2 * max8952.c - Voltage and current regulation for the Maxim 8952
4 * Copyright (C) 2010 Samsung Electronics
5 * MyungJoo Ham <myungjoo.ham@samsung.com>
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.
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.
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
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>
29 #include <linux/gpio.h>
31 #include <linux/slab.h>
47 struct i2c_client *client;
49 struct max8952_platform_data *pdata;
50 struct regulator_dev *rdev;
57 static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
59 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
66 static int max8952_write_reg(struct max8952_data *max8952,
69 return i2c_smbus_write_byte_data(max8952->client, reg, value);
72 static int max8952_voltage(struct max8952_data *max8952, u8 mode)
74 return (max8952->pdata->dvs_mode[mode] * 10 + 770) * 1000;
77 static int max8952_list_voltage(struct regulator_dev *rdev,
78 unsigned int selector)
80 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
82 if (rdev_get_id(rdev) != 0)
85 return max8952_voltage(max8952, selector);
88 static int max8952_is_enabled(struct regulator_dev *rdev)
90 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
94 static int max8952_enable(struct regulator_dev *rdev)
96 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
98 /* If not valid, assume "ALWAYS_HIGH" */
99 if (gpio_is_valid(max8952->pdata->gpio_en))
100 gpio_set_value(max8952->pdata->gpio_en, 1);
106 static int max8952_disable(struct regulator_dev *rdev)
108 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
110 /* If not valid, assume "ALWAYS_HIGH" -> not permitted */
111 if (gpio_is_valid(max8952->pdata->gpio_en))
112 gpio_set_value(max8952->pdata->gpio_en, 0);
120 static int max8952_get_voltage(struct regulator_dev *rdev)
122 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
130 return max8952_voltage(max8952, vid);
133 static int max8952_set_voltage_sel(struct regulator_dev *rdev,
136 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
138 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
139 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
140 /* DVS not supported */
144 max8952->vid0 = selector & 0x1;
145 max8952->vid1 = (selector >> 1) & 0x1;
146 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
147 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
152 static struct regulator_ops max8952_ops = {
153 .list_voltage = max8952_list_voltage,
154 .is_enabled = max8952_is_enabled,
155 .enable = max8952_enable,
156 .disable = max8952_disable,
157 .get_voltage = max8952_get_voltage,
158 .set_voltage_sel = max8952_set_voltage_sel,
159 .set_suspend_disable = max8952_disable,
162 static const struct regulator_desc regulator = {
163 .name = "MAX8952_VOUT",
165 .n_voltages = MAX8952_NUM_DVS_MODE,
167 .type = REGULATOR_VOLTAGE,
168 .owner = THIS_MODULE,
171 static int __devinit max8952_pmic_probe(struct i2c_client *client,
172 const struct i2c_device_id *i2c_id)
174 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
175 struct max8952_platform_data *pdata = client->dev.platform_data;
176 struct regulator_config config = { };
177 struct max8952_data *max8952;
179 int ret = 0, err = 0;
182 dev_err(&client->dev, "Require the platform data\n");
186 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
189 max8952 = kzalloc(sizeof(struct max8952_data), GFP_KERNEL);
193 max8952->client = client;
194 max8952->dev = &client->dev;
195 max8952->pdata = pdata;
197 config.dev = max8952->dev;
198 config.init_data = &pdata->reg_data;
199 config.driver_data = max8952;
201 max8952->rdev = regulator_register(®ulator, &config);
203 if (IS_ERR(max8952->rdev)) {
204 ret = PTR_ERR(max8952->rdev);
205 dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
209 max8952->en = !!(pdata->reg_data.constraints.boot_on);
210 max8952->vid0 = pdata->default_mode & 0x1;
211 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
213 if (gpio_is_valid(pdata->gpio_en)) {
214 if (!gpio_request(pdata->gpio_en, "MAX8952 EN"))
215 gpio_direction_output(pdata->gpio_en, max8952->en);
222 dev_info(max8952->dev, "EN gpio invalid: assume that EN"
225 pdata->gpio_en = -1; /* Mark invalid */
230 if (gpio_is_valid(pdata->gpio_vid0) &&
231 gpio_is_valid(pdata->gpio_vid1)) {
232 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
233 gpio_direction_output(pdata->gpio_vid0,
234 (pdata->default_mode) & 0x1);
238 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
239 gpio_direction_output(pdata->gpio_vid1,
240 (pdata->default_mode >> 1) & 0x1);
243 gpio_free(pdata->gpio_vid0);
251 dev_warn(max8952->dev, "VID0/1 gpio invalid: "
252 "DVS not available.\n");
256 pdata->gpio_vid0 = -1;
257 pdata->gpio_vid1 = -1;
259 /* Disable Pulldown of EN only */
260 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
262 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
263 " do not have proper controls.\n");
266 * Disable Pulldown on EN, VID0, VID1 to reduce
267 * leakage current of MAX8952 assuming that MAX8952
268 * is turned on (EN==1). Note that without having VID0/1
269 * properly connected, turning pulldown off can be
270 * problematic. Thus, turn this off only when they are
271 * controllable by GPIO.
273 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
276 max8952_write_reg(max8952, MAX8952_REG_MODE0,
277 (max8952_read_reg(max8952,
278 MAX8952_REG_MODE0) & 0xC0) |
279 (pdata->dvs_mode[0] & 0x3F));
280 max8952_write_reg(max8952, MAX8952_REG_MODE1,
281 (max8952_read_reg(max8952,
282 MAX8952_REG_MODE1) & 0xC0) |
283 (pdata->dvs_mode[1] & 0x3F));
284 max8952_write_reg(max8952, MAX8952_REG_MODE2,
285 (max8952_read_reg(max8952,
286 MAX8952_REG_MODE2) & 0xC0) |
287 (pdata->dvs_mode[2] & 0x3F));
288 max8952_write_reg(max8952, MAX8952_REG_MODE3,
289 (max8952_read_reg(max8952,
290 MAX8952_REG_MODE3) & 0xC0) |
291 (pdata->dvs_mode[3] & 0x3F));
293 max8952_write_reg(max8952, MAX8952_REG_SYNC,
294 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
295 ((pdata->sync_freq & 0x3) << 6));
296 max8952_write_reg(max8952, MAX8952_REG_RAMP,
297 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
298 ((pdata->ramp_speed & 0x7) << 5));
300 i2c_set_clientdata(client, max8952);
309 static int __devexit max8952_pmic_remove(struct i2c_client *client)
311 struct max8952_data *max8952 = i2c_get_clientdata(client);
312 struct max8952_platform_data *pdata = max8952->pdata;
313 struct regulator_dev *rdev = max8952->rdev;
315 regulator_unregister(rdev);
317 gpio_free(pdata->gpio_vid0);
318 gpio_free(pdata->gpio_vid1);
319 gpio_free(pdata->gpio_en);
325 static const struct i2c_device_id max8952_ids[] = {
329 MODULE_DEVICE_TABLE(i2c, max8952_ids);
331 static struct i2c_driver max8952_pmic_driver = {
332 .probe = max8952_pmic_probe,
333 .remove = __devexit_p(max8952_pmic_remove),
337 .id_table = max8952_ids,
340 static int __init max8952_pmic_init(void)
342 return i2c_add_driver(&max8952_pmic_driver);
344 subsys_initcall(max8952_pmic_init);
346 static void __exit max8952_pmic_exit(void)
348 i2c_del_driver(&max8952_pmic_driver);
350 module_exit(max8952_pmic_exit);
352 MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
353 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
354 MODULE_LICENSE("GPL");