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