLK);
-
-	if (clock == 0)
+	if (clock == 0) {
+		/* Disable interface clock at initial state. */
+		sdhci_set_clock(host, clock);
 		return;
+	}
 
 	/* Rockchip platform only support 375KHz for identify mode */
 	if (clock <= 400000)
@@ -213,9 +233,21 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
 	extra &= ~BIT(0);
 	sdhci_writel(host, extra, reg);
 
-	if (clock <= 400000) {
-		/* Disable DLL to reset sample clock */
+	if (clock <= 52000000) {
+		/* Disable DLL and reset both of sample and drive clock */
 		sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_CTRL);
+		sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_RXCLK);
+		sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_TXCLK);
+		sdhci_writel(host, 0, DECMSHC_EMMC_DLL_CMDOUT);
+		/*
+		 * Before switching to hs400es mode, the driver will enable
+		 * enhanced strobe first. PHY needs to configure the parameters
+		 * of enhanced strobe first.
+		 */
+		extra = DWCMSHC_EMMC_DLL_DLYENA |
+			DLL_STRBIN_DELAY_NUM_SEL |
+			DLL_STRBIN_DELAY_NUM_DEFAULT << DLL_STRBIN_DELAY_NUM_OFFSET;
+		sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
 		return;
 	}
 
@@ -224,6 +256,15 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
 	udelay(1);
 	sdhci_writel(host, 0x0, DWCMSHC_EMMC_DLL_CTRL);
 
+	/*
+	 * We shouldn't set DLL_RXCLK_NO_INVERTER for identify mode but
+	 * we must set it in higher speed mode.
+	 */
+	extra = DWCMSHC_EMMC_DLL_DLYENA;
+	if (priv->devtype == DWCMSHC_RK3568)
+		extra |= DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL;
+	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_RXCLK);
+
 	/* Init DLL settings */
 	extra = 0x5 << DWCMSHC_EMMC_DLL_START_POINT |
 		0x2 << DWCMSHC_EMMC_DLL_INC |
@@ -246,8 +287,20 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock
 	    host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
 		txclk_tapnum = priv->txclk_tapnum;
 
+	if ((priv->devtype == DWCMSHC_RK3588) && host->mmc->ios.timing == MMC_TIMING_MMC_HS400) {
+		txclk_tapnum = DLL_TXCLK_TAPNUM_90_DEGREES;
+
+		extra = DLL_CMDOUT_SRC_CLK_NEG |
+			DLL_CMDOUT_EN_SRC_CLK_NEG |
+			DWCMSHC_EMMC_DLL_DLYENA |
+			DLL_CMDOUT_TAPNUM_90_DEGREES |
+			DLL_CMDOUT_TAPNUM_FROM_SW;
+		sdhci_writel(host, extra, DECMSHC_EMMC_DLL_CMDOUT);
+	}
+
 	extra = DWCMSHC_EMMC_DLL_DLYENA |
 		DLL_TXCLK_TAPNUM_FROM_SW |
+		DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL |
 		txclk_tapnum;
 	sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_TXCLK);
 
@@ -345,7 +398,25 @@ static int dwcmshc_rk35xx_init(struct sdhci_host *host, struct dwcmshc_priv *dwc
 	return 0;
 }
 
+static void dwcmshc_rk35xx_postinit(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
+{
+	/*
+	 * Don't support highspeed bus mode with low clk speed as we
+	 * cannot use DLL for this condition.
+	 */
+	if (host->mmc->f_max <= 52000000) {
+		dev_info(mmc_dev(host->mmc), "Disabling HS200/HS400, frequency too low (%d)\n",
+			 host->mmc->f_max);
+		host->mmc->caps2 &= ~(MMC_CAP2_HS200 | MMC_CAP2_HS400);
+		host->mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR);
+	}
+}
+
 static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
+	{
+		.compatible = "rockchip,rk3588-dwcmshc",
+		.data = &sdhci_dwcmshc_rk35xx_pdata,
+	},
 	{
 		.compatible = "rockchip,rk3568-dwcmshc",
 		.data = &sdhci_dwcmshc_rk35xx_pdata,
@@ -433,6 +504,11 @@ static int dwcmshc_probe(struct platform_device *pdev)
 			goto err_clk;
 		}
 
+		if (of_device_is_compatible(pdev->dev.of_node, "rockchip,rk3588-dwcmshc"))
+			rk_priv->devtype = DWCMSHC_RK3588;
+		else
+			rk_priv->devtype = DWCMSHC_RK3568;
+
 		priv->priv = rk_priv;
 
 		err = dwcmshc_rk35xx_init(host, priv);
@@ -442,12 +518,21 @@ static int dwcmshc_probe(struct platform_device *pdev)
 
 	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
 
-	err = sdhci_add_host(host);
+	err = sdhci_setup_host(host);
 	if (err)
 		goto err_clk;
 
+	if (rk_priv)
+		dwcmshc_rk35xx_postinit(host, priv);
+
+	err = __sdhci_add_host(host);
+	if (err)
+		goto err_setup_host;
+
 	return 0;
 
+err_setup_host:
+	sdhci_cleanup_host(host);
 err_clk:
 	clk_disable_unprepare(pltfm_host->clk);
 	clk_disable_unprepare(priv->bus_clk);