xref: /openbmc/linux/drivers/regulator/ltc3589.c (revision cfbb9be8)
1 /*
2  * Linear Technology LTC3589,LTC3589-1 regulator support
3  *
4  * Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
5  *
6  * See file CREDITS for list of people who contributed to this
7  * project.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2
11  * as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  */
19 #include <linux/i2c.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/regmap.h>
27 #include <linux/regulator/driver.h>
28 #include <linux/regulator/of_regulator.h>
29 
30 #define DRIVER_NAME		"ltc3589"
31 
32 #define LTC3589_IRQSTAT		0x02
33 #define LTC3589_SCR1		0x07
34 #define LTC3589_OVEN		0x10
35 #define LTC3589_SCR2		0x12
36 #define LTC3589_PGSTAT		0x13
37 #define LTC3589_VCCR		0x20
38 #define LTC3589_CLIRQ		0x21
39 #define LTC3589_B1DTV1		0x23
40 #define LTC3589_B1DTV2		0x24
41 #define LTC3589_VRRCR		0x25
42 #define LTC3589_B2DTV1		0x26
43 #define LTC3589_B2DTV2		0x27
44 #define LTC3589_B3DTV1		0x29
45 #define LTC3589_B3DTV2		0x2a
46 #define LTC3589_L2DTV1		0x32
47 #define LTC3589_L2DTV2		0x33
48 
49 #define LTC3589_IRQSTAT_PGOOD_TIMEOUT	BIT(3)
50 #define LTC3589_IRQSTAT_UNDERVOLT_WARN	BIT(4)
51 #define LTC3589_IRQSTAT_UNDERVOLT_FAULT	BIT(5)
52 #define LTC3589_IRQSTAT_THERMAL_WARN	BIT(6)
53 #define LTC3589_IRQSTAT_THERMAL_FAULT	BIT(7)
54 
55 #define LTC3589_OVEN_SW1		BIT(0)
56 #define LTC3589_OVEN_SW2		BIT(1)
57 #define LTC3589_OVEN_SW3		BIT(2)
58 #define LTC3589_OVEN_BB_OUT		BIT(3)
59 #define LTC3589_OVEN_LDO2		BIT(4)
60 #define LTC3589_OVEN_LDO3		BIT(5)
61 #define LTC3589_OVEN_LDO4		BIT(6)
62 #define LTC3589_OVEN_SW_CTRL		BIT(7)
63 
64 #define LTC3589_VCCR_SW1_GO		BIT(0)
65 #define LTC3589_VCCR_SW2_GO		BIT(2)
66 #define LTC3589_VCCR_SW3_GO		BIT(4)
67 #define LTC3589_VCCR_LDO2_GO		BIT(6)
68 
69 enum ltc3589_variant {
70 	LTC3589,
71 	LTC3589_1,
72 	LTC3589_2,
73 };
74 
75 enum ltc3589_reg {
76 	LTC3589_SW1,
77 	LTC3589_SW2,
78 	LTC3589_SW3,
79 	LTC3589_BB_OUT,
80 	LTC3589_LDO1,
81 	LTC3589_LDO2,
82 	LTC3589_LDO3,
83 	LTC3589_LDO4,
84 	LTC3589_NUM_REGULATORS,
85 };
86 
87 struct ltc3589_regulator {
88 	struct regulator_desc desc;
89 
90 	/* External feedback voltage divider */
91 	unsigned int r1;
92 	unsigned int r2;
93 };
94 
95 struct ltc3589 {
96 	struct regmap *regmap;
97 	struct device *dev;
98 	enum ltc3589_variant variant;
99 	struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
100 	struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
101 };
102 
103 static const int ltc3589_ldo4[] = {
104 	2800000, 2500000, 1800000, 3300000,
105 };
106 
107 static const int ltc3589_12_ldo4[] = {
108 	1200000, 1800000, 2500000, 3200000,
109 };
110 
111 static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
112 {
113 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
114 	int sel, shift;
115 
116 	if (unlikely(ramp_delay <= 0))
117 		return -EINVAL;
118 
119 	/* VRRCR slew rate offsets are the same as VCCR go bit offsets */
120 	shift = ffs(rdev->desc->apply_bit) - 1;
121 
122 	/* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
123 	for (sel = 0; sel < 4; sel++) {
124 		if ((880 << sel) >= ramp_delay) {
125 			return regmap_update_bits(ltc3589->regmap,
126 						  LTC3589_VRRCR,
127 						  0x3 << shift, sel << shift);
128 		}
129 	}
130 	return -EINVAL;
131 }
132 
133 static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
134 {
135 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
136 	int sel;
137 
138 	sel = regulator_map_voltage_linear(rdev, uV, uV);
139 	if (sel < 0)
140 		return sel;
141 
142 	/* DTV2 register follows right after the corresponding DTV1 register */
143 	return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
144 				  rdev->desc->vsel_mask, sel);
145 }
146 
147 static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
148 				    unsigned int mode)
149 {
150 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
151 	int mask, bit = 0;
152 
153 	/* VCCR reference selects are right next to the VCCR go bits */
154 	mask = rdev->desc->apply_bit << 1;
155 
156 	if (mode == REGULATOR_MODE_STANDBY)
157 		bit = mask;	/* Select DTV2 */
158 
159 	mask |= rdev->desc->apply_bit;
160 	bit |= rdev->desc->apply_bit;
161 	return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
162 }
163 
164 /* SW1, SW2, SW3, LDO2 */
165 static const struct regulator_ops ltc3589_linear_regulator_ops = {
166 	.enable = regulator_enable_regmap,
167 	.disable = regulator_disable_regmap,
168 	.is_enabled = regulator_is_enabled_regmap,
169 	.list_voltage = regulator_list_voltage_linear,
170 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
171 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
172 	.set_ramp_delay = ltc3589_set_ramp_delay,
173 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
174 	.set_suspend_voltage = ltc3589_set_suspend_voltage,
175 	.set_suspend_mode = ltc3589_set_suspend_mode,
176 };
177 
178 /* BB_OUT, LDO3 */
179 static const struct regulator_ops ltc3589_fixed_regulator_ops = {
180 	.enable = regulator_enable_regmap,
181 	.disable = regulator_disable_regmap,
182 	.is_enabled = regulator_is_enabled_regmap,
183 };
184 
185 /* LDO1 */
186 static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
187 };
188 
189 /* LDO4 */
190 static const struct regulator_ops ltc3589_table_regulator_ops = {
191 	.enable = regulator_enable_regmap,
192 	.disable = regulator_disable_regmap,
193 	.is_enabled = regulator_is_enabled_regmap,
194 	.list_voltage = regulator_list_voltage_table,
195 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
196 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
197 };
198 
199 
200 #define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit)	\
201 	[LTC3589_ ## _name] = {						\
202 		.desc = {						\
203 			.name = #_name,					\
204 			.n_voltages = (dtv_mask) + 1,			\
205 			.min_uV = (go_bit) ? 362500 : 0,		\
206 			.uV_step = (go_bit) ? 12500 : 0,		\
207 			.ramp_delay = (go_bit) ? 1750 : 0,		\
208 			.fixed_uV = (dtv_mask) ? 0 : 800000,		\
209 			.ops = &ltc3589_ ## _ops ## _regulator_ops,	\
210 			.type = REGULATOR_VOLTAGE,			\
211 			.id = LTC3589_ ## _name,			\
212 			.owner = THIS_MODULE,				\
213 			.vsel_reg = (dtv1_reg),			\
214 			.vsel_mask = (dtv_mask),			\
215 			.apply_reg = (go_bit) ? LTC3589_VCCR : 0,	\
216 			.apply_bit = (go_bit),				\
217 			.enable_reg = (en_bit) ? LTC3589_OVEN : 0,	\
218 			.enable_mask = (en_bit),			\
219 		},							\
220 	}
221 
222 #define LTC3589_LINEAR_REG(_name, _dtv1)				\
223 	LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name,		\
224 		    LTC3589_ ## _dtv1, 0x1f,				\
225 		    LTC3589_VCCR_ ## _name ## _GO)
226 
227 #define LTC3589_FIXED_REG(_name) \
228 	LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
229 
230 static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
231 	LTC3589_LINEAR_REG(SW1, B1DTV1),
232 	LTC3589_LINEAR_REG(SW2, B2DTV1),
233 	LTC3589_LINEAR_REG(SW3, B3DTV1),
234 	LTC3589_FIXED_REG(BB_OUT),
235 	LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
236 	LTC3589_LINEAR_REG(LDO2, L2DTV1),
237 	LTC3589_FIXED_REG(LDO3),
238 	LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
239 };
240 
241 #ifdef CONFIG_OF
242 static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
243 	{ .name = "sw1",    },
244 	{ .name = "sw2",    },
245 	{ .name = "sw3",    },
246 	{ .name = "bb-out", },
247 	{ .name = "ldo1",   }, /* standby */
248 	{ .name = "ldo2",   },
249 	{ .name = "ldo3",   },
250 	{ .name = "ldo4",   },
251 };
252 
253 static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
254 {
255 	struct device *dev = ltc3589->dev;
256 	struct device_node *node;
257 	int i, ret;
258 
259 	node = of_get_child_by_name(dev->of_node, "regulators");
260 	if (!node) {
261 		dev_err(dev, "regulators node not found\n");
262 		return -EINVAL;
263 	}
264 
265 	ret = of_regulator_match(dev, node, ltc3589_matches,
266 				 ARRAY_SIZE(ltc3589_matches));
267 	of_node_put(node);
268 	if (ret < 0) {
269 		dev_err(dev, "Error parsing regulator init data: %d\n", ret);
270 		return ret;
271 	}
272 	if (ret != LTC3589_NUM_REGULATORS) {
273 		dev_err(dev, "Only %d regulators described in device tree\n",
274 			ret);
275 		return -EINVAL;
276 	}
277 
278 	/* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
279 	for (i = 0; i < LTC3589_LDO3; i++) {
280 		struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
281 		struct device_node *np = ltc3589_matches[i].of_node;
282 		u32 vdiv[2];
283 
284 		ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
285 						 vdiv, 2);
286 		if (ret) {
287 			dev_err(dev, "Failed to parse voltage divider: %d\n",
288 				ret);
289 			return ret;
290 		}
291 
292 		desc->r1 = vdiv[0];
293 		desc->r2 = vdiv[1];
294 	}
295 
296 	return 0;
297 }
298 
299 static inline struct regulator_init_data *match_init_data(int index)
300 {
301 	return ltc3589_matches[index].init_data;
302 }
303 
304 static inline struct device_node *match_of_node(int index)
305 {
306 	return ltc3589_matches[index].of_node;
307 }
308 #else
309 static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
310 {
311 	return 0;
312 }
313 
314 static inline struct regulator_init_data *match_init_data(int index)
315 {
316 	return NULL;
317 }
318 
319 static inline struct device_node *match_of_node(int index)
320 {
321 	return NULL;
322 }
323 #endif
324 
325 static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
326 {
327 	switch (reg) {
328 	case LTC3589_IRQSTAT:
329 	case LTC3589_SCR1:
330 	case LTC3589_OVEN:
331 	case LTC3589_SCR2:
332 	case LTC3589_VCCR:
333 	case LTC3589_CLIRQ:
334 	case LTC3589_B1DTV1:
335 	case LTC3589_B1DTV2:
336 	case LTC3589_VRRCR:
337 	case LTC3589_B2DTV1:
338 	case LTC3589_B2DTV2:
339 	case LTC3589_B3DTV1:
340 	case LTC3589_B3DTV2:
341 	case LTC3589_L2DTV1:
342 	case LTC3589_L2DTV2:
343 		return true;
344 	}
345 	return false;
346 }
347 
348 static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
349 {
350 	switch (reg) {
351 	case LTC3589_IRQSTAT:
352 	case LTC3589_SCR1:
353 	case LTC3589_OVEN:
354 	case LTC3589_SCR2:
355 	case LTC3589_PGSTAT:
356 	case LTC3589_VCCR:
357 	case LTC3589_B1DTV1:
358 	case LTC3589_B1DTV2:
359 	case LTC3589_VRRCR:
360 	case LTC3589_B2DTV1:
361 	case LTC3589_B2DTV2:
362 	case LTC3589_B3DTV1:
363 	case LTC3589_B3DTV2:
364 	case LTC3589_L2DTV1:
365 	case LTC3589_L2DTV2:
366 		return true;
367 	}
368 	return false;
369 }
370 
371 static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
372 {
373 	switch (reg) {
374 	case LTC3589_IRQSTAT:
375 	case LTC3589_PGSTAT:
376 	case LTC3589_VCCR:
377 		return true;
378 	}
379 	return false;
380 }
381 
382 static const struct reg_default ltc3589_reg_defaults[] = {
383 	{ LTC3589_SCR1,   0x00 },
384 	{ LTC3589_OVEN,   0x00 },
385 	{ LTC3589_SCR2,   0x00 },
386 	{ LTC3589_VCCR,   0x00 },
387 	{ LTC3589_B1DTV1, 0x19 },
388 	{ LTC3589_B1DTV2, 0x19 },
389 	{ LTC3589_VRRCR,  0xff },
390 	{ LTC3589_B2DTV1, 0x19 },
391 	{ LTC3589_B2DTV2, 0x19 },
392 	{ LTC3589_B3DTV1, 0x19 },
393 	{ LTC3589_B3DTV2, 0x19 },
394 	{ LTC3589_L2DTV1, 0x19 },
395 	{ LTC3589_L2DTV2, 0x19 },
396 };
397 
398 static const struct regmap_config ltc3589_regmap_config = {
399 	.reg_bits = 8,
400 	.val_bits = 8,
401 	.writeable_reg = ltc3589_writeable_reg,
402 	.readable_reg = ltc3589_readable_reg,
403 	.volatile_reg = ltc3589_volatile_reg,
404 	.max_register = LTC3589_L2DTV2,
405 	.reg_defaults = ltc3589_reg_defaults,
406 	.num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
407 	.use_single_rw = true,
408 	.cache_type = REGCACHE_RBTREE,
409 };
410 
411 
412 static irqreturn_t ltc3589_isr(int irq, void *dev_id)
413 {
414 	struct ltc3589 *ltc3589 = dev_id;
415 	unsigned int i, irqstat, event;
416 
417 	regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
418 
419 	if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
420 		event = REGULATOR_EVENT_OVER_TEMP;
421 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
422 			regulator_notifier_call_chain(ltc3589->regulators[i],
423 						      event, NULL);
424 	}
425 
426 	if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
427 		event = REGULATOR_EVENT_UNDER_VOLTAGE;
428 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
429 			regulator_notifier_call_chain(ltc3589->regulators[i],
430 						      event, NULL);
431 	}
432 
433 	/* Clear warning condition */
434 	regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
435 
436 	return IRQ_HANDLED;
437 }
438 
439 static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
440 {
441 	uint64_t tmp;
442 	if (uV == 0)
443 		return 0;
444 	tmp = (uint64_t)uV * r1;
445 	do_div(tmp, r2);
446 	return uV + (unsigned int)tmp;
447 }
448 
449 static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
450 {
451 	struct regulator_desc *desc = &rdesc->desc;
452 
453 	if (!rdesc->r1 || !rdesc->r2)
454 		return;
455 
456 	desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
457 	desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
458 	desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
459 }
460 
461 static int ltc3589_probe(struct i2c_client *client,
462 			 const struct i2c_device_id *id)
463 {
464 	struct device *dev = &client->dev;
465 	struct ltc3589_regulator *descs;
466 	struct ltc3589 *ltc3589;
467 	int i, ret;
468 
469 	ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
470 	if (!ltc3589)
471 		return -ENOMEM;
472 
473 	i2c_set_clientdata(client, ltc3589);
474 	if (client->dev.of_node)
475 		ltc3589->variant = (enum ltc3589_variant)
476 			of_device_get_match_data(&client->dev);
477 	else
478 		ltc3589->variant = id->driver_data;
479 	ltc3589->dev = dev;
480 
481 	descs = ltc3589->regulator_descs;
482 	memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
483 	if (ltc3589->variant == LTC3589) {
484 		descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
485 		descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
486 	} else {
487 		descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
488 		descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
489 	}
490 
491 	ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
492 	if (IS_ERR(ltc3589->regmap)) {
493 		ret = PTR_ERR(ltc3589->regmap);
494 		dev_err(dev, "failed to initialize regmap: %d\n", ret);
495 		return ret;
496 	}
497 
498 	ret = ltc3589_parse_regulators_dt(ltc3589);
499 	if (ret)
500 		return ret;
501 
502 	for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
503 		struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
504 		struct regulator_desc *desc = &rdesc->desc;
505 		struct regulator_init_data *init_data;
506 		struct regulator_config config = { };
507 
508 		init_data = match_init_data(i);
509 
510 		if (i < LTC3589_LDO3)
511 			ltc3589_apply_fb_voltage_divider(rdesc);
512 
513 		config.dev = dev;
514 		config.init_data = init_data;
515 		config.driver_data = ltc3589;
516 		config.of_node = match_of_node(i);
517 
518 		ltc3589->regulators[i] = devm_regulator_register(dev, desc,
519 								 &config);
520 		if (IS_ERR(ltc3589->regulators[i])) {
521 			ret = PTR_ERR(ltc3589->regulators[i]);
522 			dev_err(dev, "failed to register regulator %s: %d\n",
523 				desc->name, ret);
524 			return ret;
525 		}
526 	}
527 
528 	if (client->irq) {
529 		ret = devm_request_threaded_irq(dev, client->irq, NULL,
530 						ltc3589_isr,
531 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
532 						client->name, ltc3589);
533 		if (ret) {
534 			dev_err(dev, "Failed to request IRQ: %d\n", ret);
535 			return ret;
536 		}
537 	}
538 
539 	return 0;
540 }
541 
542 static const struct i2c_device_id ltc3589_i2c_id[] = {
543 	{ "ltc3589",   LTC3589   },
544 	{ "ltc3589-1", LTC3589_1 },
545 	{ "ltc3589-2", LTC3589_2 },
546 	{ }
547 };
548 MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
549 
550 static const struct of_device_id ltc3589_of_match[] = {
551 	{
552 		.compatible = "lltc,ltc3589",
553 		.data = (void *)LTC3589,
554 	},
555 	{
556 		.compatible = "lltc,ltc3589-1",
557 		.data = (void *)LTC3589_1,
558 	},
559 	{
560 		.compatible = "lltc,ltc3589-2",
561 		.data = (void *)LTC3589_2,
562 	},
563 	{ },
564 };
565 MODULE_DEVICE_TABLE(of, ltc3589_of_match);
566 
567 static struct i2c_driver ltc3589_driver = {
568 	.driver = {
569 		.name = DRIVER_NAME,
570 		.of_match_table = of_match_ptr(ltc3589_of_match),
571 	},
572 	.probe = ltc3589_probe,
573 	.id_table = ltc3589_i2c_id,
574 };
575 module_i2c_driver(ltc3589_driver);
576 
577 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
578 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
579 MODULE_LICENSE("GPL v2");
580