drivers/phy/phy-rockchip-usb.c

   1 /*
   2  * Rockchip usb PHY driver
   3  *
   4  * Copyright (C) 2014 Yunzhi Li <lyz@rock-chips.com>
   5  * Copyright (C) 2014 ROCKCHIP, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk.h>
  18 #include <linux/io.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/of.h>
  23 #include <linux/of_address.h>
  24 #include <linux/phy/phy.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/regulator/consumer.h>
  27 #include <linux/reset.h>
  28 #include <linux/regmap.h>
  29 #include <linux/mfd/syscon.h>
  30
  31 /*
  32  * The higher 16-bit of this register is used for write protection
  33  * only if BIT(13 + 16) set to 1 the BIT(13) can be written.
  34  */
  35 #define SIDDQ_WRITE_ENA BIT(29)
  36 #define SIDDQ_ON                BIT(13)
  37 #define SIDDQ_OFF               (0 << 13)
  38
  39 struct rockchip_usb_phy_base {
  40         struct device *dev;
  41         struct regmap *reg_base;
  42 };
  43
  44 struct rockchip_usb_phy {
  45         struct rockchip_usb_phy_base *base;
  46         unsigned int    reg_offset;
  47         struct clk      *clk;
  48         struct phy      *phy;
  49 };
  50
  51 static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
  52                                            bool siddq)
  53 {
  54         return regmap_write(phy->base->reg_base, phy->reg_offset,
  55                             SIDDQ_WRITE_ENA | (siddq ? SIDDQ_ON : SIDDQ_OFF));
  56 }
  57
  58 static int rockchip_usb_phy_power_off(struct phy *_phy)
  59 {
  60         struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
  61         int ret = 0;
  62
  63         /* Power down usb phy analog blocks by set siddq 1 */
  64         ret = rockchip_usb_phy_power(phy, 1);
  65         if (ret)
  66                 return ret;
  67
  68         clk_disable_unprepare(phy->clk);
  69
  70         return 0;
  71 }
  72
  73 static int rockchip_usb_phy_power_on(struct phy *_phy)
  74 {
  75         struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
  76         int ret = 0;
  77
  78         ret = clk_prepare_enable(phy->clk);
  79         if (ret)
  80                 return ret;
  81
  82         /* Power up usb phy analog blocks by set siddq 0 */
  83         ret = rockchip_usb_phy_power(phy, 0);
  84         if (ret) {
  85                 clk_disable_unprepare(phy->clk);
  86                 return ret;
  87         }
  88
  89         return 0;
  90 }
  91
  92 static const struct phy_ops ops = {
  93         .power_on       = rockchip_usb_phy_power_on,
  94         .power_off      = rockchip_usb_phy_power_off,
  95         .owner          = THIS_MODULE,
  96 };
  97
  98 static void rockchip_usb_phy_action(void *data)
  99 {
 100         struct rockchip_usb_phy *rk_phy = data;
 101
 102         if (rk_phy->clk)
 103                 clk_put(rk_phy->clk);
 104 }
 105
 106 static int rockchip_usb_phy_init(struct rockchip_usb_phy_base *base,
 107                                  struct device_node *child)
 108 {
 109         struct rockchip_usb_phy *rk_phy;
 110         unsigned int reg_offset;
 111         int err;
 112
 113         rk_phy = devm_kzalloc(base->dev, sizeof(*rk_phy), GFP_KERNEL);
 114         if (!rk_phy)
 115                 return -ENOMEM;
 116
 117         rk_phy->base = base;
 118
 119         if (of_property_read_u32(child, "reg", &reg_offset)) {
 120                 dev_err(base->dev, "missing reg property in node %s\n",
 121                         child->name);
 122                 return -EINVAL;
 123         }
 124
 125         rk_phy->reg_offset = reg_offset;
 126
 127         err = devm_add_action(base->dev, rockchip_usb_phy_action, rk_phy);
 128         if (err)
 129                 return err;
 130
 131         rk_phy->clk = of_clk_get_by_name(child, "phyclk");
 132         if (IS_ERR(rk_phy->clk))
 133                 rk_phy->clk = NULL;
 134
 135         rk_phy->phy = devm_phy_create(base->dev, child, &ops);
 136         if (IS_ERR(rk_phy->phy)) {
 137                 dev_err(base->dev, "failed to create PHY\n");
 138                 return PTR_ERR(rk_phy->phy);
 139         }
 140         phy_set_drvdata(rk_phy->phy, rk_phy);
 141
 142         /* only power up usb phy when it use, so disable it when init*/
 143         return rockchip_usb_phy_power(rk_phy, 1);
 144 }
 145
 146 static int rockchip_usb_phy_probe(struct platform_device *pdev)
 147 {
 148         struct device *dev = &pdev->dev;
 149         struct rockchip_usb_phy_base *phy_base;
 150         struct phy_provider *phy_provider;
 151         struct device_node *child;
 152         int err;
 153
 154         phy_base = devm_kzalloc(dev, sizeof(*phy_base), GFP_KERNEL);
 155         if (!phy_base)
 156                 return -ENOMEM;
 157
 158         phy_base->dev = dev;
 159         phy_base->reg_base = syscon_regmap_lookup_by_phandle(dev->of_node,
 160                                                              "rockchip,grf");
 161         if (IS_ERR(phy_base->reg_base)) {
 162                 dev_err(&pdev->dev, "Missing rockchip,grf property\n");
 163                 return PTR_ERR(phy_base->reg_base);
 164         }
 165
 166         for_each_available_child_of_node(dev->of_node, child) {
 167                 err = rockchip_usb_phy_init(phy_base, child);
 168                 if (err) {
 169                         of_node_put(child);
 170                         return err;
 171                 }
 172         }
 173
 174         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 175         return PTR_ERR_OR_ZERO(phy_provider);
 176 }
 177
 178 static const struct of_device_id rockchip_usb_phy_dt_ids[] = {
 179         { .compatible = "rockchip,rk3288-usb-phy" },
 180         {}
 181 };
 182
 183 MODULE_DEVICE_TABLE(of, rockchip_usb_phy_dt_ids);
 184
 185 static struct platform_driver rockchip_usb_driver = {
 186         .probe          = rockchip_usb_phy_probe,
 187         .driver         = {
 188                 .name   = "rockchip-usb-phy",
 189                 .of_match_table = rockchip_usb_phy_dt_ids,
 190         },
 191 };
 192
 193 module_platform_driver(rockchip_usb_driver);
 194
 195 MODULE_AUTHOR("Yunzhi Li <lyz@rock-chips.com>");
 196 MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");
 197 MODULE_LICENSE("GPL v2");