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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 | ||
66 | enum { | |
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 | ||
81 | struct max8660 { | |
82 | struct i2c_client *client; | |
83 | u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ | |
84 | }; | |
85 | ||
86 | static 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 | ||
111 | static 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 | ||
120 | static 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 | ||
128 | static 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 | ||
136 | static 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 | ||
145 | static 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 | ||
162 | static 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 | ||
175 | static 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 | ||
183 | static 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 | ||
197 | static 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 | ||
209 | static 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 | ||
218 | static 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 | ||
226 | static 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 | ||
234 | static 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 | ||
243 | static 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 | ||
255 | static 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 | ||
265 | static 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 | ||
318 | enum { | |
319 | MAX8660 = 0, | |
320 | MAX8661 = 1, | |
321 | }; | |
322 | ||
323 | #ifdef CONFIG_OF | |
324 | static const struct of_device_id max8660_dt_ids[] = { | |
325 | { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, | |
326 | { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, | |
327 | { } | |
328 | }; | |
329 | MODULE_DEVICE_TABLE(of, max8660_dt_ids); | |
330 | ||
331 | static 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_kzalloc(dev, sizeof(struct max8660_subdev_data) * | |
355 | matched, GFP_KERNEL); | |
356 | if (!pdata->subdevs) | |
357 | return -ENOMEM; | |
358 | ||
359 | pdata->num_subdevs = matched; | |
360 | sub = pdata->subdevs; | |
361 | ||
362 | for (i = 0; i < matched; i++) { | |
363 | sub->id = i; | |
364 | sub->name = rmatch[i].name; | |
365 | sub->platform_data = rmatch[i].init_data; | |
366 | of_node[i] = rmatch[i].of_node; | |
367 | sub++; | |
368 | } | |
369 | ||
370 | return 0; | |
371 | } | |
372 | #else | |
373 | static inline int max8660_pdata_from_dt(struct device *dev, | |
374 | struct device_node **of_node, | |
375 | struct max8660_platform_data *pdata) | |
376 | { | |
377 | return 0; | |
378 | } | |
379 | #endif | |
380 | ||
381 | static int max8660_probe(struct i2c_client *client, | |
382 | const struct i2c_device_id *i2c_id) | |
383 | { | |
384 | struct device *dev = &client->dev; | |
385 | struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); | |
386 | struct regulator_config config = { }; | |
387 | struct max8660 *max8660; | |
388 | int boot_on, i, id, ret = -EINVAL; | |
389 | struct device_node *of_node[MAX8660_V_END]; | |
390 | unsigned long type; | |
391 | ||
392 | if (dev->of_node && !pdata) { | |
393 | const struct of_device_id *id; | |
394 | ||
395 | id = of_match_device(of_match_ptr(max8660_dt_ids), dev); | |
396 | if (!id) | |
397 | return -ENODEV; | |
398 | ||
399 | ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); | |
400 | if (ret < 0) | |
401 | return ret; | |
402 | ||
403 | pdata = &pdata_of; | |
404 | type = (unsigned long) id->data; | |
405 | } else { | |
406 | type = i2c_id->driver_data; | |
407 | memset(of_node, 0, sizeof(of_node)); | |
408 | } | |
409 | ||
410 | if (pdata->num_subdevs > MAX8660_V_END) { | |
411 | dev_err(dev, "Too many regulators found!\n"); | |
412 | return -EINVAL; | |
413 | } | |
414 | ||
415 | max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); | |
416 | if (!max8660) | |
417 | return -ENOMEM; | |
418 | ||
419 | max8660->client = client; | |
420 | ||
421 | if (pdata->en34_is_high) { | |
422 | /* Simulate always on */ | |
423 | max8660->shadow_regs[MAX8660_OVER1] = 5; | |
424 | } else { | |
425 | /* Otherwise devices can be toggled via software */ | |
426 | max8660_dcdc_ops.enable = max8660_dcdc_enable; | |
427 | max8660_dcdc_ops.disable = max8660_dcdc_disable; | |
428 | } | |
429 | ||
430 | /* | |
431 | * First, set up shadow registers to prevent glitches. As some | |
432 | * registers are shared between regulators, everything must be properly | |
433 | * set up for all regulators in advance. | |
434 | */ | |
435 | max8660->shadow_regs[MAX8660_ADTV1] = | |
436 | max8660->shadow_regs[MAX8660_ADTV2] = | |
437 | max8660->shadow_regs[MAX8660_SDTV1] = | |
438 | max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; | |
439 | max8660->shadow_regs[MAX8660_MDTV1] = | |
440 | max8660->shadow_regs[MAX8660_MDTV2] = 0x04; | |
441 | ||
442 | for (i = 0; i < pdata->num_subdevs; i++) { | |
443 | ||
444 | if (!pdata->subdevs[i].platform_data) | |
445 | boot_on = false; | |
446 | else | |
447 | boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; | |
448 | ||
449 | switch (pdata->subdevs[i].id) { | |
450 | case MAX8660_V3: | |
451 | if (boot_on) | |
452 | max8660->shadow_regs[MAX8660_OVER1] |= 1; | |
453 | break; | |
454 | ||
455 | case MAX8660_V4: | |
456 | if (boot_on) | |
457 | max8660->shadow_regs[MAX8660_OVER1] |= 4; | |
458 | break; | |
459 | ||
460 | case MAX8660_V5: | |
461 | break; | |
462 | ||
463 | case MAX8660_V6: | |
464 | if (boot_on) | |
465 | max8660->shadow_regs[MAX8660_OVER2] |= 2; | |
466 | break; | |
467 | ||
468 | case MAX8660_V7: | |
469 | if (type == MAX8661) { | |
470 | dev_err(dev, "Regulator not on this chip!\n"); | |
471 | return -EINVAL; | |
472 | } | |
473 | ||
474 | if (boot_on) | |
475 | max8660->shadow_regs[MAX8660_OVER2] |= 4; | |
476 | break; | |
477 | ||
478 | default: | |
479 | dev_err(dev, "invalid regulator %s\n", | |
480 | pdata->subdevs[i].name); | |
481 | return ret; | |
482 | } | |
483 | } | |
484 | ||
485 | /* Finally register devices */ | |
486 | for (i = 0; i < pdata->num_subdevs; i++) { | |
487 | struct regulator_dev *rdev; | |
488 | ||
489 | id = pdata->subdevs[i].id; | |
490 | ||
491 | config.dev = dev; | |
492 | config.init_data = pdata->subdevs[i].platform_data; | |
493 | config.of_node = of_node[i]; | |
494 | config.driver_data = max8660; | |
495 | ||
496 | rdev = devm_regulator_register(&client->dev, | |
497 | &max8660_reg[id], &config); | |
498 | if (IS_ERR(rdev)) { | |
499 | ret = PTR_ERR(rdev); | |
500 | dev_err(&client->dev, "failed to register %s\n", | |
501 | max8660_reg[id].name); | |
502 | return PTR_ERR(rdev); | |
503 | } | |
504 | } | |
505 | ||
506 | i2c_set_clientdata(client, max8660); | |
507 | return 0; | |
508 | } | |
509 | ||
510 | static const struct i2c_device_id max8660_id[] = { | |
511 | { .name = "max8660", .driver_data = MAX8660 }, | |
512 | { .name = "max8661", .driver_data = MAX8661 }, | |
513 | { } | |
514 | }; | |
515 | MODULE_DEVICE_TABLE(i2c, max8660_id); | |
516 | ||
517 | static struct i2c_driver max8660_driver = { | |
518 | .probe = max8660_probe, | |
519 | .driver = { | |
520 | .name = "max8660", | |
521 | }, | |
522 | .id_table = max8660_id, | |
523 | }; | |
524 | ||
525 | static int __init max8660_init(void) | |
526 | { | |
527 | return i2c_add_driver(&max8660_driver); | |
528 | } | |
529 | subsys_initcall(max8660_init); | |
530 | ||
531 | static void __exit max8660_exit(void) | |
532 | { | |
533 | i2c_del_driver(&max8660_driver); | |
534 | } | |
535 | module_exit(max8660_exit); | |
536 | ||
537 | /* Module information */ | |
538 | MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); | |
539 | MODULE_AUTHOR("Wolfram Sang"); | |
540 | MODULE_LICENSE("GPL v2"); |