1 /*
2  * tps62360.c -- TI tps62360
3  *
4  * Driver for processor core supply tps62360 and tps62361B
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/platform_device.h>
30 #include <linux/regulator/driver.h>
31 #include <linux/regulator/machine.h>
32 #include <linux/regulator/tps62360.h>
33 #include <linux/gpio.h>
34 #include <linux/i2c.h>
35 #include <linux/delay.h>
36 #include <linux/slab.h>
37 #include <linux/regmap.h>
38 
39 /* Register definitions */
40 #define REG_VSET0		0
41 #define REG_VSET1		1
42 #define REG_VSET2		2
43 #define REG_VSET3		3
44 #define REG_CONTROL		4
45 #define REG_TEMP		5
46 #define REG_RAMPCTRL		6
47 #define REG_CHIPID		8
48 
49 enum chips {TPS62360, TPS62361};
50 
51 #define TPS62360_BASE_VOLTAGE	770
52 #define TPS62360_N_VOLTAGES	64
53 
54 #define TPS62361_BASE_VOLTAGE	500
55 #define TPS62361_N_VOLTAGES	128
56 
57 /* tps 62360 chip information */
58 struct tps62360_chip {
59 	const char *name;
60 	struct device *dev;
61 	struct regulator_desc desc;
62 	struct i2c_client *client;
63 	struct regulator_dev *rdev;
64 	struct regmap *regmap;
65 	int chip_id;
66 	int vsel0_gpio;
67 	int vsel1_gpio;
68 	int voltage_base;
69 	u8 voltage_reg_mask;
70 	bool en_internal_pulldn;
71 	bool en_force_pwm;
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 	for (i = 0; i < 4; ++i) {
103 		if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
104 			new_vset_reg = tps->lru_index[i];
105 			found_index = i;
106 			found = true;
107 			goto update_lru_index;
108 		}
109 	}
110 
111 update_lru_index:
112 	for (i = found_index; i > 0; i--)
113 		tps->lru_index[i] = tps->lru_index[i - 1];
114 
115 	tps->lru_index[0] = new_vset_reg;
116 	*vset_reg_id = new_vset_reg;
117 	return found;
118 }
119 
120 static int tps62360_dcdc_get_voltage(struct regulator_dev *dev)
121 {
122 	struct tps62360_chip *tps = rdev_get_drvdata(dev);
123 	int vsel;
124 	unsigned int data;
125 	int ret;
126 
127 	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
128 	if (ret < 0) {
129 		dev_err(tps->dev, "%s: Error in reading register %d\n",
130 			__func__, REG_VSET0 + tps->curr_vset_id);
131 		return ret;
132 	}
133 	vsel = (int)data & tps->voltage_reg_mask;
134 	return (tps->voltage_base + vsel * 10) * 1000;
135 }
136 
137 static int tps62360_dcdc_set_voltage(struct regulator_dev *dev,
138 	     int min_uV, int max_uV, unsigned *selector)
139 {
140 	struct tps62360_chip *tps = rdev_get_drvdata(dev);
141 	int vsel;
142 	int ret;
143 	bool found = false;
144 	int new_vset_id = tps->curr_vset_id;
145 
146 	if (max_uV < min_uV)
147 		return -EINVAL;
148 
149 	if (min_uV >
150 		((tps->voltage_base + (tps->desc.n_voltages - 1) * 10) * 1000))
151 		return -EINVAL;
152 
153 	if (max_uV < tps->voltage_base * 1000)
154 		return -EINVAL;
155 
156 	vsel = DIV_ROUND_UP(min_uV - (tps->voltage_base * 1000), 10000);
157 	if (selector)
158 		*selector = (vsel & tps->voltage_reg_mask);
159 
160 	/*
161 	 * If gpios are available to select the VSET register then least
162 	 * recently used register for new configuration.
163 	 */
164 	if (tps->valid_gpios)
165 		found = find_voltage_set_register(tps, vsel, &new_vset_id);
166 
167 	if (!found) {
168 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
169 				tps->voltage_reg_mask, vsel);
170 		if (ret < 0) {
171 			dev_err(tps->dev, "%s: Error in updating register %d\n",
172 				 __func__, REG_VSET0 + new_vset_id);
173 			return ret;
174 		}
175 		tps->curr_vset_id = new_vset_id;
176 		tps->curr_vset_vsel[new_vset_id] = vsel;
177 	}
178 
179 	/* Select proper VSET register vio gpios */
180 	if (tps->valid_gpios) {
181 		gpio_set_value_cansleep(tps->vsel0_gpio,
182 					new_vset_id & 0x1);
183 		gpio_set_value_cansleep(tps->vsel1_gpio,
184 					(new_vset_id >> 1) & 0x1);
185 	}
186 	return 0;
187 }
188 
189 static int tps62360_dcdc_list_voltage(struct regulator_dev *dev,
190 					unsigned selector)
191 {
192 	struct tps62360_chip *tps = rdev_get_drvdata(dev);
193 
194 	if (selector >= tps->desc.n_voltages)
195 		return -EINVAL;
196 	return (tps->voltage_base + selector * 10) * 1000;
197 }
198 
199 static struct regulator_ops tps62360_dcdc_ops = {
200 	.get_voltage = tps62360_dcdc_get_voltage,
201 	.set_voltage = tps62360_dcdc_set_voltage,
202 	.list_voltage = tps62360_dcdc_list_voltage,
203 };
204 
205 static int tps62360_init_force_pwm(struct tps62360_chip *tps,
206 	struct tps62360_regulator_platform_data *pdata,
207 	int vset_id)
208 {
209 	unsigned int data;
210 	int ret;
211 	ret = regmap_read(tps->regmap, REG_VSET0 + vset_id, &data);
212 	if (ret < 0) {
213 		dev_err(tps->dev, "%s() fails in writing reg %d\n",
214 			__func__, REG_VSET0 + vset_id);
215 		return ret;
216 	}
217 	tps->curr_vset_vsel[vset_id] = data & tps->voltage_reg_mask;
218 	if (pdata->en_force_pwm)
219 		data |= BIT(7);
220 	else
221 		data &= ~BIT(7);
222 	ret = regmap_write(tps->regmap, REG_VSET0 + vset_id, data);
223 	if (ret < 0)
224 		dev_err(tps->dev, "%s() fails in writing reg %d\n",
225 				__func__, REG_VSET0 + vset_id);
226 	return ret;
227 }
228 
229 static int tps62360_init_dcdc(struct tps62360_chip *tps,
230 		struct tps62360_regulator_platform_data *pdata)
231 {
232 	int ret;
233 	int i;
234 
235 	/* Initailize internal pull up/down control */
236 	if (tps->en_internal_pulldn)
237 		ret = regmap_write(tps->regmap, REG_CONTROL, 0xE0);
238 	else
239 		ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
240 	if (ret < 0) {
241 		dev_err(tps->dev, "%s() fails in writing reg %d\n",
242 			__func__, REG_CONTROL);
243 		return ret;
244 	}
245 
246 	/* Initailize force PWM mode */
247 	if (tps->valid_gpios) {
248 		for (i = 0; i < 4; ++i) {
249 			ret = tps62360_init_force_pwm(tps, pdata, i);
250 			if (ret < 0)
251 				return ret;
252 		}
253 	} else {
254 		ret = tps62360_init_force_pwm(tps, pdata, tps->curr_vset_id);
255 		if (ret < 0)
256 			return ret;
257 	}
258 
259 	/* Reset output discharge path to reduce power consumption */
260 	ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), 0);
261 	if (ret < 0)
262 		dev_err(tps->dev, "%s() fails in updating reg %d\n",
263 			__func__, REG_RAMPCTRL);
264 	return ret;
265 }
266 
267 static const struct regmap_config tps62360_regmap_config = {
268 	.reg_bits = 8,
269 	.val_bits = 8,
270 };
271 
272 static int __devinit tps62360_probe(struct i2c_client *client,
273 				     const struct i2c_device_id *id)
274 {
275 	struct tps62360_regulator_platform_data *pdata;
276 	struct regulator_dev *rdev;
277 	struct tps62360_chip *tps;
278 	int ret;
279 	int i;
280 
281 	pdata = client->dev.platform_data;
282 	if (!pdata) {
283 		dev_err(&client->dev, "%s() Err: Platform data not found\n",
284 						__func__);
285 		return -EIO;
286 	}
287 
288 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
289 	if (!tps) {
290 		dev_err(&client->dev, "%s() Err: Memory allocation fails\n",
291 						__func__);
292 		return -ENOMEM;
293 	}
294 
295 	tps->en_force_pwm = pdata->en_force_pwm;
296 	tps->en_discharge = pdata->en_discharge;
297 	tps->en_internal_pulldn = pdata->en_internal_pulldn;
298 	tps->vsel0_gpio = pdata->vsel0_gpio;
299 	tps->vsel1_gpio = pdata->vsel1_gpio;
300 	tps->client = client;
301 	tps->dev = &client->dev;
302 	tps->name = id->name;
303 	tps->voltage_base = (id->driver_data == TPS62360) ?
304 				TPS62360_BASE_VOLTAGE : TPS62361_BASE_VOLTAGE;
305 	tps->voltage_reg_mask = (id->driver_data == TPS62360) ? 0x3F : 0x7F;
306 
307 	tps->desc.name = id->name;
308 	tps->desc.id = 0;
309 	tps->desc.n_voltages = (id->driver_data == TPS62360) ?
310 				TPS62360_N_VOLTAGES : TPS62361_N_VOLTAGES;
311 	tps->desc.ops = &tps62360_dcdc_ops;
312 	tps->desc.type = REGULATOR_VOLTAGE;
313 	tps->desc.owner = THIS_MODULE;
314 	tps->regmap = regmap_init_i2c(client, &tps62360_regmap_config);
315 	if (IS_ERR(tps->regmap)) {
316 		ret = PTR_ERR(tps->regmap);
317 		dev_err(&client->dev, "%s() Err: Failed to allocate register"
318 			"map: %d\n", __func__, ret);
319 		return ret;
320 	}
321 	i2c_set_clientdata(client, tps);
322 
323 	tps->curr_vset_id = (pdata->vsel1_def_state & 1) * 2 +
324 				(pdata->vsel0_def_state & 1);
325 	tps->lru_index[0] = tps->curr_vset_id;
326 	tps->valid_gpios = false;
327 
328 	if (gpio_is_valid(tps->vsel0_gpio) && gpio_is_valid(tps->vsel1_gpio)) {
329 		ret = gpio_request(tps->vsel0_gpio, "tps62360-vsel0");
330 		if (ret) {
331 			dev_err(&client->dev,
332 				"Err: Could not obtain vsel0 GPIO %d: %d\n",
333 						tps->vsel0_gpio, ret);
334 			goto err_gpio0;
335 		}
336 		ret = gpio_direction_output(tps->vsel0_gpio,
337 					pdata->vsel0_def_state);
338 		if (ret) {
339 			dev_err(&client->dev, "Err: Could not set direction of"
340 				"vsel0 GPIO %d: %d\n", tps->vsel0_gpio, ret);
341 			gpio_free(tps->vsel0_gpio);
342 			goto err_gpio0;
343 		}
344 
345 		ret = gpio_request(tps->vsel1_gpio, "tps62360-vsel1");
346 		if (ret) {
347 			dev_err(&client->dev,
348 				"Err: Could not obtain vsel1 GPIO %d: %d\n",
349 						tps->vsel1_gpio, ret);
350 			goto err_gpio1;
351 		}
352 		ret = gpio_direction_output(tps->vsel1_gpio,
353 					pdata->vsel1_def_state);
354 		if (ret) {
355 			dev_err(&client->dev, "Err: Could not set direction of"
356 				"vsel1 GPIO %d: %d\n", tps->vsel1_gpio, ret);
357 			gpio_free(tps->vsel1_gpio);
358 			goto err_gpio1;
359 		}
360 		tps->valid_gpios = true;
361 
362 		/*
363 		 * Initialize the lru index with vset_reg id
364 		 * The index 0 will be most recently used and
365 		 * set with the tps->curr_vset_id */
366 		for (i = 0; i < 4; ++i)
367 			tps->lru_index[i] = i;
368 		tps->lru_index[0] = tps->curr_vset_id;
369 		tps->lru_index[tps->curr_vset_id] = 0;
370 	}
371 
372 	ret = tps62360_init_dcdc(tps, pdata);
373 	if (ret < 0) {
374 		dev_err(tps->dev, "%s() Err: Init fails with = %d\n",
375 				__func__, ret);
376 		goto err_init;
377 	}
378 
379 	/* Register the regulators */
380 	rdev = regulator_register(&tps->desc, &client->dev,
381 				&pdata->reg_init_data, tps, NULL);
382 	if (IS_ERR(rdev)) {
383 		dev_err(tps->dev, "%s() Err: Failed to register %s\n",
384 				__func__, id->name);
385 		ret = PTR_ERR(rdev);
386 		goto err_init;
387 	}
388 
389 	tps->rdev = rdev;
390 	return 0;
391 
392 err_init:
393 	if (gpio_is_valid(tps->vsel1_gpio))
394 		gpio_free(tps->vsel1_gpio);
395 err_gpio1:
396 	if (gpio_is_valid(tps->vsel0_gpio))
397 		gpio_free(tps->vsel0_gpio);
398 err_gpio0:
399 	regmap_exit(tps->regmap);
400 	return ret;
401 }
402 
403 /**
404  * tps62360_remove - tps62360 driver i2c remove handler
405  * @client: i2c driver client device structure
406  *
407  * Unregister TPS driver as an i2c client device driver
408  */
409 static int __devexit tps62360_remove(struct i2c_client *client)
410 {
411 	struct tps62360_chip *tps = i2c_get_clientdata(client);
412 
413 	if (gpio_is_valid(tps->vsel1_gpio))
414 		gpio_free(tps->vsel1_gpio);
415 
416 	if (gpio_is_valid(tps->vsel0_gpio))
417 		gpio_free(tps->vsel0_gpio);
418 
419 	regulator_unregister(tps->rdev);
420 	regmap_exit(tps->regmap);
421 	return 0;
422 }
423 
424 static void tps62360_shutdown(struct i2c_client *client)
425 {
426 	struct tps62360_chip *tps = i2c_get_clientdata(client);
427 	int st;
428 
429 	if (!tps->en_discharge)
430 		return;
431 
432 	/* Configure the output discharge path */
433 	st = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
434 	if (st < 0)
435 		dev_err(tps->dev, "%s() fails in updating reg %d\n",
436 			__func__, REG_RAMPCTRL);
437 }
438 
439 static const struct i2c_device_id tps62360_id[] = {
440 	{.name = "tps62360", .driver_data = TPS62360},
441 	{.name = "tps62361", .driver_data = TPS62361},
442 	{},
443 };
444 
445 MODULE_DEVICE_TABLE(i2c, tps62360_id);
446 
447 static struct i2c_driver tps62360_i2c_driver = {
448 	.driver = {
449 		.name = "tps62360",
450 		.owner = THIS_MODULE,
451 	},
452 	.probe = tps62360_probe,
453 	.remove = __devexit_p(tps62360_remove),
454 	.shutdown = tps62360_shutdown,
455 	.id_table = tps62360_id,
456 };
457 
458 static int __init tps62360_init(void)
459 {
460 	return i2c_add_driver(&tps62360_i2c_driver);
461 }
462 subsys_initcall(tps62360_init);
463 
464 static void __exit tps62360_cleanup(void)
465 {
466 	i2c_del_driver(&tps62360_i2c_driver);
467 }
468 module_exit(tps62360_cleanup);
469 
470 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
471 MODULE_DESCRIPTION("TPS62360 voltage regulator driver");
472 MODULE_LICENSE("GPL v2");
473