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MyungJoo Ham202f4f52010-08-20 14:43:56 +09001/*
2 * max8952.c - Voltage and current regulation for the Maxim 8952
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * MyungJoo Ham <myungjoo.ham@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/i2c.h>
25#include <linux/err.h>
26#include <linux/platform_device.h>
27#include <linux/regulator/driver.h>
28#include <linux/regulator/max8952.h>
MyungJoo Ham202f4f52010-08-20 14:43:56 +090029#include <linux/gpio.h>
30#include <linux/io.h>
Tomasz Figa3ff4aa92013-04-04 18:17:20 +020031#include <linux/of.h>
32#include <linux/of_gpio.h>
33#include <linux/regulator/of_regulator.h>
MyungJoo Ham202f4f52010-08-20 14:43:56 +090034#include <linux/slab.h>
35
36/* Registers */
37enum {
38 MAX8952_REG_MODE0,
39 MAX8952_REG_MODE1,
40 MAX8952_REG_MODE2,
41 MAX8952_REG_MODE3,
42 MAX8952_REG_CONTROL,
43 MAX8952_REG_SYNC,
44 MAX8952_REG_RAMP,
45 MAX8952_REG_CHIP_ID1,
46 MAX8952_REG_CHIP_ID2,
47};
48
49struct max8952_data {
50 struct i2c_client *client;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090051 struct max8952_platform_data *pdata;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090052
53 bool vid0;
54 bool vid1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090055};
56
57static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
58{
59 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
Sachin Kamata5f8f962014-03-18 15:53:04 +053060
MyungJoo Ham202f4f52010-08-20 14:43:56 +090061 if (ret > 0)
62 ret &= 0xff;
63
64 return ret;
65}
66
67static int max8952_write_reg(struct max8952_data *max8952,
68 u8 reg, u8 value)
69{
70 return i2c_smbus_write_byte_data(max8952->client, reg, value);
71}
72
MyungJoo Ham202f4f52010-08-20 14:43:56 +090073static int max8952_list_voltage(struct regulator_dev *rdev,
74 unsigned int selector)
75{
76 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
77
78 if (rdev_get_id(rdev) != 0)
79 return -EINVAL;
80
Axel Linb9b49af2012-04-20 18:36:14 +080081 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090082}
83
Axel Linb9b49af2012-04-20 18:36:14 +080084static int max8952_get_voltage_sel(struct regulator_dev *rdev)
MyungJoo Ham202f4f52010-08-20 14:43:56 +090085{
86 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
87 u8 vid = 0;
88
89 if (max8952->vid0)
90 vid += 1;
91 if (max8952->vid1)
92 vid += 2;
93
Axel Linb9b49af2012-04-20 18:36:14 +080094 return vid;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090095}
96
Axel Lin6ea67d02012-03-26 09:20:58 +080097static int max8952_set_voltage_sel(struct regulator_dev *rdev,
98 unsigned selector)
MyungJoo Ham202f4f52010-08-20 14:43:56 +090099{
100 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900101
102 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
Jonghwan Choie2cf3132011-06-15 17:54:12 +0900103 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900104 /* DVS not supported */
105 return -EPERM;
106 }
107
Axel Lin6ea67d02012-03-26 09:20:58 +0800108 max8952->vid0 = selector & 0x1;
109 max8952->vid1 = (selector >> 1) & 0x1;
110 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
111 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900112
113 return 0;
114}
115
116static struct regulator_ops max8952_ops = {
117 .list_voltage = max8952_list_voltage,
Axel Linb9b49af2012-04-20 18:36:14 +0800118 .get_voltage_sel = max8952_get_voltage_sel,
Axel Lin6ea67d02012-03-26 09:20:58 +0800119 .set_voltage_sel = max8952_set_voltage_sel,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900120};
121
Axel Linbd6ff0d2012-04-06 08:29:49 +0800122static const struct regulator_desc regulator = {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900123 .name = "MAX8952_VOUT",
124 .id = 0,
125 .n_voltages = MAX8952_NUM_DVS_MODE,
126 .ops = &max8952_ops,
127 .type = REGULATOR_VOLTAGE,
128 .owner = THIS_MODULE,
129};
130
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200131#ifdef CONFIG_OF
Jingoo Hancfe6e332014-05-07 17:06:34 +0900132static const struct of_device_id max8952_dt_match[] = {
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200133 { .compatible = "maxim,max8952" },
134 {},
135};
136MODULE_DEVICE_TABLE(of, max8952_dt_match);
137
138static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
139{
140 struct max8952_platform_data *pd;
141 struct device_node *np = dev->of_node;
142 int ret;
143 int i;
144
145 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
Sachin Kamat7752d962014-02-20 14:23:08 +0530146 if (!pd)
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200147 return NULL;
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200148
149 pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
150 pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
151 pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
152
153 if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
154 dev_warn(dev, "Default mode not specified, assuming 0\n");
155
156 ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
157 pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
158 if (ret) {
159 dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
160 return NULL;
161 }
162
163 for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
164 if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
165 dev_err(dev, "DVS voltage %d out of range\n", i);
166 return NULL;
167 }
168 pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
169 }
170
171 if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
172 dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
173
174 if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
175 dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
176
177 pd->reg_data = of_get_regulator_init_data(dev, np);
178 if (!pd->reg_data) {
179 dev_err(dev, "Failed to parse regulator init data\n");
180 return NULL;
181 }
182
183 return pd;
184}
185#else
186static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
187{
188 return NULL;
189}
190#endif
191
Bill Pembertona5023572012-11-19 13:22:22 -0500192static int max8952_pmic_probe(struct i2c_client *client,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900193 const struct i2c_device_id *i2c_id)
194{
195 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
Jingoo Handff91d02013-07-30 17:20:47 +0900196 struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
Mark Brownc1727082012-04-04 00:50:22 +0100197 struct regulator_config config = { };
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900198 struct max8952_data *max8952;
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100199 struct regulator_dev *rdev;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900200
201 int ret = 0, err = 0;
202
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200203 if (client->dev.of_node)
204 pdata = max8952_parse_dt(&client->dev);
205
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900206 if (!pdata) {
207 dev_err(&client->dev, "Require the platform data\n");
208 return -EINVAL;
209 }
210
211 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
212 return -EIO;
213
Axel Lin372de4a2012-05-16 12:50:47 +0800214 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
215 GFP_KERNEL);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900216 if (!max8952)
217 return -ENOMEM;
218
219 max8952->client = client;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900220 max8952->pdata = pdata;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900221
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100222 config.dev = &client->dev;
Tomasz Figa3ec6eb92013-04-04 18:17:19 +0200223 config.init_data = pdata->reg_data;
Mark Brownc1727082012-04-04 00:50:22 +0100224 config.driver_data = max8952;
Axel Lin71622e12013-04-25 22:15:21 +0800225 config.of_node = client->dev.of_node;
Mark Brownc1727082012-04-04 00:50:22 +0100226
Axel Linb669e0a2012-07-10 06:10:12 +0800227 config.ena_gpio = pdata->gpio_en;
Tomasz Figa3ec6eb92013-04-04 18:17:19 +0200228 if (pdata->reg_data->constraints.boot_on)
Axel Linb669e0a2012-07-10 06:10:12 +0800229 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
230
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100231 rdev = devm_regulator_register(&client->dev, &regulator, &config);
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100232 if (IS_ERR(rdev)) {
233 ret = PTR_ERR(rdev);
234 dev_err(&client->dev, "regulator init failed (%d)\n", ret);
Axel Lin372de4a2012-05-16 12:50:47 +0800235 return ret;
Axel Linda057382010-10-25 10:11:07 +0800236 }
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900237
Axel Linc8237f02012-03-15 08:47:48 +0800238 max8952->vid0 = pdata->default_mode & 0x1;
239 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900240
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900241 if (gpio_is_valid(pdata->gpio_vid0) &&
242 gpio_is_valid(pdata->gpio_vid1)) {
Axel Lind7da1522014-06-16 10:12:25 +0800243 unsigned long gpio_flags;
244
245 gpio_flags = max8952->vid0 ?
246 GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
247 if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
248 gpio_flags, "MAX8952 VID0"))
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900249 err = 1;
250
Axel Lind7da1522014-06-16 10:12:25 +0800251 gpio_flags = max8952->vid1 ?
252 GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
253 if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
254 gpio_flags, "MAX8952 VID1"))
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900255 err = 2;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900256 } else
257 err = 3;
258
259 if (err) {
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100260 dev_warn(&client->dev, "VID0/1 gpio invalid: "
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300261 "DVS not available.\n");
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900262 max8952->vid0 = 0;
263 max8952->vid1 = 0;
264 /* Mark invalid */
265 pdata->gpio_vid0 = -1;
266 pdata->gpio_vid1 = -1;
267
268 /* Disable Pulldown of EN only */
269 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
270
Krzysztof Kozlowskib874f412014-03-10 09:32:50 +0100271 dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900272 " do not have proper controls.\n");
273 } else {
274 /*
275 * Disable Pulldown on EN, VID0, VID1 to reduce
276 * leakage current of MAX8952 assuming that MAX8952
277 * is turned on (EN==1). Note that without having VID0/1
278 * properly connected, turning pulldown off can be
279 * problematic. Thus, turn this off only when they are
280 * controllable by GPIO.
281 */
282 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
283 }
284
285 max8952_write_reg(max8952, MAX8952_REG_MODE0,
286 (max8952_read_reg(max8952,
287 MAX8952_REG_MODE0) & 0xC0) |
288 (pdata->dvs_mode[0] & 0x3F));
289 max8952_write_reg(max8952, MAX8952_REG_MODE1,
290 (max8952_read_reg(max8952,
291 MAX8952_REG_MODE1) & 0xC0) |
292 (pdata->dvs_mode[1] & 0x3F));
293 max8952_write_reg(max8952, MAX8952_REG_MODE2,
294 (max8952_read_reg(max8952,
295 MAX8952_REG_MODE2) & 0xC0) |
296 (pdata->dvs_mode[2] & 0x3F));
297 max8952_write_reg(max8952, MAX8952_REG_MODE3,
298 (max8952_read_reg(max8952,
299 MAX8952_REG_MODE3) & 0xC0) |
300 (pdata->dvs_mode[3] & 0x3F));
301
302 max8952_write_reg(max8952, MAX8952_REG_SYNC,
303 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
304 ((pdata->sync_freq & 0x3) << 6));
305 max8952_write_reg(max8952, MAX8952_REG_RAMP,
306 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
307 ((pdata->ramp_speed & 0x7) << 5));
308
309 i2c_set_clientdata(client, max8952);
310
Axel Linda057382010-10-25 10:11:07 +0800311 return 0;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900312}
313
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900314static const struct i2c_device_id max8952_ids[] = {
315 { "max8952", 0 },
316 { },
317};
318MODULE_DEVICE_TABLE(i2c, max8952_ids);
319
320static struct i2c_driver max8952_pmic_driver = {
321 .probe = max8952_pmic_probe,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900322 .driver = {
323 .name = "max8952",
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200324 .of_match_table = of_match_ptr(max8952_dt_match),
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900325 },
326 .id_table = max8952_ids,
327};
328
329static int __init max8952_pmic_init(void)
330{
331 return i2c_add_driver(&max8952_pmic_driver);
332}
333subsys_initcall(max8952_pmic_init);
334
335static void __exit max8952_pmic_exit(void)
336{
337 i2c_del_driver(&max8952_pmic_driver);
338}
339module_exit(max8952_pmic_exit);
340
341MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
342MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
343MODULE_LICENSE("GPL");