linux/drivers/phy/phy-stih41x-usb.c
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   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 */
  36struct 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 */
  50struct stih41x_usb_phy {
  51        struct device *dev;
  52        struct regmap *regmap;
  53        const struct stih41x_usb_cfg *cfg;
  54        struct clk *clk;
  55};
  56
  57static struct stih41x_usb_cfg stih415_usb_phy_cfg = {
  58        .syscfg = SYSCFG332,
  59        .cfg_mask = 0x3f,
  60        .cfg = 0x38,
  61        .oscok = BIT(6),
  62};
  63
  64static struct stih41x_usb_cfg stih416_usb_phy_cfg = {
  65        .syscfg = SYSCFG2520,
  66        .cfg_mask = 0x33f,
  67        .cfg = 0x238,
  68        .oscok = BIT(6),
  69};
  70
  71static 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
  79static 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        return regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
  91                        phy_dev->cfg->oscok, phy_dev->cfg->oscok);
  92}
  93
  94static int stih41x_usb_phy_power_off(struct phy *phy)
  95{
  96        struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
  97        int ret;
  98
  99        ret = regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
 100                        phy_dev->cfg->oscok, 0);
 101        if (ret) {
 102                dev_err(phy_dev->dev, "Failed to clear oscok bit\n");
 103                return ret;
 104        }
 105
 106        clk_disable_unprepare(phy_dev->clk);
 107
 108        return 0;
 109}
 110
 111static struct phy_ops stih41x_usb_phy_ops = {
 112        .init           = stih41x_usb_phy_init,
 113        .power_on       = stih41x_usb_phy_power_on,
 114        .power_off      = stih41x_usb_phy_power_off,
 115        .owner          = THIS_MODULE,
 116};
 117
 118static const struct of_device_id stih41x_usb_phy_of_match[];
 119
 120static int stih41x_usb_phy_probe(struct platform_device *pdev)
 121{
 122        struct device_node *np = pdev->dev.of_node;
 123        const struct of_device_id *match;
 124        struct stih41x_usb_phy *phy_dev;
 125        struct device *dev = &pdev->dev;
 126        struct phy_provider *phy_provider;
 127        struct phy *phy;
 128
 129        phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
 130        if (!phy_dev)
 131                return -ENOMEM;
 132
 133        match = of_match_device(stih41x_usb_phy_of_match, &pdev->dev);
 134        if (!match)
 135                return -ENODEV;
 136
 137        phy_dev->cfg = match->data;
 138
 139        phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 140        if (IS_ERR(phy_dev->regmap)) {
 141                dev_err(dev, "No syscfg phandle specified\n");
 142                return PTR_ERR(phy_dev->regmap);
 143        }
 144
 145        phy_dev->clk = devm_clk_get(dev, "osc_phy");
 146        if (IS_ERR(phy_dev->clk)) {
 147                dev_err(dev, "osc_phy clk not found\n");
 148                return PTR_ERR(phy_dev->clk);
 149        }
 150
 151        phy = devm_phy_create(dev, NULL, &stih41x_usb_phy_ops);
 152
 153        if (IS_ERR(phy)) {
 154                dev_err(dev, "failed to create phy\n");
 155                return PTR_ERR(phy);
 156        }
 157
 158        phy_dev->dev = dev;
 159
 160        phy_set_drvdata(phy, phy_dev);
 161
 162        phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 163        return PTR_ERR_OR_ZERO(phy_provider);
 164}
 165
 166static const struct of_device_id stih41x_usb_phy_of_match[] = {
 167        { .compatible = "st,stih415-usb-phy", .data = &stih415_usb_phy_cfg },
 168        { .compatible = "st,stih416-usb-phy", .data = &stih416_usb_phy_cfg },
 169        { /* sentinel */ },
 170};
 171MODULE_DEVICE_TABLE(of, stih41x_usb_phy_of_match);
 172
 173static struct platform_driver stih41x_usb_phy_driver = {
 174        .probe  = stih41x_usb_phy_probe,
 175        .driver = {
 176                .name   = "stih41x-usb-phy",
 177                .of_match_table = stih41x_usb_phy_of_match,
 178        }
 179};
 180module_platform_driver(stih41x_usb_phy_driver);
 181
 182MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@st.com>");
 183MODULE_DESCRIPTION("STMicroelectronics USB PHY driver for STiH41x series");
 184MODULE_LICENSE("GPL v2");
 185