drivers/phy/phy-exynos5250-sata.c

   1 /*
   2  * Samsung SATA SerDes(PHY) driver
   3  *
   4  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   5  * Authors: Girish K S <ks.giri@samsung.com>
   6  *         Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/delay.h>
  15 #include <linux/io.h>
  16 #include <linux/i2c.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/of_address.h>
  21 #include <linux/phy/phy.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/regmap.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/mfd/syscon.h>
  26
  27 #define SATAPHY_CONTROL_OFFSET          0x0724
  28 #define EXYNOS5_SATAPHY_PMU_ENABLE      BIT(0)
  29 #define EXYNOS5_SATA_RESET              0x4
  30 #define RESET_GLOBAL_RST_N              BIT(0)
  31 #define RESET_CMN_RST_N                 BIT(1)
  32 #define RESET_CMN_BLOCK_RST_N           BIT(2)
  33 #define RESET_CMN_I2C_RST_N             BIT(3)
  34 #define RESET_TX_RX_PIPE_RST_N          BIT(4)
  35 #define RESET_TX_RX_BLOCK_RST_N         BIT(5)
  36 #define RESET_TX_RX_I2C_RST_N           (BIT(6) | BIT(7))
  37 #define LINK_RESET                      0xf0000
  38 #define EXYNOS5_SATA_MODE0              0x10
  39 #define SATA_SPD_GEN3                   BIT(1)
  40 #define EXYNOS5_SATA_CTRL0              0x14
  41 #define CTRL0_P0_PHY_CALIBRATED_SEL     BIT(9)
  42 #define CTRL0_P0_PHY_CALIBRATED         BIT(8)
  43 #define EXYNOS5_SATA_PHSATA_CTRLM       0xe0
  44 #define PHCTRLM_REF_RATE                BIT(1)
  45 #define PHCTRLM_HIGH_SPEED              BIT(0)
  46 #define EXYNOS5_SATA_PHSATA_STATM       0xf0
  47 #define PHSTATM_PLL_LOCKED              BIT(0)
  48
  49 #define PHY_PLL_TIMEOUT (usecs_to_jiffies(1000))
  50
  51 struct exynos_sata_phy {
  52         struct phy *phy;
  53         struct clk *phyclk;
  54         void __iomem *regs;
  55         struct regmap *pmureg;
  56         struct i2c_client *client;
  57 };
  58
  59 static int wait_for_reg_status(void __iomem *base, u32 reg, u32 checkbit,
  60                                 u32 status)
  61 {
  62         unsigned long timeout = jiffies + PHY_PLL_TIMEOUT;
  63
  64         while (time_before(jiffies, timeout)) {
  65                 if ((readl(base + reg) & checkbit) == status)
  66                         return 0;
  67         }
  68
  69         return -EFAULT;
  70 }
  71
  72 static int exynos_sata_phy_power_on(struct phy *phy)
  73 {
  74         struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
  75
  76         return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
  77                         EXYNOS5_SATAPHY_PMU_ENABLE, true);
  78
  79 }
  80
  81 static int exynos_sata_phy_power_off(struct phy *phy)
  82 {
  83         struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
  84
  85         return regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
  86                         EXYNOS5_SATAPHY_PMU_ENABLE, false);
  87
  88 }
  89
  90 static int exynos_sata_phy_init(struct phy *phy)
  91 {
  92         u32 val = 0;
  93         int ret = 0;
  94         u8 buf[] = { 0x3a, 0x0b };
  95         struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
  96
  97         ret = regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
  98                         EXYNOS5_SATAPHY_PMU_ENABLE, true);
  99         if (ret != 0)
 100                 dev_err(&sata_phy->phy->dev, "phy init failed\n");
 101
 102         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 103
 104         val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
 105         val |= RESET_GLOBAL_RST_N | RESET_CMN_RST_N | RESET_CMN_BLOCK_RST_N
 106                 | RESET_CMN_I2C_RST_N | RESET_TX_RX_PIPE_RST_N
 107                 | RESET_TX_RX_BLOCK_RST_N | RESET_TX_RX_I2C_RST_N;
 108         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 109
 110         val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
 111         val |= LINK_RESET;
 112         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 113
 114         val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
 115         val |= RESET_CMN_RST_N;
 116         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 117
 118         val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
 119         val &= ~PHCTRLM_REF_RATE;
 120         writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
 121
 122         /* High speed enable for Gen3 */
 123         val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
 124         val |= PHCTRLM_HIGH_SPEED;
 125         writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
 126
 127         val = readl(sata_phy->regs + EXYNOS5_SATA_CTRL0);
 128         val |= CTRL0_P0_PHY_CALIBRATED_SEL | CTRL0_P0_PHY_CALIBRATED;
 129         writel(val, sata_phy->regs + EXYNOS5_SATA_CTRL0);
 130
 131         val = readl(sata_phy->regs + EXYNOS5_SATA_MODE0);
 132         val |= SATA_SPD_GEN3;
 133         writel(val, sata_phy->regs + EXYNOS5_SATA_MODE0);
 134
 135         ret = i2c_master_send(sata_phy->client, buf, sizeof(buf));
 136         if (ret < 0)
 137                 return ret;
 138
 139         /* release cmu reset */
 140         val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
 141         val &= ~RESET_CMN_RST_N;
 142         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 143
 144         val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
 145         val |= RESET_CMN_RST_N;
 146         writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
 147
 148         ret = wait_for_reg_status(sata_phy->regs,
 149                                 EXYNOS5_SATA_PHSATA_STATM,
 150                                 PHSTATM_PLL_LOCKED, 1);
 151         if (ret < 0)
 152                 dev_err(&sata_phy->phy->dev,
 153                         "PHY PLL locking failed\n");
 154         return ret;
 155 }
 156
 157 static const struct phy_ops exynos_sata_phy_ops = {
 158         .init           = exynos_sata_phy_init,
 159         .power_on       = exynos_sata_phy_power_on,
 160         .power_off      = exynos_sata_phy_power_off,
 161         .owner          = THIS_MODULE,
 162 };
 163
 164 static int exynos_sata_phy_probe(struct platform_device *pdev)
 165 {
 166         struct exynos_sata_phy *sata_phy;
 167         struct device *dev = &pdev->dev;
 168         struct resource *res;
 169         struct phy_provider *phy_provider;
 170         struct device_node *node;
 171         int ret = 0;
 172
 173         sata_phy = devm_kzalloc(dev, sizeof(*sata_phy), GFP_KERNEL);
 174         if (!sata_phy)
 175                 return -ENOMEM;
 176
 177         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 178
 179         sata_phy->regs = devm_ioremap_resource(dev, res);
 180         if (IS_ERR(sata_phy->regs))
 181                 return PTR_ERR(sata_phy->regs);
 182
 183         sata_phy->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
 184                                         "samsung,syscon-phandle");
 185         if (IS_ERR(sata_phy->pmureg)) {
 186                 dev_err(dev, "syscon regmap lookup failed.\n");
 187                 return PTR_ERR(sata_phy->pmureg);
 188         }
 189
 190         node = of_parse_phandle(dev->of_node,
 191                         "samsung,exynos-sataphy-i2c-phandle", 0);
 192         if (!node)
 193                 return -EINVAL;
 194
 195         sata_phy->client = of_find_i2c_device_by_node(node);
 196         if (!sata_phy->client)
 197                 return -EPROBE_DEFER;
 198
 199         dev_set_drvdata(dev, sata_phy);
 200
 201         sata_phy->phyclk = devm_clk_get(dev, "sata_phyctrl");
 202         if (IS_ERR(sata_phy->phyclk)) {
 203                 dev_err(dev, "failed to get clk for PHY\n");
 204                 return PTR_ERR(sata_phy->phyclk);
 205         }
 206
 207         ret = clk_prepare_enable(sata_phy->phyclk);
 208         if (ret < 0) {
 209                 dev_err(dev, "failed to enable source clk\n");
 210                 return ret;
 211         }
 212
 213         sata_phy->phy = devm_phy_create(dev, NULL, &exynos_sata_phy_ops);
 214         if (IS_ERR(sata_phy->phy)) {
 215                 clk_disable_unprepare(sata_phy->phyclk);
 216                 dev_err(dev, "failed to create PHY\n");
 217                 return PTR_ERR(sata_phy->phy);
 218         }
 219
 220         phy_set_drvdata(sata_phy->phy, sata_phy);
 221
 222         phy_provider = devm_of_phy_provider_register(dev,
 223                                         of_phy_simple_xlate);
 224         if (IS_ERR(phy_provider)) {
 225                 clk_disable_unprepare(sata_phy->phyclk);
 226                 return PTR_ERR(phy_provider);
 227         }
 228
 229         return 0;
 230 }
 231
 232 static const struct of_device_id exynos_sata_phy_of_match[] = {
 233         { .compatible = "samsung,exynos5250-sata-phy" },
 234         { },
 235 };
 236 MODULE_DEVICE_TABLE(of, exynos_sata_phy_of_match);
 237
 238 static struct platform_driver exynos_sata_phy_driver = {
 239         .probe  = exynos_sata_phy_probe,
 240         .driver = {
 241                 .of_match_table = exynos_sata_phy_of_match,
 242                 .name  = "samsung,sata-phy",
 243         }
 244 };
 245 module_platform_driver(exynos_sata_phy_driver);
 246
 247 MODULE_DESCRIPTION("Samsung SerDes PHY driver");
 248 MODULE_LICENSE("GPL v2");
 249 MODULE_AUTHOR("Girish K S <ks.giri@samsung.com>");
 250 MODULE_AUTHOR("Yuvaraj C D <yuvaraj.cd@samsung.com>");