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 {
  40         unsigned int    reg_offset;
  41         struct regmap   *reg_base;
  42         struct clk      *clk;
  43         struct phy      *phy;
  44 };
  45
  46 static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
  47                                            bool siddq)
  48 {
  49         return regmap_write(phy->reg_base, phy->reg_offset,
  50                             SIDDQ_WRITE_ENA | (siddq ? SIDDQ_ON : SIDDQ_OFF));
  51 }
  52
  53 static int rockchip_usb_phy_power_off(struct phy *_phy)
  54 {
  55         struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
  56         int ret = 0;
  57
  58         /* Power down usb phy analog blocks by set siddq 1 */
  59         ret = rockchip_usb_phy_power(phy, 1);
  60         if (ret)
  61                 return ret;
  62
  63         clk_disable_unprepare(phy->clk);
  64
  65         return 0;
  66 }
  67
  68 static int rockchip_usb_phy_power_on(struct phy *_phy)
  69 {
  70         struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
  71         int ret = 0;
  72
  73         ret = clk_prepare_enable(phy->clk);
  74         if (ret)
  75                 return ret;
  76
  77         /* Power up usb phy analog blocks by set siddq 0 */
  78         ret = rockchip_usb_phy_power(phy, 0);
  79         if (ret) {
  80                 clk_disable_unprepare(phy->clk);
  81                 return ret;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static const struct phy_ops ops = {
  88         .power_on       = rockchip_usb_phy_power_on,
  89         .power_off      = rockchip_usb_phy_power_off,
  90         .owner          = THIS_MODULE,
  91 };
  92
  93 static int rockchip_usb_phy_probe(struct platform_device *pdev)
  94 {
  95         struct device *dev = &pdev->dev;
  96         struct rockchip_usb_phy *rk_phy;
  97         struct phy_provider *phy_provider;
  98         struct device_node *child;
  99         struct regmap *grf;
 100         unsigned int reg_offset;
 101         int err;
 102
 103         grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
 104         if (IS_ERR(grf)) {
 105                 dev_err(&pdev->dev, "Missing rockchip,grf property\n");
 106                 return PTR_ERR(grf);
 107         }
 108
 109         for_each_available_child_of_node(dev->of_node, child) {
 110                 rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL);
 111                 if (!rk_phy) {
 112                         err = -ENOMEM;
 113                         goto put_child;
 114                 }
 115
 116                 if (of_property_read_u32(child, "reg", &reg_offset)) {
 117                         dev_err(dev, "missing reg property in node %s\n",
 118                                 child->name);
 119                         err = -EINVAL;
 120                         goto put_child;
 121                 }
 122
 123                 rk_phy->reg_offset = reg_offset;
 124                 rk_phy->reg_base = grf;
 125
 126                 rk_phy->clk = of_clk_get_by_name(child, "phyclk");
 127                 if (IS_ERR(rk_phy->clk))
 128                         rk_phy->clk = NULL;
 129
 130                 rk_phy->phy = devm_phy_create(dev, child, &ops);
 131                 if (IS_ERR(rk_phy->phy)) {
 132                         dev_err(dev, "failed to create PHY\n");
 133                         err = PTR_ERR(rk_phy->phy);
 134                         goto put_child;
 135                 }
 136                 phy_set_drvdata(rk_phy->phy, rk_phy);
 137
 138                 /* only power up usb phy when it use, so disable it when init*/
 139                 err = rockchip_usb_phy_power(rk_phy, 1);
 140                 if (err)
 141                         goto put_child;
 142         }
 143
 144         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 145         return PTR_ERR_OR_ZERO(phy_provider);
 146 put_child:
 147         of_node_put(child);
 148         return err;
 149 }
 150
 151 static const struct of_device_id rockchip_usb_phy_dt_ids[] = {
 152         { .compatible = "rockchip,rk3288-usb-phy" },
 153         {}
 154 };
 155
 156 MODULE_DEVICE_TABLE(of, rockchip_usb_phy_dt_ids);
 157
 158 static struct platform_driver rockchip_usb_driver = {
 159         .probe          = rockchip_usb_phy_probe,
 160         .driver         = {
 161                 .name   = "rockchip-usb-phy",
 162                 .of_match_table = rockchip_usb_phy_dt_ids,
 163         },
 164 };
 165
 166 module_platform_driver(rockchip_usb_driver);
 167
 168 MODULE_AUTHOR("Yunzhi Li <lyz@rock-chips.com>");
 169 MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");
 170 MODULE_LICENSE("GPL v2");