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 */
83enum 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. */
93static const unsigned int mcp16502_ramp_b1l12[] = {
94	6250, 3125, 2083, 1563
95};
96
97/* Ramp delay (uV/us) for buck2, buck3, buck4. */
98static const unsigned int mcp16502_ramp_b234[] = {
99	3125, 1563, 1042, 781
100};
101
102static 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, _ranges, _ops, _ramp_table)	\
111	[_id] = {							\
112		.name			= _name,			\
113		.regulators_node	= "regulators",			\
114		.id			= _id,				\
115		.ops			= &(_ops),			\
116		.type			= REGULATOR_VOLTAGE,		\
117		.owner			= THIS_MODULE,			\
118		.n_voltages		= MCP16502_VSEL + 1,		\
119		.linear_ranges		= _ranges,			\
120		.linear_min_sel		= VDD_LOW_SEL,			\
121		.n_linear_ranges	= ARRAY_SIZE(_ranges),		\
122		.of_match		= _name,			\
123		.of_map_mode		= mcp16502_of_map_mode,		\
124		.vsel_reg		= (((_id) + 1) << 4),		\
125		.vsel_mask		= MCP16502_VSEL,		\
126		.enable_reg		= (((_id) + 1) << 4),		\
127		.enable_mask		= MCP16502_EN,			\
128		.ramp_reg		= MCP16502_REG_BASE(_id, CFG),	\
129		.ramp_mask		= MCP16502_DVSR,		\
130		.ramp_delay_table	= _ramp_table,			\
131		.n_ramp_values		= ARRAY_SIZE(_ramp_table),	\
132	}
133
134enum {
135	BUCK1 = 0,
136	BUCK2,
137	BUCK3,
138	BUCK4,
139	LDO1,
140	LDO2,
141	NUM_REGULATORS
142};
143
144/*
145 * struct mcp16502 - PMIC representation
146 * @lpm: LPM GPIO descriptor
147 */
148struct mcp16502 {
149	struct gpio_desc *lpm;
150};
151
152/*
153 * mcp16502_gpio_set_mode() - set the GPIO corresponding value
154 *
155 * Used to prepare transitioning into hibernate or resuming from it.
156 */
157static void mcp16502_gpio_set_mode(struct mcp16502 *mcp, int mode)
158{
159	switch (mode) {
160	case MCP16502_OPMODE_ACTIVE:
161		gpiod_set_value(mcp->lpm, 0);
162		break;
163	case MCP16502_OPMODE_LPM:
164	case MCP16502_OPMODE_HIB:
165		gpiod_set_value(mcp->lpm, 1);
166		break;
167	default:
168		pr_err("%s: %d invalid\n", __func__, mode);
169	}
170}
171
172/*
173 * mcp16502_get_reg() - get the PMIC's state configuration register for opmode
174 *
175 * @rdev: the regulator whose register we are searching
176 * @opmode: the PMIC's operating mode ACTIVE, Low-power, Hibernate
177 */
178static int mcp16502_get_state_reg(struct regulator_dev *rdev, int opmode)
179{
180	switch (opmode) {
181	case MCP16502_OPMODE_ACTIVE:
182		return MCP16502_REG_BASE(rdev_get_id(rdev), A);
183	case MCP16502_OPMODE_LPM:
184		return MCP16502_REG_BASE(rdev_get_id(rdev), LPM);
185	case MCP16502_OPMODE_HIB:
186		return MCP16502_REG_BASE(rdev_get_id(rdev), HIB);
187	default:
188		return -EINVAL;
189	}
190}
191
192/*
193 * mcp16502_get_mode() - return the current operating mode of a regulator
194 *
195 * Note: all functions that are not part of entering/exiting standby/suspend
196 *	 use the Active mode registers.
197 *
198 * Note: this is different from the PMIC's operatig mode, it is the
199 *	 MODE bit from the regulator's register.
200 */
201static unsigned int mcp16502_get_mode(struct regulator_dev *rdev)
202{
203	unsigned int val;
204	int ret, reg;
205
206	reg = mcp16502_get_state_reg(rdev, MCP16502_OPMODE_ACTIVE);
207	if (reg < 0)
208		return reg;
209
210	ret = regmap_read(rdev->regmap, reg, &val);
211	if (ret)
212		return ret;
213
214	switch (val & MCP16502_MODE) {
215	case MCP16502_MODE_FPWM:
216		return REGULATOR_MODE_NORMAL;
217	case MCP16502_MODE_AUTO_PFM:
218		return REGULATOR_MODE_IDLE;
219	default:
220		return REGULATOR_MODE_INVALID;
221	}
222}
223
224/*
225 * _mcp16502_set_mode() - helper for set_mode and set_suspend_mode
226 *
227 * @rdev: the regulator for which we are setting the mode
228 * @mode: the regulator's mode (the one from MODE bit)
229 * @opmode: the PMIC's operating mode: Active/Low-power/Hibernate
230 */
231static int _mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode,
232			      unsigned int op_mode)
233{
234	int val;
235	int reg;
236
237	reg = mcp16502_get_state_reg(rdev, op_mode);
238	if (reg < 0)
239		return reg;
240
241	switch (mode) {
242	case REGULATOR_MODE_NORMAL:
243		val = MCP16502_MODE_FPWM;
244		break;
245	case REGULATOR_MODE_IDLE:
246		val = MCP16502_MODE_AUTO_PFM;
247		break;
248	default:
249		return -EINVAL;
250	}
251
252	reg = regmap_update_bits(rdev->regmap, reg, MCP16502_MODE, val);
253	return reg;
254}
255
256/*
257 * mcp16502_set_mode() - regulator_ops set_mode
258 */
259static int mcp16502_set_mode(struct regulator_dev *rdev, unsigned int mode)
260{
261	return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_ACTIVE);
262}
263
264/*
265 * mcp16502_get_status() - regulator_ops get_status
266 */
267static int mcp16502_get_status(struct regulator_dev *rdev)
268{
269	int ret;
270	unsigned int val;
271
272	ret = regmap_read(rdev->regmap, MCP16502_STAT_BASE(rdev_get_id(rdev)),
273			  &val);
274	if (ret)
275		return ret;
276
277	if (val & MCP16502_FLT)
278		return REGULATOR_STATUS_ERROR;
279	else if (val & MCP16502_ENS)
280		return REGULATOR_STATUS_ON;
281	else if (!(val & MCP16502_ENS))
282		return REGULATOR_STATUS_OFF;
283
284	return REGULATOR_STATUS_UNDEFINED;
285}
286
287static int mcp16502_set_voltage_time_sel(struct regulator_dev *rdev,
288					 unsigned int old_sel,
289					 unsigned int new_sel)
290{
291	static const u8 us_ramp[] = { 8, 16, 24, 32 };
292	int id = rdev_get_id(rdev);
293	unsigned int uV_delta, val;
294	int ret;
295
296	ret = regmap_read(rdev->regmap, MCP16502_REG_BASE(id, CFG), &val);
297	if (ret)
298		return ret;
299
300	val = (val & MCP16502_DVSR) >> 2;
301	uV_delta = abs(new_sel * rdev->desc->linear_ranges->step -
302		       old_sel * rdev->desc->linear_ranges->step);
303	switch (id) {
304	case BUCK1:
305	case LDO1:
306	case LDO2:
307		ret = DIV_ROUND_CLOSEST(uV_delta * us_ramp[val],
308					mcp16502_ramp_b1l12[val]);
309		break;
310
311	case BUCK2:
312	case BUCK3:
313	case BUCK4:
314		ret = DIV_ROUND_CLOSEST(uV_delta * us_ramp[val],
315					mcp16502_ramp_b234[val]);
316		break;
317
318	default:
319		return -EINVAL;
320	}
321
322	return ret;
323}
324
325#ifdef CONFIG_SUSPEND
326/*
327 * mcp16502_suspend_get_target_reg() - get the reg of the target suspend PMIC
328 *				       mode
329 */
330static int mcp16502_suspend_get_target_reg(struct regulator_dev *rdev)
331{
332	switch (pm_suspend_target_state) {
333	case PM_SUSPEND_STANDBY:
334		return mcp16502_get_state_reg(rdev, MCP16502_OPMODE_LPM);
335	case PM_SUSPEND_ON:
336	case PM_SUSPEND_MEM:
337		return mcp16502_get_state_reg(rdev, MCP16502_OPMODE_HIB);
338	default:
339		dev_err(&rdev->dev, "invalid suspend target: %d\n",
340			pm_suspend_target_state);
341	}
342
343	return -EINVAL;
344}
345
346/*
347 * mcp16502_set_suspend_voltage() - regulator_ops set_suspend_voltage
348 */
349static int mcp16502_set_suspend_voltage(struct regulator_dev *rdev, int uV)
350{
351	int sel = regulator_map_voltage_linear_range(rdev, uV, uV);
352	int reg = mcp16502_suspend_get_target_reg(rdev);
353
354	if (sel < 0)
355		return sel;
356
357	if (reg < 0)
358		return reg;
359
360	return regmap_update_bits(rdev->regmap, reg, MCP16502_VSEL, sel);
361}
362
363/*
364 * mcp16502_set_suspend_mode() - regulator_ops set_suspend_mode
365 */
366static int mcp16502_set_suspend_mode(struct regulator_dev *rdev,
367				     unsigned int mode)
368{
369	switch (pm_suspend_target_state) {
370	case PM_SUSPEND_STANDBY:
371		return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_LPM);
372	case PM_SUSPEND_ON:
373	case PM_SUSPEND_MEM:
374		return _mcp16502_set_mode(rdev, mode, MCP16502_OPMODE_HIB);
375	default:
376		dev_err(&rdev->dev, "invalid suspend target: %d\n",
377			pm_suspend_target_state);
378	}
379
380	return -EINVAL;
381}
382
383/*
384 * mcp16502_set_suspend_enable() - regulator_ops set_suspend_enable
385 */
386static int mcp16502_set_suspend_enable(struct regulator_dev *rdev)
387{
388	int reg = mcp16502_suspend_get_target_reg(rdev);
389
390	if (reg < 0)
391		return reg;
392
393	return regmap_update_bits(rdev->regmap, reg, MCP16502_EN, MCP16502_EN);
394}
395
396/*
397 * mcp16502_set_suspend_disable() - regulator_ops set_suspend_disable
398 */
399static int mcp16502_set_suspend_disable(struct regulator_dev *rdev)
400{
401	int reg = mcp16502_suspend_get_target_reg(rdev);
402
403	if (reg < 0)
404		return reg;
405
406	return regmap_update_bits(rdev->regmap, reg, MCP16502_EN, 0);
407}
408#endif /* CONFIG_SUSPEND */
409
410static const struct regulator_ops mcp16502_buck_ops = {
411	.list_voltage			= regulator_list_voltage_linear_range,
412	.map_voltage			= regulator_map_voltage_linear_range,
413	.get_voltage_sel		= regulator_get_voltage_sel_regmap,
414	.set_voltage_sel		= regulator_set_voltage_sel_regmap,
415	.enable				= regulator_enable_regmap,
416	.disable			= regulator_disable_regmap,
417	.is_enabled			= regulator_is_enabled_regmap,
418	.get_status			= mcp16502_get_status,
419	.set_voltage_time_sel		= mcp16502_set_voltage_time_sel,
420	.set_ramp_delay			= regulator_set_ramp_delay_regmap,
421
422	.set_mode			= mcp16502_set_mode,
423	.get_mode			= mcp16502_get_mode,
424
425#ifdef CONFIG_SUSPEND
426	.set_suspend_voltage		= mcp16502_set_suspend_voltage,
427	.set_suspend_mode		= mcp16502_set_suspend_mode,
428	.set_suspend_enable		= mcp16502_set_suspend_enable,
429	.set_suspend_disable		= mcp16502_set_suspend_disable,
430#endif /* CONFIG_SUSPEND */
431};
432
433/*
434 * LDOs cannot change operating modes.
435 */
436static const struct regulator_ops mcp16502_ldo_ops = {
437	.list_voltage			= regulator_list_voltage_linear_range,
438	.map_voltage			= regulator_map_voltage_linear_range,
439	.get_voltage_sel		= regulator_get_voltage_sel_regmap,
440	.set_voltage_sel		= regulator_set_voltage_sel_regmap,
441	.enable				= regulator_enable_regmap,
442	.disable			= regulator_disable_regmap,
443	.is_enabled			= regulator_is_enabled_regmap,
444	.get_status			= mcp16502_get_status,
445	.set_voltage_time_sel		= mcp16502_set_voltage_time_sel,
446	.set_ramp_delay			= regulator_set_ramp_delay_regmap,
447
448#ifdef CONFIG_SUSPEND
449	.set_suspend_voltage		= mcp16502_set_suspend_voltage,
450	.set_suspend_enable		= mcp16502_set_suspend_enable,
451	.set_suspend_disable		= mcp16502_set_suspend_disable,
452#endif /* CONFIG_SUSPEND */
453};
454
455static const struct of_device_id mcp16502_ids[] = {
456	{ .compatible = "microchip,mcp16502", },
457	{}
458};
459MODULE_DEVICE_TABLE(of, mcp16502_ids);
460
461static const struct linear_range b1l12_ranges[] = {
462	REGULATOR_LINEAR_RANGE(1200000, VDD_LOW_SEL, VDD_HIGH_SEL, 50000),
463};
464
465static const struct linear_range b234_ranges[] = {
466	REGULATOR_LINEAR_RANGE(600000, VDD_LOW_SEL, VDD_HIGH_SEL, 25000),
467};
468
469static const struct regulator_desc mcp16502_desc[] = {
470	/* MCP16502_REGULATOR(_name, _id, ranges, regulator_ops, ramp_table) */
471	MCP16502_REGULATOR("VDD_IO", BUCK1, b1l12_ranges, mcp16502_buck_ops,
472			   mcp16502_ramp_b1l12),
473	MCP16502_REGULATOR("VDD_DDR", BUCK2, b234_ranges, mcp16502_buck_ops,
474			   mcp16502_ramp_b234),
475	MCP16502_REGULATOR("VDD_CORE", BUCK3, b234_ranges, mcp16502_buck_ops,
476			   mcp16502_ramp_b234),
477	MCP16502_REGULATOR("VDD_OTHER", BUCK4, b234_ranges, mcp16502_buck_ops,
478			   mcp16502_ramp_b234),
479	MCP16502_REGULATOR("LDO1", LDO1, b1l12_ranges, mcp16502_ldo_ops,
480			   mcp16502_ramp_b1l12),
481	MCP16502_REGULATOR("LDO2", LDO2, b1l12_ranges, mcp16502_ldo_ops,
482			   mcp16502_ramp_b1l12)
483};
484
485static const struct regmap_range mcp16502_ranges[] = {
486	regmap_reg_range(MCP16502_MIN_REG, MCP16502_MAX_REG)
487};
488
489static const struct regmap_access_table mcp16502_yes_reg_table = {
490	.yes_ranges = mcp16502_ranges,
491	.n_yes_ranges = ARRAY_SIZE(mcp16502_ranges),
492};
493
494static const struct regmap_config mcp16502_regmap_config = {
495	.reg_bits	= 8,
496	.val_bits	= 8,
497	.max_register	= MCP16502_MAX_REG,
498	.cache_type	= REGCACHE_NONE,
499	.rd_table	= &mcp16502_yes_reg_table,
500	.wr_table	= &mcp16502_yes_reg_table,
501};
502
503static int mcp16502_probe(struct i2c_client *client)
504{
505	struct regulator_config config = { };
506	struct regulator_dev *rdev;
507	struct device *dev;
508	struct mcp16502 *mcp;
509	struct regmap *rmap;
510	int i, ret;
511
512	dev = &client->dev;
513	config.dev = dev;
514
515	mcp = devm_kzalloc(dev, sizeof(*mcp), GFP_KERNEL);
516	if (!mcp)
517		return -ENOMEM;
518
519	rmap = devm_regmap_init_i2c(client, &mcp16502_regmap_config);
520	if (IS_ERR(rmap)) {
521		ret = PTR_ERR(rmap);
522		dev_err(dev, "regmap init failed: %d\n", ret);
523		return ret;
524	}
525
526	i2c_set_clientdata(client, mcp);
527	config.regmap = rmap;
528	config.driver_data = mcp;
529
530	mcp->lpm = devm_gpiod_get_optional(dev, "lpm", GPIOD_OUT_LOW);
531	if (IS_ERR(mcp->lpm)) {
532		dev_err(dev, "failed to get lpm pin: %ld\n", PTR_ERR(mcp->lpm));
533		return PTR_ERR(mcp->lpm);
534	}
535
536	for (i = 0; i < NUM_REGULATORS; i++) {
537		rdev = devm_regulator_register(dev, &mcp16502_desc[i], &config);
538		if (IS_ERR(rdev)) {
539			dev_err(dev,
540				"failed to register %s regulator %ld\n",
541				mcp16502_desc[i].name, PTR_ERR(rdev));
542			return PTR_ERR(rdev);
543		}
544	}
545
546	mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
547
548	return 0;
549}
550
551#ifdef CONFIG_PM_SLEEP
552static int mcp16502_suspend_noirq(struct device *dev)
553{
554	struct i2c_client *client = to_i2c_client(dev);
555	struct mcp16502 *mcp = i2c_get_clientdata(client);
556
557	mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_LPM);
558
559	return 0;
560}
561
562static int mcp16502_resume_noirq(struct device *dev)
563{
564	struct i2c_client *client = to_i2c_client(dev);
565	struct mcp16502 *mcp = i2c_get_clientdata(client);
566
567	mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_ACTIVE);
568
569	return 0;
570}
571#endif
572
573#ifdef CONFIG_PM
574static const struct dev_pm_ops mcp16502_pm_ops = {
575	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mcp16502_suspend_noirq,
576				      mcp16502_resume_noirq)
577};
578#endif
579static const struct i2c_device_id mcp16502_i2c_id[] = {
580	{ "mcp16502", 0 },
581	{ }
582};
583MODULE_DEVICE_TABLE(i2c, mcp16502_i2c_id);
584
585static struct i2c_driver mcp16502_drv = {
586	.probe		= mcp16502_probe,
587	.driver		= {
588		.name	= "mcp16502-regulator",
589		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
590		.of_match_table	= mcp16502_ids,
591#ifdef CONFIG_PM
592		.pm = &mcp16502_pm_ops,
593#endif
594	},
595	.id_table	= mcp16502_i2c_id,
596};
597
598module_i2c_driver(mcp16502_drv);
599
600MODULE_LICENSE("GPL v2");
601MODULE_DESCRIPTION("MCP16502 PMIC driver");
602MODULE_AUTHOR("Andrei Stefanescu andrei.stefanescu@microchip.com");
603