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1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | // | |
3 | // max20086-regulator.c - MAX20086-MAX20089 camera power protector driver | |
4 | // | |
5 | // Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@idesonboard.com> | |
6 | // Copyright (C) 2018 Avnet, Inc. | |
7 | ||
8 | #include <linux/err.h> | |
9 | #include <linux/gpio.h> | |
b4c18c18 | 10 | #include <linux/gpio/consumer.h> |
bfff546a WC |
11 | #include <linux/i2c.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/regmap.h> | |
14 | #include <linux/regulator/driver.h> | |
15 | #include <linux/regulator/machine.h> | |
16 | #include <linux/regulator/of_regulator.h> | |
17 | #include <linux/slab.h> | |
18 | ||
19 | /* Register Offset */ | |
20 | #define MAX20086_REG_MASK 0x00 | |
21 | #define MAX20086_REG_CONFIG 0x01 | |
22 | #define MAX20086_REG_ID 0x02 | |
23 | #define MAX20086_REG_STAT1 0x03 | |
24 | #define MAX20086_REG_STAT2_L 0x04 | |
25 | #define MAX20086_REG_STAT2_H 0x05 | |
26 | #define MAX20086_REG_ADC1 0x06 | |
27 | #define MAX20086_REG_ADC2 0x07 | |
28 | #define MAX20086_REG_ADC3 0x08 | |
29 | #define MAX20086_REG_ADC4 0x09 | |
30 | ||
31 | /* DEVICE IDs */ | |
32 | #define MAX20086_DEVICE_ID_MAX20086 0x40 | |
33 | #define MAX20086_DEVICE_ID_MAX20087 0x20 | |
34 | #define MAX20086_DEVICE_ID_MAX20088 0x10 | |
35 | #define MAX20086_DEVICE_ID_MAX20089 0x00 | |
36 | #define DEVICE_ID_MASK 0xf0 | |
37 | ||
38 | /* Register bits */ | |
39 | #define MAX20086_EN_MASK 0x0f | |
40 | #define MAX20086_EN_OUT1 0x01 | |
41 | #define MAX20086_EN_OUT2 0x02 | |
42 | #define MAX20086_EN_OUT3 0x04 | |
43 | #define MAX20086_EN_OUT4 0x08 | |
44 | #define MAX20086_INT_DISABLE_ALL 0x3f | |
45 | ||
46 | #define MAX20086_MAX_REGULATORS 4 | |
47 | ||
48 | struct max20086_chip_info { | |
49 | u8 id; | |
50 | unsigned int num_outputs; | |
51 | }; | |
52 | ||
53 | struct max20086_regulator { | |
54 | struct device_node *of_node; | |
55 | struct regulator_init_data *init_data; | |
56 | const struct regulator_desc *desc; | |
57 | struct regulator_dev *rdev; | |
58 | }; | |
59 | ||
60 | struct max20086 { | |
61 | struct device *dev; | |
62 | struct regmap *regmap; | |
63 | struct gpio_desc *ena_gpiod; | |
64 | ||
65 | const struct max20086_chip_info *info; | |
66 | ||
67 | struct max20086_regulator regulators[MAX20086_MAX_REGULATORS]; | |
68 | }; | |
69 | ||
70 | static const struct regulator_ops max20086_buck_ops = { | |
71 | .enable = regulator_enable_regmap, | |
72 | .disable = regulator_disable_regmap, | |
73 | .is_enabled = regulator_is_enabled_regmap, | |
74 | }; | |
75 | ||
76 | #define MAX20086_REGULATOR_DESC(n) \ | |
77 | { \ | |
78 | .name = "OUT"#n, \ | |
79 | .supply_name = "in", \ | |
80 | .id = (n) - 1, \ | |
81 | .ops = &max20086_buck_ops, \ | |
82 | .type = REGULATOR_VOLTAGE, \ | |
83 | .owner = THIS_MODULE, \ | |
84 | .enable_reg = MAX20086_REG_CONFIG, \ | |
85 | .enable_mask = 1 << ((n) - 1), \ | |
86 | .enable_val = 1 << ((n) - 1), \ | |
87 | .disable_val = 0, \ | |
88 | } | |
89 | ||
90 | static const char * const max20086_output_names[] = { | |
91 | "OUT1", | |
92 | "OUT2", | |
93 | "OUT3", | |
94 | "OUT4", | |
95 | }; | |
96 | ||
97 | static const struct regulator_desc max20086_regulators[] = { | |
98 | MAX20086_REGULATOR_DESC(1), | |
99 | MAX20086_REGULATOR_DESC(2), | |
100 | MAX20086_REGULATOR_DESC(3), | |
101 | MAX20086_REGULATOR_DESC(4), | |
102 | }; | |
103 | ||
104 | static int max20086_regulators_register(struct max20086 *chip) | |
105 | { | |
106 | unsigned int i; | |
107 | ||
108 | for (i = 0; i < chip->info->num_outputs; i++) { | |
109 | struct max20086_regulator *reg = &chip->regulators[i]; | |
110 | struct regulator_config config = { }; | |
111 | struct regulator_dev *rdev; | |
112 | ||
113 | config.dev = chip->dev; | |
114 | config.init_data = reg->init_data; | |
115 | config.driver_data = chip; | |
116 | config.of_node = reg->of_node; | |
117 | config.regmap = chip->regmap; | |
118 | config.ena_gpiod = chip->ena_gpiod; | |
119 | ||
120 | rdev = devm_regulator_register(chip->dev, reg->desc, &config); | |
121 | if (IS_ERR(rdev)) { | |
122 | dev_err(chip->dev, | |
123 | "Failed to register regulator output %s\n", | |
124 | reg->desc->name); | |
125 | return PTR_ERR(rdev); | |
126 | } | |
127 | ||
128 | reg->rdev = rdev; | |
129 | } | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on) | |
135 | { | |
136 | struct of_regulator_match matches[MAX20086_MAX_REGULATORS] = { }; | |
137 | struct device_node *node; | |
138 | unsigned int i; | |
139 | int ret; | |
140 | ||
141 | node = of_get_child_by_name(chip->dev->of_node, "regulators"); | |
142 | if (!node) { | |
143 | dev_err(chip->dev, "regulators node not found\n"); | |
879cf800 | 144 | return -ENODEV; |
bfff546a WC |
145 | } |
146 | ||
147 | for (i = 0; i < chip->info->num_outputs; ++i) | |
148 | matches[i].name = max20086_output_names[i]; | |
149 | ||
150 | ret = of_regulator_match(chip->dev, node, matches, | |
151 | chip->info->num_outputs); | |
152 | of_node_put(node); | |
153 | if (ret < 0) { | |
154 | dev_err(chip->dev, "Failed to match regulators\n"); | |
155 | return -EINVAL; | |
156 | } | |
157 | ||
158 | *boot_on = false; | |
159 | ||
160 | for (i = 0; i < chip->info->num_outputs; i++) { | |
161 | struct max20086_regulator *reg = &chip->regulators[i]; | |
162 | ||
163 | reg->init_data = matches[i].init_data; | |
164 | reg->of_node = matches[i].of_node; | |
165 | reg->desc = &max20086_regulators[i]; | |
166 | ||
167 | if (reg->init_data) { | |
168 | if (reg->init_data->constraints.always_on || | |
169 | reg->init_data->constraints.boot_on) | |
170 | *boot_on = true; | |
171 | } | |
172 | } | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static int max20086_detect(struct max20086 *chip) | |
178 | { | |
179 | unsigned int data; | |
180 | int ret; | |
181 | ||
182 | ret = regmap_read(chip->regmap, MAX20086_REG_ID, &data); | |
183 | if (ret < 0) { | |
184 | dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n", ret); | |
185 | return ret; | |
186 | } | |
187 | ||
188 | if ((data & DEVICE_ID_MASK) != chip->info->id) { | |
189 | dev_err(chip->dev, "Invalid device ID 0x%02x\n", data); | |
190 | return -ENXIO; | |
191 | } | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg) | |
197 | { | |
198 | switch (reg) { | |
199 | case MAX20086_REG_MASK: | |
200 | case MAX20086_REG_CONFIG: | |
201 | return true; | |
202 | default: | |
203 | return false; | |
204 | } | |
205 | } | |
206 | ||
207 | static const struct regmap_config max20086_regmap_config = { | |
208 | .reg_bits = 8, | |
209 | .val_bits = 8, | |
210 | .writeable_reg = max20086_gen_is_writeable_reg, | |
211 | .max_register = 0x9, | |
212 | .cache_type = REGCACHE_NONE, | |
213 | }; | |
214 | ||
215 | static int max20086_i2c_probe(struct i2c_client *i2c) | |
216 | { | |
217 | struct max20086 *chip; | |
218 | enum gpiod_flags flags; | |
219 | bool boot_on; | |
220 | int ret; | |
221 | ||
222 | chip = devm_kzalloc(&i2c->dev, sizeof(*chip), GFP_KERNEL); | |
223 | if (!chip) | |
224 | return -ENOMEM; | |
225 | ||
226 | chip->dev = &i2c->dev; | |
227 | chip->info = device_get_match_data(chip->dev); | |
228 | ||
229 | i2c_set_clientdata(i2c, chip); | |
230 | ||
231 | chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config); | |
232 | if (IS_ERR(chip->regmap)) { | |
233 | ret = PTR_ERR(chip->regmap); | |
234 | dev_err(chip->dev, "Failed to allocate register map: %d\n", ret); | |
235 | return ret; | |
236 | } | |
237 | ||
238 | ret = max20086_parse_regulators_dt(chip, &boot_on); | |
239 | if (ret < 0) | |
240 | return ret; | |
241 | ||
242 | ret = max20086_detect(chip); | |
243 | if (ret < 0) | |
244 | return ret; | |
245 | ||
246 | /* Until IRQ support is added, just disable all interrupts. */ | |
247 | ret = regmap_update_bits(chip->regmap, MAX20086_REG_MASK, | |
248 | MAX20086_INT_DISABLE_ALL, | |
249 | MAX20086_INT_DISABLE_ALL); | |
250 | if (ret < 0) { | |
251 | dev_err(chip->dev, "Failed to disable interrupts: %d\n", ret); | |
252 | return ret; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Get the enable GPIO. If any of the outputs is marked as being | |
257 | * enabled at boot, request the GPIO with an initial high state to | |
258 | * avoid disabling outputs that may have been turned on by the boot | |
259 | * loader. Otherwise, request it with a low state to enter lower-power | |
260 | * shutdown. | |
261 | */ | |
262 | flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; | |
263 | chip->ena_gpiod = devm_gpiod_get(chip->dev, "enable", flags); | |
264 | if (IS_ERR(chip->ena_gpiod)) { | |
265 | ret = PTR_ERR(chip->ena_gpiod); | |
266 | dev_err(chip->dev, "Failed to get enable GPIO: %d\n", ret); | |
267 | return ret; | |
268 | } | |
269 | ||
270 | ret = max20086_regulators_register(chip); | |
271 | if (ret < 0) { | |
272 | dev_err(chip->dev, "Failed to register regulators: %d\n", ret); | |
273 | return ret; | |
274 | } | |
275 | ||
276 | return 0; | |
277 | } | |
278 | ||
279 | static const struct i2c_device_id max20086_i2c_id[] = { | |
280 | { "max20086" }, | |
281 | { "max20087" }, | |
282 | { "max20088" }, | |
283 | { "max20089" }, | |
284 | { /* Sentinel */ }, | |
285 | }; | |
286 | ||
287 | MODULE_DEVICE_TABLE(i2c, max20086_i2c_id); | |
288 | ||
4a585086 | 289 | static const struct of_device_id max20086_dt_ids[] __maybe_unused = { |
bfff546a WC |
290 | { |
291 | .compatible = "maxim,max20086", | |
292 | .data = &(const struct max20086_chip_info) { | |
293 | .id = MAX20086_DEVICE_ID_MAX20086, | |
294 | .num_outputs = 4, | |
295 | } | |
296 | }, { | |
297 | .compatible = "maxim,max20087", | |
298 | .data = &(const struct max20086_chip_info) { | |
299 | .id = MAX20086_DEVICE_ID_MAX20087, | |
300 | .num_outputs = 4, | |
301 | } | |
302 | }, { | |
303 | .compatible = "maxim,max20088", | |
304 | .data = &(const struct max20086_chip_info) { | |
305 | .id = MAX20086_DEVICE_ID_MAX20088, | |
306 | .num_outputs = 2, | |
307 | } | |
308 | }, { | |
309 | .compatible = "maxim,max20089", | |
310 | .data = &(const struct max20086_chip_info) { | |
311 | .id = MAX20086_DEVICE_ID_MAX20089, | |
312 | .num_outputs = 2, | |
313 | } | |
314 | }, | |
315 | { /* Sentinel */ }, | |
316 | }; | |
317 | ||
318 | MODULE_DEVICE_TABLE(of, max20086_dt_ids); | |
319 | ||
320 | static struct i2c_driver max20086_regulator_driver = { | |
321 | .driver = { | |
322 | .name = "max20086", | |
41cff178 | 323 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
bfff546a WC |
324 | .of_match_table = of_match_ptr(max20086_dt_ids), |
325 | }, | |
326 | .probe_new = max20086_i2c_probe, | |
327 | .id_table = max20086_i2c_id, | |
328 | }; | |
329 | ||
330 | module_i2c_driver(max20086_regulator_driver); | |
331 | ||
332 | MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>"); | |
333 | MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver"); | |
334 | MODULE_LICENSE("GPL"); |