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");
155