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Wolfram Sang27f37e42009-09-25 09:39:26 +02001/*
2 * max8660.c -- Voltage regulation for the Maxim 8660/8661
3 *
4 * based on max1586.c and wm8400-regulator.c
5 *
6 * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
19 * Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 * Some info:
22 *
23 * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf
24 *
25 * This chip is a bit nasty because it is a write-only device. Thus, the driver
26 * uses shadow registers to keep track of its values. The main problem appears
27 * to be the initialization: When Linux boots up, we cannot know if the chip is
28 * in the default state or not, so we would have to pass such information in
29 * platform_data. As this adds a bit of complexity to the driver, this is left
30 * out for now until it is really needed.
31 *
32 * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2.
33 *
34 * If the driver is feature complete, it might be worth to check if one set of
35 * functions for V3-V7 is sufficient. For maximum flexibility during
36 * development, they are separated for now.
37 *
38 */
39
40#include <linux/module.h>
41#include <linux/err.h>
42#include <linux/i2c.h>
43#include <linux/platform_device.h>
44#include <linux/regulator/driver.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090045#include <linux/slab.h>
Wolfram Sang27f37e42009-09-25 09:39:26 +020046#include <linux/regulator/max8660.h>
47
48#define MAX8660_DCDC_MIN_UV 725000
49#define MAX8660_DCDC_MAX_UV 1800000
50#define MAX8660_DCDC_STEP 25000
51#define MAX8660_DCDC_MAX_SEL 0x2b
52
53#define MAX8660_LDO5_MIN_UV 1700000
54#define MAX8660_LDO5_MAX_UV 2000000
55#define MAX8660_LDO5_STEP 25000
56#define MAX8660_LDO5_MAX_SEL 0x0c
57
58#define MAX8660_LDO67_MIN_UV 1800000
59#define MAX8660_LDO67_MAX_UV 3300000
60#define MAX8660_LDO67_STEP 100000
61#define MAX8660_LDO67_MAX_SEL 0x0f
62
63enum {
64 MAX8660_OVER1,
65 MAX8660_OVER2,
66 MAX8660_VCC1,
67 MAX8660_ADTV1,
68 MAX8660_ADTV2,
69 MAX8660_SDTV1,
70 MAX8660_SDTV2,
71 MAX8660_MDTV1,
72 MAX8660_MDTV2,
73 MAX8660_L12VCR,
74 MAX8660_FPWM,
75 MAX8660_N_REGS, /* not a real register */
76};
77
78struct max8660 {
79 struct i2c_client *client;
80 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */
81 struct regulator_dev *rdev[];
82};
83
84static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
85{
86 static const u8 max8660_addresses[MAX8660_N_REGS] =
87 { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 };
88
89 int ret;
90 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
91 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
92 max8660_addresses[reg], reg_val);
93
94 ret = i2c_smbus_write_byte_data(max8660->client,
95 max8660_addresses[reg], reg_val);
96 if (ret == 0)
97 max8660->shadow_regs[reg] = reg_val;
98
99 return ret;
100}
101
102
103/*
104 * DCDC functions
105 */
106
107static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
108{
109 struct max8660 *max8660 = rdev_get_drvdata(rdev);
110 u8 val = max8660->shadow_regs[MAX8660_OVER1];
111 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
112 return !!(val & mask);
113}
114
115static int max8660_dcdc_enable(struct regulator_dev *rdev)
116{
117 struct max8660 *max8660 = rdev_get_drvdata(rdev);
118 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
119 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
120}
121
122static int max8660_dcdc_disable(struct regulator_dev *rdev)
123{
124 struct max8660 *max8660 = rdev_get_drvdata(rdev);
125 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
126 return max8660_write(max8660, MAX8660_OVER1, mask, 0);
127}
128
129static int max8660_dcdc_list(struct regulator_dev *rdev, unsigned selector)
130{
131 if (selector > MAX8660_DCDC_MAX_SEL)
132 return -EINVAL;
133 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
134}
135
136static int max8660_dcdc_get(struct regulator_dev *rdev)
137{
138 struct max8660 *max8660 = rdev_get_drvdata(rdev);
139 u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
140 u8 selector = max8660->shadow_regs[reg];
141 return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
142}
143
Mark Brown3a93f2a2010-11-10 14:38:29 +0000144static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV,
145 unsigned int *s)
Wolfram Sang27f37e42009-09-25 09:39:26 +0200146{
147 struct max8660 *max8660 = rdev_get_drvdata(rdev);
148 u8 reg, selector, bits;
149 int ret;
150
151 if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV)
152 return -EINVAL;
153 if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV)
154 return -EINVAL;
155
Axel Linab353c22012-03-02 16:23:39 +0800156 selector = DIV_ROUND_UP(min_uV - MAX8660_DCDC_MIN_UV,
157 MAX8660_DCDC_STEP);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200158
159 ret = max8660_dcdc_list(rdev, selector);
160 if (ret < 0 || ret > max_uV)
161 return -EINVAL;
162
Axel Linab353c22012-03-02 16:23:39 +0800163 *s = selector;
164
Wolfram Sang27f37e42009-09-25 09:39:26 +0200165 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
166 ret = max8660_write(max8660, reg, 0, selector);
167 if (ret)
168 return ret;
169
170 /* Select target voltage register and activate regulation */
171 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
172 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
173}
174
175static struct regulator_ops max8660_dcdc_ops = {
176 .is_enabled = max8660_dcdc_is_enabled,
177 .list_voltage = max8660_dcdc_list,
178 .set_voltage = max8660_dcdc_set,
179 .get_voltage = max8660_dcdc_get,
180};
181
182
183/*
184 * LDO5 functions
185 */
186
187static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector)
188{
189 if (selector > MAX8660_LDO5_MAX_SEL)
190 return -EINVAL;
191 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
192}
193
194static int max8660_ldo5_get(struct regulator_dev *rdev)
195{
196 struct max8660 *max8660 = rdev_get_drvdata(rdev);
197 u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
198
199 return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
200}
201
Mark Brown3a93f2a2010-11-10 14:38:29 +0000202static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV,
203 unsigned int *s)
Wolfram Sang27f37e42009-09-25 09:39:26 +0200204{
205 struct max8660 *max8660 = rdev_get_drvdata(rdev);
206 u8 selector;
207 int ret;
208
209 if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV)
210 return -EINVAL;
211 if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV)
212 return -EINVAL;
213
Axel Linab353c22012-03-02 16:23:39 +0800214 selector = DIV_ROUND_UP(min_uV - MAX8660_LDO5_MIN_UV,
215 MAX8660_LDO5_STEP);
216
Wolfram Sang27f37e42009-09-25 09:39:26 +0200217 ret = max8660_ldo5_list(rdev, selector);
218 if (ret < 0 || ret > max_uV)
219 return -EINVAL;
220
Mark Brown3a93f2a2010-11-10 14:38:29 +0000221 *s = selector;
222
Wolfram Sang27f37e42009-09-25 09:39:26 +0200223 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
224 if (ret)
225 return ret;
226
227 /* Select target voltage register and activate regulation */
228 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
229}
230
231static struct regulator_ops max8660_ldo5_ops = {
232 .list_voltage = max8660_ldo5_list,
233 .set_voltage = max8660_ldo5_set,
234 .get_voltage = max8660_ldo5_get,
235};
236
237
238/*
239 * LDO67 functions
240 */
241
242static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
243{
244 struct max8660 *max8660 = rdev_get_drvdata(rdev);
245 u8 val = max8660->shadow_regs[MAX8660_OVER2];
246 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
247 return !!(val & mask);
248}
249
250static int max8660_ldo67_enable(struct regulator_dev *rdev)
251{
252 struct max8660 *max8660 = rdev_get_drvdata(rdev);
253 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
254 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
255}
256
257static int max8660_ldo67_disable(struct regulator_dev *rdev)
258{
259 struct max8660 *max8660 = rdev_get_drvdata(rdev);
260 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
261 return max8660_write(max8660, MAX8660_OVER2, mask, 0);
262}
263
264static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector)
265{
266 if (selector > MAX8660_LDO67_MAX_SEL)
267 return -EINVAL;
268 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
269}
270
271static int max8660_ldo67_get(struct regulator_dev *rdev)
272{
273 struct max8660 *max8660 = rdev_get_drvdata(rdev);
274 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
275 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
276
277 return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
278}
279
Mark Brown3a93f2a2010-11-10 14:38:29 +0000280static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV,
281 int max_uV, unsigned int *s)
Wolfram Sang27f37e42009-09-25 09:39:26 +0200282{
283 struct max8660 *max8660 = rdev_get_drvdata(rdev);
284 u8 selector;
285 int ret;
286
287 if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV)
288 return -EINVAL;
289 if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV)
290 return -EINVAL;
291
Axel Linab353c22012-03-02 16:23:39 +0800292 selector = DIV_ROUND_UP(min_uV - MAX8660_LDO67_MIN_UV,
293 MAX8660_LDO67_STEP);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200294
295 ret = max8660_ldo67_list(rdev, selector);
296 if (ret < 0 || ret > max_uV)
297 return -EINVAL;
298
Mark Brown3a93f2a2010-11-10 14:38:29 +0000299 *s = selector;
300
Wolfram Sang27f37e42009-09-25 09:39:26 +0200301 if (rdev_get_id(rdev) == MAX8660_V6)
302 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
303 else
304 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4);
305}
306
307static struct regulator_ops max8660_ldo67_ops = {
308 .is_enabled = max8660_ldo67_is_enabled,
309 .enable = max8660_ldo67_enable,
310 .disable = max8660_ldo67_disable,
311 .list_voltage = max8660_ldo67_list,
312 .get_voltage = max8660_ldo67_get,
313 .set_voltage = max8660_ldo67_set,
314};
315
316static struct regulator_desc max8660_reg[] = {
317 {
318 .name = "V3(DCDC)",
319 .id = MAX8660_V3,
320 .ops = &max8660_dcdc_ops,
321 .type = REGULATOR_VOLTAGE,
322 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
323 .owner = THIS_MODULE,
324 },
325 {
326 .name = "V4(DCDC)",
327 .id = MAX8660_V4,
328 .ops = &max8660_dcdc_ops,
329 .type = REGULATOR_VOLTAGE,
330 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
331 .owner = THIS_MODULE,
332 },
333 {
334 .name = "V5(LDO)",
335 .id = MAX8660_V5,
336 .ops = &max8660_ldo5_ops,
337 .type = REGULATOR_VOLTAGE,
338 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
339 .owner = THIS_MODULE,
340 },
341 {
342 .name = "V6(LDO)",
343 .id = MAX8660_V6,
344 .ops = &max8660_ldo67_ops,
345 .type = REGULATOR_VOLTAGE,
346 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
347 .owner = THIS_MODULE,
348 },
349 {
350 .name = "V7(LDO)",
351 .id = MAX8660_V7,
352 .ops = &max8660_ldo67_ops,
353 .type = REGULATOR_VOLTAGE,
354 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
355 .owner = THIS_MODULE,
356 },
357};
358
Dmitry Torokhov308f1002010-02-23 23:38:28 -0800359static int __devinit max8660_probe(struct i2c_client *client,
360 const struct i2c_device_id *i2c_id)
Wolfram Sang27f37e42009-09-25 09:39:26 +0200361{
362 struct regulator_dev **rdev;
363 struct max8660_platform_data *pdata = client->dev.platform_data;
364 struct max8660 *max8660;
365 int boot_on, i, id, ret = -EINVAL;
366
367 if (pdata->num_subdevs > MAX8660_V_END) {
Dmitry Torokhov308f1002010-02-23 23:38:28 -0800368 dev_err(&client->dev, "Too many regulators found!\n");
Wolfram Sang27f37e42009-09-25 09:39:26 +0200369 goto out;
370 }
371
372 max8660 = kzalloc(sizeof(struct max8660) +
373 sizeof(struct regulator_dev *) * MAX8660_V_END,
374 GFP_KERNEL);
375 if (!max8660) {
376 ret = -ENOMEM;
377 goto out;
378 }
379
380 max8660->client = client;
381 rdev = max8660->rdev;
382
383 if (pdata->en34_is_high) {
384 /* Simulate always on */
385 max8660->shadow_regs[MAX8660_OVER1] = 5;
386 } else {
387 /* Otherwise devices can be toggled via software */
388 max8660_dcdc_ops.enable = max8660_dcdc_enable;
389 max8660_dcdc_ops.disable = max8660_dcdc_disable;
390 }
391
392 /*
393 * First, set up shadow registers to prevent glitches. As some
394 * registers are shared between regulators, everything must be properly
395 * set up for all regulators in advance.
396 */
397 max8660->shadow_regs[MAX8660_ADTV1] =
398 max8660->shadow_regs[MAX8660_ADTV2] =
399 max8660->shadow_regs[MAX8660_SDTV1] =
400 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
401 max8660->shadow_regs[MAX8660_MDTV1] =
402 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
403
404 for (i = 0; i < pdata->num_subdevs; i++) {
405
406 if (!pdata->subdevs[i].platform_data)
407 goto err_free;
408
409 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
410
411 switch (pdata->subdevs[i].id) {
412 case MAX8660_V3:
413 if (boot_on)
414 max8660->shadow_regs[MAX8660_OVER1] |= 1;
415 break;
416
417 case MAX8660_V4:
418 if (boot_on)
419 max8660->shadow_regs[MAX8660_OVER1] |= 4;
420 break;
421
422 case MAX8660_V5:
423 break;
424
425 case MAX8660_V6:
426 if (boot_on)
427 max8660->shadow_regs[MAX8660_OVER2] |= 2;
428 break;
429
430 case MAX8660_V7:
431 if (!strcmp(i2c_id->name, "max8661")) {
432 dev_err(&client->dev, "Regulator not on this chip!\n");
433 goto err_free;
434 }
435
436 if (boot_on)
437 max8660->shadow_regs[MAX8660_OVER2] |= 4;
438 break;
439
440 default:
441 dev_err(&client->dev, "invalid regulator %s\n",
442 pdata->subdevs[i].name);
443 goto err_free;
444 }
445 }
446
447 /* Finally register devices */
448 for (i = 0; i < pdata->num_subdevs; i++) {
449
450 id = pdata->subdevs[i].id;
451
452 rdev[i] = regulator_register(&max8660_reg[id], &client->dev,
453 pdata->subdevs[i].platform_data,
Rajendra Nayak2c043bc2011-11-18 16:47:19 +0530454 max8660, NULL);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200455 if (IS_ERR(rdev[i])) {
456 ret = PTR_ERR(rdev[i]);
457 dev_err(&client->dev, "failed to register %s\n",
458 max8660_reg[id].name);
459 goto err_unregister;
460 }
461 }
462
Axel Lin53a4bef2010-08-06 13:35:27 +0800463 i2c_set_clientdata(client, max8660);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200464 dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n");
465 return 0;
466
467err_unregister:
468 while (--i >= 0)
469 regulator_unregister(rdev[i]);
470err_free:
471 kfree(max8660);
472out:
473 return ret;
474}
475
Dmitry Torokhov308f1002010-02-23 23:38:28 -0800476static int __devexit max8660_remove(struct i2c_client *client)
Wolfram Sang27f37e42009-09-25 09:39:26 +0200477{
Axel Lin53a4bef2010-08-06 13:35:27 +0800478 struct max8660 *max8660 = i2c_get_clientdata(client);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200479 int i;
480
481 for (i = 0; i < MAX8660_V_END; i++)
Axel Lin53a4bef2010-08-06 13:35:27 +0800482 if (max8660->rdev[i])
483 regulator_unregister(max8660->rdev[i]);
484 kfree(max8660);
Wolfram Sang27f37e42009-09-25 09:39:26 +0200485
486 return 0;
487}
488
489static const struct i2c_device_id max8660_id[] = {
490 { "max8660", 0 },
491 { "max8661", 0 },
492 { }
493};
494MODULE_DEVICE_TABLE(i2c, max8660_id);
495
496static struct i2c_driver max8660_driver = {
497 .probe = max8660_probe,
Dmitry Torokhov308f1002010-02-23 23:38:28 -0800498 .remove = __devexit_p(max8660_remove),
Wolfram Sang27f37e42009-09-25 09:39:26 +0200499 .driver = {
500 .name = "max8660",
Dmitry Torokhov308f1002010-02-23 23:38:28 -0800501 .owner = THIS_MODULE,
Wolfram Sang27f37e42009-09-25 09:39:26 +0200502 },
503 .id_table = max8660_id,
504};
505
506static int __init max8660_init(void)
507{
508 return i2c_add_driver(&max8660_driver);
509}
510subsys_initcall(max8660_init);
511
512static void __exit max8660_exit(void)
513{
514 i2c_del_driver(&max8660_driver);
515}
516module_exit(max8660_exit);
517
518/* Module information */
519MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
520MODULE_AUTHOR("Wolfram Sang");
521MODULE_LICENSE("GPL v2");