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 vsel0_gpio;
69 	int vsel1_gpio;
70 	u8 voltage_reg_mask;
71 	bool en_internal_pulldn;
72 	bool en_discharge;
73 	bool valid_gpios;
74 	int lru_index[4];
75 	int curr_vset_vsel[4];
76 	int curr_vset_id;
77 };
78 
79 /*
80  * find_voltage_set_register: Find new voltage configuration register
81  * (VSET) id.
82  * The finding of the new VSET register will be based on the LRU mechanism.
83  * Each VSET register will have different voltage configured . This
84  * Function will look if any of the VSET register have requested voltage set
85  * or not.
86  *     - If it is already there then it will make that register as most
87  *       recently used and return as found so that caller need not to set
88  *       the VSET register but need to set the proper gpios to select this
89  *       VSET register.
90  *     - If requested voltage is not found then it will use the least
91  *       recently mechanism to get new VSET register for new configuration
92  *       and will return not_found so that caller need to set new VSET
93  *       register and then gpios (both).
94  */
95 static bool find_voltage_set_register(struct tps62360_chip *tps,
96 		int req_vsel, int *vset_reg_id)
97 {
98 	int i;
99 	bool found = false;
100 	int new_vset_reg = tps->lru_index[3];
101 	int found_index = 3;
102 
103 	for (i = 0; i < 4; ++i) {
104 		if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
105 			new_vset_reg = tps->lru_index[i];
106 			found_index = i;
107 			found = true;
108 			goto update_lru_index;
109 		}
110 	}
111 
112 update_lru_index:
113 	for (i = found_index; i > 0; i--)
114 		tps->lru_index[i] = tps->lru_index[i - 1];
115 
116 	tps->lru_index[0] = new_vset_reg;
117 	*vset_reg_id = new_vset_reg;
118 	return found;
119 }
120 
121 static int tps62360_dcdc_get_voltage_sel(struct regulator_dev *dev)
122 {
123 	struct tps62360_chip *tps = rdev_get_drvdata(dev);
124 	int vsel;
125 	unsigned int data;
126 	int ret;
127 
128 	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
129 	if (ret < 0) {
130 		dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
131 			__func__, REG_VSET0 + tps->curr_vset_id, ret);
132 		return ret;
133 	}
134 	vsel = (int)data & tps->voltage_reg_mask;
135 	return vsel;
136 }
137 
138 static int tps62360_dcdc_set_voltage_sel(struct regulator_dev *dev,
139 					 unsigned selector)
140 {
141 	struct tps62360_chip *tps = rdev_get_drvdata(dev);
142 	int ret;
143 	bool found = false;
144 	int new_vset_id = tps->curr_vset_id;
145 
146 	/*
147 	 * If gpios are available to select the VSET register then least
148 	 * recently used register for new configuration.
149 	 */
150 	if (tps->valid_gpios)
151 		found = find_voltage_set_register(tps, selector, &new_vset_id);
152 
153 	if (!found) {
154 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
155 				tps->voltage_reg_mask, selector);
156 		if (ret < 0) {
157 			dev_err(tps->dev,
158 				"%s(): register %d update failed with err %d\n",
159 				 __func__, REG_VSET0 + new_vset_id, ret);
160 			return ret;
161 		}
162 		tps->curr_vset_id = new_vset_id;
163 		tps->curr_vset_vsel[new_vset_id] = selector;
164 	}
165 
166 	/* Select proper VSET register vio gpios */
167 	if (tps->valid_gpios) {
168 		gpio_set_value_cansleep(tps->vsel0_gpio, new_vset_id & 0x1);
169 		gpio_set_value_cansleep(tps->vsel1_gpio,
170 					(new_vset_id >> 1) & 0x1);
171 	}
172 	return 0;
173 }
174 
175 static int tps62360_set_mode(struct regulator_dev *rdev, unsigned int mode)
176 {
177 	struct tps62360_chip *tps = rdev_get_drvdata(rdev);
178 	int i;
179 	int val;
180 	int ret;
181 
182 	/* Enable force PWM mode in FAST mode only. */
183 	switch (mode) {
184 	case REGULATOR_MODE_FAST:
185 		val = FORCE_PWM_ENABLE;
186 		break;
187 
188 	case REGULATOR_MODE_NORMAL:
189 		val = 0;
190 		break;
191 
192 	default:
193 		return -EINVAL;
194 	}
195 
196 	if (!tps->valid_gpios) {
197 		ret = regmap_update_bits(tps->regmap,
198 			REG_VSET0 + tps->curr_vset_id, FORCE_PWM_ENABLE, val);
199 		if (ret < 0)
200 			dev_err(tps->dev,
201 				"%s(): register %d update failed with err %d\n",
202 				__func__, REG_VSET0 + tps->curr_vset_id, ret);
203 		return ret;
204 	}
205 
206 	/* If gpios are valid then all register set need to be control */
207 	for (i = 0; i < 4; ++i) {
208 		ret = regmap_update_bits(tps->regmap,
209 					REG_VSET0 + i, FORCE_PWM_ENABLE, val);
210 		if (ret < 0) {
211 			dev_err(tps->dev,
212 				"%s(): register %d update failed with err %d\n",
213 				__func__, REG_VSET0 + i, ret);
214 			return ret;
215 		}
216 	}
217 	return ret;
218 }
219 
220 static unsigned int tps62360_get_mode(struct regulator_dev *rdev)
221 {
222 	struct tps62360_chip *tps = rdev_get_drvdata(rdev);
223 	unsigned int data;
224 	int ret;
225 
226 	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
227 	if (ret < 0) {
228 		dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
229 			__func__, REG_VSET0 + tps->curr_vset_id, ret);
230 		return ret;
231 	}
232 	return (data & FORCE_PWM_ENABLE) ?
233 				REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
234 }
235 
236 static struct regulator_ops tps62360_dcdc_ops = {
237 	.get_voltage_sel	= tps62360_dcdc_get_voltage_sel,
238 	.set_voltage_sel	= tps62360_dcdc_set_voltage_sel,
239 	.list_voltage		= regulator_list_voltage_linear,
240 	.map_voltage		= regulator_map_voltage_linear,
241 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
242 	.set_mode		= tps62360_set_mode,
243 	.get_mode		= tps62360_get_mode,
244 };
245 
246 static int tps62360_init_dcdc(struct tps62360_chip *tps,
247 		struct tps62360_regulator_platform_data *pdata)
248 {
249 	int ret;
250 	unsigned int ramp_ctrl;
251 
252 	/* Initialize internal pull up/down control */
253 	if (tps->en_internal_pulldn)
254 		ret = regmap_write(tps->regmap, REG_CONTROL, 0xE0);
255 	else
256 		ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
257 	if (ret < 0) {
258 		dev_err(tps->dev,
259 			"%s(): register %d write failed with err %d\n",
260 			__func__, REG_CONTROL, ret);
261 		return ret;
262 	}
263 
264 	/* Reset output discharge path to reduce power consumption */
265 	ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), 0);
266 	if (ret < 0) {
267 		dev_err(tps->dev,
268 			"%s(): register %d update failed with err %d\n",
269 			__func__, REG_RAMPCTRL, ret);
270 		return ret;
271 	}
272 
273 	/* Get ramp value from ramp control register */
274 	ret = regmap_read(tps->regmap, REG_RAMPCTRL, &ramp_ctrl);
275 	if (ret < 0) {
276 		dev_err(tps->dev,
277 			"%s(): register %d read failed with err %d\n",
278 			__func__, REG_RAMPCTRL, ret);
279 		return ret;
280 	}
281 	ramp_ctrl = (ramp_ctrl >> 5) & 0x7;
282 
283 	/* ramp mV/us = 32/(2^ramp_ctrl) */
284 	tps->desc.ramp_delay = DIV_ROUND_UP(32000, BIT(ramp_ctrl));
285 	return ret;
286 }
287 
288 static const struct regmap_config tps62360_regmap_config = {
289 	.reg_bits		= 8,
290 	.val_bits		= 8,
291 	.max_register		= REG_CHIPID,
292 	.cache_type		= REGCACHE_RBTREE,
293 };
294 
295 static struct tps62360_regulator_platform_data *
296 	of_get_tps62360_platform_data(struct device *dev,
297 				      const struct regulator_desc *desc)
298 {
299 	struct tps62360_regulator_platform_data *pdata;
300 	struct device_node *np = dev->of_node;
301 
302 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
303 	if (!pdata)
304 		return NULL;
305 
306 	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node,
307 							  desc);
308 	if (!pdata->reg_init_data) {
309 		dev_err(dev, "Not able to get OF regulator init data\n");
310 		return NULL;
311 	}
312 
313 	pdata->vsel0_gpio = of_get_named_gpio(np, "vsel0-gpio", 0);
314 	pdata->vsel1_gpio = of_get_named_gpio(np, "vsel1-gpio", 0);
315 
316 	if (of_find_property(np, "ti,vsel0-state-high", NULL))
317 		pdata->vsel0_def_state = 1;
318 
319 	if (of_find_property(np, "ti,vsel1-state-high", NULL))
320 		pdata->vsel1_def_state = 1;
321 
322 	if (of_find_property(np, "ti,enable-pull-down", NULL))
323 		pdata->en_internal_pulldn = true;
324 
325 	if (of_find_property(np, "ti,enable-vout-discharge", NULL))
326 		pdata->en_discharge = true;
327 
328 	return pdata;
329 }
330 
331 #if defined(CONFIG_OF)
332 static const struct of_device_id tps62360_of_match[] = {
333 	 { .compatible = "ti,tps62360", .data = (void *)TPS62360},
334 	 { .compatible = "ti,tps62361", .data = (void *)TPS62361},
335 	 { .compatible = "ti,tps62362", .data = (void *)TPS62362},
336 	 { .compatible = "ti,tps62363", .data = (void *)TPS62363},
337 	{},
338 };
339 MODULE_DEVICE_TABLE(of, tps62360_of_match);
340 #endif
341 
342 static int tps62360_probe(struct i2c_client *client,
343 				     const struct i2c_device_id *id)
344 {
345 	struct regulator_config config = { };
346 	struct tps62360_regulator_platform_data *pdata;
347 	struct regulator_dev *rdev;
348 	struct tps62360_chip *tps;
349 	int ret;
350 	int i;
351 	int chip_id;
352 
353 	pdata = dev_get_platdata(&client->dev);
354 
355 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
356 	if (!tps)
357 		return -ENOMEM;
358 
359 	tps->desc.name = client->name;
360 	tps->desc.id = 0;
361 	tps->desc.ops = &tps62360_dcdc_ops;
362 	tps->desc.type = REGULATOR_VOLTAGE;
363 	tps->desc.owner = THIS_MODULE;
364 	tps->desc.uV_step = 10000;
365 
366 	if (client->dev.of_node) {
367 		const struct of_device_id *match;
368 		match = of_match_device(of_match_ptr(tps62360_of_match),
369 				&client->dev);
370 		if (!match) {
371 			dev_err(&client->dev, "Error: No device match found\n");
372 			return -ENODEV;
373 		}
374 		chip_id = (int)(long)match->data;
375 		if (!pdata)
376 			pdata = of_get_tps62360_platform_data(&client->dev,
377 							      &tps->desc);
378 	} else if (id) {
379 		chip_id = id->driver_data;
380 	} else {
381 		dev_err(&client->dev, "No device tree match or id table match found\n");
382 		return -ENODEV;
383 	}
384 
385 	if (!pdata) {
386 		dev_err(&client->dev, "%s(): Platform data not found\n",
387 						__func__);
388 		return -EIO;
389 	}
390 
391 	tps->en_discharge = pdata->en_discharge;
392 	tps->en_internal_pulldn = pdata->en_internal_pulldn;
393 	tps->vsel0_gpio = pdata->vsel0_gpio;
394 	tps->vsel1_gpio = pdata->vsel1_gpio;
395 	tps->dev = &client->dev;
396 
397 	switch (chip_id) {
398 	case TPS62360:
399 	case TPS62362:
400 		tps->desc.min_uV = TPS62360_BASE_VOLTAGE;
401 		tps->voltage_reg_mask = 0x3F;
402 		tps->desc.n_voltages = TPS62360_N_VOLTAGES;
403 		break;
404 	case TPS62361:
405 	case TPS62363:
406 		tps->desc.min_uV = TPS62361_BASE_VOLTAGE;
407 		tps->voltage_reg_mask = 0x7F;
408 		tps->desc.n_voltages = TPS62361_N_VOLTAGES;
409 		break;
410 	default:
411 		return -ENODEV;
412 	}
413 
414 	tps->regmap = devm_regmap_init_i2c(client, &tps62360_regmap_config);
415 	if (IS_ERR(tps->regmap)) {
416 		ret = PTR_ERR(tps->regmap);
417 		dev_err(&client->dev,
418 			"%s(): regmap allocation failed with err %d\n",
419 			__func__, ret);
420 		return ret;
421 	}
422 	i2c_set_clientdata(client, tps);
423 
424 	tps->curr_vset_id = (pdata->vsel1_def_state & 1) * 2 +
425 				(pdata->vsel0_def_state & 1);
426 	tps->lru_index[0] = tps->curr_vset_id;
427 	tps->valid_gpios = false;
428 
429 	if (gpio_is_valid(tps->vsel0_gpio) && gpio_is_valid(tps->vsel1_gpio)) {
430 		int gpio_flags;
431 		gpio_flags = (pdata->vsel0_def_state) ?
432 				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
433 		ret = devm_gpio_request_one(&client->dev, tps->vsel0_gpio,
434 				gpio_flags, "tps62360-vsel0");
435 		if (ret) {
436 			dev_err(&client->dev,
437 				"%s(): Could not obtain vsel0 GPIO %d: %d\n",
438 				__func__, tps->vsel0_gpio, ret);
439 			return ret;
440 		}
441 
442 		gpio_flags = (pdata->vsel1_def_state) ?
443 				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
444 		ret = devm_gpio_request_one(&client->dev, tps->vsel1_gpio,
445 				gpio_flags, "tps62360-vsel1");
446 		if (ret) {
447 			dev_err(&client->dev,
448 				"%s(): Could not obtain vsel1 GPIO %d: %d\n",
449 				__func__, tps->vsel1_gpio, ret);
450 			return ret;
451 		}
452 		tps->valid_gpios = true;
453 
454 		/*
455 		 * Initialize the lru index with vset_reg id
456 		 * The index 0 will be most recently used and
457 		 * set with the tps->curr_vset_id */
458 		for (i = 0; i < 4; ++i)
459 			tps->lru_index[i] = i;
460 		tps->lru_index[0] = tps->curr_vset_id;
461 		tps->lru_index[tps->curr_vset_id] = 0;
462 	}
463 
464 	ret = tps62360_init_dcdc(tps, pdata);
465 	if (ret < 0) {
466 		dev_err(tps->dev, "%s(): Init failed with err = %d\n",
467 				__func__, ret);
468 		return ret;
469 	}
470 
471 	config.dev = &client->dev;
472 	config.init_data = pdata->reg_init_data;
473 	config.driver_data = tps;
474 	config.of_node = client->dev.of_node;
475 
476 	/* Register the regulators */
477 	rdev = devm_regulator_register(&client->dev, &tps->desc, &config);
478 	if (IS_ERR(rdev)) {
479 		dev_err(tps->dev,
480 			"%s(): regulator register failed with err %s\n",
481 			__func__, id->name);
482 		return PTR_ERR(rdev);
483 	}
484 
485 	tps->rdev = rdev;
486 	return 0;
487 }
488 
489 static void tps62360_shutdown(struct i2c_client *client)
490 {
491 	struct tps62360_chip *tps = i2c_get_clientdata(client);
492 	int st;
493 
494 	if (!tps->en_discharge)
495 		return;
496 
497 	/* Configure the output discharge path */
498 	st = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
499 	if (st < 0)
500 		dev_err(tps->dev,
501 			"%s(): register %d update failed with err %d\n",
502 			__func__, REG_RAMPCTRL, st);
503 }
504 
505 static const struct i2c_device_id tps62360_id[] = {
506 	{.name = "tps62360", .driver_data = TPS62360},
507 	{.name = "tps62361", .driver_data = TPS62361},
508 	{.name = "tps62362", .driver_data = TPS62362},
509 	{.name = "tps62363", .driver_data = TPS62363},
510 	{},
511 };
512 
513 MODULE_DEVICE_TABLE(i2c, tps62360_id);
514 
515 static struct i2c_driver tps62360_i2c_driver = {
516 	.driver = {
517 		.name = "tps62360",
518 		.of_match_table = of_match_ptr(tps62360_of_match),
519 	},
520 	.probe = tps62360_probe,
521 	.shutdown = tps62360_shutdown,
522 	.id_table = tps62360_id,
523 };
524 
525 static int __init tps62360_init(void)
526 {
527 	return i2c_add_driver(&tps62360_i2c_driver);
528 }
529 subsys_initcall(tps62360_init);
530 
531 static void __exit tps62360_cleanup(void)
532 {
533 	i2c_del_driver(&tps62360_i2c_driver);
534 }
535 module_exit(tps62360_cleanup);
536 
537 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
538 MODULE_DESCRIPTION("TPS6236x voltage regulator driver");
539 MODULE_LICENSE("GPL v2");
540