1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020 Texas Instruments Incorporated - https://www.ti.com/
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/mfd/syscon.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/regmap.h>
11 
12 struct ti_syscon_gate_clk_priv {
13 	struct clk_hw hw;
14 	struct regmap *regmap;
15 	u32 reg;
16 	u32 idx;
17 };
18 
19 struct ti_syscon_gate_clk_data {
20 	char *name;
21 	u32 offset;
22 	u32 bit_idx;
23 };
24 
25 static struct
26 ti_syscon_gate_clk_priv *to_ti_syscon_gate_clk_priv(struct clk_hw *hw)
27 {
28 	return container_of(hw, struct ti_syscon_gate_clk_priv, hw);
29 }
30 
31 static int ti_syscon_gate_clk_enable(struct clk_hw *hw)
32 {
33 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
34 
35 	return regmap_write_bits(priv->regmap, priv->reg, priv->idx,
36 				 priv->idx);
37 }
38 
39 static void ti_syscon_gate_clk_disable(struct clk_hw *hw)
40 {
41 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
42 
43 	regmap_write_bits(priv->regmap, priv->reg, priv->idx, 0);
44 }
45 
46 static int ti_syscon_gate_clk_is_enabled(struct clk_hw *hw)
47 {
48 	unsigned int val;
49 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
50 
51 	regmap_read(priv->regmap, priv->reg, &val);
52 
53 	return !!(val & priv->idx);
54 }
55 
56 static const struct clk_ops ti_syscon_gate_clk_ops = {
57 	.enable		= ti_syscon_gate_clk_enable,
58 	.disable	= ti_syscon_gate_clk_disable,
59 	.is_enabled	= ti_syscon_gate_clk_is_enabled,
60 };
61 
62 static struct clk_hw
63 *ti_syscon_gate_clk_register(struct device *dev, struct regmap *regmap,
64 			     const struct ti_syscon_gate_clk_data *data)
65 {
66 	struct ti_syscon_gate_clk_priv *priv;
67 	struct clk_init_data init;
68 	int ret;
69 
70 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
71 	if (!priv)
72 		return ERR_PTR(-ENOMEM);
73 
74 	init.name = data->name;
75 	init.ops = &ti_syscon_gate_clk_ops;
76 	init.parent_names = NULL;
77 	init.num_parents = 0;
78 	init.flags = 0;
79 
80 	priv->regmap = regmap;
81 	priv->reg = data->offset;
82 	priv->idx = BIT(data->bit_idx);
83 	priv->hw.init = &init;
84 
85 	ret = devm_clk_hw_register(dev, &priv->hw);
86 	if (ret)
87 		return ERR_PTR(ret);
88 
89 	return &priv->hw;
90 }
91 
92 static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
93 {
94 	const struct ti_syscon_gate_clk_data *data, *p;
95 	struct clk_hw_onecell_data *hw_data;
96 	struct device *dev = &pdev->dev;
97 	struct regmap *regmap;
98 	int num_clks, i;
99 
100 	data = device_get_match_data(dev);
101 	if (!data)
102 		return -EINVAL;
103 
104 	regmap = syscon_node_to_regmap(dev->of_node);
105 	if (IS_ERR(regmap)) {
106 		if (PTR_ERR(regmap) == -EPROBE_DEFER)
107 			return -EPROBE_DEFER;
108 		dev_err(dev, "failed to find parent regmap\n");
109 		return PTR_ERR(regmap);
110 	}
111 
112 	num_clks = 0;
113 	for (p = data; p->name; p++)
114 		num_clks++;
115 
116 	hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks),
117 			       GFP_KERNEL);
118 	if (!hw_data)
119 		return -ENOMEM;
120 
121 	hw_data->num = num_clks;
122 
123 	for (i = 0; i < num_clks; i++) {
124 		hw_data->hws[i] = ti_syscon_gate_clk_register(dev, regmap,
125 							      &data[i]);
126 		if (IS_ERR(hw_data->hws[i]))
127 			dev_warn(dev, "failed to register %s\n",
128 				 data[i].name);
129 	}
130 
131 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
132 					   hw_data);
133 }
134 
135 #define TI_SYSCON_CLK_GATE(_name, _offset, _bit_idx)	\
136 	{						\
137 		.name = _name,				\
138 		.offset = (_offset),			\
139 		.bit_idx = (_bit_idx),			\
140 	}
141 
142 static const struct ti_syscon_gate_clk_data am654_clk_data[] = {
143 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk0", 0x0, 0),
144 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk1", 0x4, 0),
145 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk2", 0x8, 0),
146 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk3", 0xc, 0),
147 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk4", 0x10, 0),
148 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk5", 0x14, 0),
149 	{ /* Sentinel */ },
150 };
151 
152 static const struct ti_syscon_gate_clk_data am64_clk_data[] = {
153 	TI_SYSCON_CLK_GATE("epwm_tbclk0", 0x0, 0),
154 	TI_SYSCON_CLK_GATE("epwm_tbclk1", 0x0, 1),
155 	TI_SYSCON_CLK_GATE("epwm_tbclk2", 0x0, 2),
156 	TI_SYSCON_CLK_GATE("epwm_tbclk3", 0x0, 3),
157 	TI_SYSCON_CLK_GATE("epwm_tbclk4", 0x0, 4),
158 	TI_SYSCON_CLK_GATE("epwm_tbclk5", 0x0, 5),
159 	TI_SYSCON_CLK_GATE("epwm_tbclk6", 0x0, 6),
160 	TI_SYSCON_CLK_GATE("epwm_tbclk7", 0x0, 7),
161 	TI_SYSCON_CLK_GATE("epwm_tbclk8", 0x0, 8),
162 	{ /* Sentinel */ },
163 };
164 
165 static const struct of_device_id ti_syscon_gate_clk_ids[] = {
166 	{
167 		.compatible = "ti,am654-ehrpwm-tbclk",
168 		.data = &am654_clk_data,
169 	},
170 	{
171 		.compatible = "ti,am64-epwm-tbclk",
172 		.data = &am64_clk_data,
173 	},
174 	{ }
175 };
176 MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids);
177 
178 static struct platform_driver ti_syscon_gate_clk_driver = {
179 	.probe = ti_syscon_gate_clk_probe,
180 	.driver = {
181 		.name = "ti-syscon-gate-clk",
182 		.of_match_table = ti_syscon_gate_clk_ids,
183 	},
184 };
185 module_platform_driver(ti_syscon_gate_clk_driver);
186 
187 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
188 MODULE_DESCRIPTION("Syscon backed gate-clock driver");
189 MODULE_LICENSE("GPL");
190