mmc: dw_mmc: add support for hi3798cv200 specific extensions of dw-mshc

Hi3798CV200 SoC extends the dw-mshc controller for additional clock
and bus control. Add support for these extensions.

Signed-off-by: tianshuliang <tianshuliang@hisilicon.com>
Signed-off-by: Jiancheng Xue <xuejiancheng@hisilicon.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/Kconfig

@@ -718,6 +718,15 @@ config MMC_DW_EXYNOS
 	  Synopsys DesignWare Memory Card Interface driver. Select this option
 	  for platforms based on Exynos4 and Exynos5 SoC's.
 
+config MMC_DW_HI3798CV200
+	tristate "Hi3798CV200 specific extensions for Synopsys DW Memory Card Interface"
+	depends on MMC_DW
+	select MMC_DW_PLTFM
+	help
+	  This selects support for HiSilicon Hi3798CV200 SoC specific extensions to the
+	  Synopsys DesignWare Memory Card Interface driver. Select this option
+	  for platforms based on HiSilicon Hi3798CV200 SoC.
+
 config MMC_DW_K3
 	tristate "K3 specific extensions for Synopsys DW Memory Card Interface"
 	depends on MMC_DW

drivers/mmc/host/Makefile

@@ -51,6 +51,7 @@ obj-$(CONFIG_MMC_CAVIUM_THUNDERX) += thunderx-mmc.o
 obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
 obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o
 obj-$(CONFIG_MMC_DW_EXYNOS)	+= dw_mmc-exynos.o
+obj-$(CONFIG_MMC_DW_HI3798CV200) += dw_mmc-hi3798cv200.o
 obj-$(CONFIG_MMC_DW_K3)		+= dw_mmc-k3.o
 obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
 obj-$(CONFIG_MMC_DW_ROCKCHIP)	+= dw_mmc-rockchip.o

drivers/mmc/host/dw_mmc-hi3798cv200.c

@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 HiSilicon Technologies Co., Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mmc/host.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+#define ALL_INT_CLR		0x1ffff
+
+struct hi3798cv200_priv {
+	struct clk *sample_clk;
+	struct clk *drive_clk;
+};
+
+static void dw_mci_hi3798cv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+	struct hi3798cv200_priv *priv = host->priv;
+	u32 val;
+
+	val = mci_readl(host, UHS_REG);
+	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
+	    ios->timing == MMC_TIMING_UHS_DDR50)
+		val |= SDMMC_UHS_DDR;
+	else
+		val &= ~SDMMC_UHS_DDR;
+	mci_writel(host, UHS_REG, val);
+
+	val = mci_readl(host, ENABLE_SHIFT);
+	if (ios->timing == MMC_TIMING_MMC_DDR52)
+		val |= SDMMC_ENABLE_PHASE;
+	else
+		val &= ~SDMMC_ENABLE_PHASE;
+	mci_writel(host, ENABLE_SHIFT, val);
+
+	val = mci_readl(host, DDR_REG);
+	if (ios->timing == MMC_TIMING_MMC_HS400)
+		val |= SDMMC_DDR_HS400;
+	else
+		val &= ~SDMMC_DDR_HS400;
+	mci_writel(host, DDR_REG, val);
+
+	if (ios->timing == MMC_TIMING_MMC_HS ||
+	    ios->timing == MMC_TIMING_LEGACY)
+		clk_set_phase(priv->drive_clk, 180);
+	else if (ios->timing == MMC_TIMING_MMC_HS200)
+		clk_set_phase(priv->drive_clk, 135);
+}
+
+static int dw_mci_hi3798cv200_execute_tuning(struct dw_mci_slot *slot,
+					     u32 opcode)
+{
+	int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
+	struct dw_mci *host = slot->host;
+	struct hi3798cv200_priv *priv = host->priv;
+	int raise_point = -1, fall_point = -1;
+	int err, prev_err = -1;
+	int found = 0;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(degrees); i++) {
+		clk_set_phase(priv->sample_clk, degrees[i]);
+		mci_writel(host, RINTSTS, ALL_INT_CLR);
+
+		err = mmc_send_tuning(slot->mmc, opcode, NULL);
+		if (!err)
+			found = 1;
+
+		if (i > 0) {
+			if (err && !prev_err)
+				fall_point = i - 1;
+			if (!err && prev_err)
+				raise_point = i;
+		}
+
+		if (raise_point != -1 && fall_point != -1)
+			goto tuning_out;
+
+		prev_err = err;
+		err = 0;
+	}
+
+tuning_out:
+	if (found) {
+		if (raise_point == -1)
+			raise_point = 0;
+		if (fall_point == -1)
+			fall_point = ARRAY_SIZE(degrees) - 1;
+		if (fall_point < raise_point) {
+			if ((raise_point + fall_point) >
+			    (ARRAY_SIZE(degrees) - 1))
+				i = fall_point / 2;
+			else
+				i = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
+		} else {
+			i = (raise_point + fall_point) / 2;
+		}
+
+		clk_set_phase(priv->sample_clk, degrees[i]);
+		dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
+			raise_point, fall_point, degrees[i]);
+	} else {
+		dev_err(host->dev, "No valid clk_sample shift! use default\n");
+		err = -EINVAL;
+	}
+
+	mci_writel(host, RINTSTS, ALL_INT_CLR);
+	return err;
+}
+
+static int dw_mci_hi3798cv200_init(struct dw_mci *host)
+{
+	struct hi3798cv200_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
+	if (IS_ERR(priv->sample_clk)) {
+		dev_err(host->dev, "failed to get ciu-sample clock\n");
+		return PTR_ERR(priv->sample_clk);
+	}
+
+	priv->drive_clk = devm_clk_get(host->dev, "ciu-drive");
+	if (IS_ERR(priv->drive_clk)) {
+		dev_err(host->dev, "failed to get ciu-drive clock\n");
+		return PTR_ERR(priv->drive_clk);
+	}
+
+	ret = clk_prepare_enable(priv->sample_clk);
+	if (ret) {
+		dev_err(host->dev, "failed to enable ciu-sample clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(priv->drive_clk);
+	if (ret) {
+		dev_err(host->dev, "failed to enable ciu-drive clock\n");
+		goto disable_sample_clk;
+	}
+
+	host->priv = priv;
+	return 0;
+
+disable_sample_clk:
+	clk_disable_unprepare(priv->sample_clk);
+	return ret;
+}
+
+static const struct dw_mci_drv_data hi3798cv200_data = {
+	.init = dw_mci_hi3798cv200_init,
+	.set_ios = dw_mci_hi3798cv200_set_ios,
+	.execute_tuning = dw_mci_hi3798cv200_execute_tuning,
+};
+
+static int dw_mci_hi3798cv200_probe(struct platform_device *pdev)
+{
+	return dw_mci_pltfm_register(pdev, &hi3798cv200_data);
+}
+
+static int dw_mci_hi3798cv200_remove(struct platform_device *pdev)
+{
+	struct dw_mci *host = platform_get_drvdata(pdev);
+	struct hi3798cv200_priv *priv = host->priv;
+
+	clk_disable_unprepare(priv->drive_clk);
+	clk_disable_unprepare(priv->sample_clk);
+
+	return dw_mci_pltfm_remove(pdev);
+}
+
+static const struct of_device_id dw_mci_hi3798cv200_match[] = {
+	{ .compatible = "hisilicon,hi3798cv200-dw-mshc", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, dw_mci_hi3798cv200_match);
+static struct platform_driver dw_mci_hi3798cv200_driver = {
+	.probe = dw_mci_hi3798cv200_probe,
+	.remove = dw_mci_hi3798cv200_remove,
+	.driver = {
+		.name = "dwmmc_hi3798cv200",
+		.of_match_table = dw_mci_hi3798cv200_match,
+	},
+};
+module_platform_driver(dw_mci_hi3798cv200_driver);
+
+MODULE_DESCRIPTION("HiSilicon Hi3798CV200 Specific DW-MSHC Driver Extension");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dwmmc_hi3798cv200");

drivers/mmc/host/dw_mmc.h

@@ -314,6 +314,7 @@ struct dw_mci_board {
 #define SDMMC_BUFADDR		0x098
 #define SDMMC_CDTHRCTL		0x100
 #define SDMMC_UHS_REG_EXT	0x108
+#define SDMMC_DDR_REG		0x10c
 #define SDMMC_ENABLE_SHIFT	0x110
 #define SDMMC_DATA(x)		(x)
 /*
@@ -439,7 +440,12 @@ struct dw_mci_board {
 #define SDMMC_CARD_WR_THR_EN		BIT(2)
 #define SDMMC_CARD_RD_THR_EN		BIT(0)
 /* UHS-1 register defines */
+#define SDMMC_UHS_DDR			BIT(16)
 #define SDMMC_UHS_18V			BIT(0)
+/* DDR register defines */
+#define SDMMC_DDR_HS400			BIT(31)
+/* Enable shift register defines */
+#define SDMMC_ENABLE_PHASE		BIT(0)
 /* All ctrl reset bits */
 #define SDMMC_CTRL_ALL_RESET_FLAGS \
 	(SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | SDMMC_CTRL_DMA_RESET)