xref: /openbmc/linux/drivers/regulator/mcp16502.c (revision 9470114d)
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 
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, _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 
134 enum {
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  */
148 struct 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  */
157 static 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  */
178 static 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  */
201 static 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  */
231 static 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  */
259 static 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  */
267 static 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 
287 static 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  */
330 static 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  */
349 static 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  */
366 static 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  */
386 static 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  */
399 static 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 
410 static 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  */
436 static 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 
455 static const struct of_device_id mcp16502_ids[] = {
456 	{ .compatible = "microchip,mcp16502", },
457 	{}
458 };
459 MODULE_DEVICE_TABLE(of, mcp16502_ids);
460 
461 static const struct linear_range b1l12_ranges[] = {
462 	REGULATOR_LINEAR_RANGE(1200000, VDD_LOW_SEL, VDD_HIGH_SEL, 50000),
463 };
464 
465 static const struct linear_range b234_ranges[] = {
466 	REGULATOR_LINEAR_RANGE(600000, VDD_LOW_SEL, VDD_HIGH_SEL, 25000),
467 };
468 
469 static 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 
485 static const struct regmap_range mcp16502_ranges[] = {
486 	regmap_reg_range(MCP16502_MIN_REG, MCP16502_MAX_REG)
487 };
488 
489 static const struct regmap_access_table mcp16502_yes_reg_table = {
490 	.yes_ranges = mcp16502_ranges,
491 	.n_yes_ranges = ARRAY_SIZE(mcp16502_ranges),
492 };
493 
494 static 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 
503 static 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
552 static 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 
562 static 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
574 static 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
579 static const struct i2c_device_id mcp16502_i2c_id[] = {
580 	{ "mcp16502", 0 },
581 	{ }
582 };
583 MODULE_DEVICE_TABLE(i2c, mcp16502_i2c_id);
584 
585 static 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 
598 module_i2c_driver(mcp16502_drv);
599 
600 MODULE_LICENSE("GPL v2");
601 MODULE_DESCRIPTION("MCP16502 PMIC driver");
602 MODULE_AUTHOR("Andrei Stefanescu andrei.stefanescu@microchip.com");
603