summaryrefslogtreecommitdiffstats
path: root/drivers/regulator/max8952.c
blob: 6c39fff73b8acd61c57cb3fc7fc13c3af7a64bdc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
/*
 * max8952.c - Voltage and current regulation for the Maxim 8952
 *
 * Copyright (C) 2010 Samsung Electronics
 * MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/max8952.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/slab.h>

/* Registers */
enum {
	MAX8952_REG_MODE0,
	MAX8952_REG_MODE1,
	MAX8952_REG_MODE2,
	MAX8952_REG_MODE3,
	MAX8952_REG_CONTROL,
	MAX8952_REG_SYNC,
	MAX8952_REG_RAMP,
	MAX8952_REG_CHIP_ID1,
	MAX8952_REG_CHIP_ID2,
};

struct max8952_data {
	struct i2c_client	*client;
	struct max8952_platform_data *pdata;

	bool vid0;
	bool vid1;
};

static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
{
	int ret = i2c_smbus_read_byte_data(max8952->client, reg);

	if (ret > 0)
		ret &= 0xff;

	return ret;
}

static int max8952_write_reg(struct max8952_data *max8952,
		u8 reg, u8 value)
{
	return i2c_smbus_write_byte_data(max8952->client, reg, value);
}

static int max8952_list_voltage(struct regulator_dev *rdev,
		unsigned int selector)
{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

	if (rdev_get_id(rdev) != 0)
		return -EINVAL;

	return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
}

static int max8952_get_voltage_sel(struct regulator_dev *rdev)
{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
	u8 vid = 0;

	if (max8952->vid0)
		vid += 1;
	if (max8952->vid1)
		vid += 2;

	return vid;
}

static int max8952_set_voltage_sel(struct regulator_dev *rdev,
				   unsigned selector)
{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

	if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
			!gpio_is_valid(max8952->pdata->gpio_vid1)) {
		/* DVS not supported */
		return -EPERM;
	}

	max8952->vid0 = selector & 0x1;
	max8952->vid1 = (selector >> 1) & 0x1;
	gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
	gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);

	return 0;
}

static const struct regulator_ops max8952_ops = {
	.list_voltage		= max8952_list_voltage,
	.get_voltage_sel	= max8952_get_voltage_sel,
	.set_voltage_sel	= max8952_set_voltage_sel,
};

static const struct regulator_desc regulator = {
	.name		= "MAX8952_VOUT",
	.id		= 0,
	.n_voltages	= MAX8952_NUM_DVS_MODE,
	.ops		= &max8952_ops,
	.type		= REGULATOR_VOLTAGE,
	.owner		= THIS_MODULE,
};

#ifdef CONFIG_OF
static const struct of_device_id max8952_dt_match[] = {
	{ .compatible = "maxim,max8952" },
	{},
};
MODULE_DEVICE_TABLE(of, max8952_dt_match);

static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
{
	struct max8952_platform_data *pd;
	struct device_node *np = dev->of_node;
	int ret;
	int i;

	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
	if (!pd)
		return NULL;

	pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
	pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);

	if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
		dev_warn(dev, "Default mode not specified, assuming 0\n");

	ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
					pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
	if (ret) {
		dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
		return NULL;
	}

	for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
		if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
			dev_err(dev, "DVS voltage %d out of range\n", i);
			return NULL;
		}
		pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
	}

	if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
		dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");

	if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
		dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");

	pd->reg_data = of_get_regulator_init_data(dev, np, &regulator);
	if (!pd->reg_data) {
		dev_err(dev, "Failed to parse regulator init data\n");
		return NULL;
	}

	return pd;
}
#else
static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
{
	return NULL;
}
#endif

static int max8952_pmic_probe(struct i2c_client *client,
		const struct i2c_device_id *i2c_id)
{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
	struct regulator_config config = { };
	struct max8952_data *max8952;
	struct regulator_dev *rdev;
	struct gpio_desc *gpiod;
	enum gpiod_flags gflags;

	int ret = 0, err = 0;

	if (client->dev.of_node)
		pdata = max8952_parse_dt(&client->dev);

	if (!pdata) {
		dev_err(&client->dev, "Require the platform data\n");
		return -EINVAL;
	}

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
		return -EIO;

	max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
			       GFP_KERNEL);
	if (!max8952)
		return -ENOMEM;

	max8952->client = client;
	max8952->pdata = pdata;

	config.dev = &client->dev;
	config.init_data = pdata->reg_data;
	config.driver_data = max8952;
	config.of_node = client->dev.of_node;

	if (pdata->reg_data->constraints.boot_on)
		gflags = GPIOD_OUT_HIGH;
	else
		gflags = GPIOD_OUT_LOW;
	gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
	gpiod = devm_gpiod_get_optional(&client->dev,
					"max8952,en",
					gflags);
	if (IS_ERR(gpiod))
		return PTR_ERR(gpiod);
	if (gpiod)
		config.ena_gpiod = gpiod;

	rdev = devm_regulator_register(&client->dev, &regulator, &config);
	if (IS_ERR(rdev)) {
		ret = PTR_ERR(rdev);
		dev_err(&client->dev, "regulator init failed (%d)\n", ret);
		return ret;
	}

	max8952->vid0 = pdata->default_mode & 0x1;
	max8952->vid1 = (pdata->default_mode >> 1) & 0x1;

	if (gpio_is_valid(pdata->gpio_vid0) &&
			gpio_is_valid(pdata->gpio_vid1)) {
		unsigned long gpio_flags;

		gpio_flags = max8952->vid0 ?
			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
					  gpio_flags, "MAX8952 VID0"))
			err = 1;

		gpio_flags = max8952->vid1 ?
			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
					  gpio_flags, "MAX8952 VID1"))
			err = 2;
	} else
		err = 3;

	if (err) {
		dev_warn(&client->dev, "VID0/1 gpio invalid: "
				"DVS not available.\n");
		max8952->vid0 = 0;
		max8952->vid1 = 0;
		/* Mark invalid */
		pdata->gpio_vid0 = -1;
		pdata->gpio_vid1 = -1;

		/* Disable Pulldown of EN only */
		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);

		dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
				" do not have proper controls.\n");
	} else {
		/*
		 * Disable Pulldown on EN, VID0, VID1 to reduce
		 * leakage current of MAX8952 assuming that MAX8952
		 * is turned on (EN==1). Note that without having VID0/1
		 * properly connected, turning pulldown off can be
		 * problematic. Thus, turn this off only when they are
		 * controllable by GPIO.
		 */
		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
	}

	max8952_write_reg(max8952, MAX8952_REG_MODE0,
			(max8952_read_reg(max8952,
					  MAX8952_REG_MODE0) & 0xC0) |
			(pdata->dvs_mode[0] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE1,
			(max8952_read_reg(max8952,
					  MAX8952_REG_MODE1) & 0xC0) |
			(pdata->dvs_mode[1] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE2,
			(max8952_read_reg(max8952,
					  MAX8952_REG_MODE2) & 0xC0) |
			(pdata->dvs_mode[2] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE3,
			(max8952_read_reg(max8952,
					  MAX8952_REG_MODE3) & 0xC0) |
			(pdata->dvs_mode[3] & 0x3F));

	max8952_write_reg(max8952, MAX8952_REG_SYNC,
			(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
			((pdata->sync_freq & 0x3) << 6));
	max8952_write_reg(max8952, MAX8952_REG_RAMP,
			(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
			((pdata->ramp_speed & 0x7) << 5));

	i2c_set_clientdata(client, max8952);

	return 0;
}

static const struct i2c_device_id max8952_ids[] = {
	{ "max8952", 0 },
	{ },
};
MODULE_DEVICE_TABLE(i2c, max8952_ids);

static struct i2c_driver max8952_pmic_driver = {
	.probe		= max8952_pmic_probe,
	.driver		= {
		.name	= "max8952",
		.of_match_table = of_match_ptr(max8952_dt_match),
	},
	.id_table	= max8952_ids,
};

static int __init max8952_pmic_init(void)
{
	return i2c_add_driver(&max8952_pmic_driver);
}
subsys_initcall(max8952_pmic_init);

static void __exit max8952_pmic_exit(void)
{
	i2c_del_driver(&max8952_pmic_driver);
}
module_exit(max8952_pmic_exit);

MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud