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/gpio.h>
12#include <linux/i2c.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/regmap.h>
18#include <linux/regulator/driver.h>
19#include <linux/suspend.h>
20#include <linux/gpio/consumer.h>
21
22#define VDD_LOW_SEL 0x0D
23#define VDD_HIGH_SEL 0x3F
24
25#define MCP16502_FLT BIT(7)
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_BASE(i) (((i) + 1) << 4)
58#define MCP16502_STAT_BASE(i) ((i) + 5)
59
60#define MCP16502_OFFSET_MODE_A 0
61#define MCP16502_OFFSET_MODE_LPM 1
62#define MCP16502_OFFSET_MODE_HIB 2
63
64#define MCP16502_OPMODE_ACTIVE REGULATOR_MODE_NORMAL
65#define MCP16502_OPMODE_LPM REGULATOR_MODE_IDLE
66#define MCP16502_OPMODE_HIB REGULATOR_MODE_STANDBY
67
68#define MCP16502_MODE_AUTO_PFM 0
69#define MCP16502_MODE_FPWM BIT(6)
70
71#define MCP16502_VSEL 0x3F
72#define MCP16502_EN BIT(7)
73#define MCP16502_MODE BIT(6)
74
75#define MCP16502_MIN_REG 0x0
76#define MCP16502_MAX_REG 0x65
77
78static unsigned int mcp16502_of_map_mode(unsigned int mode)
79{
80 if (mode == REGULATOR_MODE_NORMAL || mode == REGULATOR_MODE_IDLE)
81 return mode;
82
83 return REGULATOR_MODE_INVALID;
84}
85
86#define MCP16502_REGULATOR(_name, _id, _ranges, _ops) \
87 [_id] = { \
88 .name = _name, \
89 .regulators_node = of_match_ptr("regulators"), \
90 .id = _id, \
91 .ops = &(_ops), \
92 .type = REGULATOR_VOLTAGE, \
93 .owner = THIS_MODULE, \
94 .n_voltages = MCP16502_VSEL + 1, \
95 .linear_ranges = _ranges, \
96 .n_linear_ranges = ARRAY_SIZE(_ranges), \
97 .of_match = of_match_ptr(_name), \
98 .of_map_mode = mcp16502_of_map_mode, \
99 .vsel_reg = (((_id) + 1) << 4), \
100 .vsel_mask = MCP16502_VSEL, \
101 .enable_reg = (((_id) + 1) << 4), \
102 .enable_mask = MCP16502_EN, \
103 }
104
105enum {
106 BUCK1 = 0,
107 BUCK2,
108 BUCK3,
109 BUCK4,
110 LDO1,
111 LDO2,
112 NUM_REGULATORS
113};
114
115/*
116 * struct mcp16502 - PMIC representation
117 * @rdev: the regulators belonging to this chip
118 * @rmap: regmap to be used for I2C communication
119 * @lpm: LPM GPIO descriptor
120 */
121struct mcp16502 {
122 struct regulator_dev *rdev[NUM_REGULATORS];
123 struct regmap *rmap;
124 struct gpio_desc *lpm;
125};
126
127/*
128 * mcp16502_gpio_set_mode() - set the GPIO corresponding value
129 *
130 * Used to prepare transitioning into hibernate or resuming from it.
131 */
132static void mcp16502_gpio_set_mode(struct mcp16502 *mcp, int mode)
133{
134 switch (mode) {
135 case MCP16502_OPMODE_ACTIVE:
136 gpiod_set_value(mcp->lpm, 0);
137 break;
138 case MCP16502_OPMODE_LPM:
139 case MCP16502_OPMODE_HIB:
140 gpiod_set_value(mcp->lpm, 1);
141 break;
142 default:
143 pr_err("%s: %d invalid\n", __func__, mode);
144 }
145}
146
147/*
148 * mcp16502_get_reg() - get the PMIC's configuration register for opmode
149 *
150 * @rdev: the regulator whose register we are searching
151 * @opmode: the PMIC's operating mode ACTIVE, Low-power, Hibernate
152 */
153static int mcp16502_get_reg(struct regulator_dev *rdev, int opmode)
154{
155 int reg = MCP16502_BASE(rdev_get_id(rdev));
156
157 switch (opmode) {
158 case MCP16502_OPMODE_ACTIVE:
159 return reg + MCP16502_OFFSET_MODE_A;
160 case MCP16502_OPMODE_LPM:
161 return reg + MCP16502_OFFSET_MODE_LPM;
162 case MCP16502_OPMODE_HIB:
163 return reg + MCP16502_OFFSET_MODE_HIB;
164 default:
165 return -EINVAL;
166 }
167}
168
169/*
170 * mcp16502_get_mode() - return the current operating mode of a regulator
171 *
172 * Note: all functions that are not part of entering/exiting standby/suspend
173 * use the Active mode registers.
174 *
175 * Note: this is different from the PMIC's operatig mode, it is the
176 * MODE bit from the regulator's register.
177 */
178static unsigned int mcp16502_get_mode(struct regulator_dev *rdev)
179{
180 unsigned int val;
181 int ret, reg;
182 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
183
184 reg = mcp16502_get_reg(rdev, MCP16502_OPMODE_ACTIVE);
185 if (reg < 0)
186 return reg;
187
188 ret = regmap_read(mcp->rmap, reg, &val);
189 if (ret)
190 return ret;
191
192 switch (val & MCP16502_MODE) {
193 case MCP16502_MODE_FPWM:
194 return REGULATOR_MODE_NORMAL;
195 case MCP16502_MODE_AUTO_PFM:
196 return REGULATOR_MODE_IDLE;
197 default:
198 return REGULATOR_MODE_INVALID;
199 }
200}
201
202/*
203 * _mcp16502_set_mode() - helper for set_mode and set_suspend_mode
204 *
205 * @rdev: the regulator for which we are setting the mode
206 * @mode: the regulator's mode (the one from MODE bit)
207 * @opmode: the PMIC's operating mode: Active/Low-power/Hibernate
208 */
209static int _mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode,
210 unsigned int op_mode)
211{
212 int val;
213 int reg;
214 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
215
216 reg = mcp16502_get_reg(rdev, op_mode);
217 if (reg < 0)
218 return reg;
219
220 switch (mode) {
221 case REGULATOR_MODE_NORMAL:
222 val = MCP16502_MODE_FPWM;
223 break;
224 case REGULATOR_MODE_IDLE:
225 val = MCP16502_MODE_AUTO_PFM;
226 break;
227 default:
228 return -EINVAL;
229 }
230
231 reg = regmap_update_bits(mcp->rmap, reg, MCP16502_MODE, val);
232 return reg;
233}
234
235/*
236 * mcp16502_set_mode() - regulator_ops set_mode
237 */
238static int mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode)
239{
240 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_ACTIVE);
241}
242
243/*
244 * mcp16502_get_status() - regulator_ops get_status
245 */
246static int mcp16502_get_status(struct regulator_dev *rdev)
247{
248 int ret;
249 unsigned int val;
250 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
251
252 ret = regmap_read(mcp->rmap, MCP16502_STAT_BASE(rdev_get_id(rdev)),
253 &val);
254 if (ret)
255 return ret;
256
257 if (val & MCP16502_FLT)
258 return REGULATOR_STATUS_ERROR;
259 else if (val & MCP16502_ENS)
260 return REGULATOR_STATUS_ON;
261 else if (!(val & MCP16502_ENS))
262 return REGULATOR_STATUS_OFF;
263
264 return REGULATOR_STATUS_UNDEFINED;
265}
266
267#ifdef CONFIG_SUSPEND
268/*
269 * mcp16502_suspend_get_target_reg() - get the reg of the target suspend PMIC
270 * mode
271 */
272static int mcp16502_suspend_get_target_reg(struct regulator_dev *rdev)
273{
274 switch (pm_suspend_target_state) {
275 case PM_SUSPEND_STANDBY:
276 return mcp16502_get_reg(rdev, MCP16502_OPMODE_LPM);
277 case PM_SUSPEND_ON:
278 case PM_SUSPEND_MEM:
279 return mcp16502_get_reg(rdev, MCP16502_OPMODE_HIB);
280 default:
281 dev_err(&rdev->dev, "invalid suspend target: %d\n",
282 pm_suspend_target_state);
283 }
284
285 return -EINVAL;
286}
287
288/*
289 * mcp16502_set_suspend_voltage() - regulator_ops set_suspend_voltage
290 */
291static int mcp16502_set_suspend_voltage(struct regulator_dev *rdev, int uV)
292{
293 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
294 int sel = regulator_map_voltage_linear_range(rdev, uV, uV);
295 int reg = mcp16502_suspend_get_target_reg(rdev);
296
297 if (sel < 0)
298 return sel;
299
300 if (reg < 0)
301 return reg;
302
303 return regmap_update_bits(mcp->rmap, reg, MCP16502_VSEL, sel);
304}
305
306/*
307 * mcp16502_set_suspend_mode() - regulator_ops set_suspend_mode
308 */
309static int mcp16502_set_suspend_mode(struct regulator_dev *rdev,
310 unsigned int mode)
311{
312 switch (pm_suspend_target_state) {
313 case PM_SUSPEND_STANDBY:
314 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_LPM);
315 case PM_SUSPEND_ON:
316 case PM_SUSPEND_MEM:
317 return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_HIB);
318 default:
319 dev_err(&rdev->dev, "invalid suspend target: %d\n",
320 pm_suspend_target_state);
321 }
322
323 return -EINVAL;
324}
325
326/*
327 * mcp16502_set_suspend_enable() - regulator_ops set_suspend_enable
328 */
329static int mcp16502_set_suspend_enable(struct regulator_dev *rdev)
330{
331 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
332 int reg = mcp16502_suspend_get_target_reg(rdev);
333
334 if (reg < 0)
335 return reg;
336
337 return regmap_update_bits(mcp->rmap, reg, MCP16502_EN, MCP16502_EN);
338}
339
340/*
341 * mcp16502_set_suspend_disable() - regulator_ops set_suspend_disable
342 */
343static int mcp16502_set_suspend_disable(struct regulator_dev *rdev)
344{
345 struct mcp16502 *mcp = rdev_get_drvdata(rdev);
346 int reg = mcp16502_suspend_get_target_reg(rdev);
347
348 if (reg < 0)
349 return reg;
350
351 return regmap_update_bits(mcp->rmap, reg, MCP16502_EN, 0);
352}
353#endif /* CONFIG_SUSPEND */
354
355static const struct regulator_ops mcp16502_buck_ops = {
356 .list_voltage = regulator_list_voltage_linear_range,
357 .map_voltage = regulator_map_voltage_linear_range,
358 .get_voltage_sel = regulator_get_voltage_sel_regmap,
359 .set_voltage_sel = regulator_set_voltage_sel_regmap,
360 .enable = regulator_enable_regmap,
361 .disable = regulator_disable_regmap,
362 .is_enabled = regulator_is_enabled_regmap,
363 .get_status = mcp16502_get_status,
364
365 .set_mode = mcp16502_set_mode,
366 .get_mode = mcp16502_get_mode,
367
368#ifdef CONFIG_SUSPEND
369 .set_suspend_voltage = mcp16502_set_suspend_voltage,
370 .set_suspend_mode = mcp16502_set_suspend_mode,
371 .set_suspend_enable = mcp16502_set_suspend_enable,
372 .set_suspend_disable = mcp16502_set_suspend_disable,
373#endif /* CONFIG_SUSPEND */
374};
375
376/*
377 * LDOs cannot change operating modes.
378 */
379static const struct regulator_ops mcp16502_ldo_ops = {
380 .list_voltage = regulator_list_voltage_linear_range,
381 .map_voltage = regulator_map_voltage_linear_range,
382 .get_voltage_sel = regulator_get_voltage_sel_regmap,
383 .set_voltage_sel = regulator_set_voltage_sel_regmap,
384 .enable = regulator_enable_regmap,
385 .disable = regulator_disable_regmap,
386 .is_enabled = regulator_is_enabled_regmap,
387 .get_status = mcp16502_get_status,
388
389#ifdef CONFIG_SUSPEND
390 .set_suspend_voltage = mcp16502_set_suspend_voltage,
391 .set_suspend_enable = mcp16502_set_suspend_enable,
392 .set_suspend_disable = mcp16502_set_suspend_disable,
393#endif /* CONFIG_SUSPEND */
394};
395
396static const struct of_device_id mcp16502_ids[] = {
397 { .compatible = "microchip,mcp16502", },
398 {}
399};
400MODULE_DEVICE_TABLE(of, mcp16502_ids);
401
402static const struct regulator_linear_range b1l12_ranges[] = {
403 REGULATOR_LINEAR_RANGE(1200000, VDD_LOW_SEL, VDD_HIGH_SEL, 50000),
404};
405
406static const struct regulator_linear_range b234_ranges[] = {
407 REGULATOR_LINEAR_RANGE(600000, VDD_LOW_SEL, VDD_HIGH_SEL, 25000),
408};
409
410static const struct regulator_desc mcp16502_desc[] = {
411 /* MCP16502_REGULATOR(_name, _id, ranges, regulator_ops) */
412 MCP16502_REGULATOR("VDD_IO", BUCK1, b1l12_ranges, mcp16502_buck_ops),
413 MCP16502_REGULATOR("VDD_DDR", BUCK2, b234_ranges, mcp16502_buck_ops),
414 MCP16502_REGULATOR("VDD_CORE", BUCK3, b234_ranges, mcp16502_buck_ops),
415 MCP16502_REGULATOR("VDD_OTHER", BUCK4, b234_ranges, mcp16502_buck_ops),
416 MCP16502_REGULATOR("LDO1", LDO1, b1l12_ranges, mcp16502_ldo_ops),
417 MCP16502_REGULATOR("LDO2", LDO2, b1l12_ranges, mcp16502_ldo_ops)
418};
419
420static const struct regmap_range mcp16502_ranges[] = {
421 regmap_reg_range(MCP16502_MIN_REG, MCP16502_MAX_REG)
422};
423
424static const struct regmap_access_table mcp16502_yes_reg_table = {
425 .yes_ranges = mcp16502_ranges,
426 .n_yes_ranges = ARRAY_SIZE(mcp16502_ranges),
427};
428
429static const struct regmap_config mcp16502_regmap_config = {
430 .reg_bits = 8,
431 .val_bits = 8,
432 .max_register = MCP16502_MAX_REG,
433 .cache_type = REGCACHE_NONE,
434 .rd_table = &mcp16502_yes_reg_table,
435 .wr_table = &mcp16502_yes_reg_table,
436};
437
438/*
439 * set_up_regulators() - initialize all regulators
440 */
441static int setup_regulators(struct mcp16502 *mcp, struct device *dev,
442 struct regulator_config config)
443{
444 int i;
445
446 for (i = 0; i < NUM_REGULATORS; i++) {
447 mcp->rdev[i] = devm_regulator_register(dev,
448 &mcp16502_desc[i],
449 &config);
450 if (IS_ERR(mcp->rdev[i])) {
451 dev_err(dev,
452 "failed to register %s regulator %ld\n",
453 mcp16502_desc[i].name, PTR_ERR(mcp->rdev[i]));
454 return PTR_ERR(mcp->rdev[i]);
455 }
456 }
457
458 return 0;
459}
460
461static int mcp16502_probe(struct i2c_client *client,
462 const struct i2c_device_id *id)
463{
464 struct regulator_config config = { };
465 struct device *dev;
466 struct mcp16502 *mcp;
467 int ret = 0;
468
469 dev = &client->dev;
470 config.dev = dev;
471
472 mcp = devm_kzalloc(dev, sizeof(*mcp), GFP_KERNEL);
473 if (!mcp)
474 return -ENOMEM;
475
476 mcp->rmap = devm_regmap_init_i2c(client, &mcp16502_regmap_config);
477 if (IS_ERR(mcp->rmap)) {
478 ret = PTR_ERR(mcp->rmap);
479 dev_err(dev, "regmap init failed: %d\n", ret);
480 return ret;
481 }
482
483 i2c_set_clientdata(client, mcp);
484 config.regmap = mcp->rmap;
485 config.driver_data = mcp;
486
487 mcp->lpm = devm_gpiod_get(dev, "lpm", GPIOD_OUT_LOW);
488 if (IS_ERR(mcp->lpm)) {
489 dev_err(dev, "failed to get lpm pin: %ld\n", PTR_ERR(mcp->lpm));
490 return PTR_ERR(mcp->lpm);
491 }
492
493 ret = setup_regulators(mcp, dev, config);
494 if (ret != 0)
495 return ret;
496
497 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
498
499 return 0;
500}
501
502#ifdef CONFIG_PM_SLEEP
503static int mcp16502_suspend_noirq(struct device *dev)
504{
505 struct i2c_client *client = to_i2c_client(dev);
506 struct mcp16502 *mcp = i2c_get_clientdata(client);
507
508 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_LPM);
509
510 return 0;
511}
512
513static int mcp16502_resume_noirq(struct device *dev)
514{
515 struct i2c_client *client = to_i2c_client(dev);
516 struct mcp16502 *mcp = i2c_get_clientdata(client);
517
518 mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
519
520 return 0;
521}
522#endif
523
524#ifdef CONFIG_PM
525static const struct dev_pm_ops mcp16502_pm_ops = {
526 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mcp16502_suspend_noirq,
527 mcp16502_resume_noirq)
528};
529#endif
530static const struct i2c_device_id mcp16502_i2c_id[] = {
531 { "mcp16502", 0 },
532 { }
533};
534MODULE_DEVICE_TABLE(i2c, mcp16502_i2c_id);
535
536static struct i2c_driver mcp16502_drv = {
537 .probe = mcp16502_probe,
538 .driver = {
539 .name = "mcp16502-regulator",
540 .of_match_table = of_match_ptr(mcp16502_ids),
541#ifdef CONFIG_PM
542 .pm = &mcp16502_pm_ops,
543#endif
544 },
545 .id_table = mcp16502_i2c_id,
546};
547
548module_i2c_driver(mcp16502_drv);
549
550MODULE_LICENSE("GPL v2");
551MODULE_DESCRIPTION("MCP16502 PMIC driver");
552MODULE_AUTHOR("Andrei Stefanescu andrei.stefanescu@microchip.com");
553