Date:   Fri, 7 Dec 2018 13:41:19 +0530
From:   Faiz Abbas <faiz_abbas@...com>
To:     <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <devicetree@...r.kernel.org>, <linux-mmc@...r.kernel.org>
CC:     <ulf.hansson@...aro.org>, <robh+dt@...nel.org>,
        <mark.rutland@....com>, <adrian.hunter@...el.com>,
        <michal.simek@...inx.com>, <kishon@...com>, <faiz_abbas@...com>
Subject: [PATCH v2 3/3] mmc: sdhci_am654: Add Initial Support for AM654 SDHCI driver

The host controllers on TI's AM654 SOCs are not compatible with
the phy and consumer model of the sdhci-of-arasan driver. It turns out
that for optimal operation at higher speeds, a special tuning procedure
needs to be implemented which involves configuration of platform
specific phy registers.

Therefore, branch out to a new sdhci_am654 driver and add the phy
register space with all phy configurations to it. Populate AM654
specific callbacks to sdhci_ops and add SDHCI_QUIRKS wherever
applicable.

Only add support for upto High Speed for SD card and upto DDR52 speed
mode for eMMC. Higher speeds will be added in subsequent patches.

Signed-off-by: Faiz Abbas <faiz_abbas@...com>
---
 drivers/mmc/host/Kconfig           |  12 +
 drivers/mmc/host/Makefile          |   1 +
 drivers/mmc/host/sdhci-of-arasan.c |  46 ----
 drivers/mmc/host/sdhci_am654.c     | 381 +++++++++++++++++++++++++++++
 4 files changed, 394 insertions(+), 46 deletions(-)
 create mode 100644 drivers/mmc/host/sdhci_am654.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739d9744..cfb2eb1a2c32 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -977,3 +977,15 @@ config MMC_SDHCI_OMAP
 	  If you have a controller with this interface, say Y or M here.
 
 	  If unsure, say N.
+
+config MMC_SDHCI_AM654
+	tristate "Support for the SDHCI Controller in TI's AM654 SOCs"
+	depends on MMC_SDHCI_PLTFM && OF
+	help
+	  This selects the Secure Digital Host Controller Interface (SDHCI)
+	  support present in TI's AM654 SOCs. The controller supports
+	  SD/MMC/SDIO devices.
+
+	  If you have a controller with this interface, say Y or M here.
+
+	  If unsure, say N.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 720d37777098..5c7770edc431 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_MMC_SDHCI_S3C)	+= sdhci-s3c.o
 obj-$(CONFIG_MMC_SDHCI_SIRF)   	+= sdhci-sirf.o
 obj-$(CONFIG_MMC_SDHCI_F_SDH30)	+= sdhci_f_sdh30.o
 obj-$(CONFIG_MMC_SDHCI_SPEAR)	+= sdhci-spear.o
+obj-$(CONFIG_MMC_SDHCI_AM654)	+= sdhci_am654.o
 obj-$(CONFIG_MMC_WBSD)		+= wbsd.o
 obj-$(CONFIG_MMC_AU1X)		+= au1xmmc.o
 obj-$(CONFIG_MMC_MTK)		+= mtk-sd.o
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 142c4b802f31..c9e3e050ccc8 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -231,25 +231,6 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 	}
 }
 
-static void sdhci_arasan_am654_set_clock(struct sdhci_host *host,
-					 unsigned int clock)
-{
-	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
-	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
-
-	if (sdhci_arasan->is_phy_on) {
-		phy_power_off(sdhci_arasan->phy);
-		sdhci_arasan->is_phy_on = false;
-	}
-
-	sdhci_set_clock(host, clock);
-
-	if (clock > PHY_CLK_TOO_SLOW_HZ) {
-		phy_power_on(sdhci_arasan->phy);
-		sdhci_arasan->is_phy_on = true;
-	}
-}
-
 static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
 					struct mmc_ios *ios)
 {
@@ -335,29 +316,6 @@ static struct sdhci_arasan_of_data sdhci_arasan_data = {
 	.pdata = &sdhci_arasan_pdata,
 };
 
-static const struct sdhci_ops sdhci_arasan_am654_ops = {
-	.set_clock = sdhci_arasan_am654_set_clock,
-	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
-	.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
-	.set_bus_width = sdhci_set_bus_width,
-	.reset = sdhci_arasan_reset,
-	.set_uhs_signaling = sdhci_set_uhs_signaling,
-};
-
-static const struct sdhci_pltfm_data sdhci_arasan_am654_pdata = {
-	.ops = &sdhci_arasan_am654_ops,
-	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN  |
-		  SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
-		  SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
-	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
-		   SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN |
-		   SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400,
-};
-
-static const struct sdhci_arasan_of_data sdhci_arasan_am654_data = {
-	.pdata = &sdhci_arasan_am654_pdata,
-};
-
 static u32 sdhci_arasan_cqhci_irq(struct sdhci_host *host, u32 intmask)
 {
 	int cmd_error = 0;
@@ -520,10 +478,6 @@ static const struct of_device_id sdhci_arasan_of_match[] = {
 		.compatible = "rockchip,rk3399-sdhci-5.1",
 		.data = &sdhci_arasan_rk3399_data,
 	},
-	{
-		.compatible = "ti,am654-sdhci-5.1",
-		.data = &sdhci_arasan_am654_data,
-	},
 	/* Generic compatible below here */
 	{
 		.compatible = "arasan,sdhci-8.9a",
diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
new file mode 100644
index 000000000000..6983438a45d0
--- /dev/null
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sdhci_am654.c - SDHCI driver for TI's AM654 SOCs
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
+ *
+ */
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include "sdhci-pltfm.h"
+
+/* CTL_CFG Registers */
+#define CTL_CFG_2		0x14
+
+#define SLOTTYPE_MASK		GENMASK(31, 30)
+#define SLOTTYPE_EMBEDDED	BIT(30)
+
+/* PHY Registers */
+#define PHY_CTRL1	0x100
+#define PHY_CTRL2	0x104
+#define PHY_CTRL3	0x108
+#define PHY_CTRL4	0x10C
+#define PHY_CTRL5	0x110
+#define PHY_CTRL6	0x114
+#define PHY_STAT1	0x130
+#define PHY_STAT2	0x134
+
+#define IOMUX_ENABLE_SHIFT	31
+#define IOMUX_ENABLE_MASK	BIT(IOMUX_ENABLE_SHIFT)
+#define OTAPDLYENA_SHIFT	20
+#define OTAPDLYENA_MASK		BIT(OTAPDLYENA_SHIFT)
+#define OTAPDLYSEL_SHIFT	12
+#define OTAPDLYSEL_MASK		GENMASK(15, 12)
+#define STRBSEL_SHIFT		24
+#define STRBSEL_MASK		GENMASK(27, 24)
+#define SEL50_SHIFT		8
+#define SEL50_MASK		BIT(SEL50_SHIFT)
+#define SEL100_SHIFT		9
+#define SEL100_MASK		BIT(SEL100_SHIFT)
+#define DLL_TRIM_ICP_SHIFT	4
+#define DLL_TRIM_ICP_MASK	GENMASK(7, 4)
+#define DR_TY_SHIFT		20
+#define DR_TY_MASK		GENMASK(22, 20)
+#define ENDLL_SHIFT		1
+#define ENDLL_MASK		BIT(ENDLL_SHIFT)
+#define DLLRDY_SHIFT		0
+#define DLLRDY_MASK		BIT(DLLRDY_SHIFT)
+#define PDB_SHIFT		0
+#define PDB_MASK		BIT(PDB_SHIFT)
+#define CALDONE_SHIFT		1
+#define CALDONE_MASK		BIT(CALDONE_SHIFT)
+#define RETRIM_SHIFT		17
+#define RETRIM_MASK		BIT(RETRIM_SHIFT)
+
+#define DRIVER_STRENGTH_50_OHM	0x0
+#define DRIVER_STRENGTH_33_OHM	0x1
+#define DRIVER_STRENGTH_66_OHM	0x2
+#define DRIVER_STRENGTH_100_OHM	0x3
+#define DRIVER_STRENGTH_40_OHM	0x4
+
+#define CLOCK_TOO_SLOW_HZ	400000
+
+static struct regmap_config sdhci_am654_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.fast_io = true,
+};
+
+struct sdhci_am654_data {
+	struct regmap *base;
+	struct clk *clk_ahb;
+	int otap_del_sel;
+	int trm_icp;
+	int drv_strength;
+	bool dll_on;
+};
+
+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;
+	u32 mask, val;
+	int ret;
+
+	if (sdhci_am654->dll_on) {
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+				   ENDLL_MASK, 0);
+
+		sdhci_am654->dll_on = false;
+	}
+
+	sdhci_set_clock(host, clock);
+
+	if (clock > CLOCK_TOO_SLOW_HZ) {
+		/* Setup DLL Output TAP delay */
+		mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
+		val = (1 << OTAPDLYENA_SHIFT) |
+		      (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL4,
+				   mask, val);
+		switch (clock) {
+		case 200000000:
+			sel50 = 0;
+			sel100 = 0;
+			break;
+		case 100000000:
+			sel50 = 0;
+			sel100 = 1;
+			break;
+		default:
+			sel50 = 1;
+			sel100 = 0;
+		}
+
+		/* 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);
+		/* Configure DLL TRIM */
+		mask = DLL_TRIM_ICP_MASK;
+		val = sdhci_am654->trm_icp << DLL_TRIM_ICP_SHIFT;
+
+		/* Configure DLL driver strength */
+		mask |= DR_TY_MASK;
+		val |= sdhci_am654->drv_strength << DR_TY_SHIFT;
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+				   mask, val);
+		/* Enable DLL */
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+				   ENDLL_MASK, 0x1 << ENDLL_SHIFT);
+		/*
+		 * Poll for DLL ready. Use a one second timeout.
+		 * Works in all experiments done so far
+		 */
+		ret = regmap_read_poll_timeout(sdhci_am654->base,
+					 PHY_STAT1, val,
+					 val & DLLRDY_MASK,
+					 1000, 1000000);
+
+		sdhci_am654->dll_on = true;
+	}
+}
+
+static void sdhci_am654_set_power(struct sdhci_host *host, unsigned char mode,
+				  unsigned short vdd)
+{
+	if (!IS_ERR(host->mmc->supply.vmmc)) {
+		struct mmc_host *mmc = host->mmc;
+
+		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
+	}
+	sdhci_set_power_noreg(host, mode, vdd);
+}
+
+struct sdhci_ops sdhci_am654_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,
+	.reset = sdhci_reset,
+};
+
+static const struct sdhci_pltfm_data sdhci_am654_pdata = {
+	.ops = &sdhci_am654_ops,
+	.quirks = SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+		  SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
+	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+};
+
+static int sdhci_am654_init(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+	u32 ctl_cfg_2 = 0;
+	u32 mask;
+	u32 val;
+	int ret;
+
+	/* Reset OTAP to default value */
+	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
+	regmap_update_bits(sdhci_am654->base, PHY_CTRL4,
+				   mask, 0x0);
+
+	regmap_read(sdhci_am654->base, PHY_STAT1, &val);
+	if (~val & CALDONE_MASK) {
+		/* Calibrate IO lines */
+		regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+				   PDB_MASK, PDB_MASK);
+		ret = regmap_read_poll_timeout(sdhci_am654->base, PHY_STAT1,
+					       val, val & CALDONE_MASK, 1, 20);
+		if (ret)
+			return ret;
+	}
+
+	/* Enable pins by setting IO mux to 0 */
+	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)
+		ctl_cfg_2 = SLOTTYPE_EMBEDDED;
+
+	regmap_update_bits(sdhci_am654->base, CTL_CFG_2,
+			   ctl_cfg_2, SLOTTYPE_MASK);
+
+	return sdhci_add_host(host);
+}
+
+static int sdhci_am654_get_of_property(struct platform_device *pdev,
+					struct sdhci_am654_data *sdhci_am654)
+{
+	struct device *dev = &pdev->dev;
+	int drv_strength;
+	int ret;
+
+	ret = device_property_read_u32(dev, "ti,trm-icp",
+				       &sdhci_am654->trm_icp);
+	if (ret)
+		return ret;
+
+	ret = device_property_read_u32(dev, "ti,otap-del-sel",
+				       &sdhci_am654->otap_del_sel);
+	if (ret)
+		return ret;
+
+	ret = device_property_read_u32(dev, "ti,driver-strength-ohm",
+				       &drv_strength);
+	if (ret)
+		return ret;
+
+	switch (drv_strength) {
+	case 50:
+		sdhci_am654->drv_strength = DRIVER_STRENGTH_50_OHM;
+		break;
+	case 33:
+		sdhci_am654->drv_strength = DRIVER_STRENGTH_33_OHM;
+		break;
+	case 66:
+		sdhci_am654->drv_strength = DRIVER_STRENGTH_66_OHM;
+		break;
+	case 100:
+		sdhci_am654->drv_strength = DRIVER_STRENGTH_100_OHM;
+		break;
+	case 40:
+		sdhci_am654->drv_strength = DRIVER_STRENGTH_40_OHM;
+		break;
+	default:
+		dev_err(dev, "Invalid driver strength\n");
+		return -EINVAL;
+	}
+
+	sdhci_get_of_property(pdev);
+
+	return 0;
+}
+
+static int sdhci_am654_probe(struct platform_device *pdev)
+{
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_am654_data *sdhci_am654;
+	struct sdhci_host *host;
+	struct resource *res;
+	struct clk *clk_xin;
+	struct device *dev = &pdev->dev;
+	void __iomem *base;
+	int ret;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_am654_pdata, sizeof(*sdhci_am654));
+	if (IS_ERR(host))
+		return PTR_ERR(host);
+
+	pltfm_host = sdhci_priv(host);
+	sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+
+	clk_xin = devm_clk_get(dev, "clk_xin");
+	if (IS_ERR(clk_xin)) {
+		dev_err(dev, "clk_xin clock not found.\n");
+		ret = PTR_ERR(clk_xin);
+		goto err_pltfm_free;
+	}
+
+	sdhci_am654->clk_ahb = devm_clk_get(dev, "clk_ahb");
+	if (IS_ERR(sdhci_am654->clk_ahb)) {
+		dev_err(dev, "clk_ahb clock not found.\n");
+		ret = PTR_ERR(sdhci_am654->clk_ahb);
+		goto err_pltfm_free;
+	}
+
+	pltfm_host->clk = clk_xin;
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		goto pm_runtime_disable;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
+		goto pm_runtime_put;
+	}
+
+	sdhci_am654->base = devm_regmap_init_mmio(dev, base,
+						  &sdhci_am654_regmap_config);
+	if (IS_ERR(sdhci_am654->base)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		ret = PTR_ERR(sdhci_am654->base);
+		goto pm_runtime_put;
+	}
+
+	ret = sdhci_am654_get_of_property(pdev, sdhci_am654);
+	if (ret)
+		goto pm_runtime_put;
+
+	ret = mmc_of_parse(host->mmc);
+	if (ret) {
+		dev_err(dev, "parsing dt failed (%d)\n", ret);
+		goto pm_runtime_put;
+	}
+
+	ret = sdhci_am654_init(host);
+	if (ret)
+		goto pm_runtime_put;
+
+	return 0;
+
+pm_runtime_put:
+	pm_runtime_put_sync(dev);
+pm_runtime_disable:
+	pm_runtime_disable(dev);
+err_pltfm_free:
+	sdhci_pltfm_free(pdev);
+	return ret;
+}
+
+static int sdhci_am654_remove(struct platform_device *pdev)
+{
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	int ret;
+
+	sdhci_remove_host(host, true);
+	ret = pm_runtime_put_sync(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	pm_runtime_disable(&pdev->dev);
+	sdhci_pltfm_free(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",
+		.of_match_table = sdhci_am654_of_match,
+	},
+	.probe = sdhci_am654_probe,
+	.remove = sdhci_am654_remove,
+};
+
+module_platform_driver(sdhci_am654_driver);
+
+MODULE_DESCRIPTION("Driver for SDHCI Controller on TI's AM654 devices");
+MODULE_AUTHOR("Faiz Abbas <faiz_abbas@...com>");
+MODULE_LICENSE("GPL");
-- 
2.19.2

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