1/*
2 * LP8755 High Performance Power Management Unit : System Interface Driver
3 * (based on rev. 0.26)
4 * Copyright 2012 Texas Instruments
5 *
6 * Author: Daniel(Geon Si) Jeong <daniel.jeong@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/i2c.h>
17#include <linux/err.h>
18#include <linux/irq.h>
19#include <linux/interrupt.h>
20#include <linux/gpio.h>
21#include <linux/regmap.h>
22#include <linux/uaccess.h>
23#include <linux/regulator/driver.h>
24#include <linux/regulator/machine.h>
25#include <linux/platform_data/lp8755.h>
26
27#define LP8755_REG_BUCK0	0x00
28#define LP8755_REG_BUCK1	0x03
29#define LP8755_REG_BUCK2	0x04
30#define LP8755_REG_BUCK3	0x01
31#define LP8755_REG_BUCK4	0x05
32#define LP8755_REG_BUCK5	0x02
33#define LP8755_REG_MAX		0xFF
34
35#define LP8755_BUCK_EN_M	BIT(7)
36#define LP8755_BUCK_LINEAR_OUT_MAX	0x76
37#define LP8755_BUCK_VOUT_M	0x7F
38
39struct lp8755_mphase {
40	int nreg;
41	int buck_num[LP8755_BUCK_MAX];
42};
43
44struct lp8755_chip {
45	struct device *dev;
46	struct regmap *regmap;
47	struct lp8755_platform_data *pdata;
48
49	int irq;
50	unsigned int irqmask;
51
52	int mphase;
53	struct regulator_dev *rdev[LP8755_BUCK_MAX];
54};
55
56/**
57 *lp8755_read : read a single register value from lp8755.
58 *@pchip : device to read from
59 *@reg   : register to read from
60 *@val   : pointer to store read value
61 */
62static int lp8755_read(struct lp8755_chip *pchip, unsigned int reg,
63		       unsigned int *val)
64{
65	return regmap_read(pchip->regmap, reg, val);
66}
67
68/**
69 *lp8755_write : write a single register value to lp8755.
70 *@pchip : device to write to
71 *@reg   : register to write to
72 *@val   : value to be written
73 */
74static int lp8755_write(struct lp8755_chip *pchip, unsigned int reg,
75			unsigned int val)
76{
77	return regmap_write(pchip->regmap, reg, val);
78}
79
80/**
81 *lp8755_update_bits : set the values of bit fields in lp8755 register.
82 *@pchip : device to read from
83 *@reg   : register to update
84 *@mask  : bitmask to be changed
85 *@val   : value for bitmask
86 */
87static int lp8755_update_bits(struct lp8755_chip *pchip, unsigned int reg,
88			      unsigned int mask, unsigned int val)
89{
90	return regmap_update_bits(pchip->regmap, reg, mask, val);
91}
92
93static int lp8755_buck_enable_time(struct regulator_dev *rdev)
94{
95	int ret;
96	unsigned int regval;
97	enum lp8755_bucks id = rdev_get_id(rdev);
98	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);
99
100	ret = lp8755_read(pchip, 0x12 + id, &regval);
101	if (ret < 0) {
102		dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
103		return ret;
104	}
105	return (regval & 0xff) * 100;
106}
107
108static int lp8755_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
109{
110	int ret;
111	unsigned int regbval = 0x0;
112	enum lp8755_bucks id = rdev_get_id(rdev);
113	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);
114
115	switch (mode) {
116	case REGULATOR_MODE_FAST:
117		/* forced pwm mode */
118		regbval = (0x01 << id);
119		break;
120	case REGULATOR_MODE_NORMAL:
121		/* enable automatic pwm/pfm mode */
122		ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x00);
123		if (ret < 0)
124			goto err_i2c;
125		break;
126	case REGULATOR_MODE_IDLE:
127		/* enable automatic pwm/pfm/lppfm mode */
128		ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x20);
129		if (ret < 0)
130			goto err_i2c;
131
132		ret = lp8755_update_bits(pchip, 0x10, 0x01, 0x01);
133		if (ret < 0)
134			goto err_i2c;
135		break;
136	default:
137		dev_err(pchip->dev, "Not supported buck mode %s\n", __func__);
138		/* forced pwm mode */
139		regbval = (0x01 << id);
140	}
141
142	ret = lp8755_update_bits(pchip, 0x06, 0x01 << id, regbval);
143	if (ret < 0)
144		goto err_i2c;
145	return ret;
146err_i2c:
147	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
148	return ret;
149}
150
151static unsigned int lp8755_buck_get_mode(struct regulator_dev *rdev)
152{
153	int ret;
154	unsigned int regval;
155	enum lp8755_bucks id = rdev_get_id(rdev);
156	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);
157
158	ret = lp8755_read(pchip, 0x06, &regval);
159	if (ret < 0)
160		goto err_i2c;
161
162	/* mode fast means forced pwm mode */
163	if (regval & (0x01 << id))
164		return REGULATOR_MODE_FAST;
165
166	ret = lp8755_read(pchip, 0x08 + id, &regval);
167	if (ret < 0)
168		goto err_i2c;
169
170	/* mode idle means automatic pwm/pfm/lppfm mode */
171	if (regval & 0x20)
172		return REGULATOR_MODE_IDLE;
173
174	/* mode normal means automatic pwm/pfm mode */
175	return REGULATOR_MODE_NORMAL;
176
177err_i2c:
178	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
179	return 0;
180}
181
182static int lp8755_buck_set_ramp(struct regulator_dev *rdev, int ramp)
183{
184	int ret;
185	unsigned int regval = 0x00;
186	enum lp8755_bucks id = rdev_get_id(rdev);
187	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);
188
189	/* uV/us */
190	switch (ramp) {
191	case 0 ... 230:
192		regval = 0x07;
193		break;
194	case 231 ... 470:
195		regval = 0x06;
196		break;
197	case 471 ... 940:
198		regval = 0x05;
199		break;
200	case 941 ... 1900:
201		regval = 0x04;
202		break;
203	case 1901 ... 3800:
204		regval = 0x03;
205		break;
206	case 3801 ... 7500:
207		regval = 0x02;
208		break;
209	case 7501 ... 15000:
210		regval = 0x01;
211		break;
212	case 15001 ... 30000:
213		regval = 0x00;
214		break;
215	default:
216		dev_err(pchip->dev,
217			"Not supported ramp value %d %s\n", ramp, __func__);
218		return -EINVAL;
219	}
220
221	ret = lp8755_update_bits(pchip, 0x07 + id, 0x07, regval);
222	if (ret < 0)
223		goto err_i2c;
224	return ret;
225err_i2c:
226	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
227	return ret;
228}
229
230static struct regulator_ops lp8755_buck_ops = {
231	.map_voltage = regulator_map_voltage_linear,
232	.list_voltage = regulator_list_voltage_linear,
233	.set_voltage_sel = regulator_set_voltage_sel_regmap,
234	.get_voltage_sel = regulator_get_voltage_sel_regmap,
235	.enable = regulator_enable_regmap,
236	.disable = regulator_disable_regmap,
237	.is_enabled = regulator_is_enabled_regmap,
238	.enable_time = lp8755_buck_enable_time,
239	.set_mode = lp8755_buck_set_mode,
240	.get_mode = lp8755_buck_get_mode,
241	.set_ramp_delay = lp8755_buck_set_ramp,
242};
243
244#define lp8755_rail(_id) "lp8755_buck"#_id
245#define lp8755_buck_init(_id)\
246{\
247	.constraints = {\
248		.name = lp8755_rail(_id),\
249		.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,\
250		.min_uV = 500000,\
251		.max_uV = 1675000,\
252	},\
253}
254
255static struct regulator_init_data lp8755_reg_default[LP8755_BUCK_MAX] = {
256	[LP8755_BUCK0] = lp8755_buck_init(0),
257	[LP8755_BUCK1] = lp8755_buck_init(1),
258	[LP8755_BUCK2] = lp8755_buck_init(2),
259	[LP8755_BUCK3] = lp8755_buck_init(3),
260	[LP8755_BUCK4] = lp8755_buck_init(4),
261	[LP8755_BUCK5] = lp8755_buck_init(5),
262};
263
264static const struct lp8755_mphase mphase_buck[MPHASE_CONF_MAX] = {
265	{ 3, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK5 } },
266	{ 6, { LP8755_BUCK0, LP8755_BUCK1, LP8755_BUCK2, LP8755_BUCK3,
267	       LP8755_BUCK4, LP8755_BUCK5 } },
268	{ 5, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK4,
269	       LP8755_BUCK5} },
270	{ 4, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK4, LP8755_BUCK5} },
271	{ 3, { LP8755_BUCK0, LP8755_BUCK4, LP8755_BUCK5} },
272	{ 2, { LP8755_BUCK0, LP8755_BUCK5} },
273	{ 1, { LP8755_BUCK0} },
274	{ 2, { LP8755_BUCK0, LP8755_BUCK3} },
275	{ 4, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK5} },
276};
277
278static int lp8755_init_data(struct lp8755_chip *pchip)
279{
280	unsigned int regval;
281	int ret, icnt, buck_num;
282	struct lp8755_platform_data *pdata = pchip->pdata;
283
284	/* read back  muti-phase configuration */
285	ret = lp8755_read(pchip, 0x3D, &regval);
286	if (ret < 0)
287		goto out_i2c_error;
288	pchip->mphase = regval & 0x0F;
289
290	/* set default data based on multi-phase config */
291	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
292		buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
293		pdata->buck_data[buck_num] = &lp8755_reg_default[buck_num];
294	}
295	return ret;
296
297out_i2c_error:
298	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
299	return ret;
300}
301
302#define lp8755_buck_desc(_id)\
303{\
304	.name = lp8755_rail(_id),\
305	.id   = LP8755_BUCK##_id,\
306	.ops  = &lp8755_buck_ops,\
307	.n_voltages = LP8755_BUCK_LINEAR_OUT_MAX+1,\
308	.uV_step = 10000,\
309	.min_uV = 500000,\
310	.type = REGULATOR_VOLTAGE,\
311	.owner = THIS_MODULE,\
312	.enable_reg = LP8755_REG_BUCK##_id,\
313	.enable_mask = LP8755_BUCK_EN_M,\
314	.vsel_reg = LP8755_REG_BUCK##_id,\
315	.vsel_mask = LP8755_BUCK_VOUT_M,\
316}
317
318static struct regulator_desc lp8755_regulators[] = {
319	lp8755_buck_desc(0),
320	lp8755_buck_desc(1),
321	lp8755_buck_desc(2),
322	lp8755_buck_desc(3),
323	lp8755_buck_desc(4),
324	lp8755_buck_desc(5),
325};
326
327static int lp8755_regulator_init(struct lp8755_chip *pchip)
328{
329	int ret, icnt, buck_num;
330	struct lp8755_platform_data *pdata = pchip->pdata;
331	struct regulator_config rconfig = { };
332
333	rconfig.regmap = pchip->regmap;
334	rconfig.dev = pchip->dev;
335	rconfig.driver_data = pchip;
336
337	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
338		buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
339		rconfig.init_data = pdata->buck_data[buck_num];
340		rconfig.of_node = pchip->dev->of_node;
341		pchip->rdev[buck_num] =
342		    devm_regulator_register(pchip->dev,
343				    &lp8755_regulators[buck_num], &rconfig);
344		if (IS_ERR(pchip->rdev[buck_num])) {
345			ret = PTR_ERR(pchip->rdev[buck_num]);
346			pchip->rdev[buck_num] = NULL;
347			dev_err(pchip->dev, "regulator init failed: buck %d\n",
348				buck_num);
349			return ret;
350		}
351	}
352
353	return 0;
354}
355
356static irqreturn_t lp8755_irq_handler(int irq, void *data)
357{
358	int ret, icnt;
359	unsigned int flag0, flag1;
360	struct lp8755_chip *pchip = data;
361
362	/* read flag0 register */
363	ret = lp8755_read(pchip, 0x0D, &flag0);
364	if (ret < 0)
365		goto err_i2c;
366	/* clear flag register to pull up int. pin */
367	ret = lp8755_write(pchip, 0x0D, 0x00);
368	if (ret < 0)
369		goto err_i2c;
370
371	/* sent power fault detection event to specific regulator */
372	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
373		if ((flag0 & (0x4 << icnt))
374		    && (pchip->irqmask & (0x04 << icnt))
375		    && (pchip->rdev[icnt] != NULL))
376			regulator_notifier_call_chain(pchip->rdev[icnt],
377						      LP8755_EVENT_PWR_FAULT,
378						      NULL);
379
380	/* read flag1 register */
381	ret = lp8755_read(pchip, 0x0E, &flag1);
382	if (ret < 0)
383		goto err_i2c;
384	/* clear flag register to pull up int. pin */
385	ret = lp8755_write(pchip, 0x0E, 0x00);
386	if (ret < 0)
387		goto err_i2c;
388
389	/* send OCP event to all regualtor devices */
390	if ((flag1 & 0x01) && (pchip->irqmask & 0x01))
391		for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
392			if (pchip->rdev[icnt] != NULL)
393				regulator_notifier_call_chain(pchip->rdev[icnt],
394							      LP8755_EVENT_OCP,
395							      NULL);
396
397	/* send OVP event to all regualtor devices */
398	if ((flag1 & 0x02) && (pchip->irqmask & 0x02))
399		for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
400			if (pchip->rdev[icnt] != NULL)
401				regulator_notifier_call_chain(pchip->rdev[icnt],
402							      LP8755_EVENT_OVP,
403							      NULL);
404	return IRQ_HANDLED;
405
406err_i2c:
407	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
408	return IRQ_NONE;
409}
410
411static int lp8755_int_config(struct lp8755_chip *pchip)
412{
413	int ret;
414	unsigned int regval;
415
416	if (pchip->irq == 0) {
417		dev_warn(pchip->dev, "not use interrupt : %s\n", __func__);
418		return 0;
419	}
420
421	ret = lp8755_read(pchip, 0x0F, &regval);
422	if (ret < 0)
423		goto err_i2c;
424	pchip->irqmask = regval;
425	ret = request_threaded_irq(pchip->irq, NULL, lp8755_irq_handler,
426				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
427				   "lp8755-irq", pchip);
428	if (ret)
429		return ret;
430
431	return ret;
432
433err_i2c:
434	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
435	return ret;
436}
437
438static const struct regmap_config lp8755_regmap = {
439	.reg_bits = 8,
440	.val_bits = 8,
441	.max_register = LP8755_REG_MAX,
442};
443
444static int lp8755_probe(struct i2c_client *client,
445			const struct i2c_device_id *id)
446{
447	int ret, icnt;
448	struct lp8755_chip *pchip;
449	struct lp8755_platform_data *pdata = dev_get_platdata(&client->dev);
450
451	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
452		dev_err(&client->dev, "i2c functionality check fail.\n");
453		return -EOPNOTSUPP;
454	}
455
456	pchip = devm_kzalloc(&client->dev,
457			     sizeof(struct lp8755_chip), GFP_KERNEL);
458	if (!pchip)
459		return -ENOMEM;
460
461	pchip->dev = &client->dev;
462	pchip->regmap = devm_regmap_init_i2c(client, &lp8755_regmap);
463	if (IS_ERR(pchip->regmap)) {
464		ret = PTR_ERR(pchip->regmap);
465		dev_err(&client->dev, "fail to allocate regmap %d\n", ret);
466		return ret;
467	}
468	i2c_set_clientdata(client, pchip);
469
470	if (pdata != NULL) {
471		pchip->pdata = pdata;
472		pchip->mphase = pdata->mphase;
473	} else {
474		pchip->pdata = devm_kzalloc(pchip->dev,
475					    sizeof(struct lp8755_platform_data),
476					    GFP_KERNEL);
477		if (!pchip->pdata)
478			return -ENOMEM;
479		ret = lp8755_init_data(pchip);
480		if (ret < 0) {
481			dev_err(&client->dev, "fail to initialize chip\n");
482			return ret;
483		}
484	}
485
486	ret = lp8755_regulator_init(pchip);
487	if (ret < 0) {
488		dev_err(&client->dev, "fail to initialize regulators\n");
489		goto err;
490	}
491
492	pchip->irq = client->irq;
493	ret = lp8755_int_config(pchip);
494	if (ret < 0) {
495		dev_err(&client->dev, "fail to irq config\n");
496		goto err;
497	}
498
499	return ret;
500
501err:
502	/* output disable */
503	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
504		lp8755_write(pchip, icnt, 0x00);
505
506	return ret;
507}
508
509static int lp8755_remove(struct i2c_client *client)
510{
511	int icnt;
512	struct lp8755_chip *pchip = i2c_get_clientdata(client);
513
514	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
515		lp8755_write(pchip, icnt, 0x00);
516
517	if (pchip->irq != 0)
518		free_irq(pchip->irq, pchip);
519
520	return 0;
521}
522
523static const struct i2c_device_id lp8755_id[] = {
524	{LP8755_NAME, 0},
525	{}
526};
527
528MODULE_DEVICE_TABLE(i2c, lp8755_id);
529
530static struct i2c_driver lp8755_i2c_driver = {
531	.driver = {
532		   .name = LP8755_NAME,
533		   },
534	.probe = lp8755_probe,
535	.remove = lp8755_remove,
536	.id_table = lp8755_id,
537};
538
539static int __init lp8755_init(void)
540{
541	return i2c_add_driver(&lp8755_i2c_driver);
542}
543
544subsys_initcall(lp8755_init);
545
546static void __exit lp8755_exit(void)
547{
548	i2c_del_driver(&lp8755_i2c_driver);
549}
550
551module_exit(lp8755_exit);
552
553MODULE_DESCRIPTION("Texas Instruments lp8755 driver");
554MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
555MODULE_LICENSE("GPL v2");
556