PHY: Exynos: Add Exynos5250 SATA PHY driver

This patch adds the SATA PHY driver for Exynos5250.This driver uses the
generic PHY framework to deal with SATA PHY.Exynos5250 SATA PHY comprises
of CMU and TRSV blocks which are of I2C register Map.So this driver
configures the CMU and TRSV block of exynos5250 SATA PHY using i2c.

Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Vasanth Ananthan <vasanth.a@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 251 insertions, 0 deletions

diff --git a/drivers/phy/phy-exynos5250-sata.c b/drivers/phy/phy-exynos5250-sata.c
new file mode 100644
index 000000000000..c9361b731fa6
--- /dev/null
+++ b/drivers/phy/phy-exynos5250-sata.c
@@ -0,0 +1,251 @@
+/*
+ * Samsung SATA SerDes(PHY) driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Authors: Girish K S <ks.giri@samsung.com>
+ *         Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
+
+#define SATAPHY_CONTROL_OFFSET		0x0724
+#define EXYNOS5_SATAPHY_PMU_ENABLE	BIT(0)
+#define EXYNOS5_SATA_RESET		0x4
+#define RESET_GLOBAL_RST_N		BIT(0)
+#define RESET_CMN_RST_N			BIT(1)
+#define RESET_CMN_BLOCK_RST_N		BIT(2)
+#define RESET_CMN_I2C_RST_N		BIT(3)
+#define RESET_TX_RX_PIPE_RST_N		BIT(4)
+#define RESET_TX_RX_BLOCK_RST_N		BIT(5)
+#define RESET_TX_RX_I2C_RST_N		(BIT(6) | BIT(7))
+#define LINK_RESET			0xf0000
+#define EXYNOS5_SATA_MODE0		0x10
+#define SATA_SPD_GEN3			BIT(1)
+#define EXYNOS5_SATA_CTRL0		0x14
+#define CTRL0_P0_PHY_CALIBRATED_SEL	BIT(9)
+#define CTRL0_P0_PHY_CALIBRATED		BIT(8)
+#define EXYNOS5_SATA_PHSATA_CTRLM	0xe0
+#define PHCTRLM_REF_RATE		BIT(1)
+#define PHCTRLM_HIGH_SPEED		BIT(0)
+#define EXYNOS5_SATA_PHSATA_STATM	0xf0
+#define PHSTATM_PLL_LOCKED		BIT(0)
+
+#define PHY_PLL_TIMEOUT (usecs_to_jiffies(1000))
+
+struct exynos_sata_phy {
+	struct phy *phy;
+	struct clk *phyclk;
+	void __iomem *regs;
+	struct regmap *pmureg;
+	struct i2c_client *client;
+};
+
+static int wait_for_reg_status(void __iomem *base, u32 reg, u32 checkbit,
+				u32 status)
+{
+	unsigned long timeout = jiffies + PHY_PLL_TIMEOUT;
+
+	while (time_before(jiffies, timeout)) {
+		if ((readl(base + reg) & checkbit) == status)
+			return 0;
+	}
+
+	return -EFAULT;
+}
+
+static int exynos_sata_phy_power_on(struct phy *phy)
+{
+	struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
+
+	return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
+			EXYNOS5_SATAPHY_PMU_ENABLE, true);
+
+}
+
+static int exynos_sata_phy_power_off(struct phy *phy)
+{
+	struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
+
+	return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
+			EXYNOS5_SATAPHY_PMU_ENABLE, false);
+
+}
+
+static int exynos_sata_phy_init(struct phy *phy)
+{
+	u32 val = 0;
+	int ret = 0;
+	u8 buf[] = { 0x3a, 0x0b };
+	struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
+
+	ret = regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
+			EXYNOS5_SATAPHY_PMU_ENABLE, true);
+	if (ret != 0)
+		dev_err(&sata_phy->phy->dev, "phy init failed\n");
+
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
+	val |= RESET_GLOBAL_RST_N | RESET_CMN_RST_N | RESET_CMN_BLOCK_RST_N
+		| RESET_CMN_I2C_RST_N | RESET_TX_RX_PIPE_RST_N
+		| RESET_TX_RX_BLOCK_RST_N | RESET_TX_RX_I2C_RST_N;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
+	val |= LINK_RESET;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
+	val |= RESET_CMN_RST_N;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
+	val &= ~PHCTRLM_REF_RATE;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
+
+	/* High speed enable for Gen3 */
+	val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
+	val |= PHCTRLM_HIGH_SPEED;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_CTRL0);
+	val |= CTRL0_P0_PHY_CALIBRATED_SEL | CTRL0_P0_PHY_CALIBRATED;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_CTRL0);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_MODE0);
+	val |= SATA_SPD_GEN3;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_MODE0);
+
+	ret = i2c_master_send(sata_phy->client, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	/* release cmu reset */
+	val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
+	val &= ~RESET_CMN_RST_N;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
+	val |= RESET_CMN_RST_N;
+	writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
+
+	ret = wait_for_reg_status(sata_phy->regs,
+				EXYNOS5_SATA_PHSATA_STATM,
+				PHSTATM_PLL_LOCKED, 1);
+	if (ret < 0)
+		dev_err(&sata_phy->phy->dev,
+			"PHY PLL locking failed\n");
+	return ret;
+}
+
+static struct phy_ops exynos_sata_phy_ops = {
+	.init		= exynos_sata_phy_init,
+	.power_on	= exynos_sata_phy_power_on,
+	.power_off	= exynos_sata_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int exynos_sata_phy_probe(struct platform_device *pdev)
+{
+	struct exynos_sata_phy *sata_phy;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct phy_provider *phy_provider;
+	struct device_node *node;
+	int ret = 0;
+
+	sata_phy = devm_kzalloc(dev, sizeof(*sata_phy), GFP_KERNEL);
+	if (!sata_phy)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	sata_phy->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(sata_phy->regs))
+		return PTR_ERR(sata_phy->regs);
+
+	sata_phy->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
+					"samsung,syscon-phandle");
+	if (IS_ERR(sata_phy->pmureg)) {
+		dev_err(dev, "syscon regmap lookup failed.\n");
+		return PTR_ERR(sata_phy->pmureg);
+	}
+
+	node = of_parse_phandle(dev->of_node,
+			"samsung,exynos-sataphy-i2c-phandle", 0);
+	if (!node)
+		return -EINVAL;
+
+	sata_phy->client = of_find_i2c_device_by_node(node);
+	if (!sata_phy->client)
+		return -EPROBE_DEFER;
+
+	dev_set_drvdata(dev, sata_phy);
+
+	sata_phy->phyclk = devm_clk_get(dev, "sata_phyctrl");
+	if (IS_ERR(sata_phy->phyclk)) {
+		dev_err(dev, "failed to get clk for PHY\n");
+		return PTR_ERR(sata_phy->phyclk);
+	}
+
+	ret = clk_prepare_enable(sata_phy->phyclk);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable source clk\n");
+		return ret;
+	}
+
+	sata_phy->phy = devm_phy_create(dev, &exynos_sata_phy_ops, NULL);
+	if (IS_ERR(sata_phy->phy)) {
+		clk_disable_unprepare(sata_phy->phyclk);
+		dev_err(dev, "failed to create PHY\n");
+		return PTR_ERR(sata_phy->phy);
+	}
+
+	phy_set_drvdata(sata_phy->phy, sata_phy);
+
+	phy_provider = devm_of_phy_provider_register(dev,
+					of_phy_simple_xlate);
+	if (IS_ERR(phy_provider)) {
+		clk_disable_unprepare(sata_phy->phyclk);
+		return PTR_ERR(phy_provider);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id exynos_sata_phy_of_match[] = {
+	{ .compatible = "samsung,exynos5250-sata-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, exynos_sata_phy_of_match);
+
+static struct platform_driver exynos_sata_phy_driver = {
+	.probe	= exynos_sata_phy_probe,
+	.driver = {
+		.of_match_table	= exynos_sata_phy_of_match,
+		.name  = "samsung,sata-phy",
+		.owner = THIS_MODULE,
+	}
+};
+module_platform_driver(exynos_sata_phy_driver);
+
+MODULE_DESCRIPTION("Samsung SerDes PHY driver");
+MODULE_LICENSE("GPL V2");
+MODULE_AUTHOR("Girish K S <ks.giri@samsung.com>");
+MODULE_AUTHOR("Yuvaraj C D <yuvaraj.cd@samsung.com>");