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 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 */
95static 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
112update_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
121static 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
138static 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
175static 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
220static 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
236static 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
246static 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
288static 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
295static 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)
332static 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};
339MODULE_DEVICE_TABLE(of, tps62360_of_match);
340#endif
341
342static 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
489static 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
505static 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
513MODULE_DEVICE_TABLE(i2c, tps62360_id);
514
515static struct i2c_driver tps62360_i2c_driver = {
516	.driver = {
517		.name = "tps62360",
518		.owner = THIS_MODULE,
519		.of_match_table = of_match_ptr(tps62360_of_match),
520	},
521	.probe = tps62360_probe,
522	.shutdown = tps62360_shutdown,
523	.id_table = tps62360_id,
524};
525
526static int __init tps62360_init(void)
527{
528	return i2c_add_driver(&tps62360_i2c_driver);
529}
530subsys_initcall(tps62360_init);
531
532static void __exit tps62360_cleanup(void)
533{
534	i2c_del_driver(&tps62360_i2c_driver);
535}
536module_exit(tps62360_cleanup);
537
538MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
539MODULE_DESCRIPTION("TPS6236x voltage regulator driver");
540MODULE_LICENSE("GPL v2");
541