xref: /linux/drivers/regulator/max20086-regulator.c (revision 34dc1baba215b826e454b8d19e4f24adbeb7d00d) 
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(chip->dev, reg->desc, &config);
120 		if (IS_ERR(rdev)) {
121 			dev_err(chip->dev,
122 				"Failed to register regulator output %s\n",
123 				reg->desc->name);
124 			return PTR_ERR(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(chip->dev->of_node, "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(chip->dev, node, matches,
150 				 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(chip->regmap, MAX20086_REG_ID, &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(&i2c->dev, sizeof(*chip), GFP_KERNEL);
222 	if (!chip)
223 		return -ENOMEM;
224 
225 	chip->dev = &i2c->dev;
226 	chip->info = device_get_match_data(chip->dev);
227 
228 	i2c_set_clientdata(i2c, chip);
229 
230 	chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config);
231 	if (IS_ERR(chip->regmap)) {
232 		ret = PTR_ERR(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);
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(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(chip->dev, "enable", flags);
263 	if (IS_ERR(chip->ena_gpiod)) {
264 		ret = PTR_ERR(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 i2c_device_id max20086_i2c_id[] = {
279 	{ "max20086" },
280 	{ "max20087" },
281 	{ "max20088" },
282 	{ "max20089" },
283 	{ /* Sentinel */ },
284 };
285 
286 MODULE_DEVICE_TABLE(i2c, max20086_i2c_id);
287 
288 static const struct of_device_id max20086_dt_ids[] __maybe_unused = {
289 	{
290 		.compatible = "maxim,max20086",
291 		.data = &(const struct max20086_chip_info) {
292 			.id = MAX20086_DEVICE_ID_MAX20086,
293 			.num_outputs = 4,
294 		}
295 	}, {
296 		.compatible = "maxim,max20087",
297 		.data = &(const struct max20086_chip_info) {
298 			.id = MAX20086_DEVICE_ID_MAX20087,
299 			.num_outputs = 4,
300 		}
301 	}, {
302 		.compatible = "maxim,max20088",
303 		.data = &(const struct max20086_chip_info) {
304 			.id = MAX20086_DEVICE_ID_MAX20088,
305 			.num_outputs = 2,
306 		}
307 	}, {
308 		.compatible = "maxim,max20089",
309 		.data = &(const struct max20086_chip_info) {
310 			.id = MAX20086_DEVICE_ID_MAX20089,
311 			.num_outputs = 2,
312 		}
313 	},
314 	{ /* Sentinel */ },
315 };
316 
317 MODULE_DEVICE_TABLE(of, max20086_dt_ids);
318 
319 static struct i2c_driver max20086_regulator_driver = {
320 	.driver = {
321 		.name = "max20086",
322 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
323 		.of_match_table = of_match_ptr(max20086_dt_ids),
324 	},
325 	.probe = max20086_i2c_probe,
326 	.id_table = max20086_i2c_id,
327 };
328 
329 module_i2c_driver(max20086_regulator_driver);
330 
331 MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>");
332 MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");
333 MODULE_LICENSE("GPL");
334