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/kernel.h>
8 #include <linux/mfd/syscon.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/regmap.h>
12 #include <linux/slab.h>
13 
14 struct ti_syscon_gate_clk_priv {
15 	struct clk_hw hw;
16 	struct regmap *regmap;
17 	u32 reg;
18 	u32 idx;
19 };
20 
21 struct ti_syscon_gate_clk_data {
22 	char *name;
23 	u32 offset;
24 	u32 bit_idx;
25 };
26 
27 static struct
to_ti_syscon_gate_clk_priv(struct clk_hw * hw)28 ti_syscon_gate_clk_priv *to_ti_syscon_gate_clk_priv(struct clk_hw *hw)
29 {
30 	return container_of(hw, struct ti_syscon_gate_clk_priv, hw);
31 }
32 
ti_syscon_gate_clk_enable(struct clk_hw * hw)33 static int ti_syscon_gate_clk_enable(struct clk_hw *hw)
34 {
35 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
36 
37 	return regmap_write_bits(priv->regmap, priv->reg, priv->idx,
38 				 priv->idx);
39 }
40 
ti_syscon_gate_clk_disable(struct clk_hw * hw)41 static void ti_syscon_gate_clk_disable(struct clk_hw *hw)
42 {
43 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
44 
45 	regmap_write_bits(priv->regmap, priv->reg, priv->idx, 0);
46 }
47 
ti_syscon_gate_clk_is_enabled(struct clk_hw * hw)48 static int ti_syscon_gate_clk_is_enabled(struct clk_hw *hw)
49 {
50 	unsigned int val;
51 	struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
52 
53 	regmap_read(priv->regmap, priv->reg, &val);
54 
55 	return !!(val & priv->idx);
56 }
57 
58 static const struct clk_ops ti_syscon_gate_clk_ops = {
59 	.enable		= ti_syscon_gate_clk_enable,
60 	.disable	= ti_syscon_gate_clk_disable,
61 	.is_enabled	= ti_syscon_gate_clk_is_enabled,
62 };
63 
64 static struct clk_hw
ti_syscon_gate_clk_register(struct device * dev,struct regmap * regmap,const char * parent_name,const struct ti_syscon_gate_clk_data * data)65 *ti_syscon_gate_clk_register(struct device *dev, struct regmap *regmap,
66 			     const char *parent_name,
67 			     const struct ti_syscon_gate_clk_data *data)
68 {
69 	struct ti_syscon_gate_clk_priv *priv;
70 	struct clk_init_data init;
71 	char *name = NULL;
72 	int ret;
73 
74 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
75 	if (!priv)
76 		return ERR_PTR(-ENOMEM);
77 
78 	init.ops = &ti_syscon_gate_clk_ops;
79 	if (parent_name) {
80 		name = kasprintf(GFP_KERNEL, "%s:%s", data->name, parent_name);
81 		init.name = name;
82 		init.parent_names = &parent_name;
83 		init.num_parents = 1;
84 		init.flags = CLK_SET_RATE_PARENT;
85 	} else {
86 		init.name = data->name;
87 		init.parent_names = NULL;
88 		init.num_parents = 0;
89 		init.flags = 0;
90 	}
91 
92 	priv->regmap = regmap;
93 	priv->reg = data->offset;
94 	priv->idx = BIT(data->bit_idx);
95 	priv->hw.init = &init;
96 
97 	ret = devm_clk_hw_register(dev, &priv->hw);
98 
99 	if (name)
100 		kfree(init.name);
101 
102 	if (ret)
103 		return ERR_PTR(ret);
104 
105 	return &priv->hw;
106 }
107 
ti_syscon_gate_clk_probe(struct platform_device * pdev)108 static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
109 {
110 	const struct ti_syscon_gate_clk_data *data, *p;
111 	struct clk_hw_onecell_data *hw_data;
112 	struct device *dev = &pdev->dev;
113 	int num_clks, num_parents, i;
114 	const char *parent_name;
115 	struct regmap *regmap;
116 
117 	data = device_get_match_data(dev);
118 	if (!data)
119 		return -EINVAL;
120 
121 	regmap = device_node_to_regmap(dev->of_node);
122 	if (IS_ERR(regmap))
123 		return dev_err_probe(dev, PTR_ERR(regmap),
124 				     "failed to get regmap\n");
125 
126 	num_clks = 0;
127 	for (p = data; p->name; p++)
128 		num_clks++;
129 
130 	num_parents = of_clk_get_parent_count(dev->of_node);
131 	if (of_device_is_compatible(dev->of_node, "ti,am62-audio-refclk") &&
132 	    num_parents == 0) {
133 		return dev_err_probe(dev, -EINVAL,
134 				     "must specify a parent clock\n");
135 	}
136 
137 	hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks),
138 			       GFP_KERNEL);
139 	if (!hw_data)
140 		return -ENOMEM;
141 
142 	hw_data->num = num_clks;
143 
144 	parent_name = of_clk_get_parent_name(dev->of_node, 0);
145 	for (i = 0; i < num_clks; i++) {
146 		hw_data->hws[i] = ti_syscon_gate_clk_register(dev, regmap,
147 							      parent_name,
148 							      &data[i]);
149 		if (IS_ERR(hw_data->hws[i]))
150 			dev_warn(dev, "failed to register %s\n",
151 				 data[i].name);
152 	}
153 
154 	if (num_clks == 1)
155 		return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
156 						   hw_data->hws[0]);
157 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
158 }
159 
160 #define TI_SYSCON_CLK_GATE(_name, _offset, _bit_idx)	\
161 	{						\
162 		.name = _name,				\
163 		.offset = (_offset),			\
164 		.bit_idx = (_bit_idx),			\
165 	}
166 
167 static const struct ti_syscon_gate_clk_data am654_clk_data[] = {
168 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk0", 0x0, 0),
169 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk1", 0x4, 0),
170 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk2", 0x8, 0),
171 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk3", 0xc, 0),
172 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk4", 0x10, 0),
173 	TI_SYSCON_CLK_GATE("ehrpwm_tbclk5", 0x14, 0),
174 	{ /* Sentinel */ },
175 };
176 
177 static const struct ti_syscon_gate_clk_data am64_clk_data[] = {
178 	TI_SYSCON_CLK_GATE("epwm_tbclk0", 0x0, 0),
179 	TI_SYSCON_CLK_GATE("epwm_tbclk1", 0x0, 1),
180 	TI_SYSCON_CLK_GATE("epwm_tbclk2", 0x0, 2),
181 	TI_SYSCON_CLK_GATE("epwm_tbclk3", 0x0, 3),
182 	TI_SYSCON_CLK_GATE("epwm_tbclk4", 0x0, 4),
183 	TI_SYSCON_CLK_GATE("epwm_tbclk5", 0x0, 5),
184 	TI_SYSCON_CLK_GATE("epwm_tbclk6", 0x0, 6),
185 	TI_SYSCON_CLK_GATE("epwm_tbclk7", 0x0, 7),
186 	TI_SYSCON_CLK_GATE("epwm_tbclk8", 0x0, 8),
187 	{ /* Sentinel */ },
188 };
189 
190 static const struct ti_syscon_gate_clk_data am62_clk_data[] = {
191 	TI_SYSCON_CLK_GATE("epwm_tbclk0", 0x0, 0),
192 	TI_SYSCON_CLK_GATE("epwm_tbclk1", 0x0, 1),
193 	TI_SYSCON_CLK_GATE("epwm_tbclk2", 0x0, 2),
194 	{ /* Sentinel */ },
195 };
196 
197 static const struct ti_syscon_gate_clk_data am62_audio_clk_data[] = {
198 	TI_SYSCON_CLK_GATE("audio_refclk", 0x0, 15),
199 	{ /* Sentinel */ },
200 };
201 
202 static const struct of_device_id ti_syscon_gate_clk_ids[] = {
203 	{
204 		.compatible = "ti,am654-ehrpwm-tbclk",
205 		.data = &am654_clk_data,
206 	},
207 	{
208 		.compatible = "ti,am64-epwm-tbclk",
209 		.data = &am64_clk_data,
210 	},
211 	{
212 		.compatible = "ti,am62-epwm-tbclk",
213 		.data = &am62_clk_data,
214 	},
215 	{
216 		.compatible = "ti,am62-audio-refclk",
217 		.data = &am62_audio_clk_data,
218 	},
219 	{ }
220 };
221 MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids);
222 
223 static struct platform_driver ti_syscon_gate_clk_driver = {
224 	.probe = ti_syscon_gate_clk_probe,
225 	.driver = {
226 		.name = "ti-syscon-gate-clk",
227 		.of_match_table = ti_syscon_gate_clk_ids,
228 	},
229 };
230 module_platform_driver(ti_syscon_gate_clk_driver);
231 
232 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
233 MODULE_DESCRIPTION("Syscon backed gate-clock driver");
234 MODULE_LICENSE("GPL");
235