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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> | |
202f4f53 MH |
29 | #include <linux/gpio.h> |
30 | #include <linux/io.h> | |
31 | #include <linux/slab.h> | |
32 | ||
33 | /* Registers */ | |
34 | enum { | |
35 | MAX8952_REG_MODE0, | |
36 | MAX8952_REG_MODE1, | |
37 | MAX8952_REG_MODE2, | |
38 | MAX8952_REG_MODE3, | |
39 | MAX8952_REG_CONTROL, | |
40 | MAX8952_REG_SYNC, | |
41 | MAX8952_REG_RAMP, | |
42 | MAX8952_REG_CHIP_ID1, | |
43 | MAX8952_REG_CHIP_ID2, | |
44 | }; | |
45 | ||
46 | struct max8952_data { | |
47 | struct i2c_client *client; | |
48 | struct device *dev; | |
202f4f53 MH |
49 | struct max8952_platform_data *pdata; |
50 | struct regulator_dev *rdev; | |
51 | ||
52 | bool vid0; | |
53 | bool vid1; | |
54 | bool en; | |
55 | }; | |
56 | ||
57 | static int max8952_read_reg(struct max8952_data *max8952, u8 reg) | |
58 | { | |
59 | int ret = i2c_smbus_read_byte_data(max8952->client, reg); | |
60 | if (ret > 0) | |
61 | ret &= 0xff; | |
62 | ||
63 | return ret; | |
64 | } | |
65 | ||
66 | static int max8952_write_reg(struct max8952_data *max8952, | |
67 | u8 reg, u8 value) | |
68 | { | |
69 | return i2c_smbus_write_byte_data(max8952->client, reg, value); | |
70 | } | |
71 | ||
72 | static int max8952_voltage(struct max8952_data *max8952, u8 mode) | |
73 | { | |
74 | return (max8952->pdata->dvs_mode[mode] * 10 + 770) * 1000; | |
75 | } | |
76 | ||
77 | static int max8952_list_voltage(struct regulator_dev *rdev, | |
78 | unsigned int selector) | |
79 | { | |
80 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
81 | ||
82 | if (rdev_get_id(rdev) != 0) | |
83 | return -EINVAL; | |
84 | ||
85 | return max8952_voltage(max8952, selector); | |
86 | } | |
87 | ||
88 | static int max8952_is_enabled(struct regulator_dev *rdev) | |
89 | { | |
90 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
91 | return max8952->en; | |
92 | } | |
93 | ||
94 | static int max8952_enable(struct regulator_dev *rdev) | |
95 | { | |
96 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
97 | ||
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); | |
101 | ||
102 | max8952->en = true; | |
103 | return 0; | |
104 | } | |
105 | ||
106 | static int max8952_disable(struct regulator_dev *rdev) | |
107 | { | |
108 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
109 | ||
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); | |
113 | else | |
114 | return -EPERM; | |
115 | ||
116 | max8952->en = false; | |
117 | return 0; | |
118 | } | |
119 | ||
120 | static int max8952_get_voltage(struct regulator_dev *rdev) | |
121 | { | |
122 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
123 | u8 vid = 0; | |
124 | ||
125 | if (max8952->vid0) | |
126 | vid += 1; | |
127 | if (max8952->vid1) | |
128 | vid += 2; | |
129 | ||
130 | return max8952_voltage(max8952, vid); | |
131 | } | |
132 | ||
133 | static int max8952_set_voltage(struct regulator_dev *rdev, | |
3a93f2a9 | 134 | int min_uV, int max_uV, unsigned *selector) |
202f4f53 MH |
135 | { |
136 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
ec10b0e9 | 137 | s8 vid = -1, i; |
202f4f53 MH |
138 | |
139 | if (!gpio_is_valid(max8952->pdata->gpio_vid0) || | |
e2cf3137 | 140 | !gpio_is_valid(max8952->pdata->gpio_vid1)) { |
202f4f53 MH |
141 | /* DVS not supported */ |
142 | return -EPERM; | |
143 | } | |
144 | ||
145 | for (i = 0; i < MAX8952_NUM_DVS_MODE; i++) { | |
146 | int volt = max8952_voltage(max8952, i); | |
147 | ||
148 | /* Set the voltage as low as possible within the range */ | |
149 | if (volt <= max_uV && volt >= min_uV) | |
150 | if (vid == -1 || max8952_voltage(max8952, vid) > volt) | |
151 | vid = i; | |
152 | } | |
153 | ||
154 | if (vid >= 0 && vid < MAX8952_NUM_DVS_MODE) { | |
155 | max8952->vid0 = (vid % 2 == 1); | |
156 | max8952->vid1 = (((vid >> 1) % 2) == 1); | |
3a93f2a9 | 157 | *selector = vid; |
202f4f53 MH |
158 | gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0); |
159 | gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1); | |
160 | } else | |
161 | return -EINVAL; | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | static struct regulator_ops max8952_ops = { | |
167 | .list_voltage = max8952_list_voltage, | |
168 | .is_enabled = max8952_is_enabled, | |
169 | .enable = max8952_enable, | |
170 | .disable = max8952_disable, | |
171 | .get_voltage = max8952_get_voltage, | |
172 | .set_voltage = max8952_set_voltage, | |
173 | .set_suspend_disable = max8952_disable, | |
174 | }; | |
175 | ||
176 | static struct regulator_desc regulator = { | |
177 | .name = "MAX8952_VOUT", | |
178 | .id = 0, | |
179 | .n_voltages = MAX8952_NUM_DVS_MODE, | |
180 | .ops = &max8952_ops, | |
181 | .type = REGULATOR_VOLTAGE, | |
182 | .owner = THIS_MODULE, | |
183 | }; | |
184 | ||
185 | static int __devinit max8952_pmic_probe(struct i2c_client *client, | |
186 | const struct i2c_device_id *i2c_id) | |
187 | { | |
188 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
189 | struct max8952_platform_data *pdata = client->dev.platform_data; | |
190 | struct max8952_data *max8952; | |
191 | ||
192 | int ret = 0, err = 0; | |
193 | ||
194 | if (!pdata) { | |
195 | dev_err(&client->dev, "Require the platform data\n"); | |
196 | return -EINVAL; | |
197 | } | |
198 | ||
199 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) | |
200 | return -EIO; | |
201 | ||
202 | max8952 = kzalloc(sizeof(struct max8952_data), GFP_KERNEL); | |
203 | if (!max8952) | |
204 | return -ENOMEM; | |
205 | ||
206 | max8952->client = client; | |
207 | max8952->dev = &client->dev; | |
208 | max8952->pdata = pdata; | |
202f4f53 MH |
209 | |
210 | max8952->rdev = regulator_register(®ulator, max8952->dev, | |
2c043bcb | 211 | &pdata->reg_data, max8952, NULL); |
202f4f53 | 212 | |
da05738e AL |
213 | if (IS_ERR(max8952->rdev)) { |
214 | ret = PTR_ERR(max8952->rdev); | |
202f4f53 | 215 | dev_err(max8952->dev, "regulator init failed (%d)\n", ret); |
da05738e AL |
216 | goto err_reg; |
217 | } | |
202f4f53 MH |
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: " | |
25985edc | 262 | "DVS not available.\n"); |
202f4f53 MH |
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 | ||
da05738e AL |
312 | return 0; |
313 | ||
314 | err_reg: | |
315 | kfree(max8952); | |
202f4f53 MH |
316 | return ret; |
317 | } | |
318 | ||
319 | static int __devexit max8952_pmic_remove(struct i2c_client *client) | |
320 | { | |
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); | |
329 | gpio_free(pdata->gpio_en); | |
330 | ||
331 | kfree(max8952); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | static const struct i2c_device_id max8952_ids[] = { | |
336 | { "max8952", 0 }, | |
337 | { }, | |
338 | }; | |
339 | MODULE_DEVICE_TABLE(i2c, max8952_ids); | |
340 | ||
341 | static struct i2c_driver max8952_pmic_driver = { | |
342 | .probe = max8952_pmic_probe, | |
343 | .remove = __devexit_p(max8952_pmic_remove), | |
344 | .driver = { | |
345 | .name = "max8952", | |
346 | }, | |
347 | .id_table = max8952_ids, | |
348 | }; | |
349 | ||
350 | static int __init max8952_pmic_init(void) | |
351 | { | |
352 | return i2c_add_driver(&max8952_pmic_driver); | |
353 | } | |
354 | subsys_initcall(max8952_pmic_init); | |
355 | ||
356 | static void __exit max8952_pmic_exit(void) | |
357 | { | |
358 | i2c_del_driver(&max8952_pmic_driver); | |
359 | } | |
360 | module_exit(max8952_pmic_exit); | |
361 | ||
362 | MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); | |
363 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
364 | MODULE_LICENSE("GPL"); |