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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;
51 struct device *dev;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090052 struct max8952_platform_data *pdata;
53 struct regulator_dev *rdev;
54
55 bool vid0;
56 bool vid1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090057};
58
59static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
60{
61 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
62 if (ret > 0)
63 ret &= 0xff;
64
65 return ret;
66}
67
68static int max8952_write_reg(struct max8952_data *max8952,
69 u8 reg, u8 value)
70{
71 return i2c_smbus_write_byte_data(max8952->client, reg, value);
72}
73
MyungJoo Ham202f4f52010-08-20 14:43:56 +090074static int max8952_list_voltage(struct regulator_dev *rdev,
75 unsigned int selector)
76{
77 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
78
79 if (rdev_get_id(rdev) != 0)
80 return -EINVAL;
81
Axel Linb9b49af2012-04-20 18:36:14 +080082 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090083}
84
Axel Linb9b49af2012-04-20 18:36:14 +080085static int max8952_get_voltage_sel(struct regulator_dev *rdev)
MyungJoo Ham202f4f52010-08-20 14:43:56 +090086{
87 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
88 u8 vid = 0;
89
90 if (max8952->vid0)
91 vid += 1;
92 if (max8952->vid1)
93 vid += 2;
94
Axel Linb9b49af2012-04-20 18:36:14 +080095 return vid;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090096}
97
Axel Lin6ea67d02012-03-26 09:20:58 +080098static int max8952_set_voltage_sel(struct regulator_dev *rdev,
99 unsigned selector)
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900100{
101 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900102
103 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
Jonghwan Choie2cf3132011-06-15 17:54:12 +0900104 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900105 /* DVS not supported */
106 return -EPERM;
107 }
108
Axel Lin6ea67d02012-03-26 09:20:58 +0800109 max8952->vid0 = selector & 0x1;
110 max8952->vid1 = (selector >> 1) & 0x1;
111 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
112 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900113
114 return 0;
115}
116
117static struct regulator_ops max8952_ops = {
118 .list_voltage = max8952_list_voltage,
Axel Linb9b49af2012-04-20 18:36:14 +0800119 .get_voltage_sel = max8952_get_voltage_sel,
Axel Lin6ea67d02012-03-26 09:20:58 +0800120 .set_voltage_sel = max8952_set_voltage_sel,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900121};
122
Axel Linbd6ff0d2012-04-06 08:29:49 +0800123static const struct regulator_desc regulator = {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900124 .name = "MAX8952_VOUT",
125 .id = 0,
126 .n_voltages = MAX8952_NUM_DVS_MODE,
127 .ops = &max8952_ops,
128 .type = REGULATOR_VOLTAGE,
129 .owner = THIS_MODULE,
130};
131
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200132#ifdef CONFIG_OF
133static struct of_device_id max8952_dt_match[] = {
134 { .compatible = "maxim,max8952" },
135 {},
136};
137MODULE_DEVICE_TABLE(of, max8952_dt_match);
138
139static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
140{
141 struct max8952_platform_data *pd;
142 struct device_node *np = dev->of_node;
143 int ret;
144 int i;
145
146 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
147 if (!pd) {
148 dev_err(dev, "Failed to allocate platform data\n");
149 return NULL;
150 }
151
152 pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
153 pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
154 pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
155
156 if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
157 dev_warn(dev, "Default mode not specified, assuming 0\n");
158
159 ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
160 pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
161 if (ret) {
162 dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
163 return NULL;
164 }
165
166 for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
167 if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
168 dev_err(dev, "DVS voltage %d out of range\n", i);
169 return NULL;
170 }
171 pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
172 }
173
174 if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
175 dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
176
177 if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
178 dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
179
180 pd->reg_data = of_get_regulator_init_data(dev, np);
181 if (!pd->reg_data) {
182 dev_err(dev, "Failed to parse regulator init data\n");
183 return NULL;
184 }
185
186 return pd;
187}
188#else
189static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
190{
191 return NULL;
192}
193#endif
194
Bill Pembertona5023572012-11-19 13:22:22 -0500195static int max8952_pmic_probe(struct i2c_client *client,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900196 const struct i2c_device_id *i2c_id)
197{
198 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
199 struct max8952_platform_data *pdata = client->dev.platform_data;
Mark Brownc1727082012-04-04 00:50:22 +0100200 struct regulator_config config = { };
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900201 struct max8952_data *max8952;
202
203 int ret = 0, err = 0;
204
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200205 if (client->dev.of_node)
206 pdata = max8952_parse_dt(&client->dev);
207
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900208 if (!pdata) {
209 dev_err(&client->dev, "Require the platform data\n");
210 return -EINVAL;
211 }
212
213 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
214 return -EIO;
215
Axel Lin372de4a2012-05-16 12:50:47 +0800216 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
217 GFP_KERNEL);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900218 if (!max8952)
219 return -ENOMEM;
220
221 max8952->client = client;
222 max8952->dev = &client->dev;
223 max8952->pdata = pdata;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900224
Mark Brownc1727082012-04-04 00:50:22 +0100225 config.dev = max8952->dev;
Tomasz Figa3ec6eb92013-04-04 18:17:19 +0200226 config.init_data = pdata->reg_data;
Mark Brownc1727082012-04-04 00:50:22 +0100227 config.driver_data = max8952;
228
Axel Linb669e0a2012-07-10 06:10:12 +0800229 config.ena_gpio = pdata->gpio_en;
Tomasz Figa3ec6eb92013-04-04 18:17:19 +0200230 if (pdata->reg_data->constraints.boot_on)
Axel Linb669e0a2012-07-10 06:10:12 +0800231 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
232
Mark Brownc1727082012-04-04 00:50:22 +0100233 max8952->rdev = regulator_register(&regulator, &config);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900234
Axel Linda057382010-10-25 10:11:07 +0800235 if (IS_ERR(max8952->rdev)) {
236 ret = PTR_ERR(max8952->rdev);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900237 dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
Axel Lin372de4a2012-05-16 12:50:47 +0800238 return ret;
Axel Linda057382010-10-25 10:11:07 +0800239 }
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900240
Axel Linc8237f02012-03-15 08:47:48 +0800241 max8952->vid0 = pdata->default_mode & 0x1;
242 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900243
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900244 if (gpio_is_valid(pdata->gpio_vid0) &&
245 gpio_is_valid(pdata->gpio_vid1)) {
246 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
247 gpio_direction_output(pdata->gpio_vid0,
Axel Linc8237f02012-03-15 08:47:48 +0800248 (pdata->default_mode) & 0x1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900249 else
250 err = 1;
251
252 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
253 gpio_direction_output(pdata->gpio_vid1,
Axel Linc8237f02012-03-15 08:47:48 +0800254 (pdata->default_mode >> 1) & 0x1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900255 else {
256 if (!err)
257 gpio_free(pdata->gpio_vid0);
258 err = 2;
259 }
260
261 } else
262 err = 3;
263
264 if (err) {
265 dev_warn(max8952->dev, "VID0/1 gpio invalid: "
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300266 "DVS not available.\n");
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900267 max8952->vid0 = 0;
268 max8952->vid1 = 0;
269 /* Mark invalid */
270 pdata->gpio_vid0 = -1;
271 pdata->gpio_vid1 = -1;
272
273 /* Disable Pulldown of EN only */
274 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
275
276 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
277 " do not have proper controls.\n");
278 } else {
279 /*
280 * Disable Pulldown on EN, VID0, VID1 to reduce
281 * leakage current of MAX8952 assuming that MAX8952
282 * is turned on (EN==1). Note that without having VID0/1
283 * properly connected, turning pulldown off can be
284 * problematic. Thus, turn this off only when they are
285 * controllable by GPIO.
286 */
287 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
288 }
289
290 max8952_write_reg(max8952, MAX8952_REG_MODE0,
291 (max8952_read_reg(max8952,
292 MAX8952_REG_MODE0) & 0xC0) |
293 (pdata->dvs_mode[0] & 0x3F));
294 max8952_write_reg(max8952, MAX8952_REG_MODE1,
295 (max8952_read_reg(max8952,
296 MAX8952_REG_MODE1) & 0xC0) |
297 (pdata->dvs_mode[1] & 0x3F));
298 max8952_write_reg(max8952, MAX8952_REG_MODE2,
299 (max8952_read_reg(max8952,
300 MAX8952_REG_MODE2) & 0xC0) |
301 (pdata->dvs_mode[2] & 0x3F));
302 max8952_write_reg(max8952, MAX8952_REG_MODE3,
303 (max8952_read_reg(max8952,
304 MAX8952_REG_MODE3) & 0xC0) |
305 (pdata->dvs_mode[3] & 0x3F));
306
307 max8952_write_reg(max8952, MAX8952_REG_SYNC,
308 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
309 ((pdata->sync_freq & 0x3) << 6));
310 max8952_write_reg(max8952, MAX8952_REG_RAMP,
311 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
312 ((pdata->ramp_speed & 0x7) << 5));
313
314 i2c_set_clientdata(client, max8952);
315
Axel Linda057382010-10-25 10:11:07 +0800316 return 0;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900317}
318
Bill Pemberton8dc995f2012-11-19 13:26:10 -0500319static int max8952_pmic_remove(struct i2c_client *client)
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900320{
321 struct max8952_data *max8952 = i2c_get_clientdata(client);
322 struct max8952_platform_data *pdata = max8952->pdata;
323 struct regulator_dev *rdev = max8952->rdev;
324
325 regulator_unregister(rdev);
326
327 gpio_free(pdata->gpio_vid0);
328 gpio_free(pdata->gpio_vid1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900329 return 0;
330}
331
332static const struct i2c_device_id max8952_ids[] = {
333 { "max8952", 0 },
334 { },
335};
336MODULE_DEVICE_TABLE(i2c, max8952_ids);
337
338static struct i2c_driver max8952_pmic_driver = {
339 .probe = max8952_pmic_probe,
Bill Pemberton5eb9f2b2012-11-19 13:20:42 -0500340 .remove = max8952_pmic_remove,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900341 .driver = {
342 .name = "max8952",
Tomasz Figa3ff4aa92013-04-04 18:17:20 +0200343 .of_match_table = of_match_ptr(max8952_dt_match),
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900344 },
345 .id_table = max8952_ids,
346};
347
348static int __init max8952_pmic_init(void)
349{
350 return i2c_add_driver(&max8952_pmic_driver);
351}
352subsys_initcall(max8952_pmic_init);
353
354static void __exit max8952_pmic_exit(void)
355{
356 i2c_del_driver(&max8952_pmic_driver);
357}
358module_exit(max8952_pmic_exit);
359
360MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
361MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
362MODULE_LICENSE("GPL");