1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // clk-max77686.c - Clock driver for Maxim 77686/MAX77802
4 //
5 // Copyright (C) 2012 Samsung Electornics
6 // Jonghwa Lee <jonghwa3.lee@samsung.com>
7
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/err.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/mfd/max77620.h>
14 #include <linux/mfd/max77686.h>
15 #include <linux/mfd/max77686-private.h>
16 #include <linux/clk-provider.h>
17 #include <linux/mutex.h>
18 #include <linux/clkdev.h>
19 #include <linux/of.h>
20 #include <linux/regmap.h>
21
22 #include <dt-bindings/clock/maxim,max77686.h>
23 #include <dt-bindings/clock/maxim,max77802.h>
24 #include <dt-bindings/clock/maxim,max77620.h>
25
26 #define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
27
28 enum max77686_chip_name {
29 CHIP_MAX77686,
30 CHIP_MAX77802,
31 CHIP_MAX77620,
32 };
33
34 struct max77686_hw_clk_info {
35 const char *name;
36 u32 clk_reg;
37 u32 clk_enable_mask;
38 u32 flags;
39 };
40
41 struct max77686_clk_init_data {
42 struct regmap *regmap;
43 struct clk_hw hw;
44 struct clk_init_data clk_idata;
45 const struct max77686_hw_clk_info *clk_info;
46 };
47
48 struct max77686_clk_driver_data {
49 enum max77686_chip_name chip;
50 struct max77686_clk_init_data *max_clk_data;
51 size_t num_clks;
52 };
53
54 static const struct
55 max77686_hw_clk_info max77686_hw_clks_info[MAX77686_CLKS_NUM] = {
56 [MAX77686_CLK_AP] = {
57 .name = "32khz_ap",
58 .clk_reg = MAX77686_REG_32KHZ,
59 .clk_enable_mask = BIT(MAX77686_CLK_AP),
60 },
61 [MAX77686_CLK_CP] = {
62 .name = "32khz_cp",
63 .clk_reg = MAX77686_REG_32KHZ,
64 .clk_enable_mask = BIT(MAX77686_CLK_CP),
65 },
66 [MAX77686_CLK_PMIC] = {
67 .name = "32khz_pmic",
68 .clk_reg = MAX77686_REG_32KHZ,
69 .clk_enable_mask = BIT(MAX77686_CLK_PMIC),
70 },
71 };
72
73 static const struct
74 max77686_hw_clk_info max77802_hw_clks_info[MAX77802_CLKS_NUM] = {
75 [MAX77802_CLK_32K_AP] = {
76 .name = "32khz_ap",
77 .clk_reg = MAX77802_REG_32KHZ,
78 .clk_enable_mask = BIT(MAX77802_CLK_32K_AP),
79 },
80 [MAX77802_CLK_32K_CP] = {
81 .name = "32khz_cp",
82 .clk_reg = MAX77802_REG_32KHZ,
83 .clk_enable_mask = BIT(MAX77802_CLK_32K_CP),
84 },
85 };
86
87 static const struct
88 max77686_hw_clk_info max77620_hw_clks_info[MAX77620_CLKS_NUM] = {
89 [MAX77620_CLK_32K_OUT0] = {
90 .name = "32khz_out0",
91 .clk_reg = MAX77620_REG_CNFG1_32K,
92 .clk_enable_mask = MAX77620_CNFG1_32K_OUT0_EN,
93 },
94 };
95
to_max77686_clk_init_data(struct clk_hw * hw)96 static struct max77686_clk_init_data *to_max77686_clk_init_data(
97 struct clk_hw *hw)
98 {
99 return container_of(hw, struct max77686_clk_init_data, hw);
100 }
101
max77686_clk_prepare(struct clk_hw * hw)102 static int max77686_clk_prepare(struct clk_hw *hw)
103 {
104 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
105
106 return regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
107 max77686->clk_info->clk_enable_mask,
108 max77686->clk_info->clk_enable_mask);
109 }
110
max77686_clk_unprepare(struct clk_hw * hw)111 static void max77686_clk_unprepare(struct clk_hw *hw)
112 {
113 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
114
115 regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
116 max77686->clk_info->clk_enable_mask,
117 ~max77686->clk_info->clk_enable_mask);
118 }
119
max77686_clk_is_prepared(struct clk_hw * hw)120 static int max77686_clk_is_prepared(struct clk_hw *hw)
121 {
122 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
123 int ret;
124 u32 val;
125
126 ret = regmap_read(max77686->regmap, max77686->clk_info->clk_reg, &val);
127
128 if (ret < 0)
129 return -EINVAL;
130
131 return val & max77686->clk_info->clk_enable_mask;
132 }
133
max77686_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)134 static unsigned long max77686_recalc_rate(struct clk_hw *hw,
135 unsigned long parent_rate)
136 {
137 return 32768;
138 }
139
140 static const struct clk_ops max77686_clk_ops = {
141 .prepare = max77686_clk_prepare,
142 .unprepare = max77686_clk_unprepare,
143 .is_prepared = max77686_clk_is_prepared,
144 .recalc_rate = max77686_recalc_rate,
145 };
146
147 static struct clk_hw *
of_clk_max77686_get(struct of_phandle_args * clkspec,void * data)148 of_clk_max77686_get(struct of_phandle_args *clkspec, void *data)
149 {
150 struct max77686_clk_driver_data *drv_data = data;
151 unsigned int idx = clkspec->args[0];
152
153 if (idx >= drv_data->num_clks) {
154 pr_err("%s: invalid index %u\n", __func__, idx);
155 return ERR_PTR(-EINVAL);
156 }
157
158 return &drv_data->max_clk_data[idx].hw;
159 }
160
max77686_clk_probe(struct platform_device * pdev)161 static int max77686_clk_probe(struct platform_device *pdev)
162 {
163 struct device *dev = &pdev->dev;
164 struct device *parent = dev->parent;
165 const struct platform_device_id *id = platform_get_device_id(pdev);
166 struct max77686_clk_driver_data *drv_data;
167 const struct max77686_hw_clk_info *hw_clks;
168 struct regmap *regmap;
169 int i, ret, num_clks;
170
171 drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
172 if (!drv_data)
173 return -ENOMEM;
174
175 regmap = dev_get_regmap(parent, NULL);
176 if (!regmap) {
177 dev_err(dev, "Failed to get rtc regmap\n");
178 return -ENODEV;
179 }
180
181 drv_data->chip = id->driver_data;
182
183 switch (drv_data->chip) {
184 case CHIP_MAX77686:
185 num_clks = MAX77686_CLKS_NUM;
186 hw_clks = max77686_hw_clks_info;
187 break;
188
189 case CHIP_MAX77802:
190 num_clks = MAX77802_CLKS_NUM;
191 hw_clks = max77802_hw_clks_info;
192 break;
193
194 case CHIP_MAX77620:
195 num_clks = MAX77620_CLKS_NUM;
196 hw_clks = max77620_hw_clks_info;
197 break;
198
199 default:
200 dev_err(dev, "Unknown Chip ID\n");
201 return -EINVAL;
202 }
203
204 drv_data->num_clks = num_clks;
205 drv_data->max_clk_data = devm_kcalloc(dev, num_clks,
206 sizeof(*drv_data->max_clk_data),
207 GFP_KERNEL);
208 if (!drv_data->max_clk_data)
209 return -ENOMEM;
210
211 for (i = 0; i < num_clks; i++) {
212 struct max77686_clk_init_data *max_clk_data;
213 const char *clk_name;
214
215 max_clk_data = &drv_data->max_clk_data[i];
216
217 max_clk_data->regmap = regmap;
218 max_clk_data->clk_info = &hw_clks[i];
219 max_clk_data->clk_idata.flags = hw_clks[i].flags;
220 max_clk_data->clk_idata.ops = &max77686_clk_ops;
221
222 if (parent->of_node &&
223 !of_property_read_string_index(parent->of_node,
224 "clock-output-names",
225 i, &clk_name))
226 max_clk_data->clk_idata.name = clk_name;
227 else
228 max_clk_data->clk_idata.name = hw_clks[i].name;
229
230 max_clk_data->hw.init = &max_clk_data->clk_idata;
231
232 ret = devm_clk_hw_register(dev, &max_clk_data->hw);
233 if (ret) {
234 dev_err(dev, "Failed to clock register: %d\n", ret);
235 return ret;
236 }
237
238 ret = devm_clk_hw_register_clkdev(dev, &max_clk_data->hw,
239 max_clk_data->clk_idata.name,
240 NULL);
241 if (ret < 0) {
242 dev_err(dev, "Failed to clkdev register: %d\n", ret);
243 return ret;
244 }
245 }
246
247 if (parent->of_node) {
248 ret = devm_of_clk_add_hw_provider(dev, of_clk_max77686_get,
249 drv_data);
250
251 if (ret < 0) {
252 dev_err(dev, "Failed to register OF clock provider: %d\n",
253 ret);
254 return ret;
255 }
256 }
257
258 /* MAX77802: Enable low-jitter mode on the 32khz clocks. */
259 if (drv_data->chip == CHIP_MAX77802) {
260 ret = regmap_update_bits(regmap, MAX77802_REG_32KHZ,
261 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
262 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
263 if (ret < 0) {
264 dev_err(dev, "Failed to config low-jitter: %d\n", ret);
265 return ret;
266 }
267 }
268
269 return 0;
270 }
271
272 static const struct platform_device_id max77686_clk_id[] = {
273 { "max77686-clk", .driver_data = CHIP_MAX77686, },
274 { "max77802-clk", .driver_data = CHIP_MAX77802, },
275 { "max77620-clock", .driver_data = CHIP_MAX77620, },
276 {},
277 };
278 MODULE_DEVICE_TABLE(platform, max77686_clk_id);
279
280 static struct platform_driver max77686_clk_driver = {
281 .driver = {
282 .name = "max77686-clk",
283 },
284 .probe = max77686_clk_probe,
285 .id_table = max77686_clk_id,
286 };
287
288 module_platform_driver(max77686_clk_driver);
289
290 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
291 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
292 MODULE_LICENSE("GPL");
293
