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 
54 enum 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 */
63 struct 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  */
98 static 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 
115 update_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 
124 static 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 
141 static 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 
178 static 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 
195 static 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 
240 static 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 
256 static 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 
266 static 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 
308 static 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 
315 static 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)
352 static 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 };
359 MODULE_DEVICE_TABLE(of, tps62360_of_match);
360 #endif
361 
362 static 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 
508 err_init:
509 	if (gpio_is_valid(tps->vsel1_gpio))
510 		gpio_free(tps->vsel1_gpio);
511 err_gpio1:
512 	if (gpio_is_valid(tps->vsel0_gpio))
513 		gpio_free(tps->vsel0_gpio);
514 err_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  */
524 static 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 
538 static 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 
554 static 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 
562 MODULE_DEVICE_TABLE(i2c, tps62360_id);
563 
564 static 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 
576 static int __init tps62360_init(void)
577 {
578 	return i2c_add_driver(&tps62360_i2c_driver);
579 }
580 subsys_initcall(tps62360_init);
581 
582 static void __exit tps62360_cleanup(void)
583 {
584 	i2c_del_driver(&tps62360_i2c_driver);
585 }
586 module_exit(tps62360_cleanup);
587 
588 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
589 MODULE_DESCRIPTION("TPS6236x voltage regulator driver");
590 MODULE_LICENSE("GPL v2");
591