xref: /linux/drivers/regulator/mcp16502.c (revision 37744feebc086908fd89760650f458ab19071750)
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 
78 static 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 
105 enum {
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  */
121 struct 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  */
130 static 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  */
151 static 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  */
176 static 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  */
206 static 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  */
234 static 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  */
242 static 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  */
267 static 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  */
286 static 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  */
303 static 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  */
323 static 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  */
336 static 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 
347 static 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  */
371 static 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 
388 static const struct of_device_id mcp16502_ids[] = {
389 	{ .compatible = "microchip,mcp16502", },
390 	{}
391 };
392 MODULE_DEVICE_TABLE(of, mcp16502_ids);
393 
394 static const struct regulator_linear_range b1l12_ranges[] = {
395 	REGULATOR_LINEAR_RANGE(1200000, VDD_LOW_SEL, VDD_HIGH_SEL, 50000),
396 };
397 
398 static const struct regulator_linear_range b234_ranges[] = {
399 	REGULATOR_LINEAR_RANGE(600000, VDD_LOW_SEL, VDD_HIGH_SEL, 25000),
400 };
401 
402 static 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 
412 static const struct regmap_range mcp16502_ranges[] = {
413 	regmap_reg_range(MCP16502_MIN_REG, MCP16502_MAX_REG)
414 };
415 
416 static const struct regmap_access_table mcp16502_yes_reg_table = {
417 	.yes_ranges = mcp16502_ranges,
418 	.n_yes_ranges = ARRAY_SIZE(mcp16502_ranges),
419 };
420 
421 static 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 
430 static 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
480 static 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 
490 static 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
502 static 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
507 static const struct i2c_device_id mcp16502_i2c_id[] = {
508 	{ "mcp16502", 0 },
509 	{ }
510 };
511 MODULE_DEVICE_TABLE(i2c, mcp16502_i2c_id);
512 
513 static 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 
525 module_i2c_driver(mcp16502_drv);
526 
527 MODULE_LICENSE("GPL v2");
528 MODULE_DESCRIPTION("MCP16502 PMIC driver");
529 MODULE_AUTHOR("Andrei Stefanescu andrei.stefanescu@microchip.com");
530