1 /*
2  * Regulator driver for tps65090 power management chip.
3  *
4  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
5 
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9 
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14 
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>
17  */
18 
19 #include <linux/module.h>
20 #include <linux/delay.h>
21 #include <linux/init.h>
22 #include <linux/gpio.h>
23 #include <linux/of_gpio.h>
24 #include <linux/slab.h>
25 #include <linux/err.h>
26 #include <linux/platform_device.h>
27 #include <linux/regulator/driver.h>
28 #include <linux/regulator/machine.h>
29 #include <linux/regulator/of_regulator.h>
30 #include <linux/mfd/tps65090.h>
31 
32 #define MAX_CTRL_READ_TRIES	5
33 #define MAX_FET_ENABLE_TRIES	1000
34 
35 #define CTRL_EN_BIT		0 /* Regulator enable bit, active high */
36 #define CTRL_WT_BIT		2 /* Regulator wait time 0 bit */
37 #define CTRL_PG_BIT		4 /* Regulator power good bit, 1=good */
38 #define CTRL_TO_BIT		7 /* Regulator timeout bit, 1=wait */
39 
40 #define MAX_OVERCURRENT_WAIT	3 /* Overcurrent wait must be <= this */
41 
42 /**
43  * struct tps65090_regulator - Per-regulator data for a tps65090 regulator
44  *
45  * @dev: Pointer to our device.
46  * @desc: The struct regulator_desc for the regulator.
47  * @rdev: The struct regulator_dev for the regulator.
48  * @overcurrent_wait_valid: True if overcurrent_wait is valid.
49  * @overcurrent_wait: For FETs, the value to put in the WTFET bitfield.
50  */
51 
52 struct tps65090_regulator {
53 	struct device		*dev;
54 	struct regulator_desc	*desc;
55 	struct regulator_dev	*rdev;
56 	bool			overcurrent_wait_valid;
57 	int			overcurrent_wait;
58 };
59 
60 static struct regulator_ops tps65090_ext_control_ops = {
61 };
62 
63 /**
64  * tps65090_reg_set_overcurrent_wait - Setup overcurrent wait
65  *
66  * This will set the overcurrent wait time based on what's in the regulator
67  * info.
68  *
69  * @ri:		Overall regulator data
70  * @rdev:	Regulator device
71  *
72  * Return: 0 if no error, non-zero if there was an error writing the register.
73  */
74 static int tps65090_reg_set_overcurrent_wait(struct tps65090_regulator *ri,
75 					     struct regulator_dev *rdev)
76 {
77 	int ret;
78 
79 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
80 				 MAX_OVERCURRENT_WAIT << CTRL_WT_BIT,
81 				 ri->overcurrent_wait << CTRL_WT_BIT);
82 	if (ret) {
83 		dev_err(&rdev->dev, "Error updating overcurrent wait %#x\n",
84 			rdev->desc->enable_reg);
85 	}
86 
87 	return ret;
88 }
89 
90 /**
91  * tps65090_try_enable_fet - Try to enable a FET
92  *
93  * @rdev:	Regulator device
94  *
95  * Return: 0 if ok, -ENOTRECOVERABLE if the FET power good bit did not get
96  * set, or some other -ve value if another error occurred (e.g. i2c error)
97  */
98 static int tps65090_try_enable_fet(struct regulator_dev *rdev)
99 {
100 	unsigned int control;
101 	int ret, i;
102 
103 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
104 				 rdev->desc->enable_mask,
105 				 rdev->desc->enable_mask);
106 	if (ret < 0) {
107 		dev_err(&rdev->dev, "Error in updating reg %#x\n",
108 			rdev->desc->enable_reg);
109 		return ret;
110 	}
111 
112 	for (i = 0; i < MAX_CTRL_READ_TRIES; i++) {
113 		ret = regmap_read(rdev->regmap, rdev->desc->enable_reg,
114 				  &control);
115 		if (ret < 0)
116 			return ret;
117 
118 		if (!(control & BIT(CTRL_TO_BIT)))
119 			break;
120 
121 		usleep_range(1000, 1500);
122 	}
123 	if (!(control & BIT(CTRL_PG_BIT)))
124 		return -ENOTRECOVERABLE;
125 
126 	return 0;
127 }
128 
129 /**
130  * tps65090_fet_enable - Enable a FET, trying a few times if it fails
131  *
132  * Some versions of the tps65090 have issues when turning on the FETs.
133  * This function goes through several steps to ensure the best chance of the
134  * FET going on.  Specifically:
135  * - We'll make sure that we bump the "overcurrent wait" to the maximum, which
136  *   increases the chances that we'll turn on properly.
137  * - We'll retry turning the FET on multiple times (turning off in between).
138  *
139  * @rdev:	Regulator device
140  *
141  * Return: 0 if ok, non-zero if it fails.
142  */
143 static int tps65090_fet_enable(struct regulator_dev *rdev)
144 {
145 	int ret, tries;
146 
147 	/*
148 	 * Try enabling multiple times until we succeed since sometimes the
149 	 * first try times out.
150 	 */
151 	tries = 0;
152 	while (true) {
153 		ret = tps65090_try_enable_fet(rdev);
154 		if (!ret)
155 			break;
156 		if (ret != -ENOTRECOVERABLE || tries == MAX_FET_ENABLE_TRIES)
157 			goto err;
158 
159 		/* Try turning the FET off (and then on again) */
160 		ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
161 					 rdev->desc->enable_mask, 0);
162 		if (ret)
163 			goto err;
164 
165 		tries++;
166 	}
167 
168 	if (tries)
169 		dev_warn(&rdev->dev, "reg %#x enable ok after %d tries\n",
170 			 rdev->desc->enable_reg, tries);
171 
172 	return 0;
173 err:
174 	dev_warn(&rdev->dev, "reg %#x enable failed\n", rdev->desc->enable_reg);
175 	WARN_ON(1);
176 
177 	return ret;
178 }
179 
180 static struct regulator_ops tps65090_reg_control_ops = {
181 	.enable		= regulator_enable_regmap,
182 	.disable	= regulator_disable_regmap,
183 	.is_enabled	= regulator_is_enabled_regmap,
184 };
185 
186 static struct regulator_ops tps65090_fet_control_ops = {
187 	.enable		= tps65090_fet_enable,
188 	.disable	= regulator_disable_regmap,
189 	.is_enabled	= regulator_is_enabled_regmap,
190 };
191 
192 static struct regulator_ops tps65090_ldo_ops = {
193 };
194 
195 #define tps65090_REG_DESC(_id, _sname, _en_reg, _en_bits, _ops)	\
196 {							\
197 	.name = "TPS65090_RAILS"#_id,			\
198 	.supply_name = _sname,				\
199 	.id = TPS65090_REGULATOR_##_id,			\
200 	.ops = &_ops,					\
201 	.enable_reg = _en_reg,				\
202 	.enable_val = _en_bits,				\
203 	.enable_mask = _en_bits,			\
204 	.type = REGULATOR_VOLTAGE,			\
205 	.owner = THIS_MODULE,				\
206 }
207 
208 static struct regulator_desc tps65090_regulator_desc[] = {
209 	tps65090_REG_DESC(DCDC1, "vsys1",   0x0C, BIT(CTRL_EN_BIT),
210 			  tps65090_reg_control_ops),
211 	tps65090_REG_DESC(DCDC2, "vsys2",   0x0D, BIT(CTRL_EN_BIT),
212 			  tps65090_reg_control_ops),
213 	tps65090_REG_DESC(DCDC3, "vsys3",   0x0E, BIT(CTRL_EN_BIT),
214 			  tps65090_reg_control_ops),
215 
216 	tps65090_REG_DESC(FET1,  "infet1",  0x0F,
217 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
218 			  tps65090_fet_control_ops),
219 	tps65090_REG_DESC(FET2,  "infet2",  0x10,
220 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
221 			  tps65090_fet_control_ops),
222 	tps65090_REG_DESC(FET3,  "infet3",  0x11,
223 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
224 			  tps65090_fet_control_ops),
225 	tps65090_REG_DESC(FET4,  "infet4",  0x12,
226 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
227 			  tps65090_fet_control_ops),
228 	tps65090_REG_DESC(FET5,  "infet5",  0x13,
229 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
230 			  tps65090_fet_control_ops),
231 	tps65090_REG_DESC(FET6,  "infet6",  0x14,
232 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
233 			  tps65090_fet_control_ops),
234 	tps65090_REG_DESC(FET7,  "infet7",  0x15,
235 			  BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
236 			  tps65090_fet_control_ops),
237 
238 	tps65090_REG_DESC(LDO1,  "vsys-l1", 0, 0,
239 			  tps65090_ldo_ops),
240 	tps65090_REG_DESC(LDO2,  "vsys-l2", 0, 0,
241 			  tps65090_ldo_ops),
242 };
243 
244 static inline bool is_dcdc(int id)
245 {
246 	switch (id) {
247 	case TPS65090_REGULATOR_DCDC1:
248 	case TPS65090_REGULATOR_DCDC2:
249 	case TPS65090_REGULATOR_DCDC3:
250 		return true;
251 	default:
252 		return false;
253 	}
254 }
255 
256 static int tps65090_config_ext_control(
257 	struct tps65090_regulator *ri, bool enable)
258 {
259 	int ret;
260 	struct device *parent = ri->dev->parent;
261 	unsigned int reg_en_reg = ri->desc->enable_reg;
262 
263 	if (enable)
264 		ret = tps65090_set_bits(parent, reg_en_reg, 1);
265 	else
266 		ret =  tps65090_clr_bits(parent, reg_en_reg, 1);
267 	if (ret < 0)
268 		dev_err(ri->dev, "Error in updating reg 0x%x\n", reg_en_reg);
269 	return ret;
270 }
271 
272 static int tps65090_regulator_disable_ext_control(
273 		struct tps65090_regulator *ri,
274 		struct tps65090_regulator_plat_data *tps_pdata)
275 {
276 	int ret = 0;
277 	struct device *parent = ri->dev->parent;
278 	unsigned int reg_en_reg = ri->desc->enable_reg;
279 
280 	/*
281 	 * First enable output for internal control if require.
282 	 * And then disable external control.
283 	 */
284 	if (tps_pdata->reg_init_data->constraints.always_on ||
285 			tps_pdata->reg_init_data->constraints.boot_on) {
286 		ret =  tps65090_set_bits(parent, reg_en_reg, 0);
287 		if (ret < 0) {
288 			dev_err(ri->dev, "Error in set reg 0x%x\n", reg_en_reg);
289 			return ret;
290 		}
291 	}
292 	return tps65090_config_ext_control(ri, false);
293 }
294 
295 static void tps65090_configure_regulator_config(
296 		struct tps65090_regulator_plat_data *tps_pdata,
297 		struct regulator_config *config)
298 {
299 	if (gpio_is_valid(tps_pdata->gpio)) {
300 		int gpio_flag = GPIOF_OUT_INIT_LOW;
301 
302 		if (tps_pdata->reg_init_data->constraints.always_on ||
303 				tps_pdata->reg_init_data->constraints.boot_on)
304 			gpio_flag = GPIOF_OUT_INIT_HIGH;
305 
306 		config->ena_gpio = tps_pdata->gpio;
307 		config->ena_gpio_flags = gpio_flag;
308 	}
309 }
310 
311 #ifdef CONFIG_OF
312 static struct of_regulator_match tps65090_matches[] = {
313 	{ .name = "dcdc1", },
314 	{ .name = "dcdc2", },
315 	{ .name = "dcdc3", },
316 	{ .name = "fet1",  },
317 	{ .name = "fet2",  },
318 	{ .name = "fet3",  },
319 	{ .name = "fet4",  },
320 	{ .name = "fet5",  },
321 	{ .name = "fet6",  },
322 	{ .name = "fet7",  },
323 	{ .name = "ldo1",  },
324 	{ .name = "ldo2",  },
325 };
326 
327 static struct tps65090_platform_data *tps65090_parse_dt_reg_data(
328 		struct platform_device *pdev,
329 		struct of_regulator_match **tps65090_reg_matches)
330 {
331 	struct tps65090_platform_data *tps65090_pdata;
332 	struct device_node *np = pdev->dev.parent->of_node;
333 	struct device_node *regulators;
334 	int idx = 0, ret;
335 	struct tps65090_regulator_plat_data *reg_pdata;
336 
337 	tps65090_pdata = devm_kzalloc(&pdev->dev, sizeof(*tps65090_pdata),
338 				GFP_KERNEL);
339 	if (!tps65090_pdata)
340 		return ERR_PTR(-ENOMEM);
341 
342 	reg_pdata = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX *
343 				sizeof(*reg_pdata), GFP_KERNEL);
344 	if (!reg_pdata)
345 		return ERR_PTR(-ENOMEM);
346 
347 	regulators = of_get_child_by_name(np, "regulators");
348 	if (!regulators) {
349 		dev_err(&pdev->dev, "regulator node not found\n");
350 		return ERR_PTR(-ENODEV);
351 	}
352 
353 	ret = of_regulator_match(&pdev->dev, regulators, tps65090_matches,
354 			ARRAY_SIZE(tps65090_matches));
355 	of_node_put(regulators);
356 	if (ret < 0) {
357 		dev_err(&pdev->dev,
358 			"Error parsing regulator init data: %d\n", ret);
359 		return ERR_PTR(ret);
360 	}
361 
362 	*tps65090_reg_matches = tps65090_matches;
363 	for (idx = 0; idx < ARRAY_SIZE(tps65090_matches); idx++) {
364 		struct regulator_init_data *ri_data;
365 		struct tps65090_regulator_plat_data *rpdata;
366 
367 		rpdata = &reg_pdata[idx];
368 		ri_data = tps65090_matches[idx].init_data;
369 		if (!ri_data || !tps65090_matches[idx].of_node)
370 			continue;
371 
372 		rpdata->reg_init_data = ri_data;
373 		rpdata->enable_ext_control = of_property_read_bool(
374 					tps65090_matches[idx].of_node,
375 					"ti,enable-ext-control");
376 		if (rpdata->enable_ext_control)
377 			rpdata->gpio = of_get_named_gpio(np,
378 					"dcdc-ext-control-gpios", 0);
379 
380 		if (of_property_read_u32(tps65090_matches[idx].of_node,
381 					 "ti,overcurrent-wait",
382 					 &rpdata->overcurrent_wait) == 0)
383 			rpdata->overcurrent_wait_valid = true;
384 
385 		tps65090_pdata->reg_pdata[idx] = rpdata;
386 	}
387 	return tps65090_pdata;
388 }
389 #else
390 static inline struct tps65090_platform_data *tps65090_parse_dt_reg_data(
391 			struct platform_device *pdev,
392 			struct of_regulator_match **tps65090_reg_matches)
393 {
394 	*tps65090_reg_matches = NULL;
395 	return NULL;
396 }
397 #endif
398 
399 static int tps65090_regulator_probe(struct platform_device *pdev)
400 {
401 	struct tps65090 *tps65090_mfd = dev_get_drvdata(pdev->dev.parent);
402 	struct tps65090_regulator *ri = NULL;
403 	struct regulator_config config = { };
404 	struct regulator_dev *rdev;
405 	struct tps65090_regulator_plat_data *tps_pdata;
406 	struct tps65090_regulator *pmic;
407 	struct tps65090_platform_data *tps65090_pdata;
408 	struct of_regulator_match *tps65090_reg_matches = NULL;
409 	int num;
410 	int ret;
411 
412 	dev_dbg(&pdev->dev, "Probing regulator\n");
413 
414 	tps65090_pdata = dev_get_platdata(pdev->dev.parent);
415 	if (!tps65090_pdata && tps65090_mfd->dev->of_node)
416 		tps65090_pdata = tps65090_parse_dt_reg_data(pdev,
417 					&tps65090_reg_matches);
418 	if (IS_ERR_OR_NULL(tps65090_pdata)) {
419 		dev_err(&pdev->dev, "Platform data missing\n");
420 		return tps65090_pdata ? PTR_ERR(tps65090_pdata) : -EINVAL;
421 	}
422 
423 	pmic = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX * sizeof(*pmic),
424 			GFP_KERNEL);
425 	if (!pmic)
426 		return -ENOMEM;
427 
428 	for (num = 0; num < TPS65090_REGULATOR_MAX; num++) {
429 		tps_pdata = tps65090_pdata->reg_pdata[num];
430 
431 		ri = &pmic[num];
432 		ri->dev = &pdev->dev;
433 		ri->desc = &tps65090_regulator_desc[num];
434 		if (tps_pdata) {
435 			ri->overcurrent_wait_valid =
436 				tps_pdata->overcurrent_wait_valid;
437 			ri->overcurrent_wait = tps_pdata->overcurrent_wait;
438 		}
439 
440 		/*
441 		 * TPS5090 DCDC support the control from external digital input.
442 		 * Configure it as per platform data.
443 		 */
444 		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data) {
445 			if (tps_pdata->enable_ext_control) {
446 				tps65090_configure_regulator_config(
447 						tps_pdata, &config);
448 				ri->desc->ops = &tps65090_ext_control_ops;
449 			} else {
450 				ret = tps65090_regulator_disable_ext_control(
451 						ri, tps_pdata);
452 				if (ret < 0) {
453 					dev_err(&pdev->dev,
454 						"failed disable ext control\n");
455 					return ret;
456 				}
457 			}
458 		}
459 
460 		config.dev = pdev->dev.parent;
461 		config.driver_data = ri;
462 		config.regmap = tps65090_mfd->rmap;
463 		if (tps_pdata)
464 			config.init_data = tps_pdata->reg_init_data;
465 		else
466 			config.init_data = NULL;
467 		if (tps65090_reg_matches)
468 			config.of_node = tps65090_reg_matches[num].of_node;
469 		else
470 			config.of_node = NULL;
471 
472 		rdev = devm_regulator_register(&pdev->dev, ri->desc, &config);
473 		if (IS_ERR(rdev)) {
474 			dev_err(&pdev->dev, "failed to register regulator %s\n",
475 				ri->desc->name);
476 			return PTR_ERR(rdev);
477 		}
478 		ri->rdev = rdev;
479 
480 		if (ri->overcurrent_wait_valid) {
481 			ret = tps65090_reg_set_overcurrent_wait(ri, rdev);
482 			if (ret < 0)
483 				return ret;
484 		}
485 
486 		/* Enable external control if it is require */
487 		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data &&
488 				tps_pdata->enable_ext_control) {
489 			ret = tps65090_config_ext_control(ri, true);
490 			if (ret < 0)
491 				return ret;
492 		}
493 	}
494 
495 	platform_set_drvdata(pdev, pmic);
496 	return 0;
497 }
498 
499 static struct platform_driver tps65090_regulator_driver = {
500 	.driver	= {
501 		.name	= "tps65090-pmic",
502 		.owner	= THIS_MODULE,
503 	},
504 	.probe		= tps65090_regulator_probe,
505 };
506 
507 static int __init tps65090_regulator_init(void)
508 {
509 	return platform_driver_register(&tps65090_regulator_driver);
510 }
511 subsys_initcall(tps65090_regulator_init);
512 
513 static void __exit tps65090_regulator_exit(void)
514 {
515 	platform_driver_unregister(&tps65090_regulator_driver);
516 }
517 module_exit(tps65090_regulator_exit);
518 
519 MODULE_DESCRIPTION("tps65090 regulator driver");
520 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
521 MODULE_LICENSE("GPL v2");
522 MODULE_ALIAS("platform:tps65090-pmic");
523