1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * max8660.c -- Voltage regulation for the Maxim 8660/8661 |
4 | * |
5 | * based on max1586.c and wm8400-regulator.c |
6 | * |
7 | * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K. |
8 | * |
9 | * Some info: |
10 | * |
11 | * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf |
12 | * |
13 | * This chip is a bit nasty because it is a write-only device. Thus, the driver |
14 | * uses shadow registers to keep track of its values. The main problem appears |
15 | * to be the initialization: When Linux boots up, we cannot know if the chip is |
16 | * in the default state or not, so we would have to pass such information in |
17 | * platform_data. As this adds a bit of complexity to the driver, this is left |
18 | * out for now until it is really needed. |
19 | * |
20 | * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2. |
21 | * |
22 | * If the driver is feature complete, it might be worth to check if one set of |
23 | * functions for V3-V7 is sufficient. For maximum flexibility during |
24 | * development, they are separated for now. |
25 | */ |
26 | |
27 | #include <linux/module.h> |
28 | #include <linux/err.h> |
29 | #include <linux/i2c.h> |
30 | #include <linux/platform_device.h> |
31 | #include <linux/regulator/driver.h> |
32 | #include <linux/slab.h> |
33 | #include <linux/regulator/max8660.h> |
34 | #include <linux/of.h> |
35 | #include <linux/of_device.h> |
36 | #include <linux/regulator/of_regulator.h> |
37 | |
38 | #define MAX8660_DCDC_MIN_UV 725000 |
39 | #define MAX8660_DCDC_MAX_UV 1800000 |
40 | #define MAX8660_DCDC_STEP 25000 |
41 | #define MAX8660_DCDC_MAX_SEL 0x2b |
42 | |
43 | #define MAX8660_LDO5_MIN_UV 1700000 |
44 | #define MAX8660_LDO5_MAX_UV 2000000 |
45 | #define MAX8660_LDO5_STEP 25000 |
46 | #define MAX8660_LDO5_MAX_SEL 0x0c |
47 | |
48 | #define MAX8660_LDO67_MIN_UV 1800000 |
49 | #define MAX8660_LDO67_MAX_UV 3300000 |
50 | #define MAX8660_LDO67_STEP 100000 |
51 | #define MAX8660_LDO67_MAX_SEL 0x0f |
52 | |
53 | enum { |
54 | MAX8660_OVER1, |
55 | MAX8660_OVER2, |
56 | MAX8660_VCC1, |
57 | MAX8660_ADTV1, |
58 | MAX8660_ADTV2, |
59 | MAX8660_SDTV1, |
60 | MAX8660_SDTV2, |
61 | MAX8660_MDTV1, |
62 | MAX8660_MDTV2, |
63 | MAX8660_L12VCR, |
64 | MAX8660_FPWM, |
65 | MAX8660_N_REGS, /* not a real register */ |
66 | }; |
67 | |
68 | struct max8660 { |
69 | struct i2c_client *client; |
70 | u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ |
71 | }; |
72 | |
73 | static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) |
74 | { |
75 | static const u8 max8660_addresses[MAX8660_N_REGS] = { |
76 | 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 |
77 | }; |
78 | |
79 | int ret; |
80 | u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; |
81 | |
82 | dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n" , |
83 | max8660_addresses[reg], reg_val); |
84 | |
85 | ret = i2c_smbus_write_byte_data(client: max8660->client, |
86 | command: max8660_addresses[reg], value: reg_val); |
87 | if (ret == 0) |
88 | max8660->shadow_regs[reg] = reg_val; |
89 | |
90 | return ret; |
91 | } |
92 | |
93 | |
94 | /* |
95 | * DCDC functions |
96 | */ |
97 | |
98 | static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) |
99 | { |
100 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
101 | u8 val = max8660->shadow_regs[MAX8660_OVER1]; |
102 | u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; |
103 | |
104 | return !!(val & mask); |
105 | } |
106 | |
107 | static int max8660_dcdc_enable(struct regulator_dev *rdev) |
108 | { |
109 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
110 | u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; |
111 | |
112 | return max8660_write(max8660, reg: MAX8660_OVER1, mask: 0xff, val: bit); |
113 | } |
114 | |
115 | static int max8660_dcdc_disable(struct regulator_dev *rdev) |
116 | { |
117 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
118 | u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; |
119 | |
120 | return max8660_write(max8660, reg: MAX8660_OVER1, mask, val: 0); |
121 | } |
122 | |
123 | static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) |
124 | { |
125 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
126 | u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; |
127 | u8 selector = max8660->shadow_regs[reg]; |
128 | |
129 | return selector; |
130 | } |
131 | |
132 | static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, |
133 | unsigned int selector) |
134 | { |
135 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
136 | u8 reg, bits; |
137 | int ret; |
138 | |
139 | reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; |
140 | ret = max8660_write(max8660, reg, mask: 0, val: selector); |
141 | if (ret) |
142 | return ret; |
143 | |
144 | /* Select target voltage register and activate regulation */ |
145 | bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; |
146 | return max8660_write(max8660, reg: MAX8660_VCC1, mask: 0xff, val: bits); |
147 | } |
148 | |
149 | static struct regulator_ops max8660_dcdc_ops = { |
150 | .is_enabled = max8660_dcdc_is_enabled, |
151 | .list_voltage = regulator_list_voltage_linear, |
152 | .map_voltage = regulator_map_voltage_linear, |
153 | .set_voltage_sel = max8660_dcdc_set_voltage_sel, |
154 | .get_voltage_sel = max8660_dcdc_get_voltage_sel, |
155 | }; |
156 | |
157 | |
158 | /* |
159 | * LDO5 functions |
160 | */ |
161 | |
162 | static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) |
163 | { |
164 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
165 | |
166 | u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; |
167 | return selector; |
168 | } |
169 | |
170 | static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, |
171 | unsigned int selector) |
172 | { |
173 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
174 | int ret; |
175 | |
176 | ret = max8660_write(max8660, reg: MAX8660_MDTV2, mask: 0, val: selector); |
177 | if (ret) |
178 | return ret; |
179 | |
180 | /* Select target voltage register and activate regulation */ |
181 | return max8660_write(max8660, reg: MAX8660_VCC1, mask: 0xff, val: 0xc0); |
182 | } |
183 | |
184 | static const struct regulator_ops max8660_ldo5_ops = { |
185 | .list_voltage = regulator_list_voltage_linear, |
186 | .map_voltage = regulator_map_voltage_linear, |
187 | .set_voltage_sel = max8660_ldo5_set_voltage_sel, |
188 | .get_voltage_sel = max8660_ldo5_get_voltage_sel, |
189 | }; |
190 | |
191 | |
192 | /* |
193 | * LDO67 functions |
194 | */ |
195 | |
196 | static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) |
197 | { |
198 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
199 | u8 val = max8660->shadow_regs[MAX8660_OVER2]; |
200 | u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; |
201 | |
202 | return !!(val & mask); |
203 | } |
204 | |
205 | static int max8660_ldo67_enable(struct regulator_dev *rdev) |
206 | { |
207 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
208 | u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; |
209 | |
210 | return max8660_write(max8660, reg: MAX8660_OVER2, mask: 0xff, val: bit); |
211 | } |
212 | |
213 | static int max8660_ldo67_disable(struct regulator_dev *rdev) |
214 | { |
215 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
216 | u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; |
217 | |
218 | return max8660_write(max8660, reg: MAX8660_OVER2, mask, val: 0); |
219 | } |
220 | |
221 | static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) |
222 | { |
223 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
224 | u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; |
225 | u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; |
226 | |
227 | return selector; |
228 | } |
229 | |
230 | static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, |
231 | unsigned int selector) |
232 | { |
233 | struct max8660 *max8660 = rdev_get_drvdata(rdev); |
234 | |
235 | if (rdev_get_id(rdev) == MAX8660_V6) |
236 | return max8660_write(max8660, reg: MAX8660_L12VCR, mask: 0xf0, val: selector); |
237 | else |
238 | return max8660_write(max8660, reg: MAX8660_L12VCR, mask: 0x0f, |
239 | val: selector << 4); |
240 | } |
241 | |
242 | static const struct regulator_ops max8660_ldo67_ops = { |
243 | .is_enabled = max8660_ldo67_is_enabled, |
244 | .enable = max8660_ldo67_enable, |
245 | .disable = max8660_ldo67_disable, |
246 | .list_voltage = regulator_list_voltage_linear, |
247 | .map_voltage = regulator_map_voltage_linear, |
248 | .get_voltage_sel = max8660_ldo67_get_voltage_sel, |
249 | .set_voltage_sel = max8660_ldo67_set_voltage_sel, |
250 | }; |
251 | |
252 | static const struct regulator_desc max8660_reg[] = { |
253 | { |
254 | .name = "V3(DCDC)" , |
255 | .id = MAX8660_V3, |
256 | .ops = &max8660_dcdc_ops, |
257 | .type = REGULATOR_VOLTAGE, |
258 | .n_voltages = MAX8660_DCDC_MAX_SEL + 1, |
259 | .owner = THIS_MODULE, |
260 | .min_uV = MAX8660_DCDC_MIN_UV, |
261 | .uV_step = MAX8660_DCDC_STEP, |
262 | }, |
263 | { |
264 | .name = "V4(DCDC)" , |
265 | .id = MAX8660_V4, |
266 | .ops = &max8660_dcdc_ops, |
267 | .type = REGULATOR_VOLTAGE, |
268 | .n_voltages = MAX8660_DCDC_MAX_SEL + 1, |
269 | .owner = THIS_MODULE, |
270 | .min_uV = MAX8660_DCDC_MIN_UV, |
271 | .uV_step = MAX8660_DCDC_STEP, |
272 | }, |
273 | { |
274 | .name = "V5(LDO)" , |
275 | .id = MAX8660_V5, |
276 | .ops = &max8660_ldo5_ops, |
277 | .type = REGULATOR_VOLTAGE, |
278 | .n_voltages = MAX8660_LDO5_MAX_SEL + 1, |
279 | .owner = THIS_MODULE, |
280 | .min_uV = MAX8660_LDO5_MIN_UV, |
281 | .uV_step = MAX8660_LDO5_STEP, |
282 | }, |
283 | { |
284 | .name = "V6(LDO)" , |
285 | .id = MAX8660_V6, |
286 | .ops = &max8660_ldo67_ops, |
287 | .type = REGULATOR_VOLTAGE, |
288 | .n_voltages = MAX8660_LDO67_MAX_SEL + 1, |
289 | .owner = THIS_MODULE, |
290 | .min_uV = MAX8660_LDO67_MIN_UV, |
291 | .uV_step = MAX8660_LDO67_STEP, |
292 | }, |
293 | { |
294 | .name = "V7(LDO)" , |
295 | .id = MAX8660_V7, |
296 | .ops = &max8660_ldo67_ops, |
297 | .type = REGULATOR_VOLTAGE, |
298 | .n_voltages = MAX8660_LDO67_MAX_SEL + 1, |
299 | .owner = THIS_MODULE, |
300 | .min_uV = MAX8660_LDO67_MIN_UV, |
301 | .uV_step = MAX8660_LDO67_STEP, |
302 | }, |
303 | }; |
304 | |
305 | enum { |
306 | MAX8660 = 0, |
307 | MAX8661 = 1, |
308 | }; |
309 | |
310 | #ifdef CONFIG_OF |
311 | static const struct of_device_id max8660_dt_ids[] = { |
312 | { .compatible = "maxim,max8660" , .data = (void *) MAX8660 }, |
313 | { .compatible = "maxim,max8661" , .data = (void *) MAX8661 }, |
314 | { } |
315 | }; |
316 | MODULE_DEVICE_TABLE(of, max8660_dt_ids); |
317 | |
318 | static int max8660_pdata_from_dt(struct device *dev, |
319 | struct device_node **of_node, |
320 | struct max8660_platform_data *pdata) |
321 | { |
322 | int matched, i; |
323 | struct device_node *np; |
324 | struct max8660_subdev_data *sub; |
325 | struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { }; |
326 | |
327 | np = of_get_child_by_name(node: dev->of_node, name: "regulators" ); |
328 | if (!np) { |
329 | dev_err(dev, "missing 'regulators' subnode in DT\n" ); |
330 | return -EINVAL; |
331 | } |
332 | |
333 | for (i = 0; i < ARRAY_SIZE(rmatch); i++) |
334 | rmatch[i].name = max8660_reg[i].name; |
335 | |
336 | matched = of_regulator_match(dev, node: np, matches: rmatch, ARRAY_SIZE(rmatch)); |
337 | of_node_put(node: np); |
338 | if (matched <= 0) |
339 | return matched; |
340 | |
341 | pdata->subdevs = devm_kcalloc(dev, |
342 | n: matched, |
343 | size: sizeof(struct max8660_subdev_data), |
344 | GFP_KERNEL); |
345 | if (!pdata->subdevs) |
346 | return -ENOMEM; |
347 | |
348 | pdata->num_subdevs = matched; |
349 | sub = pdata->subdevs; |
350 | |
351 | for (i = 0; i < matched; i++) { |
352 | sub->id = i; |
353 | sub->name = rmatch[i].name; |
354 | sub->platform_data = rmatch[i].init_data; |
355 | of_node[i] = rmatch[i].of_node; |
356 | sub++; |
357 | } |
358 | |
359 | return 0; |
360 | } |
361 | #else |
362 | static inline int max8660_pdata_from_dt(struct device *dev, |
363 | struct device_node **of_node, |
364 | struct max8660_platform_data *pdata) |
365 | { |
366 | return 0; |
367 | } |
368 | #endif |
369 | |
370 | static int max8660_probe(struct i2c_client *client) |
371 | { |
372 | const struct i2c_device_id *i2c_id = i2c_client_get_device_id(client); |
373 | struct device *dev = &client->dev; |
374 | struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); |
375 | struct regulator_config config = { }; |
376 | struct max8660 *max8660; |
377 | int boot_on, i, id, ret = -EINVAL; |
378 | struct device_node *of_node[MAX8660_V_END]; |
379 | unsigned long type; |
380 | |
381 | if (dev->of_node && !pdata) { |
382 | const struct of_device_id *id; |
383 | |
384 | id = of_match_device(of_match_ptr(max8660_dt_ids), dev); |
385 | if (!id) |
386 | return -ENODEV; |
387 | |
388 | ret = max8660_pdata_from_dt(dev, of_node, pdata: &pdata_of); |
389 | if (ret < 0) |
390 | return ret; |
391 | |
392 | pdata = &pdata_of; |
393 | type = (unsigned long) id->data; |
394 | } else { |
395 | type = i2c_id->driver_data; |
396 | memset(of_node, 0, sizeof(of_node)); |
397 | } |
398 | |
399 | if (pdata->num_subdevs > MAX8660_V_END) { |
400 | dev_err(dev, "Too many regulators found!\n" ); |
401 | return -EINVAL; |
402 | } |
403 | |
404 | max8660 = devm_kzalloc(dev, size: sizeof(struct max8660), GFP_KERNEL); |
405 | if (!max8660) |
406 | return -ENOMEM; |
407 | |
408 | max8660->client = client; |
409 | |
410 | if (pdata->en34_is_high) { |
411 | /* Simulate always on */ |
412 | max8660->shadow_regs[MAX8660_OVER1] = 5; |
413 | } else { |
414 | /* Otherwise devices can be toggled via software */ |
415 | max8660_dcdc_ops.enable = max8660_dcdc_enable; |
416 | max8660_dcdc_ops.disable = max8660_dcdc_disable; |
417 | } |
418 | |
419 | /* |
420 | * First, set up shadow registers to prevent glitches. As some |
421 | * registers are shared between regulators, everything must be properly |
422 | * set up for all regulators in advance. |
423 | */ |
424 | max8660->shadow_regs[MAX8660_ADTV1] = |
425 | max8660->shadow_regs[MAX8660_ADTV2] = |
426 | max8660->shadow_regs[MAX8660_SDTV1] = |
427 | max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; |
428 | max8660->shadow_regs[MAX8660_MDTV1] = |
429 | max8660->shadow_regs[MAX8660_MDTV2] = 0x04; |
430 | |
431 | for (i = 0; i < pdata->num_subdevs; i++) { |
432 | |
433 | if (!pdata->subdevs[i].platform_data) |
434 | boot_on = false; |
435 | else |
436 | boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; |
437 | |
438 | switch (pdata->subdevs[i].id) { |
439 | case MAX8660_V3: |
440 | if (boot_on) |
441 | max8660->shadow_regs[MAX8660_OVER1] |= 1; |
442 | break; |
443 | |
444 | case MAX8660_V4: |
445 | if (boot_on) |
446 | max8660->shadow_regs[MAX8660_OVER1] |= 4; |
447 | break; |
448 | |
449 | case MAX8660_V5: |
450 | break; |
451 | |
452 | case MAX8660_V6: |
453 | if (boot_on) |
454 | max8660->shadow_regs[MAX8660_OVER2] |= 2; |
455 | break; |
456 | |
457 | case MAX8660_V7: |
458 | if (type == MAX8661) { |
459 | dev_err(dev, "Regulator not on this chip!\n" ); |
460 | return -EINVAL; |
461 | } |
462 | |
463 | if (boot_on) |
464 | max8660->shadow_regs[MAX8660_OVER2] |= 4; |
465 | break; |
466 | |
467 | default: |
468 | dev_err(dev, "invalid regulator %s\n" , |
469 | pdata->subdevs[i].name); |
470 | return ret; |
471 | } |
472 | } |
473 | |
474 | /* Finally register devices */ |
475 | for (i = 0; i < pdata->num_subdevs; i++) { |
476 | struct regulator_dev *rdev; |
477 | |
478 | id = pdata->subdevs[i].id; |
479 | |
480 | config.dev = dev; |
481 | config.init_data = pdata->subdevs[i].platform_data; |
482 | config.of_node = of_node[i]; |
483 | config.driver_data = max8660; |
484 | |
485 | rdev = devm_regulator_register(dev: &client->dev, |
486 | regulator_desc: &max8660_reg[id], config: &config); |
487 | if (IS_ERR(ptr: rdev)) { |
488 | dev_err(&client->dev, "failed to register %s\n" , |
489 | max8660_reg[id].name); |
490 | return PTR_ERR(ptr: rdev); |
491 | } |
492 | } |
493 | |
494 | i2c_set_clientdata(client, data: max8660); |
495 | return 0; |
496 | } |
497 | |
498 | static const struct i2c_device_id max8660_id[] = { |
499 | { .name = "max8660" , .driver_data = MAX8660 }, |
500 | { .name = "max8661" , .driver_data = MAX8661 }, |
501 | { } |
502 | }; |
503 | MODULE_DEVICE_TABLE(i2c, max8660_id); |
504 | |
505 | static struct i2c_driver max8660_driver = { |
506 | .probe = max8660_probe, |
507 | .driver = { |
508 | .name = "max8660" , |
509 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
510 | }, |
511 | .id_table = max8660_id, |
512 | }; |
513 | |
514 | static int __init max8660_init(void) |
515 | { |
516 | return i2c_add_driver(&max8660_driver); |
517 | } |
518 | subsys_initcall(max8660_init); |
519 | |
520 | static void __exit max8660_exit(void) |
521 | { |
522 | i2c_del_driver(driver: &max8660_driver); |
523 | } |
524 | module_exit(max8660_exit); |
525 | |
526 | /* Module information */ |
527 | MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver" ); |
528 | MODULE_AUTHOR("Wolfram Sang" ); |
529 | MODULE_LICENSE("GPL v2" ); |
530 | |