drivers/phy/phy-stih41x-usb.c

   1 /*
   2  * Copyright (C) 2014 STMicroelectronics
   3  *
   4  * STMicroelectronics PHY driver for STiH41x USB.
   5  *
   6  * Author: Maxime Coquelin <maxime.coquelin@st.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
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/clk.h>
  21 #include <linux/phy/phy.h>
  22 #include <linux/regmap.h>
  23 #include <linux/mfd/syscon.h>
  24
  25 #define SYSCFG332  0x80
  26 #define SYSCFG2520 0x820
  27
  28 /**
  29  * struct stih41x_usb_cfg - SoC specific PHY register mapping
  30  * @syscfg: Offset in syscfg registers bank
  31  * @cfg_mask: Bits mask for PHY configuration
  32  * @cfg: Static configuration value for PHY
  33  * @oscok: Notify the PHY oscillator clock is ready
  34  *         Setting this bit enable the PHY
  35  */
  36 struct stih41x_usb_cfg {
  37         u32 syscfg;
  38         u32 cfg_mask;
  39         u32 cfg;
  40         u32 oscok;
  41 };
  42
  43 /**
  44  * struct stih41x_usb_phy - Private data for the PHY
  45  * @dev: device for this controller
  46  * @regmap: Syscfg registers bank in which PHY is configured
  47  * @cfg: SoC specific PHY register mapping
  48  * @clk: Oscillator used by the PHY
  49  */
  50 struct stih41x_usb_phy {
  51         struct device *dev;
  52         struct regmap *regmap;
  53         const struct stih41x_usb_cfg *cfg;
  54         struct clk *clk;
  55 };
  56
  57 static struct stih41x_usb_cfg stih415_usb_phy_cfg = {
  58         .syscfg = SYSCFG332,
  59         .cfg_mask = 0x3f,
  60         .cfg = 0x38,
  61         .oscok = BIT(6),
  62 };
  63
  64 static struct stih41x_usb_cfg stih416_usb_phy_cfg = {
  65         .syscfg = SYSCFG2520,
  66         .cfg_mask = 0x33f,
  67         .cfg = 0x238,
  68         .oscok = BIT(6),
  69 };
  70
  71 static int stih41x_usb_phy_init(struct phy *phy)
  72 {
  73         struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
  74
  75         return regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
  76                            phy_dev->cfg->cfg_mask, phy_dev->cfg->cfg);
  77 }
  78
  79 static int stih41x_usb_phy_power_on(struct phy *phy)
  80 {
  81         struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
  82         int ret;
  83
  84         ret = clk_prepare_enable(phy_dev->clk);
  85         if (ret) {
  86                 dev_err(phy_dev->dev, "Failed to enable osc_phy clock\n");
  87                 return ret;
  88         }
  89
  90         ret = regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
  91                                  phy_dev->cfg->oscok, phy_dev->cfg->oscok);
  92         if (ret)
  93                 clk_disable_unprepare(phy_dev->clk);
  94
  95         return ret;
  96 }
  97
  98 static int stih41x_usb_phy_power_off(struct phy *phy)
  99 {
 100         struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
 101         int ret;
 102
 103         ret = regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
 104                         phy_dev->cfg->oscok, 0);
 105         if (ret) {
 106                 dev_err(phy_dev->dev, "Failed to clear oscok bit\n");
 107                 return ret;
 108         }
 109
 110         clk_disable_unprepare(phy_dev->clk);
 111
 112         return 0;
 113 }
 114
 115 static struct phy_ops stih41x_usb_phy_ops = {
 116         .init           = stih41x_usb_phy_init,
 117         .power_on       = stih41x_usb_phy_power_on,
 118         .power_off      = stih41x_usb_phy_power_off,
 119         .owner          = THIS_MODULE,
 120 };
 121
 122 static const struct of_device_id stih41x_usb_phy_of_match[];
 123
 124 static int stih41x_usb_phy_probe(struct platform_device *pdev)
 125 {
 126         struct device_node *np = pdev->dev.of_node;
 127         const struct of_device_id *match;
 128         struct stih41x_usb_phy *phy_dev;
 129         struct device *dev = &pdev->dev;
 130         struct phy_provider *phy_provider;
 131         struct phy *phy;
 132
 133         phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
 134         if (!phy_dev)
 135                 return -ENOMEM;
 136
 137         match = of_match_device(stih41x_usb_phy_of_match, &pdev->dev);
 138         if (!match)
 139                 return -ENODEV;
 140
 141         phy_dev->cfg = match->data;
 142
 143         phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 144         if (IS_ERR(phy_dev->regmap)) {
 145                 dev_err(dev, "No syscfg phandle specified\n");
 146                 return PTR_ERR(phy_dev->regmap);
 147         }
 148
 149         phy_dev->clk = devm_clk_get(dev, "osc_phy");
 150         if (IS_ERR(phy_dev->clk)) {
 151                 dev_err(dev, "osc_phy clk not found\n");
 152                 return PTR_ERR(phy_dev->clk);
 153         }
 154
 155         phy = devm_phy_create(dev, NULL, &stih41x_usb_phy_ops);
 156
 157         if (IS_ERR(phy)) {
 158                 dev_err(dev, "failed to create phy\n");
 159                 return PTR_ERR(phy);
 160         }
 161
 162         phy_dev->dev = dev;
 163
 164         phy_set_drvdata(phy, phy_dev);
 165
 166         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 167         return PTR_ERR_OR_ZERO(phy_provider);
 168 }
 169
 170 static const struct of_device_id stih41x_usb_phy_of_match[] = {
 171         { .compatible = "st,stih415-usb-phy", .data = &stih415_usb_phy_cfg },
 172         { .compatible = "st,stih416-usb-phy", .data = &stih416_usb_phy_cfg },
 173         { /* sentinel */ },
 174 };
 175 MODULE_DEVICE_TABLE(of, stih41x_usb_phy_of_match);
 176
 177 static struct platform_driver stih41x_usb_phy_driver = {
 178         .probe  = stih41x_usb_phy_probe,
 179         .driver = {
 180                 .name   = "stih41x-usb-phy",
 181                 .of_match_table = stih41x_usb_phy_of_match,
 182         }
 183 };
 184 module_platform_driver(stih41x_usb_phy_driver);
 185
 186 MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@st.com>");
 187 MODULE_DESCRIPTION("STMicroelectronics USB PHY driver for STiH41x series");
 188 MODULE_LICENSE("GPL v2");