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