1/*
  2 * tps62360.c -- TI tps62360
  3 *
  4 * Driver for processor core supply tps62360, tps62361B, tps62362 and tps62363.
  5 *
  6 * Copyright (c) 2012, NVIDIA Corporation.
  7 *
  8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
  9 *
 10 * This program is free software; you can redistribute it and/or
 11 * modify it under the terms of the GNU General Public License as
 12 * published by the Free Software Foundation version 2.
 13 *
 14 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
 15 * whether express or implied; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 17 * General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License
 20 * along with this program; if not, write to the Free Software
 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 22 * 02111-1307, USA
 23 */
 24
 25#include <linux/kernel.h>
 26#include <linux/module.h>
 27#include <linux/init.h>
 28#include <linux/err.h>
 29#include <linux/of.h>
 30#include <linux/of_device.h>
 31#include <linux/of_gpio.h>
 32#include <linux/regulator/of_regulator.h>
 33#include <linux/platform_device.h>
 34#include <linux/regulator/driver.h>
 35#include <linux/regulator/machine.h>
 36#include <linux/regulator/tps62360.h>
 37#include <linux/gpio.h>
 38#include <linux/i2c.h>
 39#include <linux/slab.h>
 40#include <linux/regmap.h>
 41
 42/* Register definitions */
 43#define REG_VSET0		0
 44#define REG_VSET1		1
 45#define REG_VSET2		2
 46#define REG_VSET3		3
 47#define REG_CONTROL		4
 48#define REG_TEMP		5
 49#define REG_RAMPCTRL		6
 50#define REG_CHIPID		8
 51
 52#define FORCE_PWM_ENABLE	BIT(7)
 53
 54enum chips {TPS62360, TPS62361, TPS62362, TPS62363};
 55
 56#define TPS62360_BASE_VOLTAGE	770000
 57#define TPS62360_N_VOLTAGES	64
 58
 59#define TPS62361_BASE_VOLTAGE	500000
 60#define TPS62361_N_VOLTAGES	128
 61
 62/* tps 62360 chip information */
 63struct tps62360_chip {
 64	struct device *dev;
 65	struct regulator_desc desc;
 66	struct regulator_dev *rdev;
 67	struct regmap *regmap;
 68	int chip_id;
 69	int vsel0_gpio;
 70	int vsel1_gpio;
 71	int voltage_base;
 72	u8 voltage_reg_mask;
 73	bool en_internal_pulldn;
 74	bool en_discharge;
 75	bool valid_gpios;
 76	int lru_index[4];
 77	int curr_vset_vsel[4];
 78	int curr_vset_id;
 79	int change_uv_per_us;
 80};
 81
 82/*
 83 * find_voltage_set_register: Find new voltage configuration register
 84 * (VSET) id.
 85 * The finding of the new VSET register will be based on the LRU mechanism.
 86 * Each VSET register will have different voltage configured . This
 87 * Function will look if any of the VSET register have requested voltage set
 88 * or not.
 89 *     - If it is already there then it will make that register as most
 90 *       recently used and return as found so that caller need not to set
 91 *       the VSET register but need to set the proper gpios to select this
 92 *       VSET register.
 93 *     - If requested voltage is not found then it will use the least
 94 *       recently mechanism to get new VSET register for new configuration
 95 *       and will return not_found so that caller need to set new VSET
 96 *       register and then gpios (both).
 97 */
 98static bool find_voltage_set_register(struct tps62360_chip *tps,
 99		int req_vsel, int *vset_reg_id)
100{
101	int i;
102	bool found = false;
103	int new_vset_reg = tps->lru_index[3];
104	int found_index = 3;
105
106	for (i = 0; i < 4; ++i) {
107		if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
108			new_vset_reg = tps->lru_index[i];
109			found_index = i;
110			found = true;
111			goto update_lru_index;
112		}
113	}
114
115update_lru_index:
116	for (i = found_index; i > 0; i--)
117		tps->lru_index[i] = tps->lru_index[i - 1];
118
119	tps->lru_index[0] = new_vset_reg;
120	*vset_reg_id = new_vset_reg;
121	return found;
122}
123
124static int tps62360_dcdc_get_voltage_sel(struct regulator_dev *dev)
125{
126	struct tps62360_chip *tps = rdev_get_drvdata(dev);
127	int vsel;
128	unsigned int data;
129	int ret;
130
131	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
132	if (ret < 0) {
133		dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
134			__func__, REG_VSET0 + tps->curr_vset_id, ret);
135		return ret;
136	}
137	vsel = (int)data & tps->voltage_reg_mask;
138	return vsel;
139}
140
141static int tps62360_dcdc_set_voltage_sel(struct regulator_dev *dev,
142					 unsigned selector)
143{
144	struct tps62360_chip *tps = rdev_get_drvdata(dev);
145	int ret;
146	bool found = false;
147	int new_vset_id = tps->curr_vset_id;
148
149	/*
150	 * If gpios are available to select the VSET register then least
151	 * recently used register for new configuration.
152	 */
153	if (tps->valid_gpios)
154		found = find_voltage_set_register(tps, selector, &new_vset_id);
155
156	if (!found) {
157		ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
158				tps->voltage_reg_mask, selector);
159		if (ret < 0) {
160			dev_err(tps->dev,
161				"%s(): register %d update failed with err %d\n",
162				 __func__, REG_VSET0 + new_vset_id, ret);
163			return ret;
164		}
165		tps->curr_vset_id = new_vset_id;
166		tps->curr_vset_vsel[new_vset_id] = selector;
167	}
168
169	/* Select proper VSET register vio gpios */
170	if (tps->valid_gpios) {
171		gpio_set_value_cansleep(tps->vsel0_gpio, new_vset_id & 0x1);
172		gpio_set_value_cansleep(tps->vsel1_gpio,
173					(new_vset_id >> 1) & 0x1);
174	}
175	return 0;
176}
177
178static int tps62360_set_voltage_time_sel(struct regulator_dev *rdev,
179		unsigned int old_selector, unsigned int new_selector)
180{
181	struct tps62360_chip *tps = rdev_get_drvdata(rdev);
182	int old_uV, new_uV;
183
184	old_uV = regulator_list_voltage_linear(rdev, old_selector);
185	if (old_uV < 0)
186		return old_uV;
187
188	new_uV = regulator_list_voltage_linear(rdev, new_selector);
189	if (new_uV < 0)
190		return new_uV;
191
192	return DIV_ROUND_UP(abs(old_uV - new_uV), tps->change_uv_per_us);
193}
194
195static int tps62360_set_mode(struct regulator_dev *rdev, unsigned int mode)
196{
197	struct tps62360_chip *tps = rdev_get_drvdata(rdev);
198	int i;
199	int val;
200	int ret;
201
202	/* Enable force PWM mode in FAST mode only. */
203	switch (mode) {
204	case REGULATOR_MODE_FAST:
205		val = FORCE_PWM_ENABLE;
206		break;
207
208	case REGULATOR_MODE_NORMAL:
209		val = 0;
210		break;
211
212	default:
213		return -EINVAL;
214	}
215
216	if (!tps->valid_gpios) {
217		ret = regmap_update_bits(tps->regmap,
218			REG_VSET0 + tps->curr_vset_id, FORCE_PWM_ENABLE, val);
219		if (ret < 0)
220			dev_err(tps->dev,
221				"%s(): register %d update failed with err %d\n",
222				__func__, REG_VSET0 + tps->curr_vset_id, ret);
223		return ret;
224	}
225
226	/* If gpios are valid then all register set need to be control */
227	for (i = 0; i < 4; ++i) {
228		ret = regmap_update_bits(tps->regmap,
229					REG_VSET0 + i, FORCE_PWM_ENABLE, val);
230		if (ret < 0) {
231			dev_err(tps->dev,
232				"%s(): register %d update failed with err %d\n",
233				__func__, REG_VSET0 + i, ret);
234			return ret;
235		}
236	}
237	return ret;
238}
239
240static unsigned int tps62360_get_mode(struct regulator_dev *rdev)
241{
242	struct tps62360_chip *tps = rdev_get_drvdata(rdev);
243	unsigned int data;
244	int ret;
245
246	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
247	if (ret < 0) {
248		dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
249			__func__, REG_VSET0 + tps->curr_vset_id, ret);
250		return ret;
251	}
252	return (data & FORCE_PWM_ENABLE) ?
253				REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
254}
255
256static struct regulator_ops tps62360_dcdc_ops = {
257	.get_voltage_sel	= tps62360_dcdc_get_voltage_sel,
258	.set_voltage_sel	= tps62360_dcdc_set_voltage_sel,
259	.list_voltage		= regulator_list_voltage_linear,
260	.map_voltage		= regulator_map_voltage_linear,
261	.set_voltage_time_sel	= tps62360_set_voltage_time_sel,
262	.set_mode		= tps62360_set_mode,
263	.get_mode		= tps62360_get_mode,
264};
265
266static int __devinit tps62360_init_dcdc(struct tps62360_chip *tps,
267		struct tps62360_regulator_platform_data *pdata)
268{
269	int ret;
270	unsigned int ramp_ctrl;
271
272	/* Initialize internal pull up/down control */
273	if (tps->en_internal_pulldn)
274		ret = regmap_write(tps->regmap, REG_CONTROL, 0xE0);
275	else
276		ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
277	if (ret < 0) {
278		dev_err(tps->dev,
279			"%s(): register %d write failed with err %d\n",
280			__func__, REG_CONTROL, ret);
281		return ret;
282	}
283
284	/* Reset output discharge path to reduce power consumption */
285	ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), 0);
286	if (ret < 0) {
287		dev_err(tps->dev,
288			"%s(): register %d update failed with err %d\n",
289			__func__, REG_RAMPCTRL, ret);
290		return ret;
291	}
292
293	/* Get ramp value from ramp control register */
294	ret = regmap_read(tps->regmap, REG_RAMPCTRL, &ramp_ctrl);
295	if (ret < 0) {
296		dev_err(tps->dev,
297			"%s(): register %d read failed with err %d\n",
298			__func__, REG_RAMPCTRL, ret);
299		return ret;
300	}
301	ramp_ctrl = (ramp_ctrl >> 4) & 0x7;
302
303	/* ramp mV/us = 32/(2^ramp_ctrl) */
304	tps->change_uv_per_us = DIV_ROUND_UP(32000, BIT(ramp_ctrl));
305	return ret;
306}
307
308static const struct regmap_config tps62360_regmap_config = {
309	.reg_bits		= 8,
310	.val_bits		= 8,
311	.max_register		= REG_CHIPID,
312	.cache_type		= REGCACHE_RBTREE,
313};
314
315static struct tps62360_regulator_platform_data *
316	of_get_tps62360_platform_data(struct device *dev)
317{
318	struct tps62360_regulator_platform_data *pdata;
319	struct device_node *np = dev->of_node;
320
321	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
322	if (!pdata) {
323		dev_err(dev, "Memory alloc failed for platform data\n");
324		return NULL;
325	}
326
327	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node);
328	if (!pdata->reg_init_data) {
329		dev_err(dev, "Not able to get OF regulator init data\n");
330		return NULL;
331	}
332
333	pdata->vsel0_gpio = of_get_named_gpio(np, "vsel0-gpio", 0);
334	pdata->vsel1_gpio = of_get_named_gpio(np, "vsel1-gpio", 0);
335
336	if (of_find_property(np, "ti,vsel0-state-high", NULL))
337		pdata->vsel0_def_state = 1;
338
339	if (of_find_property(np, "ti,vsel1-state-high", NULL))
340		pdata->vsel1_def_state = 1;
341
342	if (of_find_property(np, "ti,enable-pull-down", NULL))
343		pdata->en_internal_pulldn = true;
344
345	if (of_find_property(np, "ti,enable-vout-discharge", NULL))
346		pdata->en_discharge = true;
347
348	return pdata;
349}
350
351#if defined(CONFIG_OF)
352static const struct of_device_id tps62360_of_match[] = {
353	 { .compatible = "ti,tps62360", .data = (void *)TPS62360},
354	 { .compatible = "ti,tps62361", .data = (void *)TPS62361},
355	 { .compatible = "ti,tps62362", .data = (void *)TPS62362},
356	 { .compatible = "ti,tps62363", .data = (void *)TPS62363},
357	{},
358};
359MODULE_DEVICE_TABLE(of, tps62360_of_match);
360#endif
361
362static int __devinit tps62360_probe(struct i2c_client *client,
363				     const struct i2c_device_id *id)
364{
365	struct regulator_config config = { };
366	struct tps62360_regulator_platform_data *pdata;
367	struct regulator_dev *rdev;
368	struct tps62360_chip *tps;
369	int ret;
370	int i;
371	int chip_id;
372
373	pdata = client->dev.platform_data;
374	chip_id = id->driver_data;
375
376	if (client->dev.of_node) {
377		const struct of_device_id *match;
378		match = of_match_device(of_match_ptr(tps62360_of_match),
379				&client->dev);
380		if (!match) {
381			dev_err(&client->dev, "Error: No device match found\n");
382			return -ENODEV;
383		}
384		chip_id = (int)match->data;
385		if (!pdata)
386			pdata = of_get_tps62360_platform_data(&client->dev);
387	}
388
389	if (!pdata) {
390		dev_err(&client->dev, "%s(): Platform data not found\n",
391						__func__);
392		return -EIO;
393	}
394
395	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
396	if (!tps) {
397		dev_err(&client->dev, "%s(): Memory allocation failed\n",
398						__func__);
399		return -ENOMEM;
400	}
401
402	tps->en_discharge = pdata->en_discharge;
403	tps->en_internal_pulldn = pdata->en_internal_pulldn;
404	tps->vsel0_gpio = pdata->vsel0_gpio;
405	tps->vsel1_gpio = pdata->vsel1_gpio;
406	tps->dev = &client->dev;
407
408	switch (chip_id) {
409	case TPS62360:
410	case TPS62362:
411		tps->voltage_base = TPS62360_BASE_VOLTAGE;
412		tps->voltage_reg_mask = 0x3F;
413		tps->desc.n_voltages = TPS62360_N_VOLTAGES;
414		break;
415	case TPS62361:
416	case TPS62363:
417		tps->voltage_base = TPS62361_BASE_VOLTAGE;
418		tps->voltage_reg_mask = 0x7F;
419		tps->desc.n_voltages = TPS62361_N_VOLTAGES;
420		break;
421	default:
422		return -ENODEV;
423	}
424
425	tps->desc.name = id->name;
426	tps->desc.id = 0;
427	tps->desc.ops = &tps62360_dcdc_ops;
428	tps->desc.type = REGULATOR_VOLTAGE;
429	tps->desc.owner = THIS_MODULE;
430	tps->desc.min_uV = tps->voltage_base;
431	tps->desc.uV_step = 10000;
432
433	tps->regmap = devm_regmap_init_i2c(client, &tps62360_regmap_config);
434	if (IS_ERR(tps->regmap)) {
435		ret = PTR_ERR(tps->regmap);
436		dev_err(&client->dev,
437			"%s(): regmap allocation failed with err %d\n",
438			__func__, ret);
439		return ret;
440	}
441	i2c_set_clientdata(client, tps);
442
443	tps->curr_vset_id = (pdata->vsel1_def_state & 1) * 2 +
444				(pdata->vsel0_def_state & 1);
445	tps->lru_index[0] = tps->curr_vset_id;
446	tps->valid_gpios = false;
447
448	if (gpio_is_valid(tps->vsel0_gpio) && gpio_is_valid(tps->vsel1_gpio)) {
449		int gpio_flags;
450		gpio_flags = (pdata->vsel0_def_state) ?
451				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
452		ret = gpio_request_one(tps->vsel0_gpio,
453				gpio_flags, "tps62360-vsel0");
454		if (ret) {
455			dev_err(&client->dev,
456				"%s(): Could not obtain vsel0 GPIO %d: %d\n",
457				__func__, tps->vsel0_gpio, ret);
458			goto err_gpio0;
459		}
460
461		gpio_flags = (pdata->vsel1_def_state) ?
462				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
463		ret = gpio_request_one(tps->vsel1_gpio,
464				gpio_flags, "tps62360-vsel1");
465		if (ret) {
466			dev_err(&client->dev,
467				"%s(): Could not obtain vsel1 GPIO %d: %d\n",
468				__func__, tps->vsel1_gpio, ret);
469			goto err_gpio1;
470		}
471		tps->valid_gpios = true;
472
473		/*
474		 * Initialize the lru index with vset_reg id
475		 * The index 0 will be most recently used and
476		 * set with the tps->curr_vset_id */
477		for (i = 0; i < 4; ++i)
478			tps->lru_index[i] = i;
479		tps->lru_index[0] = tps->curr_vset_id;
480		tps->lru_index[tps->curr_vset_id] = 0;
481	}
482
483	ret = tps62360_init_dcdc(tps, pdata);
484	if (ret < 0) {
485		dev_err(tps->dev, "%s(): Init failed with err = %d\n",
486				__func__, ret);
487		goto err_init;
488	}
489
490	config.dev = &client->dev;
491	config.init_data = pdata->reg_init_data;
492	config.driver_data = tps;
493	config.of_node = client->dev.of_node;
494
495	/* Register the regulators */
496	rdev = regulator_register(&tps->desc, &config);
497	if (IS_ERR(rdev)) {
498		dev_err(tps->dev,
499			"%s(): regulator register failed with err %s\n",
500			__func__, id->name);
501		ret = PTR_ERR(rdev);
502		goto err_init;
503	}
504
505	tps->rdev = rdev;
506	return 0;
507
508err_init:
509	if (gpio_is_valid(tps->vsel1_gpio))
510		gpio_free(tps->vsel1_gpio);
511err_gpio1:
512	if (gpio_is_valid(tps->vsel0_gpio))
513		gpio_free(tps->vsel0_gpio);
514err_gpio0:
515	return ret;
516}
517
518/**
519 * tps62360_remove - tps62360 driver i2c remove handler
520 * @client: i2c driver client device structure
521 *
522 * Unregister TPS driver as an i2c client device driver
523 */
524static int __devexit tps62360_remove(struct i2c_client *client)
525{
526	struct tps62360_chip *tps = i2c_get_clientdata(client);
527
528	if (gpio_is_valid(tps->vsel1_gpio))
529		gpio_free(tps->vsel1_gpio);
530
531	if (gpio_is_valid(tps->vsel0_gpio))
532		gpio_free(tps->vsel0_gpio);
533
534	regulator_unregister(tps->rdev);
535	return 0;
536}
537
538static void tps62360_shutdown(struct i2c_client *client)
539{
540	struct tps62360_chip *tps = i2c_get_clientdata(client);
541	int st;
542
543	if (!tps->en_discharge)
544		return;
545
546	/* Configure the output discharge path */
547	st = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
548	if (st < 0)
549		dev_err(tps->dev,
550			"%s(): register %d update failed with err %d\n",
551			__func__, REG_RAMPCTRL, st);
552}
553
554static const struct i2c_device_id tps62360_id[] = {
555	{.name = "tps62360", .driver_data = TPS62360},
556	{.name = "tps62361", .driver_data = TPS62361},
557	{.name = "tps62362", .driver_data = TPS62362},
558	{.name = "tps62363", .driver_data = TPS62363},
559	{},
560};
561
562MODULE_DEVICE_TABLE(i2c, tps62360_id);
563
564static struct i2c_driver tps62360_i2c_driver = {
565	.driver = {
566		.name = "tps62360",
567		.owner = THIS_MODULE,
568		.of_match_table = of_match_ptr(tps62360_of_match),
569	},
570	.probe = tps62360_probe,
571	.remove = __devexit_p(tps62360_remove),
572	.shutdown = tps62360_shutdown,
573	.id_table = tps62360_id,
574};
575
576static int __init tps62360_init(void)
577{
578	return i2c_add_driver(&tps62360_i2c_driver);
579}
580subsys_initcall(tps62360_init);
581
582static void __exit tps62360_cleanup(void)
583{
584	i2c_del_driver(&tps62360_i2c_driver);
585}
586module_exit(tps62360_cleanup);
587
588MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
589MODULE_DESCRIPTION("TPS6236x voltage regulator driver");
590MODULE_LICENSE("GPL v2");