1/*
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>
45#include <linux/slab.h>
46#include <linux/regulator/max8660.h>
47#include <linux/of.h>
48#include <linux/of_device.h>
49#include <linux/regulator/of_regulator.h>
50
51#define MAX8660_DCDC_MIN_UV 725000
52#define MAX8660_DCDC_MAX_UV 1800000
53#define MAX8660_DCDC_STEP 25000
54#define MAX8660_DCDC_MAX_SEL 0x2b
55
56#define MAX8660_LDO5_MIN_UV 1700000
57#define MAX8660_LDO5_MAX_UV 2000000
58#define MAX8660_LDO5_STEP 25000
59#define MAX8660_LDO5_MAX_SEL 0x0c
60
61#define MAX8660_LDO67_MIN_UV 1800000
62#define MAX8660_LDO67_MAX_UV 3300000
63#define MAX8660_LDO67_STEP 100000
64#define MAX8660_LDO67_MAX_SEL 0x0f
65
66enum {
67 MAX8660_OVER1,
68 MAX8660_OVER2,
69 MAX8660_VCC1,
70 MAX8660_ADTV1,
71 MAX8660_ADTV2,
72 MAX8660_SDTV1,
73 MAX8660_SDTV2,
74 MAX8660_MDTV1,
75 MAX8660_MDTV2,
76 MAX8660_L12VCR,
77 MAX8660_FPWM,
78 MAX8660_N_REGS, /* not a real register */
79};
80
81struct max8660 {
82 struct i2c_client *client;
83 u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */
84};
85
86static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
87{
88 static const u8 max8660_addresses[MAX8660_N_REGS] = {
89 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80
90 };
91
92 int ret;
93 u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
94
95 dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
96 max8660_addresses[reg], reg_val);
97
98 ret = i2c_smbus_write_byte_data(max8660->client,
99 max8660_addresses[reg], reg_val);
100 if (ret == 0)
101 max8660->shadow_regs[reg] = reg_val;
102
103 return ret;
104}
105
106
107/*
108 * DCDC functions
109 */
110
111static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
112{
113 struct max8660 *max8660 = rdev_get_drvdata(rdev);
114 u8 val = max8660->shadow_regs[MAX8660_OVER1];
115 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
116
117 return !!(val & mask);
118}
119
120static int max8660_dcdc_enable(struct regulator_dev *rdev)
121{
122 struct max8660 *max8660 = rdev_get_drvdata(rdev);
123 u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
124
125 return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
126}
127
128static int max8660_dcdc_disable(struct regulator_dev *rdev)
129{
130 struct max8660 *max8660 = rdev_get_drvdata(rdev);
131 u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
132
133 return max8660_write(max8660, MAX8660_OVER1, mask, 0);
134}
135
136static int max8660_dcdc_get_voltage_sel(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
142 return selector;
143}
144
145static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
146 unsigned int selector)
147{
148 struct max8660 *max8660 = rdev_get_drvdata(rdev);
149 u8 reg, bits;
150 int ret;
151
152 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
153 ret = max8660_write(max8660, reg, 0, selector);
154 if (ret)
155 return ret;
156
157 /* Select target voltage register and activate regulation */
158 bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
159 return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
160}
161
162static struct regulator_ops max8660_dcdc_ops = {
163 .is_enabled = max8660_dcdc_is_enabled,
164 .list_voltage = regulator_list_voltage_linear,
165 .map_voltage = regulator_map_voltage_linear,
166 .set_voltage_sel = max8660_dcdc_set_voltage_sel,
167 .get_voltage_sel = max8660_dcdc_get_voltage_sel,
168};
169
170
171/*
172 * LDO5 functions
173 */
174
175static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
176{
177 struct max8660 *max8660 = rdev_get_drvdata(rdev);
178
179 u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
180 return selector;
181}
182
183static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
184 unsigned int selector)
185{
186 struct max8660 *max8660 = rdev_get_drvdata(rdev);
187 int ret;
188
189 ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
190 if (ret)
191 return ret;
192
193 /* Select target voltage register and activate regulation */
194 return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
195}
196
197static const struct regulator_ops max8660_ldo5_ops = {
198 .list_voltage = regulator_list_voltage_linear,
199 .map_voltage = regulator_map_voltage_linear,
200 .set_voltage_sel = max8660_ldo5_set_voltage_sel,
201 .get_voltage_sel = max8660_ldo5_get_voltage_sel,
202};
203
204
205/*
206 * LDO67 functions
207 */
208
209static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
210{
211 struct max8660 *max8660 = rdev_get_drvdata(rdev);
212 u8 val = max8660->shadow_regs[MAX8660_OVER2];
213 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
214
215 return !!(val & mask);
216}
217
218static int max8660_ldo67_enable(struct regulator_dev *rdev)
219{
220 struct max8660 *max8660 = rdev_get_drvdata(rdev);
221 u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
222
223 return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
224}
225
226static int max8660_ldo67_disable(struct regulator_dev *rdev)
227{
228 struct max8660 *max8660 = rdev_get_drvdata(rdev);
229 u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
230
231 return max8660_write(max8660, MAX8660_OVER2, mask, 0);
232}
233
234static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
235{
236 struct max8660 *max8660 = rdev_get_drvdata(rdev);
237 u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
238 u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
239
240 return selector;
241}
242
243static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
244 unsigned int selector)
245{
246 struct max8660 *max8660 = rdev_get_drvdata(rdev);
247
248 if (rdev_get_id(rdev) == MAX8660_V6)
249 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
250 else
251 return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
252 selector << 4);
253}
254
255static const struct regulator_ops max8660_ldo67_ops = {
256 .is_enabled = max8660_ldo67_is_enabled,
257 .enable = max8660_ldo67_enable,
258 .disable = max8660_ldo67_disable,
259 .list_voltage = regulator_list_voltage_linear,
260 .map_voltage = regulator_map_voltage_linear,
261 .get_voltage_sel = max8660_ldo67_get_voltage_sel,
262 .set_voltage_sel = max8660_ldo67_set_voltage_sel,
263};
264
265static const struct regulator_desc max8660_reg[] = {
266 {
267 .name = "V3(DCDC)",
268 .id = MAX8660_V3,
269 .ops = &max8660_dcdc_ops,
270 .type = REGULATOR_VOLTAGE,
271 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
272 .owner = THIS_MODULE,
273 .min_uV = MAX8660_DCDC_MIN_UV,
274 .uV_step = MAX8660_DCDC_STEP,
275 },
276 {
277 .name = "V4(DCDC)",
278 .id = MAX8660_V4,
279 .ops = &max8660_dcdc_ops,
280 .type = REGULATOR_VOLTAGE,
281 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
282 .owner = THIS_MODULE,
283 .min_uV = MAX8660_DCDC_MIN_UV,
284 .uV_step = MAX8660_DCDC_STEP,
285 },
286 {
287 .name = "V5(LDO)",
288 .id = MAX8660_V5,
289 .ops = &max8660_ldo5_ops,
290 .type = REGULATOR_VOLTAGE,
291 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
292 .owner = THIS_MODULE,
293 .min_uV = MAX8660_LDO5_MIN_UV,
294 .uV_step = MAX8660_LDO5_STEP,
295 },
296 {
297 .name = "V6(LDO)",
298 .id = MAX8660_V6,
299 .ops = &max8660_ldo67_ops,
300 .type = REGULATOR_VOLTAGE,
301 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
302 .owner = THIS_MODULE,
303 .min_uV = MAX8660_LDO67_MIN_UV,
304 .uV_step = MAX8660_LDO67_STEP,
305 },
306 {
307 .name = "V7(LDO)",
308 .id = MAX8660_V7,
309 .ops = &max8660_ldo67_ops,
310 .type = REGULATOR_VOLTAGE,
311 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
312 .owner = THIS_MODULE,
313 .min_uV = MAX8660_LDO67_MIN_UV,
314 .uV_step = MAX8660_LDO67_STEP,
315 },
316};
317
318enum {
319 MAX8660 = 0,
320 MAX8661 = 1,
321};
322
323#ifdef CONFIG_OF
324static const struct of_device_id max8660_dt_ids[] = {
325 { .compatible = "maxim,max8660", .data = (void *) MAX8660 },
326 { .compatible = "maxim,max8661", .data = (void *) MAX8661 },
327 { }
328};
329MODULE_DEVICE_TABLE(of, max8660_dt_ids);
330
331static int max8660_pdata_from_dt(struct device *dev,
332 struct device_node **of_node,
333 struct max8660_platform_data *pdata)
334{
335 int matched, i;
336 struct device_node *np;
337 struct max8660_subdev_data *sub;
338 struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { };
339
340 np = of_get_child_by_name(dev->of_node, "regulators");
341 if (!np) {
342 dev_err(dev, "missing 'regulators' subnode in DT\n");
343 return -EINVAL;
344 }
345
346 for (i = 0; i < ARRAY_SIZE(rmatch); i++)
347 rmatch[i].name = max8660_reg[i].name;
348
349 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
350 of_node_put(np);
351 if (matched <= 0)
352 return matched;
353
354 pdata->subdevs = devm_kcalloc(dev,
355 matched,
356 sizeof(struct max8660_subdev_data),
357 GFP_KERNEL);
358 if (!pdata->subdevs)
359 return -ENOMEM;
360
361 pdata->num_subdevs = matched;
362 sub = pdata->subdevs;
363
364 for (i = 0; i < matched; i++) {
365 sub->id = i;
366 sub->name = rmatch[i].name;
367 sub->platform_data = rmatch[i].init_data;
368 of_node[i] = rmatch[i].of_node;
369 sub++;
370 }
371
372 return 0;
373}
374#else
375static inline int max8660_pdata_from_dt(struct device *dev,
376 struct device_node **of_node,
377 struct max8660_platform_data *pdata)
378{
379 return 0;
380}
381#endif
382
383static int max8660_probe(struct i2c_client *client,
384 const struct i2c_device_id *i2c_id)
385{
386 struct device *dev = &client->dev;
387 struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev);
388 struct regulator_config config = { };
389 struct max8660 *max8660;
390 int boot_on, i, id, ret = -EINVAL;
391 struct device_node *of_node[MAX8660_V_END];
392 unsigned long type;
393
394 if (dev->of_node && !pdata) {
395 const struct of_device_id *id;
396
397 id = of_match_device(of_match_ptr(max8660_dt_ids), dev);
398 if (!id)
399 return -ENODEV;
400
401 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of);
402 if (ret < 0)
403 return ret;
404
405 pdata = &pdata_of;
406 type = (unsigned long) id->data;
407 } else {
408 type = i2c_id->driver_data;
409 memset(of_node, 0, sizeof(of_node));
410 }
411
412 if (pdata->num_subdevs > MAX8660_V_END) {
413 dev_err(dev, "Too many regulators found!\n");
414 return -EINVAL;
415 }
416
417 max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL);
418 if (!max8660)
419 return -ENOMEM;
420
421 max8660->client = client;
422
423 if (pdata->en34_is_high) {
424 /* Simulate always on */
425 max8660->shadow_regs[MAX8660_OVER1] = 5;
426 } else {
427 /* Otherwise devices can be toggled via software */
428 max8660_dcdc_ops.enable = max8660_dcdc_enable;
429 max8660_dcdc_ops.disable = max8660_dcdc_disable;
430 }
431
432 /*
433 * First, set up shadow registers to prevent glitches. As some
434 * registers are shared between regulators, everything must be properly
435 * set up for all regulators in advance.
436 */
437 max8660->shadow_regs[MAX8660_ADTV1] =
438 max8660->shadow_regs[MAX8660_ADTV2] =
439 max8660->shadow_regs[MAX8660_SDTV1] =
440 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
441 max8660->shadow_regs[MAX8660_MDTV1] =
442 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
443
444 for (i = 0; i < pdata->num_subdevs; i++) {
445
446 if (!pdata->subdevs[i].platform_data)
447 boot_on = false;
448 else
449 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
450
451 switch (pdata->subdevs[i].id) {
452 case MAX8660_V3:
453 if (boot_on)
454 max8660->shadow_regs[MAX8660_OVER1] |= 1;
455 break;
456
457 case MAX8660_V4:
458 if (boot_on)
459 max8660->shadow_regs[MAX8660_OVER1] |= 4;
460 break;
461
462 case MAX8660_V5:
463 break;
464
465 case MAX8660_V6:
466 if (boot_on)
467 max8660->shadow_regs[MAX8660_OVER2] |= 2;
468 break;
469
470 case MAX8660_V7:
471 if (type == MAX8661) {
472 dev_err(dev, "Regulator not on this chip!\n");
473 return -EINVAL;
474 }
475
476 if (boot_on)
477 max8660->shadow_regs[MAX8660_OVER2] |= 4;
478 break;
479
480 default:
481 dev_err(dev, "invalid regulator %s\n",
482 pdata->subdevs[i].name);
483 return ret;
484 }
485 }
486
487 /* Finally register devices */
488 for (i = 0; i < pdata->num_subdevs; i++) {
489 struct regulator_dev *rdev;
490
491 id = pdata->subdevs[i].id;
492
493 config.dev = dev;
494 config.init_data = pdata->subdevs[i].platform_data;
495 config.of_node = of_node[i];
496 config.driver_data = max8660;
497
498 rdev = devm_regulator_register(&client->dev,
499 &max8660_reg[id], &config);
500 if (IS_ERR(rdev)) {
501 ret = PTR_ERR(rdev);
502 dev_err(&client->dev, "failed to register %s\n",
503 max8660_reg[id].name);
504 return PTR_ERR(rdev);
505 }
506 }
507
508 i2c_set_clientdata(client, max8660);
509 return 0;
510}
511
512static const struct i2c_device_id max8660_id[] = {
513 { .name = "max8660", .driver_data = MAX8660 },
514 { .name = "max8661", .driver_data = MAX8661 },
515 { }
516};
517MODULE_DEVICE_TABLE(i2c, max8660_id);
518
519static struct i2c_driver max8660_driver = {
520 .probe = max8660_probe,
521 .driver = {
522 .name = "max8660",
523 },
524 .id_table = max8660_id,
525};
526
527static int __init max8660_init(void)
528{
529 return i2c_add_driver(&max8660_driver);
530}
531subsys_initcall(max8660_init);
532
533static void __exit max8660_exit(void)
534{
535 i2c_del_driver(&max8660_driver);
536}
537module_exit(max8660_exit);
538
539/* Module information */
540MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
541MODULE_AUTHOR("Wolfram Sang");
542MODULE_LICENSE("GPL v2");
543