xref: /openbmc/linux/drivers/regulator/ltc3589.c (revision e15a5365) 
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Linear Technology LTC3589,LTC3589-1 regulator support
4 //
5 // Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
6 
7 #include <linux/i2c.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/regmap.h>
15 #include <linux/regulator/driver.h>
16 #include <linux/regulator/of_regulator.h>
17 
18 #define DRIVER_NAME		"ltc3589"
19 
20 #define LTC3589_IRQSTAT		0x02
21 #define LTC3589_SCR1		0x07
22 #define LTC3589_OVEN		0x10
23 #define LTC3589_SCR2		0x12
24 #define LTC3589_PGSTAT		0x13
25 #define LTC3589_VCCR		0x20
26 #define LTC3589_CLIRQ		0x21
27 #define LTC3589_B1DTV1		0x23
28 #define LTC3589_B1DTV2		0x24
29 #define LTC3589_VRRCR		0x25
30 #define LTC3589_B2DTV1		0x26
31 #define LTC3589_B2DTV2		0x27
32 #define LTC3589_B3DTV1		0x29
33 #define LTC3589_B3DTV2		0x2a
34 #define LTC3589_L2DTV1		0x32
35 #define LTC3589_L2DTV2		0x33
36 
37 #define LTC3589_IRQSTAT_PGOOD_TIMEOUT	BIT(3)
38 #define LTC3589_IRQSTAT_UNDERVOLT_WARN	BIT(4)
39 #define LTC3589_IRQSTAT_UNDERVOLT_FAULT	BIT(5)
40 #define LTC3589_IRQSTAT_THERMAL_WARN	BIT(6)
41 #define LTC3589_IRQSTAT_THERMAL_FAULT	BIT(7)
42 
43 #define LTC3589_OVEN_SW1		BIT(0)
44 #define LTC3589_OVEN_SW2		BIT(1)
45 #define LTC3589_OVEN_SW3		BIT(2)
46 #define LTC3589_OVEN_BB_OUT		BIT(3)
47 #define LTC3589_OVEN_LDO2		BIT(4)
48 #define LTC3589_OVEN_LDO3		BIT(5)
49 #define LTC3589_OVEN_LDO4		BIT(6)
50 #define LTC3589_OVEN_SW_CTRL		BIT(7)
51 
52 #define LTC3589_VCCR_SW1_GO		BIT(0)
53 #define LTC3589_VCCR_SW2_GO		BIT(2)
54 #define LTC3589_VCCR_SW3_GO		BIT(4)
55 #define LTC3589_VCCR_LDO2_GO		BIT(6)
56 
57 enum ltc3589_variant {
58 	LTC3589,
59 	LTC3589_1,
60 	LTC3589_2,
61 };
62 
63 enum ltc3589_reg {
64 	LTC3589_SW1,
65 	LTC3589_SW2,
66 	LTC3589_SW3,
67 	LTC3589_BB_OUT,
68 	LTC3589_LDO1,
69 	LTC3589_LDO2,
70 	LTC3589_LDO3,
71 	LTC3589_LDO4,
72 	LTC3589_NUM_REGULATORS,
73 };
74 
75 struct ltc3589 {
76 	struct regmap *regmap;
77 	struct device *dev;
78 	enum ltc3589_variant variant;
79 	struct regulator_desc regulator_descs[LTC3589_NUM_REGULATORS];
80 	struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
81 };
82 
83 static const int ltc3589_ldo4[] = {
84 	2800000, 2500000, 1800000, 3300000,
85 };
86 
87 static const int ltc3589_12_ldo4[] = {
88 	1200000, 1800000, 2500000, 3200000,
89 };
90 
91 static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
92 {
93 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
94 	int sel, shift;
95 
96 	if (unlikely(ramp_delay <= 0))
97 		return -EINVAL;
98 
99 	/* VRRCR slew rate offsets are the same as VCCR go bit offsets */
100 	shift = ffs(rdev->desc->apply_bit) - 1;
101 
102 	/* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
103 	for (sel = 0; sel < 4; sel++) {
104 		if ((880 << sel) >= ramp_delay) {
105 			return regmap_update_bits(ltc3589->regmap,
106 						  LTC3589_VRRCR,
107 						  0x3 << shift, sel << shift);
108 		}
109 	}
110 	return -EINVAL;
111 }
112 
113 static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
114 {
115 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
116 	int sel;
117 
118 	sel = regulator_map_voltage_linear(rdev, uV, uV);
119 	if (sel < 0)
120 		return sel;
121 
122 	/* DTV2 register follows right after the corresponding DTV1 register */
123 	return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
124 				  rdev->desc->vsel_mask, sel);
125 }
126 
127 static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
128 				    unsigned int mode)
129 {
130 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
131 	int mask, bit = 0;
132 
133 	/* VCCR reference selects are right next to the VCCR go bits */
134 	mask = rdev->desc->apply_bit << 1;
135 
136 	if (mode == REGULATOR_MODE_STANDBY)
137 		bit = mask;	/* Select DTV2 */
138 
139 	mask |= rdev->desc->apply_bit;
140 	bit |= rdev->desc->apply_bit;
141 	return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
142 }
143 
144 /* SW1, SW2, SW3, LDO2 */
145 static const struct regulator_ops ltc3589_linear_regulator_ops = {
146 	.enable = regulator_enable_regmap,
147 	.disable = regulator_disable_regmap,
148 	.is_enabled = regulator_is_enabled_regmap,
149 	.list_voltage = regulator_list_voltage_linear,
150 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
151 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
152 	.set_ramp_delay = ltc3589_set_ramp_delay,
153 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
154 	.set_suspend_voltage = ltc3589_set_suspend_voltage,
155 	.set_suspend_mode = ltc3589_set_suspend_mode,
156 };
157 
158 /* BB_OUT, LDO3 */
159 static const struct regulator_ops ltc3589_fixed_regulator_ops = {
160 	.enable = regulator_enable_regmap,
161 	.disable = regulator_disable_regmap,
162 	.is_enabled = regulator_is_enabled_regmap,
163 };
164 
165 /* LDO1 */
166 static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
167 };
168 
169 /* LDO4 */
170 static const struct regulator_ops ltc3589_table_regulator_ops = {
171 	.enable = regulator_enable_regmap,
172 	.disable = regulator_disable_regmap,
173 	.is_enabled = regulator_is_enabled_regmap,
174 	.list_voltage = regulator_list_voltage_table,
175 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
176 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
177 };
178 
179 static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
180 {
181 	uint64_t tmp;
182 
183 	if (uV == 0)
184 		return 0;
185 
186 	tmp = (uint64_t)uV * r1;
187 	do_div(tmp, r2);
188 	return uV + (unsigned int)tmp;
189 }
190 
191 static int ltc3589_of_parse_cb(struct device_node *np,
192 			       const struct regulator_desc *desc,
193 			       struct regulator_config *config)
194 {
195 	struct ltc3589 *ltc3589 = config->driver_data;
196 	struct regulator_desc *rdesc = &ltc3589->regulator_descs[desc->id];
197 	u32 r[2];
198 	int ret;
199 
200 	/* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
201 	if (desc->id >= LTC3589_LDO3)
202 		return 0;
203 
204 	ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
205 	if (ret) {
206 		dev_err(ltc3589->dev, "Failed to parse voltage divider: %d\n",
207 			ret);
208 		return ret;
209 	}
210 
211 	if (!r[0] || !r[1])
212 		return 0;
213 
214 	rdesc->min_uV = ltc3589_scale(desc->min_uV, r[0], r[1]);
215 	rdesc->uV_step = ltc3589_scale(desc->uV_step, r[0], r[1]);
216 	rdesc->fixed_uV = ltc3589_scale(desc->fixed_uV, r[0], r[1]);
217 
218 	return 0;
219 }
220 
221 #define LTC3589_REG(_name, _of_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit)\
222 	[LTC3589_ ## _name] = {						\
223 		.name = #_name,						\
224 		.of_match = of_match_ptr(#_of_name),			\
225 		.regulators_node = of_match_ptr("regulators"),		\
226 		.of_parse_cb = ltc3589_of_parse_cb,			\
227 		.n_voltages = (dtv_mask) + 1,				\
228 		.min_uV = (go_bit) ? 362500 : 0,			\
229 		.uV_step = (go_bit) ? 12500 : 0,			\
230 		.ramp_delay = (go_bit) ? 1750 : 0,			\
231 		.fixed_uV = (dtv_mask) ? 0 : 800000,			\
232 		.ops = &ltc3589_ ## _ops ## _regulator_ops,		\
233 		.type = REGULATOR_VOLTAGE,				\
234 		.id = LTC3589_ ## _name,				\
235 		.owner = THIS_MODULE,					\
236 		.vsel_reg = (dtv1_reg),					\
237 		.vsel_mask = (dtv_mask),				\
238 		.apply_reg = (go_bit) ? LTC3589_VCCR : 0,		\
239 		.apply_bit = (go_bit),					\
240 		.enable_reg = (en_bit) ? LTC3589_OVEN : 0,		\
241 		.enable_mask = (en_bit),				\
242 	}
243 
244 #define LTC3589_LINEAR_REG(_name, _of_name, _dtv1)			\
245 	LTC3589_REG(_name, _of_name, linear, LTC3589_OVEN_ ## _name,	\
246 		    LTC3589_ ## _dtv1, 0x1f,				\
247 		    LTC3589_VCCR_ ## _name ## _GO)
248 
249 #define LTC3589_FIXED_REG(_name, _of_name)				\
250 	LTC3589_REG(_name, _of_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
251 
252 static const struct regulator_desc ltc3589_regulators[] = {
253 	LTC3589_LINEAR_REG(SW1, sw1, B1DTV1),
254 	LTC3589_LINEAR_REG(SW2, sw2, B2DTV1),
255 	LTC3589_LINEAR_REG(SW3, sw3, B3DTV1),
256 	LTC3589_FIXED_REG(BB_OUT, bb-out),
257 	LTC3589_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0),
258 	LTC3589_LINEAR_REG(LDO2, ldo2, L2DTV1),
259 	LTC3589_FIXED_REG(LDO3, ldo3),
260 	LTC3589_REG(LDO4, ldo4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2,
261 		    0x60, 0),
262 };
263 
264 static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
265 {
266 	switch (reg) {
267 	case LTC3589_IRQSTAT:
268 	case LTC3589_SCR1:
269 	case LTC3589_OVEN:
270 	case LTC3589_SCR2:
271 	case LTC3589_VCCR:
272 	case LTC3589_CLIRQ:
273 	case LTC3589_B1DTV1:
274 	case LTC3589_B1DTV2:
275 	case LTC3589_VRRCR:
276 	case LTC3589_B2DTV1:
277 	case LTC3589_B2DTV2:
278 	case LTC3589_B3DTV1:
279 	case LTC3589_B3DTV2:
280 	case LTC3589_L2DTV1:
281 	case LTC3589_L2DTV2:
282 		return true;
283 	}
284 	return false;
285 }
286 
287 static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
288 {
289 	switch (reg) {
290 	case LTC3589_IRQSTAT:
291 	case LTC3589_SCR1:
292 	case LTC3589_OVEN:
293 	case LTC3589_SCR2:
294 	case LTC3589_PGSTAT:
295 	case LTC3589_VCCR:
296 	case LTC3589_B1DTV1:
297 	case LTC3589_B1DTV2:
298 	case LTC3589_VRRCR:
299 	case LTC3589_B2DTV1:
300 	case LTC3589_B2DTV2:
301 	case LTC3589_B3DTV1:
302 	case LTC3589_B3DTV2:
303 	case LTC3589_L2DTV1:
304 	case LTC3589_L2DTV2:
305 		return true;
306 	}
307 	return false;
308 }
309 
310 static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
311 {
312 	switch (reg) {
313 	case LTC3589_IRQSTAT:
314 	case LTC3589_PGSTAT:
315 	case LTC3589_VCCR:
316 		return true;
317 	}
318 	return false;
319 }
320 
321 static const struct reg_default ltc3589_reg_defaults[] = {
322 	{ LTC3589_SCR1,   0x00 },
323 	{ LTC3589_OVEN,   0x00 },
324 	{ LTC3589_SCR2,   0x00 },
325 	{ LTC3589_VCCR,   0x00 },
326 	{ LTC3589_B1DTV1, 0x19 },
327 	{ LTC3589_B1DTV2, 0x19 },
328 	{ LTC3589_VRRCR,  0xff },
329 	{ LTC3589_B2DTV1, 0x19 },
330 	{ LTC3589_B2DTV2, 0x19 },
331 	{ LTC3589_B3DTV1, 0x19 },
332 	{ LTC3589_B3DTV2, 0x19 },
333 	{ LTC3589_L2DTV1, 0x19 },
334 	{ LTC3589_L2DTV2, 0x19 },
335 };
336 
337 static const struct regmap_config ltc3589_regmap_config = {
338 	.reg_bits = 8,
339 	.val_bits = 8,
340 	.writeable_reg = ltc3589_writeable_reg,
341 	.readable_reg = ltc3589_readable_reg,
342 	.volatile_reg = ltc3589_volatile_reg,
343 	.max_register = LTC3589_L2DTV2,
344 	.reg_defaults = ltc3589_reg_defaults,
345 	.num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
346 	.use_single_read = true,
347 	.use_single_write = true,
348 	.cache_type = REGCACHE_RBTREE,
349 };
350 
351 static irqreturn_t ltc3589_isr(int irq, void *dev_id)
352 {
353 	struct ltc3589 *ltc3589 = dev_id;
354 	unsigned int i, irqstat, event;
355 
356 	regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
357 
358 	if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
359 		event = REGULATOR_EVENT_OVER_TEMP;
360 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
361 			regulator_notifier_call_chain(ltc3589->regulators[i],
362 						      event, NULL);
363 	}
364 
365 	if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
366 		event = REGULATOR_EVENT_UNDER_VOLTAGE;
367 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
368 			regulator_notifier_call_chain(ltc3589->regulators[i],
369 						      event, NULL);
370 	}
371 
372 	/* Clear warning condition */
373 	regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
374 
375 	return IRQ_HANDLED;
376 }
377 
378 static int ltc3589_probe(struct i2c_client *client,
379 			 const struct i2c_device_id *id)
380 {
381 	struct device *dev = &client->dev;
382 	struct regulator_desc *descs;
383 	struct ltc3589 *ltc3589;
384 	int i, ret;
385 
386 	ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
387 	if (!ltc3589)
388 		return -ENOMEM;
389 
390 	i2c_set_clientdata(client, ltc3589);
391 	if (client->dev.of_node)
392 		ltc3589->variant = (enum ltc3589_variant)
393 			of_device_get_match_data(&client->dev);
394 	else
395 		ltc3589->variant = id->driver_data;
396 	ltc3589->dev = dev;
397 
398 	descs = ltc3589->regulator_descs;
399 	memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
400 	if (ltc3589->variant == LTC3589) {
401 		descs[LTC3589_LDO3].fixed_uV = 1800000;
402 		descs[LTC3589_LDO4].volt_table = ltc3589_ldo4;
403 	} else {
404 		descs[LTC3589_LDO3].fixed_uV = 2800000;
405 		descs[LTC3589_LDO4].volt_table = ltc3589_12_ldo4;
406 	}
407 
408 	ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
409 	if (IS_ERR(ltc3589->regmap)) {
410 		ret = PTR_ERR(ltc3589->regmap);
411 		dev_err(dev, "failed to initialize regmap: %d\n", ret);
412 		return ret;
413 	}
414 
415 	for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
416 		struct regulator_desc *desc = &ltc3589->regulator_descs[i];
417 		struct regulator_config config = { };
418 
419 		config.dev = dev;
420 		config.driver_data = ltc3589;
421 
422 		ltc3589->regulators[i] = devm_regulator_register(dev, desc,
423 								 &config);
424 		if (IS_ERR(ltc3589->regulators[i])) {
425 			ret = PTR_ERR(ltc3589->regulators[i]);
426 			dev_err(dev, "failed to register regulator %s: %d\n",
427 				desc->name, ret);
428 			return ret;
429 		}
430 	}
431 
432 	if (client->irq) {
433 		ret = devm_request_threaded_irq(dev, client->irq, NULL,
434 						ltc3589_isr,
435 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
436 						client->name, ltc3589);
437 		if (ret) {
438 			dev_err(dev, "Failed to request IRQ: %d\n", ret);
439 			return ret;
440 		}
441 	}
442 
443 	return 0;
444 }
445 
446 static const struct i2c_device_id ltc3589_i2c_id[] = {
447 	{ "ltc3589",   LTC3589   },
448 	{ "ltc3589-1", LTC3589_1 },
449 	{ "ltc3589-2", LTC3589_2 },
450 	{ }
451 };
452 MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
453 
454 static const struct of_device_id __maybe_unused ltc3589_of_match[] = {
455 	{
456 		.compatible = "lltc,ltc3589",
457 		.data = (void *)LTC3589,
458 	},
459 	{
460 		.compatible = "lltc,ltc3589-1",
461 		.data = (void *)LTC3589_1,
462 	},
463 	{
464 		.compatible = "lltc,ltc3589-2",
465 		.data = (void *)LTC3589_2,
466 	},
467 	{ },
468 };
469 MODULE_DEVICE_TABLE(of, ltc3589_of_match);
470 
471 static struct i2c_driver ltc3589_driver = {
472 	.driver = {
473 		.name = DRIVER_NAME,
474 		.of_match_table = of_match_ptr(ltc3589_of_match),
475 	},
476 	.probe = ltc3589_probe,
477 	.id_table = ltc3589_i2c_id,
478 };
479 module_i2c_driver(ltc3589_driver);
480 
481 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
482 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
483 MODULE_LICENSE("GPL v2");
484