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202f4f53 MH |
1 | /* |
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> | |
29 | #include <linux/mutex.h> | |
30 | #include <linux/gpio.h> | |
31 | #include <linux/io.h> | |
32 | #include <linux/slab.h> | |
33 | ||
34 | /* Registers */ | |
35 | enum { | |
36 | MAX8952_REG_MODE0, | |
37 | MAX8952_REG_MODE1, | |
38 | MAX8952_REG_MODE2, | |
39 | MAX8952_REG_MODE3, | |
40 | MAX8952_REG_CONTROL, | |
41 | MAX8952_REG_SYNC, | |
42 | MAX8952_REG_RAMP, | |
43 | MAX8952_REG_CHIP_ID1, | |
44 | MAX8952_REG_CHIP_ID2, | |
45 | }; | |
46 | ||
47 | struct max8952_data { | |
48 | struct i2c_client *client; | |
49 | struct device *dev; | |
50 | struct mutex mutex; | |
51 | struct max8952_platform_data *pdata; | |
52 | struct regulator_dev *rdev; | |
53 | ||
54 | bool vid0; | |
55 | bool vid1; | |
56 | bool en; | |
57 | }; | |
58 | ||
59 | static 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 | ||
68 | static 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 | ||
74 | static int max8952_voltage(struct max8952_data *max8952, u8 mode) | |
75 | { | |
76 | return (max8952->pdata->dvs_mode[mode] * 10 + 770) * 1000; | |
77 | } | |
78 | ||
79 | static int max8952_list_voltage(struct regulator_dev *rdev, | |
80 | unsigned int selector) | |
81 | { | |
82 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
83 | ||
84 | if (rdev_get_id(rdev) != 0) | |
85 | return -EINVAL; | |
86 | ||
87 | return max8952_voltage(max8952, selector); | |
88 | } | |
89 | ||
90 | static int max8952_is_enabled(struct regulator_dev *rdev) | |
91 | { | |
92 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
93 | return max8952->en; | |
94 | } | |
95 | ||
96 | static int max8952_enable(struct regulator_dev *rdev) | |
97 | { | |
98 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
99 | ||
100 | /* If not valid, assume "ALWAYS_HIGH" */ | |
101 | if (gpio_is_valid(max8952->pdata->gpio_en)) | |
102 | gpio_set_value(max8952->pdata->gpio_en, 1); | |
103 | ||
104 | max8952->en = true; | |
105 | return 0; | |
106 | } | |
107 | ||
108 | static int max8952_disable(struct regulator_dev *rdev) | |
109 | { | |
110 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
111 | ||
112 | /* If not valid, assume "ALWAYS_HIGH" -> not permitted */ | |
113 | if (gpio_is_valid(max8952->pdata->gpio_en)) | |
114 | gpio_set_value(max8952->pdata->gpio_en, 0); | |
115 | else | |
116 | return -EPERM; | |
117 | ||
118 | max8952->en = false; | |
119 | return 0; | |
120 | } | |
121 | ||
122 | static int max8952_get_voltage(struct regulator_dev *rdev) | |
123 | { | |
124 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
125 | u8 vid = 0; | |
126 | ||
127 | if (max8952->vid0) | |
128 | vid += 1; | |
129 | if (max8952->vid1) | |
130 | vid += 2; | |
131 | ||
132 | return max8952_voltage(max8952, vid); | |
133 | } | |
134 | ||
135 | static int max8952_set_voltage(struct regulator_dev *rdev, | |
136 | int min_uV, int max_uV) | |
137 | { | |
138 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
139 | u8 vid = -1, i; | |
140 | ||
141 | if (!gpio_is_valid(max8952->pdata->gpio_vid0) || | |
142 | !gpio_is_valid(max8952->pdata->gpio_vid0)) { | |
143 | /* DVS not supported */ | |
144 | return -EPERM; | |
145 | } | |
146 | ||
147 | for (i = 0; i < MAX8952_NUM_DVS_MODE; i++) { | |
148 | int volt = max8952_voltage(max8952, i); | |
149 | ||
150 | /* Set the voltage as low as possible within the range */ | |
151 | if (volt <= max_uV && volt >= min_uV) | |
152 | if (vid == -1 || max8952_voltage(max8952, vid) > volt) | |
153 | vid = i; | |
154 | } | |
155 | ||
156 | if (vid >= 0 && vid < MAX8952_NUM_DVS_MODE) { | |
157 | max8952->vid0 = (vid % 2 == 1); | |
158 | max8952->vid1 = (((vid >> 1) % 2) == 1); | |
159 | gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0); | |
160 | gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1); | |
161 | } else | |
162 | return -EINVAL; | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | static struct regulator_ops max8952_ops = { | |
168 | .list_voltage = max8952_list_voltage, | |
169 | .is_enabled = max8952_is_enabled, | |
170 | .enable = max8952_enable, | |
171 | .disable = max8952_disable, | |
172 | .get_voltage = max8952_get_voltage, | |
173 | .set_voltage = max8952_set_voltage, | |
174 | .set_suspend_disable = max8952_disable, | |
175 | }; | |
176 | ||
177 | static struct regulator_desc regulator = { | |
178 | .name = "MAX8952_VOUT", | |
179 | .id = 0, | |
180 | .n_voltages = MAX8952_NUM_DVS_MODE, | |
181 | .ops = &max8952_ops, | |
182 | .type = REGULATOR_VOLTAGE, | |
183 | .owner = THIS_MODULE, | |
184 | }; | |
185 | ||
186 | static int __devinit max8952_pmic_probe(struct i2c_client *client, | |
187 | const struct i2c_device_id *i2c_id) | |
188 | { | |
189 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
190 | struct max8952_platform_data *pdata = client->dev.platform_data; | |
191 | struct max8952_data *max8952; | |
192 | ||
193 | int ret = 0, err = 0; | |
194 | ||
195 | if (!pdata) { | |
196 | dev_err(&client->dev, "Require the platform data\n"); | |
197 | return -EINVAL; | |
198 | } | |
199 | ||
200 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) | |
201 | return -EIO; | |
202 | ||
203 | max8952 = kzalloc(sizeof(struct max8952_data), GFP_KERNEL); | |
204 | if (!max8952) | |
205 | return -ENOMEM; | |
206 | ||
207 | max8952->client = client; | |
208 | max8952->dev = &client->dev; | |
209 | max8952->pdata = pdata; | |
210 | mutex_init(&max8952->mutex); | |
211 | ||
212 | max8952->rdev = regulator_register(®ulator, max8952->dev, | |
213 | &pdata->reg_data, max8952); | |
214 | ||
215 | ret = IS_ERR(max8952->rdev); | |
216 | if (ret) | |
217 | dev_err(max8952->dev, "regulator init failed (%d)\n", ret); | |
218 | ||
219 | max8952->en = !!(pdata->reg_data.constraints.boot_on); | |
220 | max8952->vid0 = (pdata->default_mode % 2) == 1; | |
221 | max8952->vid1 = ((pdata->default_mode >> 1) % 2) == 1; | |
222 | ||
223 | if (gpio_is_valid(pdata->gpio_en)) { | |
224 | if (!gpio_request(pdata->gpio_en, "MAX8952 EN")) | |
225 | gpio_direction_output(pdata->gpio_en, max8952->en); | |
226 | else | |
227 | err = 1; | |
228 | } else | |
229 | err = 2; | |
230 | ||
231 | if (err) { | |
232 | dev_info(max8952->dev, "EN gpio invalid: assume that EN" | |
233 | "is always High\n"); | |
234 | max8952->en = 1; | |
235 | pdata->gpio_en = -1; /* Mark invalid */ | |
236 | } | |
237 | ||
238 | err = 0; | |
239 | ||
240 | if (gpio_is_valid(pdata->gpio_vid0) && | |
241 | gpio_is_valid(pdata->gpio_vid1)) { | |
242 | if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0")) | |
243 | gpio_direction_output(pdata->gpio_vid0, | |
244 | (pdata->default_mode) % 2); | |
245 | else | |
246 | err = 1; | |
247 | ||
248 | if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1")) | |
249 | gpio_direction_output(pdata->gpio_vid1, | |
250 | (pdata->default_mode >> 1) % 2); | |
251 | else { | |
252 | if (!err) | |
253 | gpio_free(pdata->gpio_vid0); | |
254 | err = 2; | |
255 | } | |
256 | ||
257 | } else | |
258 | err = 3; | |
259 | ||
260 | if (err) { | |
261 | dev_warn(max8952->dev, "VID0/1 gpio invalid: " | |
262 | "DVS not avilable.\n"); | |
263 | max8952->vid0 = 0; | |
264 | max8952->vid1 = 0; | |
265 | /* Mark invalid */ | |
266 | pdata->gpio_vid0 = -1; | |
267 | pdata->gpio_vid1 = -1; | |
268 | ||
269 | /* Disable Pulldown of EN only */ | |
270 | max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60); | |
271 | ||
272 | dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1" | |
273 | " do not have proper controls.\n"); | |
274 | } else { | |
275 | /* | |
276 | * Disable Pulldown on EN, VID0, VID1 to reduce | |
277 | * leakage current of MAX8952 assuming that MAX8952 | |
278 | * is turned on (EN==1). Note that without having VID0/1 | |
279 | * properly connected, turning pulldown off can be | |
280 | * problematic. Thus, turn this off only when they are | |
281 | * controllable by GPIO. | |
282 | */ | |
283 | max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0); | |
284 | } | |
285 | ||
286 | max8952_write_reg(max8952, MAX8952_REG_MODE0, | |
287 | (max8952_read_reg(max8952, | |
288 | MAX8952_REG_MODE0) & 0xC0) | | |
289 | (pdata->dvs_mode[0] & 0x3F)); | |
290 | max8952_write_reg(max8952, MAX8952_REG_MODE1, | |
291 | (max8952_read_reg(max8952, | |
292 | MAX8952_REG_MODE1) & 0xC0) | | |
293 | (pdata->dvs_mode[1] & 0x3F)); | |
294 | max8952_write_reg(max8952, MAX8952_REG_MODE2, | |
295 | (max8952_read_reg(max8952, | |
296 | MAX8952_REG_MODE2) & 0xC0) | | |
297 | (pdata->dvs_mode[2] & 0x3F)); | |
298 | max8952_write_reg(max8952, MAX8952_REG_MODE3, | |
299 | (max8952_read_reg(max8952, | |
300 | MAX8952_REG_MODE3) & 0xC0) | | |
301 | (pdata->dvs_mode[3] & 0x3F)); | |
302 | ||
303 | max8952_write_reg(max8952, MAX8952_REG_SYNC, | |
304 | (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) | | |
305 | ((pdata->sync_freq & 0x3) << 6)); | |
306 | max8952_write_reg(max8952, MAX8952_REG_RAMP, | |
307 | (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) | | |
308 | ((pdata->ramp_speed & 0x7) << 5)); | |
309 | ||
310 | i2c_set_clientdata(client, max8952); | |
311 | ||
312 | return ret; | |
313 | } | |
314 | ||
315 | static int __devexit max8952_pmic_remove(struct i2c_client *client) | |
316 | { | |
317 | struct max8952_data *max8952 = i2c_get_clientdata(client); | |
318 | struct max8952_platform_data *pdata = max8952->pdata; | |
319 | struct regulator_dev *rdev = max8952->rdev; | |
320 | ||
321 | regulator_unregister(rdev); | |
322 | ||
323 | gpio_free(pdata->gpio_vid0); | |
324 | gpio_free(pdata->gpio_vid1); | |
325 | gpio_free(pdata->gpio_en); | |
326 | ||
327 | kfree(max8952); | |
328 | return 0; | |
329 | } | |
330 | ||
331 | static const struct i2c_device_id max8952_ids[] = { | |
332 | { "max8952", 0 }, | |
333 | { }, | |
334 | }; | |
335 | MODULE_DEVICE_TABLE(i2c, max8952_ids); | |
336 | ||
337 | static struct i2c_driver max8952_pmic_driver = { | |
338 | .probe = max8952_pmic_probe, | |
339 | .remove = __devexit_p(max8952_pmic_remove), | |
340 | .driver = { | |
341 | .name = "max8952", | |
342 | }, | |
343 | .id_table = max8952_ids, | |
344 | }; | |
345 | ||
346 | static int __init max8952_pmic_init(void) | |
347 | { | |
348 | return i2c_add_driver(&max8952_pmic_driver); | |
349 | } | |
350 | subsys_initcall(max8952_pmic_init); | |
351 | ||
352 | static void __exit max8952_pmic_exit(void) | |
353 | { | |
354 | i2c_del_driver(&max8952_pmic_driver); | |
355 | } | |
356 | module_exit(max8952_pmic_exit); | |
357 | ||
358 | MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); | |
359 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
360 | MODULE_LICENSE("GPL"); |