drivers/phy/phy-rockchip-dp.c

   1 /*
   2  * Rockchip DP PHY driver
   3  *
   4  * Copyright (C) 2016 FuZhou Rockchip Co., Ltd.
   5  * Author: Yakir Yang <ykk@@rock-chips.com>
   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
  12 #include <linux/clk.h>
  13 #include <linux/mfd/syscon.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/phy/phy.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/regmap.h>
  19
  20 #define GRF_SOC_CON12                           0x0274
  21
  22 #define GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK   BIT(20)
  23 #define GRF_EDP_REF_CLK_SEL_INTER               BIT(4)
  24
  25 #define GRF_EDP_PHY_SIDDQ_HIWORD_MASK           BIT(21)
  26 #define GRF_EDP_PHY_SIDDQ_ON                    0
  27 #define GRF_EDP_PHY_SIDDQ_OFF                   BIT(5)
  28
  29 struct rockchip_dp_phy {
  30         struct device  *dev;
  31         struct regmap  *grf;
  32         struct clk     *phy_24m;
  33 };
  34
  35 static int rockchip_set_phy_state(struct phy *phy, bool enable)
  36 {
  37         struct rockchip_dp_phy *dp = phy_get_drvdata(phy);
  38         int ret;
  39
  40         if (enable) {
  41                 ret = regmap_write(dp->grf, GRF_SOC_CON12,
  42                                    GRF_EDP_PHY_SIDDQ_HIWORD_MASK |
  43                                    GRF_EDP_PHY_SIDDQ_ON);
  44                 if (ret < 0) {
  45                         dev_err(dp->dev, "Can't enable PHY power %d\n", ret);
  46                         return ret;
  47                 }
  48
  49                 ret = clk_prepare_enable(dp->phy_24m);
  50         } else {
  51                 clk_disable_unprepare(dp->phy_24m);
  52
  53                 ret = regmap_write(dp->grf, GRF_SOC_CON12,
  54                                    GRF_EDP_PHY_SIDDQ_HIWORD_MASK |
  55                                    GRF_EDP_PHY_SIDDQ_OFF);
  56         }
  57
  58         return ret;
  59 }
  60
  61 static int rockchip_dp_phy_power_on(struct phy *phy)
  62 {
  63         return rockchip_set_phy_state(phy, true);
  64 }
  65
  66 static int rockchip_dp_phy_power_off(struct phy *phy)
  67 {
  68         return rockchip_set_phy_state(phy, false);
  69 }
  70
  71 static const struct phy_ops rockchip_dp_phy_ops = {
  72         .power_on       = rockchip_dp_phy_power_on,
  73         .power_off      = rockchip_dp_phy_power_off,
  74         .owner          = THIS_MODULE,
  75 };
  76
  77 static int rockchip_dp_phy_probe(struct platform_device *pdev)
  78 {
  79         struct device *dev = &pdev->dev;
  80         struct device_node *np = dev->of_node;
  81         struct phy_provider *phy_provider;
  82         struct rockchip_dp_phy *dp;
  83         struct phy *phy;
  84         int ret;
  85
  86         if (!np)
  87                 return -ENODEV;
  88
  89         if (!dev->parent || !dev->parent->of_node)
  90                 return -ENODEV;
  91
  92         dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
  93         if (!dp)
  94                 return -ENOMEM;
  95
  96         dp->dev = dev;
  97
  98         dp->phy_24m = devm_clk_get(dev, "24m");
  99         if (IS_ERR(dp->phy_24m)) {
 100                 dev_err(dev, "cannot get clock 24m\n");
 101                 return PTR_ERR(dp->phy_24m);
 102         }
 103
 104         ret = clk_set_rate(dp->phy_24m, 24000000);
 105         if (ret < 0) {
 106                 dev_err(dp->dev, "cannot set clock phy_24m %d\n", ret);
 107                 return ret;
 108         }
 109
 110         dp->grf = syscon_node_to_regmap(dev->parent->of_node);
 111         if (IS_ERR(dp->grf)) {
 112                 dev_err(dev, "rk3288-dp needs the General Register Files syscon\n");
 113                 return PTR_ERR(dp->grf);
 114         }
 115
 116         ret = regmap_write(dp->grf, GRF_SOC_CON12, GRF_EDP_REF_CLK_SEL_INTER |
 117                            GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK);
 118         if (ret != 0) {
 119                 dev_err(dp->dev, "Could not config GRF edp ref clk: %d\n", ret);
 120                 return ret;
 121         }
 122
 123         phy = devm_phy_create(dev, np, &rockchip_dp_phy_ops);
 124         if (IS_ERR(phy)) {
 125                 dev_err(dev, "failed to create phy\n");
 126                 return PTR_ERR(phy);
 127         }
 128         phy_set_drvdata(phy, dp);
 129
 130         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 131
 132         return PTR_ERR_OR_ZERO(phy_provider);
 133 }
 134
 135 static const struct of_device_id rockchip_dp_phy_dt_ids[] = {
 136         { .compatible = "rockchip,rk3288-dp-phy" },
 137         {}
 138 };
 139
 140 MODULE_DEVICE_TABLE(of, rockchip_dp_phy_dt_ids);
 141
 142 static struct platform_driver rockchip_dp_phy_driver = {
 143         .probe          = rockchip_dp_phy_probe,
 144         .driver         = {
 145                 .name   = "rockchip-dp-phy",
 146                 .of_match_table = rockchip_dp_phy_dt_ids,
 147         },
 148 };
 149
 150 module_platform_driver(rockchip_dp_phy_driver);
 151
 152 MODULE_AUTHOR("Yakir Yang <ykk@rock-chips.com>");
 153 MODULE_DESCRIPTION("Rockchip DP PHY driver");
 154 MODULE_LICENSE("GPL v2");