1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // MCP16502 PMIC driver
4 //
5 // Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries
6 //
7 // Author: Andrei Stefanescu <andrei.stefanescu@microchip.com>
8 //
9 // Inspired from tps65086-regulator.c
10
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/regmap.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/suspend.h>
19 #include <linux/gpio/consumer.h>
20
21 #define VDD_LOW_SEL 0x0D
22 #define VDD_HIGH_SEL 0x3F
23
24 #define MCP16502_FLT BIT(7)
25 #define MCP16502_DVSR GENMASK(3, 2)
26 #define MCP16502_ENS BIT(0)
27
28 /*
29 * The PMIC has four sets of registers corresponding to four power modes:
30 * Performance, Active, Low-power, Hibernate.
31 *
32 * Registers:
33 * Each regulator has a register for each power mode. To access a register
34 * for a specific regulator and mode BASE_* and OFFSET_* need to be added.
35 *
36 * Operating modes:
37 * In order for the PMIC to transition to operating modes it has to be
38 * controlled via GPIO lines called LPM and HPM.
39 *
40 * The registers are fully configurable such that you can put all regulators in
41 * a low-power state while the PMIC is in Active mode. They are supposed to be
42 * configured at startup and then simply transition to/from a global low-power
43 * state by setting the GPIO lpm pin high/low.
44 *
45 * This driver keeps the PMIC in Active mode, Low-power state is set for the
46 * regulators by enabling/disabling operating mode (FPWM or Auto PFM).
47 *
48 * The PMIC's Low-power and Hibernate modes are used during standby/suspend.
49 * To enter standby/suspend the PMIC will go to Low-power mode. From there, it
50 * will transition to Hibernate when the PWRHLD line is set to low by the MPU.
51 */
52
53 /*
54 * This function is useful for iterating over all regulators and accessing their
55 * registers in a generic way or accessing a regulator device by its id.
56 */
57 #define MCP16502_REG_BASE(i, r) ((((i) + 1) << 4) + MCP16502_REG_##r)
58 #define MCP16502_STAT_BASE(i) ((i) + 5)
59
60 #define MCP16502_OPMODE_ACTIVE REGULATOR_MODE_NORMAL
61 #define MCP16502_OPMODE_LPM REGULATOR_MODE_IDLE
62 #define MCP16502_OPMODE_HIB REGULATOR_MODE_STANDBY
63
64 #define MCP16502_MODE_AUTO_PFM 0
65 #define MCP16502_MODE_FPWM BIT(6)
66
67 #define MCP16502_VSEL 0x3F
68 #define MCP16502_EN BIT(7)
69 #define MCP16502_MODE BIT(6)
70
71 #define MCP16502_MIN_REG 0x0
72 #define MCP16502_MAX_REG 0x65
73
74 /**
75 * enum mcp16502_reg - MCP16502 regulators's registers
76 * @MCP16502_REG_A: active state register
77 * @MCP16502_REG_LPM: low power mode state register
78 * @MCP16502_REG_HIB: hibernate state register
79 * @MCP16502_REG_HPM: high-performance mode register
80 * @MCP16502_REG_SEQ: startup sequence register
81 * @MCP16502_REG_CFG: configuration register
82 */
83 enum mcp16502_reg {
84 MCP16502_REG_A,
85 MCP16502_REG_LPM,
86 MCP16502_REG_HIB,
87 MCP16502_REG_HPM,
88 MCP16502_REG_SEQ,
89 MCP16502_REG_CFG,
90 };
91
92 /* Ramp delay (uV/us) for buck1, ldo1, ldo2. */
93 static const unsigned int mcp16502_ramp_b1l12[] = {
94 6250, 3125, 2083, 1563
95 };
96
97 /* Ramp delay (uV/us) for buck2, buck3, buck4. */
98 static const unsigned int mcp16502_ramp_b234[] = {
99 3125, 1563, 1042, 781
100 };
101
mcp16502_of_map_mode(unsigned int mode)102 static unsigned int mcp16502_of_map_mode(unsigned int mode)
103 {
104 if (mode == REGULATOR_MODE_NORMAL || mode == REGULATOR_MODE_IDLE)
105 return mode;
106
107 return REGULATOR_MODE_INVALID;
108 }
109
110 #define MCP16502_REGULATOR(_name, _id, _sn, _ranges, _ops, _ramp_table) \
111 [_id] = { \
112 .name = _name, \
113 .supply_name = #_sn, \
114 .regulators_node = "regulators", \
115 .id = _id, \
116 .ops = &(_ops), \
117 .type = REGULATOR_VOLTAGE, \
118 .owner = THIS_MODULE, \
119 .n_voltages = MCP16502_VSEL + 1, \
120 .linear_ranges = _ranges, \
121 .linear_min_sel = VDD_LOW_SEL, \
122 .n_linear_ranges = ARRAY_SIZE(_ranges), \
123 .of_match = _name, \
124 .of_map_mode = mcp16502_of_map_mode, \
125 .vsel_reg = (((_id) + 1) << 4), \
126 .vsel_mask = MCP16502_VSEL, \
127 .enable_reg = (((_id) + 1) << 4), \
128 .enable_mask = MCP16502_EN, \
129 .ramp_reg = MCP16502_REG_BASE(_id, CFG), \
130 .ramp_mask = MCP16502_DVSR, \
131 .ramp_delay_table = _ramp_table, \
132 .n_ramp_values = ARRAY_SIZE(_ramp_table), \
133 }
134
135 enum {
136 BUCK1 = 0,
137 BUCK2,
138 BUCK3,
139 BUCK4,
140 LDO1,
141 LDO2,
142 NUM_REGULATORS
143 };
144
145 /*
146 * struct mcp16502 - PMIC representation
147 * @lpm: LPM GPIO descriptor
148 */
149 struct mcp16502 {
150 struct gpio_desc *lpm;
151 };
152
153 /*
154 * mcp16502_gpio_set_mode() - set the GPIO corresponding value
155 *
156 * Used to prepare transitioning into hibernate or resuming from it.
157 */
mcp16502_gpio_set_mode(struct mcp16502 * mcp,int mode)158 static void mcp16502_gpio_set_mode(struct mcp16502 *mcp, int mode)
159 {
160 switch (mode) {
161 case MCP16502_OPMODE_ACTIVE:
162 gpiod_set_value(mcp->lpm, 0);
163 break;
164 case MCP16502_OPMODE_LPM:
165 case MCP16502_OPMODE_HIB:
166 gpiod_set_value(mcp->lpm, 1);
167 break;
168 default:
169 pr_err("%s: %d invalid\n", __func__, mode);
170 }
171 }
172
173 /*
174 * mcp16502_get_reg() - get the PMIC's state configuration register for opmode
175 *
176 * @rdev: the regulator whose register we are searching
177 * @opmode: the PMIC's operating mode ACTIVE, Low-power, Hibernate
178 */
mcp16502_get_state_reg(struct regulator_dev * rdev,int opmode)179 static int mcp16502_get_state_reg(struct regulator_dev *rdev, int opmode)
180 {
181 switch (opmode) {
182 case MCP16502_OPMODE_ACTIVE:
183 return MCP16502_REG_BASE(rdev_get_id(rdev), A);
184 case MCP16502_OPMODE_LPM:
185 return MCP16502_REG_BASE(rdev_get_id(rdev), LPM);
186 case MCP16502_OPMODE_HIB:
187 return MCP16502_REG_BASE(rdev_get_id(rdev), HIB);
188 default:
189 return -EINVAL;
190 }
191 }
192
193 /*
194 * mcp16502_get_mode() - return the current operating mode of a regulator
195 *
196 * Note: all functions that are not part of entering/exiting standby/suspend
197 * use the Active mode registers.
198 *
199 * Note: this is different from the PMIC's operatig mode, it is the
200 * MODE bit from the regulator's register.
201 */
mcp16502_get_mode(struct regulator_dev * rdev)202 static unsigned int mcp16502_get_mode(struct regulator_dev *rdev)
203 {
204 unsigned int val;
205 int ret, reg;
206
207 reg = mcp16502_get_state_reg(rdev, MCP16502_OPMODE_ACTIVE);
208 if (reg < 0)
209 return reg;
210
211 ret = regmap_read(rdev->regmap, reg, &val);
212 if (ret)
213 return ret;
214
215 switch (val & MCP16502_MODE) {
216 case MCP16502_MODE_FPWM:
217 return REGULATOR_MODE_NORMAL;
218 case MCP16502_MODE_AUTO_PFM:
219 return REGULATOR_MODE_IDLE;
220 default:
221 return REGULATOR_MODE_INVALID;
222 }
223 }
224
225 /*
226 * _mcp16502_set_mode() - helper for set_mode and set_suspend_mode
227 *
228 * @rdev: the regulator for which we are setting the mode
229 * @mode: the regulator's mode (the one from MODE bit)
230 * @opmode: the PMIC's operating mode: Active/Low-power/Hibernate
231 */
_mcp16502_set_mode(struct regulator_dev * rdev,unsigned int mode,unsigned int op_mode)232 static int _mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode,
233 unsigned int op_mode)
234 {
235 int val;
236 int reg;
237
238 reg = mcp16502_get_state_reg(rdev, op_mode);
239 if (reg < 0)
240 return reg;
241
242 switch (mode) {
243 case REGULATOR_MODE_NORMAL:
244 val = MCP16502_MODE_FPWM;
245 break;
246 case REGULATOR_MODE_IDLE:
247 val = MCP16502_MODE_AUTO_PFM;
248 break;
249 default:
250 return -EINVAL;
251 }
252
253 reg = regmap_update_bits(rdev->regmap, reg, MCP16502_MODE, val);
254 return reg;
255 }
256
257 /*
258 * mcp16502_set_mode() - regulator_ops set_mode
259 */
mcp16502_set_mode(struct regulator_dev * rdev,unsigned int mode)260 static int mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode)
261 {
262 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_ACTIVE);
263 }
264
265 /*
266 * mcp16502_get_status() - regulator_ops get_status
267 */
mcp16502_get_status(struct regulator_dev * rdev)268 static int mcp16502_get_status(struct regulator_dev *rdev)
269 {
270 int ret;
271 unsigned int val;
272
273 ret = regmap_read(rdev->regmap, MCP16502_STAT_BASE(rdev_get_id(rdev)),
274 &val);
275 if (ret)
276 return ret;
277
278 if (val & MCP16502_FLT)
279 return REGULATOR_STATUS_ERROR;
280 else if (val & MCP16502_ENS)
281 return REGULATOR_STATUS_ON;
282 else if (!(val & MCP16502_ENS))
283 return REGULATOR_STATUS_OFF;
284
285 return REGULATOR_STATUS_UNDEFINED;
286 }
287
mcp16502_set_voltage_time_sel(struct regulator_dev * rdev,unsigned int old_sel,unsigned int new_sel)288 static int mcp16502_set_voltage_time_sel(struct regulator_dev *rdev,
289 unsigned int old_sel,
290 unsigned int new_sel)
291 {
292 static const u8 us_ramp[] = { 8, 16, 24, 32 };
293 int id = rdev_get_id(rdev);
294 unsigned int uV_delta, val;
295 int ret;
296
297 ret = regmap_read(rdev->regmap, MCP16502_REG_BASE(id, CFG), &val);
298 if (ret)
299 return ret;
300
301 val = (val & MCP16502_DVSR) >> 2;
302 uV_delta = abs(new_sel * rdev->desc->linear_ranges->step -
303 old_sel * rdev->desc->linear_ranges->step);
304 switch (id) {
305 case BUCK1:
306 case LDO1:
307 case LDO2:
308 ret = DIV_ROUND_CLOSEST(uV_delta * us_ramp[val],
309 mcp16502_ramp_b1l12[val]);
310 break;
311
312 case BUCK2:
313 case BUCK3:
314 case BUCK4:
315 ret = DIV_ROUND_CLOSEST(uV_delta * us_ramp[val],
316 mcp16502_ramp_b234[val]);
317 break;
318
319 default:
320 return -EINVAL;
321 }
322
323 return ret;
324 }
325
326 #ifdef CONFIG_SUSPEND
327 /*
328 * mcp16502_suspend_get_target_reg() - get the reg of the target suspend PMIC
329 * mode
330 */
mcp16502_suspend_get_target_reg(struct regulator_dev * rdev)331 static int mcp16502_suspend_get_target_reg(struct regulator_dev *rdev)
332 {
333 switch (pm_suspend_target_state) {
334 case PM_SUSPEND_STANDBY:
335 return mcp16502_get_state_reg(rdev, MCP16502_OPMODE_LPM);
336 case PM_SUSPEND_ON:
337 case PM_SUSPEND_MEM:
338 return mcp16502_get_state_reg(rdev, MCP16502_OPMODE_HIB);
339 default:
340 dev_err(&rdev->dev, "invalid suspend target: %d\n",
341 pm_suspend_target_state);
342 }
343
344 return -EINVAL;
345 }
346
347 /*
348 * mcp16502_set_suspend_voltage() - regulator_ops set_suspend_voltage
349 */
mcp16502_set_suspend_voltage(struct regulator_dev * rdev,int uV)350 static int mcp16502_set_suspend_voltage(struct regulator_dev *rdev, int uV)
351 {
352 int sel = regulator_map_voltage_linear_range(rdev, uV, uV);
353 int reg = mcp16502_suspend_get_target_reg(rdev);
354
355 if (sel < 0)
356 return sel;
357
358 if (reg < 0)
359 return reg;
360
361 return regmap_update_bits(rdev->regmap, reg, MCP16502_VSEL, sel);
362 }
363
364 /*
365 * mcp16502_set_suspend_mode() - regulator_ops set_suspend_mode
366 */
mcp16502_set_suspend_mode(struct regulator_dev * rdev,unsigned int mode)367 static int mcp16502_set_suspend_mode(struct regulator_dev *rdev,
368 unsigned int mode)
369 {
370 switch (pm_suspend_target_state) {
371 case PM_SUSPEND_STANDBY:
372 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_LPM);
373 case PM_SUSPEND_ON:
374 case PM_SUSPEND_MEM:
375 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_HIB);
376 default:
377 dev_err(&rdev->dev, "invalid suspend target: %d\n",
378 pm_suspend_target_state);
379 }
380
381 return -EINVAL;
382 }
383
384 /*
385 * mcp16502_set_suspend_enable() - regulator_ops set_suspend_enable
386 */
mcp16502_set_suspend_enable(struct regulator_dev * rdev)387 static int mcp16502_set_suspend_enable(struct regulator_dev *rdev)
388 {
389 int reg = mcp16502_suspend_get_target_reg(rdev);
390
391 if (reg < 0)
392 return reg;
393
394 return regmap_update_bits(rdev->regmap, reg, MCP16502_EN, MCP16502_EN);
395 }
396
397 /*
398 * mcp16502_set_suspend_disable() - regulator_ops set_suspend_disable
399 */
mcp16502_set_suspend_disable(struct regulator_dev * rdev)400 static int mcp16502_set_suspend_disable(struct regulator_dev *rdev)
401 {
402 int reg = mcp16502_suspend_get_target_reg(rdev);
403
404 if (reg < 0)
405 return reg;
406
407 return regmap_update_bits(rdev->regmap, reg, MCP16502_EN, 0);
408 }
409 #endif /* CONFIG_SUSPEND */
410
411 static const struct regulator_ops mcp16502_buck_ops = {
412 .list_voltage = regulator_list_voltage_linear_range,
413 .map_voltage = regulator_map_voltage_linear_range,
414 .get_voltage_sel = regulator_get_voltage_sel_regmap,
415 .set_voltage_sel = regulator_set_voltage_sel_regmap,
416 .enable = regulator_enable_regmap,
417 .disable = regulator_disable_regmap,
418 .is_enabled = regulator_is_enabled_regmap,
419 .get_status = mcp16502_get_status,
420 .set_voltage_time_sel = mcp16502_set_voltage_time_sel,
421 .set_ramp_delay = regulator_set_ramp_delay_regmap,
422
423 .set_mode = mcp16502_set_mode,
424 .get_mode = mcp16502_get_mode,
425
426 #ifdef CONFIG_SUSPEND
427 .set_suspend_voltage = mcp16502_set_suspend_voltage,
428 .set_suspend_mode = mcp16502_set_suspend_mode,
429 .set_suspend_enable = mcp16502_set_suspend_enable,
430 .set_suspend_disable = mcp16502_set_suspend_disable,
431 #endif /* CONFIG_SUSPEND */
432 };
433
434 /*
435 * LDOs cannot change operating modes.
436 */
437 static const struct regulator_ops mcp16502_ldo_ops = {
438 .list_voltage = regulator_list_voltage_linear_range,
439 .map_voltage = regulator_map_voltage_linear_range,
440 .get_voltage_sel = regulator_get_voltage_sel_regmap,
441 .set_voltage_sel = regulator_set_voltage_sel_regmap,
442 .enable = regulator_enable_regmap,
443 .disable = regulator_disable_regmap,
444 .is_enabled = regulator_is_enabled_regmap,
445 .get_status = mcp16502_get_status,
446 .set_voltage_time_sel = mcp16502_set_voltage_time_sel,
447 .set_ramp_delay = regulator_set_ramp_delay_regmap,
448
449 #ifdef CONFIG_SUSPEND
450 .set_suspend_voltage = mcp16502_set_suspend_voltage,
451 .set_suspend_enable = mcp16502_set_suspend_enable,
452 .set_suspend_disable = mcp16502_set_suspend_disable,
453 #endif /* CONFIG_SUSPEND */
454 };
455
456 static const struct of_device_id mcp16502_ids[] = {
457 { .compatible = "microchip,mcp16502", },
458 {}
459 };
460 MODULE_DEVICE_TABLE(of, mcp16502_ids);
461
462 static const struct linear_range b1l12_ranges[] = {
463 REGULATOR_LINEAR_RANGE(1200000, VDD_LOW_SEL, VDD_HIGH_SEL, 50000),
464 };
465
466 static const struct linear_range b234_ranges[] = {
467 REGULATOR_LINEAR_RANGE(600000, VDD_LOW_SEL, VDD_HIGH_SEL, 25000),
468 };
469
470 static const struct regulator_desc mcp16502_desc[] = {
471 /* MCP16502_REGULATOR(_name, _id, _sn, _ranges, _ops, _ramp_table) */
472 MCP16502_REGULATOR("VDD_IO", BUCK1, pvin1, b1l12_ranges, mcp16502_buck_ops,
473 mcp16502_ramp_b1l12),
474 MCP16502_REGULATOR("VDD_DDR", BUCK2, pvin2, b234_ranges, mcp16502_buck_ops,
475 mcp16502_ramp_b234),
476 MCP16502_REGULATOR("VDD_CORE", BUCK3, pvin3, b234_ranges, mcp16502_buck_ops,
477 mcp16502_ramp_b234),
478 MCP16502_REGULATOR("VDD_OTHER", BUCK4, pvin4, b234_ranges, mcp16502_buck_ops,
479 mcp16502_ramp_b234),
480 MCP16502_REGULATOR("LDO1", LDO1, lvin, b1l12_ranges, mcp16502_ldo_ops,
481 mcp16502_ramp_b1l12),
482 MCP16502_REGULATOR("LDO2", LDO2, lvin, b1l12_ranges, mcp16502_ldo_ops,
483 mcp16502_ramp_b1l12)
484 };
485
486 static const struct regmap_range mcp16502_ranges[] = {
487 regmap_reg_range(MCP16502_MIN_REG, MCP16502_MAX_REG)
488 };
489
490 static const struct regmap_access_table mcp16502_yes_reg_table = {
491 .yes_ranges = mcp16502_ranges,
492 .n_yes_ranges = ARRAY_SIZE(mcp16502_ranges),
493 };
494
495 static const struct regmap_config mcp16502_regmap_config = {
496 .reg_bits = 8,
497 .val_bits = 8,
498 .max_register = MCP16502_MAX_REG,
499 .cache_type = REGCACHE_NONE,
500 .rd_table = &mcp16502_yes_reg_table,
501 .wr_table = &mcp16502_yes_reg_table,
502 };
503
mcp16502_probe(struct i2c_client * client)504 static int mcp16502_probe(struct i2c_client *client)
505 {
506 struct regulator_config config = { };
507 struct regulator_dev *rdev;
508 struct device *dev;
509 struct mcp16502 *mcp;
510 struct regmap *rmap;
511 int i, ret;
512
513 dev = &client->dev;
514 config.dev = dev;
515
516 mcp = devm_kzalloc(dev, sizeof(*mcp), GFP_KERNEL);
517 if (!mcp)
518 return -ENOMEM;
519
520 rmap = devm_regmap_init_i2c(client, &mcp16502_regmap_config);
521 if (IS_ERR(rmap)) {
522 ret = PTR_ERR(rmap);
523 dev_err(dev, "regmap init failed: %d\n", ret);
524 return ret;
525 }
526
527 i2c_set_clientdata(client, mcp);
528 config.regmap = rmap;
529 config.driver_data = mcp;
530
531 mcp->lpm = devm_gpiod_get_optional(dev, "lpm", GPIOD_OUT_LOW);
532 if (IS_ERR(mcp->lpm)) {
533 dev_err(dev, "failed to get lpm pin: %ld\n", PTR_ERR(mcp->lpm));
534 return PTR_ERR(mcp->lpm);
535 }
536
537 for (i = 0; i < NUM_REGULATORS; i++) {
538 rdev = devm_regulator_register(dev, &mcp16502_desc[i], &config);
539 if (IS_ERR(rdev)) {
540 dev_err(dev,
541 "failed to register %s regulator %ld\n",
542 mcp16502_desc[i].name, PTR_ERR(rdev));
543 return PTR_ERR(rdev);
544 }
545 }
546
547 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
548
549 return 0;
550 }
551
552 #ifdef CONFIG_PM_SLEEP
mcp16502_suspend_noirq(struct device * dev)553 static int mcp16502_suspend_noirq(struct device *dev)
554 {
555 struct i2c_client *client = to_i2c_client(dev);
556 struct mcp16502 *mcp = i2c_get_clientdata(client);
557
558 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_LPM);
559
560 return 0;
561 }
562
mcp16502_resume_noirq(struct device * dev)563 static int mcp16502_resume_noirq(struct device *dev)
564 {
565 struct i2c_client *client = to_i2c_client(dev);
566 struct mcp16502 *mcp = i2c_get_clientdata(client);
567
568 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
569
570 return 0;
571 }
572 #endif
573
574 #ifdef CONFIG_PM
575 static const struct dev_pm_ops mcp16502_pm_ops = {
576 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mcp16502_suspend_noirq,
577 mcp16502_resume_noirq)
578 };
579 #endif
580 static const struct i2c_device_id mcp16502_i2c_id[] = {
581 { "mcp16502" },
582 { }
583 };
584 MODULE_DEVICE_TABLE(i2c, mcp16502_i2c_id);
585
586 static struct i2c_driver mcp16502_drv = {
587 .probe = mcp16502_probe,
588 .driver = {
589 .name = "mcp16502-regulator",
590 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
591 .of_match_table = mcp16502_ids,
592 #ifdef CONFIG_PM
593 .pm = &mcp16502_pm_ops,
594 #endif
595 },
596 .id_table = mcp16502_i2c_id,
597 };
598
599 module_i2c_driver(mcp16502_drv);
600
601 MODULE_LICENSE("GPL v2");
602 MODULE_DESCRIPTION("MCP16502 PMIC driver");
603 MODULE_AUTHOR("Andrei Stefanescu andrei.stefanescu@microchip.com");
604