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_list_voltage(struct regulator_dev
*rdev
,
73 unsigned int selector
)
75 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
77 if (rdev_get_id(rdev
) != 0)
80 return (max8952
->pdata
->dvs_mode
[selector
] * 10 + 770) * 1000;
83 static int max8952_is_enabled(struct regulator_dev
*rdev
)
85 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
89 static int max8952_enable(struct regulator_dev
*rdev
)
91 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
93 /* If not valid, assume "ALWAYS_HIGH" */
94 if (gpio_is_valid(max8952
->pdata
->gpio_en
))
95 gpio_set_value(max8952
->pdata
->gpio_en
, 1);
101 static int max8952_disable(struct regulator_dev
*rdev
)
103 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
105 /* If not valid, assume "ALWAYS_HIGH" -> not permitted */
106 if (gpio_is_valid(max8952
->pdata
->gpio_en
))
107 gpio_set_value(max8952
->pdata
->gpio_en
, 0);
115 static int max8952_get_voltage_sel(struct regulator_dev
*rdev
)
117 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
128 static int max8952_set_voltage_sel(struct regulator_dev
*rdev
,
131 struct max8952_data
*max8952
= rdev_get_drvdata(rdev
);
133 if (!gpio_is_valid(max8952
->pdata
->gpio_vid0
) ||
134 !gpio_is_valid(max8952
->pdata
->gpio_vid1
)) {
135 /* DVS not supported */
139 max8952
->vid0
= selector
& 0x1;
140 max8952
->vid1
= (selector
>> 1) & 0x1;
141 gpio_set_value(max8952
->pdata
->gpio_vid0
, max8952
->vid0
);
142 gpio_set_value(max8952
->pdata
->gpio_vid1
, max8952
->vid1
);
147 static struct regulator_ops max8952_ops
= {
148 .list_voltage
= max8952_list_voltage
,
149 .is_enabled
= max8952_is_enabled
,
150 .enable
= max8952_enable
,
151 .disable
= max8952_disable
,
152 .get_voltage_sel
= max8952_get_voltage_sel
,
153 .set_voltage_sel
= max8952_set_voltage_sel
,
156 static const struct regulator_desc regulator
= {
157 .name
= "MAX8952_VOUT",
159 .n_voltages
= MAX8952_NUM_DVS_MODE
,
161 .type
= REGULATOR_VOLTAGE
,
162 .owner
= THIS_MODULE
,
165 static int __devinit
max8952_pmic_probe(struct i2c_client
*client
,
166 const struct i2c_device_id
*i2c_id
)
168 struct i2c_adapter
*adapter
= to_i2c_adapter(client
->dev
.parent
);
169 struct max8952_platform_data
*pdata
= client
->dev
.platform_data
;
170 struct regulator_config config
= { };
171 struct max8952_data
*max8952
;
173 int ret
= 0, err
= 0;
176 dev_err(&client
->dev
, "Require the platform data\n");
180 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE
))
183 max8952
= devm_kzalloc(&client
->dev
, sizeof(struct max8952_data
),
188 max8952
->client
= client
;
189 max8952
->dev
= &client
->dev
;
190 max8952
->pdata
= pdata
;
192 config
.dev
= max8952
->dev
;
193 config
.init_data
= &pdata
->reg_data
;
194 config
.driver_data
= max8952
;
196 max8952
->rdev
= regulator_register(®ulator
, &config
);
198 if (IS_ERR(max8952
->rdev
)) {
199 ret
= PTR_ERR(max8952
->rdev
);
200 dev_err(max8952
->dev
, "regulator init failed (%d)\n", ret
);
204 max8952
->en
= !!(pdata
->reg_data
.constraints
.boot_on
);
205 max8952
->vid0
= pdata
->default_mode
& 0x1;
206 max8952
->vid1
= (pdata
->default_mode
>> 1) & 0x1;
208 if (gpio_is_valid(pdata
->gpio_en
)) {
209 if (!gpio_request(pdata
->gpio_en
, "MAX8952 EN"))
210 gpio_direction_output(pdata
->gpio_en
, max8952
->en
);
217 dev_info(max8952
->dev
, "EN gpio invalid: assume that EN"
220 pdata
->gpio_en
= -1; /* Mark invalid */
225 if (gpio_is_valid(pdata
->gpio_vid0
) &&
226 gpio_is_valid(pdata
->gpio_vid1
)) {
227 if (!gpio_request(pdata
->gpio_vid0
, "MAX8952 VID0"))
228 gpio_direction_output(pdata
->gpio_vid0
,
229 (pdata
->default_mode
) & 0x1);
233 if (!gpio_request(pdata
->gpio_vid1
, "MAX8952 VID1"))
234 gpio_direction_output(pdata
->gpio_vid1
,
235 (pdata
->default_mode
>> 1) & 0x1);
238 gpio_free(pdata
->gpio_vid0
);
246 dev_warn(max8952
->dev
, "VID0/1 gpio invalid: "
247 "DVS not available.\n");
251 pdata
->gpio_vid0
= -1;
252 pdata
->gpio_vid1
= -1;
254 /* Disable Pulldown of EN only */
255 max8952_write_reg(max8952
, MAX8952_REG_CONTROL
, 0x60);
257 dev_err(max8952
->dev
, "DVS modes disabled because VID0 and VID1"
258 " do not have proper controls.\n");
261 * Disable Pulldown on EN, VID0, VID1 to reduce
262 * leakage current of MAX8952 assuming that MAX8952
263 * is turned on (EN==1). Note that without having VID0/1
264 * properly connected, turning pulldown off can be
265 * problematic. Thus, turn this off only when they are
266 * controllable by GPIO.
268 max8952_write_reg(max8952
, MAX8952_REG_CONTROL
, 0x0);
271 max8952_write_reg(max8952
, MAX8952_REG_MODE0
,
272 (max8952_read_reg(max8952
,
273 MAX8952_REG_MODE0
) & 0xC0) |
274 (pdata
->dvs_mode
[0] & 0x3F));
275 max8952_write_reg(max8952
, MAX8952_REG_MODE1
,
276 (max8952_read_reg(max8952
,
277 MAX8952_REG_MODE1
) & 0xC0) |
278 (pdata
->dvs_mode
[1] & 0x3F));
279 max8952_write_reg(max8952
, MAX8952_REG_MODE2
,
280 (max8952_read_reg(max8952
,
281 MAX8952_REG_MODE2
) & 0xC0) |
282 (pdata
->dvs_mode
[2] & 0x3F));
283 max8952_write_reg(max8952
, MAX8952_REG_MODE3
,
284 (max8952_read_reg(max8952
,
285 MAX8952_REG_MODE3
) & 0xC0) |
286 (pdata
->dvs_mode
[3] & 0x3F));
288 max8952_write_reg(max8952
, MAX8952_REG_SYNC
,
289 (max8952_read_reg(max8952
, MAX8952_REG_SYNC
) & 0x3F) |
290 ((pdata
->sync_freq
& 0x3) << 6));
291 max8952_write_reg(max8952
, MAX8952_REG_RAMP
,
292 (max8952_read_reg(max8952
, MAX8952_REG_RAMP
) & 0x1F) |
293 ((pdata
->ramp_speed
& 0x7) << 5));
295 i2c_set_clientdata(client
, max8952
);
300 static int __devexit
max8952_pmic_remove(struct i2c_client
*client
)
302 struct max8952_data
*max8952
= i2c_get_clientdata(client
);
303 struct max8952_platform_data
*pdata
= max8952
->pdata
;
304 struct regulator_dev
*rdev
= max8952
->rdev
;
306 regulator_unregister(rdev
);
308 gpio_free(pdata
->gpio_vid0
);
309 gpio_free(pdata
->gpio_vid1
);
310 gpio_free(pdata
->gpio_en
);
314 static const struct i2c_device_id max8952_ids
[] = {
318 MODULE_DEVICE_TABLE(i2c
, max8952_ids
);
320 static struct i2c_driver max8952_pmic_driver
= {
321 .probe
= max8952_pmic_probe
,
322 .remove
= __devexit_p(max8952_pmic_remove
),
326 .id_table
= max8952_ids
,
329 static int __init
max8952_pmic_init(void)
331 return i2c_add_driver(&max8952_pmic_driver
);
333 subsys_initcall(max8952_pmic_init
);
335 static void __exit
max8952_pmic_exit(void)
337 i2c_del_driver(&max8952_pmic_driver
);
339 module_exit(max8952_pmic_exit
);
341 MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
342 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
343 MODULE_LICENSE("GPL");