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/consumer.h> |
10 | #include <linux/i2c.h> |
11 | #include <linux/module.h> |
12 | #include <linux/regmap.h> |
13 | #include <linux/regulator/driver.h> |
14 | #include <linux/regulator/machine.h> |
15 | #include <linux/regulator/of_regulator.h> |
16 | #include <linux/slab.h> |
17 | |
18 | /* Register Offset */ |
19 | #define MAX20086_REG_MASK 0x00 |
20 | #define MAX20086_REG_CONFIG 0x01 |
21 | #define MAX20086_REG_ID 0x02 |
22 | #define MAX20086_REG_STAT1 0x03 |
23 | #define MAX20086_REG_STAT2_L 0x04 |
24 | #define MAX20086_REG_STAT2_H 0x05 |
25 | #define MAX20086_REG_ADC1 0x06 |
26 | #define MAX20086_REG_ADC2 0x07 |
27 | #define MAX20086_REG_ADC3 0x08 |
28 | #define MAX20086_REG_ADC4 0x09 |
29 | |
30 | /* DEVICE IDs */ |
31 | #define MAX20086_DEVICE_ID_MAX20086 0x40 |
32 | #define MAX20086_DEVICE_ID_MAX20087 0x20 |
33 | #define MAX20086_DEVICE_ID_MAX20088 0x10 |
34 | #define MAX20086_DEVICE_ID_MAX20089 0x00 |
35 | #define DEVICE_ID_MASK 0xf0 |
36 | |
37 | /* Register bits */ |
38 | #define MAX20086_EN_MASK 0x0f |
39 | #define MAX20086_EN_OUT1 0x01 |
40 | #define MAX20086_EN_OUT2 0x02 |
41 | #define MAX20086_EN_OUT3 0x04 |
42 | #define MAX20086_EN_OUT4 0x08 |
43 | #define MAX20086_INT_DISABLE_ALL 0x3f |
44 | |
45 | #define MAX20086_MAX_REGULATORS 4 |
46 | |
47 | struct max20086_chip_info { |
48 | u8 id; |
49 | unsigned int num_outputs; |
50 | }; |
51 | |
52 | struct max20086_regulator { |
53 | struct device_node *of_node; |
54 | struct regulator_init_data *init_data; |
55 | const struct regulator_desc *desc; |
56 | struct regulator_dev *rdev; |
57 | }; |
58 | |
59 | struct max20086 { |
60 | struct device *dev; |
61 | struct regmap *regmap; |
62 | struct gpio_desc *ena_gpiod; |
63 | |
64 | const struct max20086_chip_info *info; |
65 | |
66 | struct max20086_regulator regulators[MAX20086_MAX_REGULATORS]; |
67 | }; |
68 | |
69 | static const struct regulator_ops max20086_buck_ops = { |
70 | .enable = regulator_enable_regmap, |
71 | .disable = regulator_disable_regmap, |
72 | .is_enabled = regulator_is_enabled_regmap, |
73 | }; |
74 | |
75 | #define MAX20086_REGULATOR_DESC(n) \ |
76 | { \ |
77 | .name = "OUT"#n, \ |
78 | .supply_name = "in", \ |
79 | .id = (n) - 1, \ |
80 | .ops = &max20086_buck_ops, \ |
81 | .type = REGULATOR_VOLTAGE, \ |
82 | .owner = THIS_MODULE, \ |
83 | .enable_reg = MAX20086_REG_CONFIG, \ |
84 | .enable_mask = 1 << ((n) - 1), \ |
85 | .enable_val = 1 << ((n) - 1), \ |
86 | .disable_val = 0, \ |
87 | } |
88 | |
89 | static const char * const max20086_output_names[] = { |
90 | "OUT1" , |
91 | "OUT2" , |
92 | "OUT3" , |
93 | "OUT4" , |
94 | }; |
95 | |
96 | static const struct regulator_desc max20086_regulators[] = { |
97 | MAX20086_REGULATOR_DESC(1), |
98 | MAX20086_REGULATOR_DESC(2), |
99 | MAX20086_REGULATOR_DESC(3), |
100 | MAX20086_REGULATOR_DESC(4), |
101 | }; |
102 | |
103 | static int max20086_regulators_register(struct max20086 *chip) |
104 | { |
105 | unsigned int i; |
106 | |
107 | for (i = 0; i < chip->info->num_outputs; i++) { |
108 | struct max20086_regulator *reg = &chip->regulators[i]; |
109 | struct regulator_config config = { }; |
110 | struct regulator_dev *rdev; |
111 | |
112 | config.dev = chip->dev; |
113 | config.init_data = reg->init_data; |
114 | config.driver_data = chip; |
115 | config.of_node = reg->of_node; |
116 | config.regmap = chip->regmap; |
117 | config.ena_gpiod = chip->ena_gpiod; |
118 | |
119 | rdev = devm_regulator_register(dev: chip->dev, regulator_desc: reg->desc, config: &config); |
120 | if (IS_ERR(ptr: rdev)) { |
121 | dev_err(chip->dev, |
122 | "Failed to register regulator output %s\n" , |
123 | reg->desc->name); |
124 | return PTR_ERR(ptr: rdev); |
125 | } |
126 | |
127 | reg->rdev = rdev; |
128 | } |
129 | |
130 | return 0; |
131 | } |
132 | |
133 | static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on) |
134 | { |
135 | struct of_regulator_match matches[MAX20086_MAX_REGULATORS] = { }; |
136 | struct device_node *node; |
137 | unsigned int i; |
138 | int ret; |
139 | |
140 | node = of_get_child_by_name(node: chip->dev->of_node, name: "regulators" ); |
141 | if (!node) { |
142 | dev_err(chip->dev, "regulators node not found\n" ); |
143 | return -ENODEV; |
144 | } |
145 | |
146 | for (i = 0; i < chip->info->num_outputs; ++i) |
147 | matches[i].name = max20086_output_names[i]; |
148 | |
149 | ret = of_regulator_match(dev: chip->dev, node, matches, |
150 | num_matches: chip->info->num_outputs); |
151 | of_node_put(node); |
152 | if (ret < 0) { |
153 | dev_err(chip->dev, "Failed to match regulators\n" ); |
154 | return -EINVAL; |
155 | } |
156 | |
157 | *boot_on = false; |
158 | |
159 | for (i = 0; i < chip->info->num_outputs; i++) { |
160 | struct max20086_regulator *reg = &chip->regulators[i]; |
161 | |
162 | reg->init_data = matches[i].init_data; |
163 | reg->of_node = matches[i].of_node; |
164 | reg->desc = &max20086_regulators[i]; |
165 | |
166 | if (reg->init_data) { |
167 | if (reg->init_data->constraints.always_on || |
168 | reg->init_data->constraints.boot_on) |
169 | *boot_on = true; |
170 | } |
171 | } |
172 | |
173 | return 0; |
174 | } |
175 | |
176 | static int max20086_detect(struct max20086 *chip) |
177 | { |
178 | unsigned int data; |
179 | int ret; |
180 | |
181 | ret = regmap_read(map: chip->regmap, MAX20086_REG_ID, val: &data); |
182 | if (ret < 0) { |
183 | dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n" , ret); |
184 | return ret; |
185 | } |
186 | |
187 | if ((data & DEVICE_ID_MASK) != chip->info->id) { |
188 | dev_err(chip->dev, "Invalid device ID 0x%02x\n" , data); |
189 | return -ENXIO; |
190 | } |
191 | |
192 | return 0; |
193 | } |
194 | |
195 | static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg) |
196 | { |
197 | switch (reg) { |
198 | case MAX20086_REG_MASK: |
199 | case MAX20086_REG_CONFIG: |
200 | return true; |
201 | default: |
202 | return false; |
203 | } |
204 | } |
205 | |
206 | static const struct regmap_config max20086_regmap_config = { |
207 | .reg_bits = 8, |
208 | .val_bits = 8, |
209 | .writeable_reg = max20086_gen_is_writeable_reg, |
210 | .max_register = 0x9, |
211 | .cache_type = REGCACHE_NONE, |
212 | }; |
213 | |
214 | static int max20086_i2c_probe(struct i2c_client *i2c) |
215 | { |
216 | struct max20086 *chip; |
217 | enum gpiod_flags flags; |
218 | bool boot_on; |
219 | int ret; |
220 | |
221 | chip = devm_kzalloc(dev: &i2c->dev, size: sizeof(*chip), GFP_KERNEL); |
222 | if (!chip) |
223 | return -ENOMEM; |
224 | |
225 | chip->dev = &i2c->dev; |
226 | chip->info = i2c_get_match_data(client: i2c); |
227 | |
228 | i2c_set_clientdata(client: i2c, data: chip); |
229 | |
230 | chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config); |
231 | if (IS_ERR(ptr: chip->regmap)) { |
232 | ret = PTR_ERR(ptr: chip->regmap); |
233 | dev_err(chip->dev, "Failed to allocate register map: %d\n" , ret); |
234 | return ret; |
235 | } |
236 | |
237 | ret = max20086_parse_regulators_dt(chip, boot_on: &boot_on); |
238 | if (ret < 0) |
239 | return ret; |
240 | |
241 | ret = max20086_detect(chip); |
242 | if (ret < 0) |
243 | return ret; |
244 | |
245 | /* Until IRQ support is added, just disable all interrupts. */ |
246 | ret = regmap_update_bits(map: chip->regmap, MAX20086_REG_MASK, |
247 | MAX20086_INT_DISABLE_ALL, |
248 | MAX20086_INT_DISABLE_ALL); |
249 | if (ret < 0) { |
250 | dev_err(chip->dev, "Failed to disable interrupts: %d\n" , ret); |
251 | return ret; |
252 | } |
253 | |
254 | /* |
255 | * Get the enable GPIO. If any of the outputs is marked as being |
256 | * enabled at boot, request the GPIO with an initial high state to |
257 | * avoid disabling outputs that may have been turned on by the boot |
258 | * loader. Otherwise, request it with a low state to enter lower-power |
259 | * shutdown. |
260 | */ |
261 | flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; |
262 | chip->ena_gpiod = devm_gpiod_get(dev: chip->dev, con_id: "enable" , flags); |
263 | if (IS_ERR(ptr: chip->ena_gpiod)) { |
264 | ret = PTR_ERR(ptr: chip->ena_gpiod); |
265 | dev_err(chip->dev, "Failed to get enable GPIO: %d\n" , ret); |
266 | return ret; |
267 | } |
268 | |
269 | ret = max20086_regulators_register(chip); |
270 | if (ret < 0) { |
271 | dev_err(chip->dev, "Failed to register regulators: %d\n" , ret); |
272 | return ret; |
273 | } |
274 | |
275 | return 0; |
276 | } |
277 | |
278 | static const struct max20086_chip_info max20086_chip_info = { |
279 | .id = MAX20086_DEVICE_ID_MAX20086, |
280 | .num_outputs = 4, |
281 | }; |
282 | |
283 | static const struct max20086_chip_info max20087_chip_info = { |
284 | .id = MAX20086_DEVICE_ID_MAX20087, |
285 | .num_outputs = 4, |
286 | }; |
287 | |
288 | static const struct max20086_chip_info max20088_chip_info = { |
289 | .id = MAX20086_DEVICE_ID_MAX20088, |
290 | .num_outputs = 2, |
291 | }; |
292 | |
293 | static const struct max20086_chip_info max20089_chip_info = { |
294 | .id = MAX20086_DEVICE_ID_MAX20089, |
295 | .num_outputs = 2, |
296 | }; |
297 | |
298 | static const struct i2c_device_id max20086_i2c_id[] = { |
299 | { "max20086" , (kernel_ulong_t)&max20086_chip_info }, |
300 | { "max20087" , (kernel_ulong_t)&max20087_chip_info }, |
301 | { "max20088" , (kernel_ulong_t)&max20088_chip_info }, |
302 | { "max20089" , (kernel_ulong_t)&max20089_chip_info }, |
303 | { /* Sentinel */ } |
304 | }; |
305 | MODULE_DEVICE_TABLE(i2c, max20086_i2c_id); |
306 | |
307 | static const struct of_device_id max20086_dt_ids[] __maybe_unused = { |
308 | { .compatible = "maxim,max20086" , .data = &max20086_chip_info }, |
309 | { .compatible = "maxim,max20087" , .data = &max20087_chip_info }, |
310 | { .compatible = "maxim,max20088" , .data = &max20088_chip_info }, |
311 | { .compatible = "maxim,max20089" , .data = &max20089_chip_info }, |
312 | { /* Sentinel */ } |
313 | }; |
314 | MODULE_DEVICE_TABLE(of, max20086_dt_ids); |
315 | |
316 | static struct i2c_driver max20086_regulator_driver = { |
317 | .driver = { |
318 | .name = "max20086" , |
319 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
320 | .of_match_table = of_match_ptr(max20086_dt_ids), |
321 | }, |
322 | .probe = max20086_i2c_probe, |
323 | .id_table = max20086_i2c_id, |
324 | }; |
325 | |
326 | module_i2c_driver(max20086_regulator_driver); |
327 | |
328 | MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>" ); |
329 | MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver" ); |
330 | MODULE_LICENSE("GPL" ); |
331 | |