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>

3 files changed, 267 insertions, 0 deletions

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 5bf9ed33e730..04312849501d 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -70,4 +70,19 @@ config BCM_KONA_USB2_PHY
         help
           Enable this to support the Broadcom Kona USB 2.0 PHY.
 
+config PHY_EXYNOS5250_SATA
+        tristate "Exynos5250 Sata SerDes/PHY driver"
+        depends on SOC_EXYNOS5250
+        depends on HAS_IOMEM
+        depends on OF
+        select GENERIC_PHY
+        select I2C
+        select I2C_S3C2410
+        select MFD_SYSCON
+        help
+          Enable this to support SATA SerDes/Phy found on Samsung's
+          Exynos5250 based SoCs.This SerDes/Phy supports SATA 1.5 Gb/s,
+          SATA 3.0 Gb/s, SATA 6.0 Gb/s speeds. It supports one SATA host
+          port to accept one SATA device.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index b57c25371cca..0d038224a102 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
 obj-$(CONFIG_PHY_MVEBU_SATA)            += phy-mvebu-sata.o
 obj-$(CONFIG_OMAP_USB2)                 += phy-omap-usb2.o
 obj-$(CONFIG_TWL4030_USB)               += phy-twl4030-usb.o
+obj-$(CONFIG_PHY_EXYNOS5250_SATA)       += phy-exynos5250-sata.o
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>");