1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Rockchip DP PHY driver
4  *
5  * Copyright (C) 2016 FuZhou Rockchip Co., Ltd.
6  * Author: Yakir Yang <ykk@@rock-chips.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/phy/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 
17 #define GRF_SOC_CON12                           0x0274
18 
19 #define GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK   BIT(20)
20 #define GRF_EDP_REF_CLK_SEL_INTER               BIT(4)
21 
22 #define GRF_EDP_PHY_SIDDQ_HIWORD_MASK           BIT(21)
23 #define GRF_EDP_PHY_SIDDQ_ON                    0
24 #define GRF_EDP_PHY_SIDDQ_OFF                   BIT(5)
25 
26 struct rockchip_dp_phy {
27 	struct device  *dev;
28 	struct regmap  *grf;
29 	struct clk     *phy_24m;
30 };
31 
32 static int rockchip_set_phy_state(struct phy *phy, bool enable)
33 {
34 	struct rockchip_dp_phy *dp = phy_get_drvdata(phy);
35 	int ret;
36 
37 	if (enable) {
38 		ret = regmap_write(dp->grf, GRF_SOC_CON12,
39 				   GRF_EDP_PHY_SIDDQ_HIWORD_MASK |
40 				   GRF_EDP_PHY_SIDDQ_ON);
41 		if (ret < 0) {
42 			dev_err(dp->dev, "Can't enable PHY power %d\n", ret);
43 			return ret;
44 		}
45 
46 		ret = clk_prepare_enable(dp->phy_24m);
47 	} else {
48 		clk_disable_unprepare(dp->phy_24m);
49 
50 		ret = regmap_write(dp->grf, GRF_SOC_CON12,
51 				   GRF_EDP_PHY_SIDDQ_HIWORD_MASK |
52 				   GRF_EDP_PHY_SIDDQ_OFF);
53 	}
54 
55 	return ret;
56 }
57 
58 static int rockchip_dp_phy_power_on(struct phy *phy)
59 {
60 	return rockchip_set_phy_state(phy, true);
61 }
62 
63 static int rockchip_dp_phy_power_off(struct phy *phy)
64 {
65 	return rockchip_set_phy_state(phy, false);
66 }
67 
68 static const struct phy_ops rockchip_dp_phy_ops = {
69 	.power_on	= rockchip_dp_phy_power_on,
70 	.power_off	= rockchip_dp_phy_power_off,
71 	.owner		= THIS_MODULE,
72 };
73 
74 static int rockchip_dp_phy_probe(struct platform_device *pdev)
75 {
76 	struct device *dev = &pdev->dev;
77 	struct device_node *np = dev->of_node;
78 	struct phy_provider *phy_provider;
79 	struct rockchip_dp_phy *dp;
80 	struct phy *phy;
81 	int ret;
82 
83 	if (!np)
84 		return -ENODEV;
85 
86 	if (!dev->parent || !dev->parent->of_node)
87 		return -ENODEV;
88 
89 	dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
90 	if (!dp)
91 		return -ENOMEM;
92 
93 	dp->dev = dev;
94 
95 	dp->phy_24m = devm_clk_get(dev, "24m");
96 	if (IS_ERR(dp->phy_24m)) {
97 		dev_err(dev, "cannot get clock 24m\n");
98 		return PTR_ERR(dp->phy_24m);
99 	}
100 
101 	ret = clk_set_rate(dp->phy_24m, 24000000);
102 	if (ret < 0) {
103 		dev_err(dp->dev, "cannot set clock phy_24m %d\n", ret);
104 		return ret;
105 	}
106 
107 	dp->grf = syscon_node_to_regmap(dev->parent->of_node);
108 	if (IS_ERR(dp->grf)) {
109 		dev_err(dev, "rk3288-dp needs the General Register Files syscon\n");
110 		return PTR_ERR(dp->grf);
111 	}
112 
113 	ret = regmap_write(dp->grf, GRF_SOC_CON12, GRF_EDP_REF_CLK_SEL_INTER |
114 			   GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK);
115 	if (ret != 0) {
116 		dev_err(dp->dev, "Could not config GRF edp ref clk: %d\n", ret);
117 		return ret;
118 	}
119 
120 	phy = devm_phy_create(dev, np, &rockchip_dp_phy_ops);
121 	if (IS_ERR(phy)) {
122 		dev_err(dev, "failed to create phy\n");
123 		return PTR_ERR(phy);
124 	}
125 	phy_set_drvdata(phy, dp);
126 
127 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
128 
129 	return PTR_ERR_OR_ZERO(phy_provider);
130 }
131 
132 static const struct of_device_id rockchip_dp_phy_dt_ids[] = {
133 	{ .compatible = "rockchip,rk3288-dp-phy" },
134 	{}
135 };
136 
137 MODULE_DEVICE_TABLE(of, rockchip_dp_phy_dt_ids);
138 
139 static struct platform_driver rockchip_dp_phy_driver = {
140 	.probe		= rockchip_dp_phy_probe,
141 	.driver		= {
142 		.name	= "rockchip-dp-phy",
143 		.of_match_table = rockchip_dp_phy_dt_ids,
144 	},
145 };
146 
147 module_platform_driver(rockchip_dp_phy_driver);
148 
149 MODULE_AUTHOR("Yakir Yang <ykk@rock-chips.com>");
150 MODULE_DESCRIPTION("Rockchip DP PHY driver");
151 MODULE_LICENSE("GPL v2");
152