scsi: phy: mediatek: Add UFS M-PHY driver

Add UFS M-PHY driver on MediaTek chipsets.

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 245 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/phy-mtk-ufs.c b/drivers/phy/mediatek/phy-mtk-ufs.c
new file mode 100644
index 000000000000..9a80a76d7990
--- /dev/null
+++ b/drivers/phy/mediatek/phy-mtk-ufs.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 MediaTek Inc.
+ * Author: Stanley Chu <stanley.chu@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+/* mphy register and offsets */
+#define MP_GLB_DIG_8C               0x008C
+#define FRC_PLL_ISO_EN              BIT(8)
+#define PLL_ISO_EN                  BIT(9)
+#define FRC_FRC_PWR_ON              BIT(10)
+#define PLL_PWR_ON                  BIT(11)
+
+#define MP_LN_DIG_RX_9C             0xA09C
+#define FSM_DIFZ_FRC                BIT(18)
+
+#define MP_LN_DIG_RX_AC             0xA0AC
+#define FRC_RX_SQ_EN                BIT(0)
+#define RX_SQ_EN                    BIT(1)
+
+#define MP_LN_RX_44                 0xB044
+#define FRC_CDR_PWR_ON              BIT(17)
+#define CDR_PWR_ON                  BIT(18)
+#define FRC_CDR_ISO_EN              BIT(19)
+#define CDR_ISO_EN                  BIT(20)
+
+struct ufs_mtk_phy {
+	struct device *dev;
+	void __iomem *mmio;
+	struct clk *mp_clk;
+	struct clk *unipro_clk;
+};
+
+static inline u32 mphy_readl(struct ufs_mtk_phy *phy, u32 reg)
+{
+	return readl(phy->mmio + reg);
+}
+
+static inline void mphy_writel(struct ufs_mtk_phy *phy, u32 val, u32 reg)
+{
+	writel(val, phy->mmio + reg);
+}
+
+static void mphy_set_bit(struct ufs_mtk_phy *phy, u32 reg, u32 bit)
+{
+	u32 val;
+
+	val = mphy_readl(phy, reg);
+	val |= bit;
+	mphy_writel(phy, val, reg);
+}
+
+static void mphy_clr_bit(struct ufs_mtk_phy *phy, u32 reg, u32 bit)
+{
+	u32 val;
+
+	val = mphy_readl(phy, reg);
+	val &= ~bit;
+	mphy_writel(phy, val, reg);
+}
+
+static struct ufs_mtk_phy *get_ufs_mtk_phy(struct phy *generic_phy)
+{
+	return (struct ufs_mtk_phy *)phy_get_drvdata(generic_phy);
+}
+
+static int ufs_mtk_phy_clk_init(struct ufs_mtk_phy *phy)
+{
+	struct device *dev = phy->dev;
+
+	phy->unipro_clk = devm_clk_get(dev, "unipro");
+	if (IS_ERR(phy->unipro_clk)) {
+		dev_err(dev, "failed to get clock: unipro");
+		return PTR_ERR(phy->unipro_clk);
+	}
+
+	phy->mp_clk = devm_clk_get(dev, "mp");
+	if (IS_ERR(phy->mp_clk)) {
+		dev_err(dev, "failed to get clock: mp");
+		return PTR_ERR(phy->mp_clk);
+	}
+
+	return 0;
+}
+
+static void ufs_mtk_phy_set_active(struct ufs_mtk_phy *phy)
+{
+	/* release DA_MP_PLL_PWR_ON */
+	mphy_set_bit(phy, MP_GLB_DIG_8C, PLL_PWR_ON);
+	mphy_clr_bit(phy, MP_GLB_DIG_8C, FRC_FRC_PWR_ON);
+
+	/* release DA_MP_PLL_ISO_EN */
+	mphy_clr_bit(phy, MP_GLB_DIG_8C, PLL_ISO_EN);
+	mphy_clr_bit(phy, MP_GLB_DIG_8C, FRC_PLL_ISO_EN);
+
+	/* release DA_MP_CDR_PWR_ON */
+	mphy_set_bit(phy, MP_LN_RX_44, CDR_PWR_ON);
+	mphy_clr_bit(phy, MP_LN_RX_44, FRC_CDR_PWR_ON);
+
+	/* release DA_MP_CDR_ISO_EN */
+	mphy_clr_bit(phy, MP_LN_RX_44, CDR_ISO_EN);
+	mphy_clr_bit(phy, MP_LN_RX_44, FRC_CDR_ISO_EN);
+
+	/* release DA_MP_RX0_SQ_EN */
+	mphy_set_bit(phy, MP_LN_DIG_RX_AC, RX_SQ_EN);
+	mphy_clr_bit(phy, MP_LN_DIG_RX_AC, FRC_RX_SQ_EN);
+
+	/* delay 1us to wait DIFZ stable */
+	udelay(1);
+
+	/* release DIFZ */
+	mphy_clr_bit(phy, MP_LN_DIG_RX_9C, FSM_DIFZ_FRC);
+}
+
+static void ufs_mtk_phy_set_deep_hibern(struct ufs_mtk_phy *phy)
+{
+	/* force DIFZ */
+	mphy_set_bit(phy, MP_LN_DIG_RX_9C, FSM_DIFZ_FRC);
+
+	/* force DA_MP_RX0_SQ_EN */
+	mphy_set_bit(phy, MP_LN_DIG_RX_AC, FRC_RX_SQ_EN);
+	mphy_clr_bit(phy, MP_LN_DIG_RX_AC, RX_SQ_EN);
+
+	/* force DA_MP_CDR_ISO_EN */
+	mphy_set_bit(phy, MP_LN_RX_44, FRC_CDR_ISO_EN);
+	mphy_set_bit(phy, MP_LN_RX_44, CDR_ISO_EN);
+
+	/* force DA_MP_CDR_PWR_ON */
+	mphy_set_bit(phy, MP_LN_RX_44, FRC_CDR_PWR_ON);
+	mphy_clr_bit(phy, MP_LN_RX_44, CDR_PWR_ON);
+
+	/* force DA_MP_PLL_ISO_EN */
+	mphy_set_bit(phy, MP_GLB_DIG_8C, FRC_PLL_ISO_EN);
+	mphy_set_bit(phy, MP_GLB_DIG_8C, PLL_ISO_EN);
+
+	/* force DA_MP_PLL_PWR_ON */
+	mphy_set_bit(phy, MP_GLB_DIG_8C, FRC_FRC_PWR_ON);
+	mphy_clr_bit(phy, MP_GLB_DIG_8C, PLL_PWR_ON);
+}
+
+static int ufs_mtk_phy_power_on(struct phy *generic_phy)
+{
+	struct ufs_mtk_phy *phy = get_ufs_mtk_phy(generic_phy);
+	int ret;
+
+	ret = clk_prepare_enable(phy->unipro_clk);
+	if (ret) {
+		dev_err(phy->dev, "unipro_clk enable failed %d\n", ret);
+		goto out;
+	}
+
+	ret = clk_prepare_enable(phy->mp_clk);
+	if (ret) {
+		dev_err(phy->dev, "mp_clk enable failed %d\n", ret);
+		goto out_unprepare_unipro_clk;
+	}
+
+	ufs_mtk_phy_set_active(phy);
+
+	return 0;
+
+out_unprepare_unipro_clk:
+	clk_disable_unprepare(phy->unipro_clk);
+out:
+	return ret;
+}
+
+static int ufs_mtk_phy_power_off(struct phy *generic_phy)
+{
+	struct ufs_mtk_phy *phy = get_ufs_mtk_phy(generic_phy);
+
+	ufs_mtk_phy_set_deep_hibern(phy);
+
+	clk_disable_unprepare(phy->unipro_clk);
+	clk_disable_unprepare(phy->mp_clk);
+
+	return 0;
+}
+
+static const struct phy_ops ufs_mtk_phy_ops = {
+	.power_on       = ufs_mtk_phy_power_on,
+	.power_off      = ufs_mtk_phy_power_off,
+	.owner          = THIS_MODULE,
+};
+
+static int ufs_mtk_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy *generic_phy;
+	struct phy_provider *phy_provider;
+	struct resource *res;
+	struct ufs_mtk_phy *phy;
+	int ret;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	phy->mmio = devm_ioremap_resource(dev, res);
+	if (IS_ERR(phy->mmio))
+		return PTR_ERR(phy->mmio);
+
+	phy->dev = dev;
+
+	ret = ufs_mtk_phy_clk_init(phy);
+	if (ret)
+		return ret;
+
+	generic_phy = devm_phy_create(dev, NULL, &ufs_mtk_phy_ops);
+	if (IS_ERR(generic_phy))
+		return PTR_ERR(generic_phy);
+
+	phy_set_drvdata(generic_phy, phy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id ufs_mtk_phy_of_match[] = {
+	{.compatible = "mediatek,mt8183-ufsphy"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ufs_mtk_phy_of_match);
+
+static struct platform_driver ufs_mtk_phy_driver = {
+	.probe = ufs_mtk_phy_probe,
+	.driver = {
+		.of_match_table = ufs_mtk_phy_of_match,
+		.name = "ufs_mtk_phy",
+	},
+};
+module_platform_driver(ufs_mtk_phy_driver);
+
+MODULE_DESCRIPTION("Universal Flash Storage (UFS) MediaTek MPHY");
+MODULE_AUTHOR("Stanley Chu <stanley.chu@medaitek.com>");
+MODULE_LICENSE("GPL v2");