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
to_ti_syscon_gate_clk_priv(struct clk_hw * hw)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
ti_syscon_gate_clk_enable(struct clk_hw * hw)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
ti_syscon_gate_clk_disable(struct clk_hw * hw)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
ti_syscon_gate_clk_is_enabled(struct clk_hw * hw)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
ti_syscon_gate_clk_register(struct device * dev,struct regmap * regmap,const struct ti_syscon_gate_clk_data * data)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
ti_syscon_gate_clk_probe(struct platform_device * pdev)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 of_device_id ti_syscon_gate_clk_ids[] = {
153 {
154 .compatible = "ti,am654-ehrpwm-tbclk",
155 .data = &am654_clk_data,
156 },
157 { }
158 };
159 MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids);
160
161 static struct platform_driver ti_syscon_gate_clk_driver = {
162 .probe = ti_syscon_gate_clk_probe,
163 .driver = {
164 .name = "ti-syscon-gate-clk",
165 .of_match_table = ti_syscon_gate_clk_ids,
166 },
167 };
168 module_platform_driver(ti_syscon_gate_clk_driver);
169
170 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
171 MODULE_DESCRIPTION("Syscon backed gate-clock driver");
172 MODULE_LICENSE("GPL");
173