mmc: sdhci_am654: Add Support for 8 bit IP on J721E

The 8 bit IP on the TI's J721E device departs from the AM654x IP in some
ways which require special handling. Create a driver_data structure
which holds the pltfm_data and a flags field which is used to indicate
these differences. These are the following:

1. The pins are not muxed with anything else inside the SoC and hence the
   IOMUX_ENABLE field does not exist. Add a flag which is used to
   indicate the presence of the field.

2. The register field used to select DLL frequency is 3 bit wide as
   compared to 2 bits in AM65x. Add another flag which differentiates
   between 3 bit and 2 bit fields.

3. The strobe select field is 8 bit wide as compared to 4 bits for
   AM65x. Add yet another flag to indicate this difference. Strobe select
   is used only for HS400 speed mode, support for which has not yet been
   added in AM65x.
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci_am654.c

@@ -6,6 +6,7 @@
  *
  */
 #include <linux/clk.h>
+#include <linux/of.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
@@ -36,11 +37,14 @@
 #define OTAPDLYSEL_SHIFT	12
 #define OTAPDLYSEL_MASK		GENMASK(15, 12)
 #define STRBSEL_SHIFT		24
-#define STRBSEL_MASK		GENMASK(27, 24)
+#define STRBSEL_4BIT_MASK	GENMASK(27, 24)
+#define STRBSEL_8BIT_MASK	GENMASK(31, 24)
 #define SEL50_SHIFT		8
 #define SEL50_MASK		BIT(SEL50_SHIFT)
 #define SEL100_SHIFT		9
 #define SEL100_MASK		BIT(SEL100_SHIFT)
+#define FREQSEL_SHIFT		8
+#define FREQSEL_MASK		GENMASK(10, 8)
 #define DLL_TRIM_ICP_SHIFT	4
 #define DLL_TRIM_ICP_MASK	GENMASK(7, 4)
 #define DR_TY_SHIFT		20
@@ -77,13 +81,23 @@ struct sdhci_am654_data {
 	int trm_icp;
 	int drv_strength;
 	bool dll_on;
+	int strb_sel;
+	u32 flags;
+};
+
+struct sdhci_am654_driver_data {
+	const struct sdhci_pltfm_data *pdata;
+	u32 flags;
+#define IOMUX_PRESENT	(1 << 0)
+#define FREQSEL_2_BIT	(1 << 1)
+#define STRBSEL_4_BIT	(1 << 2)
 };
 
 static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
-	int sel50, sel100;
+	int sel50, sel100, freqsel;
 	u32 mask, val;
 	int ret;
 
@@ -101,6 +115,19 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 		val = (1 << OTAPDLYENA_SHIFT) |
 		      (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
 		regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
+		/* Write to STRBSEL for HS400 speed mode */
+		if (host->mmc->ios.timing == MMC_TIMING_MMC_HS400) {
+			if (sdhci_am654->flags & STRBSEL_4_BIT)
+				mask = STRBSEL_4BIT_MASK;
+			else
+				mask = STRBSEL_8BIT_MASK;
+
+			regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask,
+					   sdhci_am654->strb_sel <<
+					   STRBSEL_SHIFT);
+		}
+
+		if (sdhci_am654->flags & FREQSEL_2_BIT) {
 			switch (clock) {
 			case 200000000:
 				sel50 = 0;
@@ -118,7 +145,22 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 			/* Configure PHY DLL frequency */
 			mask = SEL50_MASK | SEL100_MASK;
 			val = (sel50 << SEL50_SHIFT) | (sel100 << SEL100_SHIFT);
-		regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask, val);
+			regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask,
+					   val);
+		} else {
+			switch (clock) {
+			case 200000000:
+				freqsel = 0x0;
+				break;
+			default:
+				freqsel = 0x4;
+			}
+
+			regmap_update_bits(sdhci_am654->base, PHY_CTRL5,
+					   FREQSEL_MASK,
+					   freqsel << FREQSEL_SHIFT);
+		}
+
 		/* Configure DLL TRIM */
 		mask = DLL_TRIM_ICP_MASK;
 		val = sdhci_am654->trm_icp << DLL_TRIM_ICP_SHIFT;
@@ -196,6 +238,33 @@ static const struct sdhci_pltfm_data sdhci_am654_pdata = {
 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
 };
 
+static const struct sdhci_am654_driver_data sdhci_am654_drvdata = {
+	.pdata = &sdhci_am654_pdata,
+	.flags = IOMUX_PRESENT | FREQSEL_2_BIT | STRBSEL_4_BIT,
+};
+
+struct sdhci_ops sdhci_j721e_8bit_ops = {
+	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
+	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
+	.set_uhs_signaling = sdhci_set_uhs_signaling,
+	.set_bus_width = sdhci_set_bus_width,
+	.set_power = sdhci_am654_set_power,
+	.set_clock = sdhci_am654_set_clock,
+	.write_b = sdhci_am654_write_b,
+	.reset = sdhci_reset,
+};
+
+static const struct sdhci_pltfm_data sdhci_j721e_8bit_pdata = {
+	.ops = &sdhci_j721e_8bit_ops,
+	.quirks = SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+		  SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
+	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+};
+
+static const struct sdhci_am654_driver_data sdhci_j721e_8bit_drvdata = {
+	.pdata = &sdhci_j721e_8bit_pdata,
+};
+
 static int sdhci_am654_init(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -221,7 +290,9 @@ static int sdhci_am654_init(struct sdhci_host *host)
 	}
 
 	/* Enable pins by setting IO mux to 0 */
-	regmap_update_bits(sdhci_am654->base, PHY_CTRL1, IOMUX_ENABLE_MASK, 0);
+	if (sdhci_am654->flags & IOMUX_PRESENT)
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+				   IOMUX_ENABLE_MASK, 0);
 
 	/* Set slot type based on SD or eMMC */
 	if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
@@ -276,15 +347,31 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
 		return -EINVAL;
 	}
 
+	device_property_read_u32(dev, "ti,strobe-sel", &sdhci_am654->strb_sel);
+
 	sdhci_get_of_property(pdev);
 
 	return 0;
 }
 
+static const struct of_device_id sdhci_am654_of_match[] = {
+	{
+		.compatible = "ti,am654-sdhci-5.1",
+		.data = &sdhci_am654_drvdata,
+	},
+	{
+		.compatible = "ti,j721e-sdhci-8bit",
+		.data = &sdhci_j721e_8bit_drvdata,
+	},
+	{ /* sentinel */ }
+};
+
 static int sdhci_am654_probe(struct platform_device *pdev)
 {
+	const struct sdhci_am654_driver_data *drvdata;
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_am654_data *sdhci_am654;
+	const struct of_device_id *match;
 	struct sdhci_host *host;
 	struct resource *res;
 	struct clk *clk_xin;
@@ -292,12 +379,15 @@ static int sdhci_am654_probe(struct platform_device *pdev)
 	void __iomem *base;
 	int ret;
 
-	host = sdhci_pltfm_init(pdev, &sdhci_am654_pdata, sizeof(*sdhci_am654));
+	match = of_match_node(sdhci_am654_of_match, pdev->dev.of_node);
+	drvdata = match->data;
+	host = sdhci_pltfm_init(pdev, drvdata->pdata, sizeof(*sdhci_am654));
 	if (IS_ERR(host))
 		return PTR_ERR(host);
 
 	pltfm_host = sdhci_priv(host);
 	sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+	sdhci_am654->flags = drvdata->flags;
 
 	clk_xin = devm_clk_get(dev, "clk_xin");
 	if (IS_ERR(clk_xin)) {
@@ -372,11 +462,6 @@ static int sdhci_am654_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id sdhci_am654_of_match[] = {
-	{ .compatible = "ti,am654-sdhci-5.1" },
-	{ /* sentinel */ }
-};
-
 static struct platform_driver sdhci_am654_driver = {
 	.driver = {
 		.name = "sdhci-am654",