xref: /linux/drivers/regulator/max20086-regulator.c (revision 52990390f91c1c39ca742fc8f390b29891d95127) 
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>
10 #include <linux/gpio/consumer.h>
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");
144 		return -ENODEV;
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 
289 static const struct of_device_id max20086_dt_ids[] __maybe_unused = {
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",
323 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
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");
335