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, _nvolt, _volt, _ops) \
196 {							\
197 	.name = "TPS65090_RAILS"#_id,			\
198 	.supply_name = _sname,				\
199 	.id = TPS65090_REGULATOR_##_id,			\
200 	.n_voltages = _nvolt,				\
201 	.ops = &_ops,					\
202 	.fixed_uV = _volt,				\
203 	.enable_reg = _en_reg,				\
204 	.enable_val = _en_bits,				\
205 	.enable_mask = _en_bits,			\
206 	.type = REGULATOR_VOLTAGE,			\
207 	.owner = THIS_MODULE,				\
208 }
209 
210 #define tps65090_REG_FIXEDV(_id, _sname, en_reg, _en_bits, _volt, _ops) \
211 	tps65090_REG_DESC(_id, _sname, en_reg, _en_bits, 1, _volt, _ops)
212 
213 #define tps65090_REG_SWITCH(_id, _sname, en_reg, _en_bits, _ops) \
214 	tps65090_REG_DESC(_id, _sname, en_reg, _en_bits, 0, 0, _ops)
215 
216 static struct regulator_desc tps65090_regulator_desc[] = {
217 	tps65090_REG_FIXEDV(DCDC1, "vsys1",   0x0C, BIT(CTRL_EN_BIT), 5000000,
218 			    tps65090_reg_control_ops),
219 	tps65090_REG_FIXEDV(DCDC2, "vsys2",   0x0D, BIT(CTRL_EN_BIT), 3300000,
220 			    tps65090_reg_control_ops),
221 	tps65090_REG_SWITCH(DCDC3, "vsys3",   0x0E, BIT(CTRL_EN_BIT),
222 			    tps65090_reg_control_ops),
223 
224 	tps65090_REG_SWITCH(FET1,  "infet1",  0x0F,
225 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
226 			    tps65090_fet_control_ops),
227 	tps65090_REG_SWITCH(FET2,  "infet2",  0x10,
228 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
229 			    tps65090_fet_control_ops),
230 	tps65090_REG_SWITCH(FET3,  "infet3",  0x11,
231 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
232 			    tps65090_fet_control_ops),
233 	tps65090_REG_SWITCH(FET4,  "infet4",  0x12,
234 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
235 			    tps65090_fet_control_ops),
236 	tps65090_REG_SWITCH(FET5,  "infet5",  0x13,
237 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
238 			    tps65090_fet_control_ops),
239 	tps65090_REG_SWITCH(FET6,  "infet6",  0x14,
240 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
241 			    tps65090_fet_control_ops),
242 	tps65090_REG_SWITCH(FET7,  "infet7",  0x15,
243 			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
244 			    tps65090_fet_control_ops),
245 
246 	tps65090_REG_FIXEDV(LDO1,  "vsys-l1", 0, 0, 5000000,
247 			    tps65090_ldo_ops),
248 	tps65090_REG_FIXEDV(LDO2,  "vsys-l2", 0, 0, 3300000,
249 			    tps65090_ldo_ops),
250 };
251 
252 static inline bool is_dcdc(int id)
253 {
254 	switch (id) {
255 	case TPS65090_REGULATOR_DCDC1:
256 	case TPS65090_REGULATOR_DCDC2:
257 	case TPS65090_REGULATOR_DCDC3:
258 		return true;
259 	default:
260 		return false;
261 	}
262 }
263 
264 static int tps65090_config_ext_control(
265 	struct tps65090_regulator *ri, bool enable)
266 {
267 	int ret;
268 	struct device *parent = ri->dev->parent;
269 	unsigned int reg_en_reg = ri->desc->enable_reg;
270 
271 	if (enable)
272 		ret = tps65090_set_bits(parent, reg_en_reg, 1);
273 	else
274 		ret =  tps65090_clr_bits(parent, reg_en_reg, 1);
275 	if (ret < 0)
276 		dev_err(ri->dev, "Error in updating reg 0x%x\n", reg_en_reg);
277 	return ret;
278 }
279 
280 static int tps65090_regulator_disable_ext_control(
281 		struct tps65090_regulator *ri,
282 		struct tps65090_regulator_plat_data *tps_pdata)
283 {
284 	int ret = 0;
285 	struct device *parent = ri->dev->parent;
286 	unsigned int reg_en_reg = ri->desc->enable_reg;
287 
288 	/*
289 	 * First enable output for internal control if require.
290 	 * And then disable external control.
291 	 */
292 	if (tps_pdata->reg_init_data->constraints.always_on ||
293 			tps_pdata->reg_init_data->constraints.boot_on) {
294 		ret =  tps65090_set_bits(parent, reg_en_reg, 0);
295 		if (ret < 0) {
296 			dev_err(ri->dev, "Error in set reg 0x%x\n", reg_en_reg);
297 			return ret;
298 		}
299 	}
300 	return tps65090_config_ext_control(ri, false);
301 }
302 
303 static void tps65090_configure_regulator_config(
304 		struct tps65090_regulator_plat_data *tps_pdata,
305 		struct regulator_config *config)
306 {
307 	if (gpio_is_valid(tps_pdata->gpio)) {
308 		int gpio_flag = GPIOF_OUT_INIT_LOW;
309 
310 		if (tps_pdata->reg_init_data->constraints.always_on ||
311 				tps_pdata->reg_init_data->constraints.boot_on)
312 			gpio_flag = GPIOF_OUT_INIT_HIGH;
313 
314 		config->ena_gpio = tps_pdata->gpio;
315 		config->ena_gpio_flags = gpio_flag;
316 	}
317 }
318 
319 #ifdef CONFIG_OF
320 static struct of_regulator_match tps65090_matches[] = {
321 	{ .name = "dcdc1", },
322 	{ .name = "dcdc2", },
323 	{ .name = "dcdc3", },
324 	{ .name = "fet1",  },
325 	{ .name = "fet2",  },
326 	{ .name = "fet3",  },
327 	{ .name = "fet4",  },
328 	{ .name = "fet5",  },
329 	{ .name = "fet6",  },
330 	{ .name = "fet7",  },
331 	{ .name = "ldo1",  },
332 	{ .name = "ldo2",  },
333 };
334 
335 static struct tps65090_platform_data *tps65090_parse_dt_reg_data(
336 		struct platform_device *pdev,
337 		struct of_regulator_match **tps65090_reg_matches)
338 {
339 	struct tps65090_platform_data *tps65090_pdata;
340 	struct device_node *np = pdev->dev.parent->of_node;
341 	struct device_node *regulators;
342 	int idx = 0, ret;
343 	struct tps65090_regulator_plat_data *reg_pdata;
344 
345 	tps65090_pdata = devm_kzalloc(&pdev->dev, sizeof(*tps65090_pdata),
346 				GFP_KERNEL);
347 	if (!tps65090_pdata)
348 		return ERR_PTR(-ENOMEM);
349 
350 	reg_pdata = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX *
351 				sizeof(*reg_pdata), GFP_KERNEL);
352 	if (!reg_pdata)
353 		return ERR_PTR(-ENOMEM);
354 
355 	regulators = of_get_child_by_name(np, "regulators");
356 	if (!regulators) {
357 		dev_err(&pdev->dev, "regulator node not found\n");
358 		return ERR_PTR(-ENODEV);
359 	}
360 
361 	ret = of_regulator_match(&pdev->dev, regulators, tps65090_matches,
362 			ARRAY_SIZE(tps65090_matches));
363 	of_node_put(regulators);
364 	if (ret < 0) {
365 		dev_err(&pdev->dev,
366 			"Error parsing regulator init data: %d\n", ret);
367 		return ERR_PTR(ret);
368 	}
369 
370 	*tps65090_reg_matches = tps65090_matches;
371 	for (idx = 0; idx < ARRAY_SIZE(tps65090_matches); idx++) {
372 		struct regulator_init_data *ri_data;
373 		struct tps65090_regulator_plat_data *rpdata;
374 
375 		rpdata = &reg_pdata[idx];
376 		ri_data = tps65090_matches[idx].init_data;
377 		if (!ri_data || !tps65090_matches[idx].of_node)
378 			continue;
379 
380 		rpdata->reg_init_data = ri_data;
381 		rpdata->enable_ext_control = of_property_read_bool(
382 					tps65090_matches[idx].of_node,
383 					"ti,enable-ext-control");
384 		if (rpdata->enable_ext_control)
385 			rpdata->gpio = of_get_named_gpio(np,
386 					"dcdc-ext-control-gpios", 0);
387 
388 		if (of_property_read_u32(tps65090_matches[idx].of_node,
389 					 "ti,overcurrent-wait",
390 					 &rpdata->overcurrent_wait) == 0)
391 			rpdata->overcurrent_wait_valid = true;
392 
393 		tps65090_pdata->reg_pdata[idx] = rpdata;
394 	}
395 	return tps65090_pdata;
396 }
397 #else
398 static inline struct tps65090_platform_data *tps65090_parse_dt_reg_data(
399 			struct platform_device *pdev,
400 			struct of_regulator_match **tps65090_reg_matches)
401 {
402 	*tps65090_reg_matches = NULL;
403 	return NULL;
404 }
405 #endif
406 
407 static int tps65090_regulator_probe(struct platform_device *pdev)
408 {
409 	struct tps65090 *tps65090_mfd = dev_get_drvdata(pdev->dev.parent);
410 	struct tps65090_regulator *ri = NULL;
411 	struct regulator_config config = { };
412 	struct regulator_dev *rdev;
413 	struct tps65090_regulator_plat_data *tps_pdata;
414 	struct tps65090_regulator *pmic;
415 	struct tps65090_platform_data *tps65090_pdata;
416 	struct of_regulator_match *tps65090_reg_matches = NULL;
417 	int num;
418 	int ret;
419 
420 	dev_dbg(&pdev->dev, "Probing regulator\n");
421 
422 	tps65090_pdata = dev_get_platdata(pdev->dev.parent);
423 	if (!tps65090_pdata && tps65090_mfd->dev->of_node)
424 		tps65090_pdata = tps65090_parse_dt_reg_data(pdev,
425 					&tps65090_reg_matches);
426 	if (IS_ERR_OR_NULL(tps65090_pdata)) {
427 		dev_err(&pdev->dev, "Platform data missing\n");
428 		return tps65090_pdata ? PTR_ERR(tps65090_pdata) : -EINVAL;
429 	}
430 
431 	pmic = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX * sizeof(*pmic),
432 			GFP_KERNEL);
433 	if (!pmic)
434 		return -ENOMEM;
435 
436 	for (num = 0; num < TPS65090_REGULATOR_MAX; num++) {
437 		tps_pdata = tps65090_pdata->reg_pdata[num];
438 
439 		ri = &pmic[num];
440 		ri->dev = &pdev->dev;
441 		ri->desc = &tps65090_regulator_desc[num];
442 		if (tps_pdata) {
443 			ri->overcurrent_wait_valid =
444 				tps_pdata->overcurrent_wait_valid;
445 			ri->overcurrent_wait = tps_pdata->overcurrent_wait;
446 		}
447 
448 		/*
449 		 * TPS5090 DCDC support the control from external digital input.
450 		 * Configure it as per platform data.
451 		 */
452 		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data) {
453 			if (tps_pdata->enable_ext_control) {
454 				tps65090_configure_regulator_config(
455 						tps_pdata, &config);
456 				ri->desc->ops = &tps65090_ext_control_ops;
457 			} else {
458 				ret = tps65090_regulator_disable_ext_control(
459 						ri, tps_pdata);
460 				if (ret < 0) {
461 					dev_err(&pdev->dev,
462 						"failed disable ext control\n");
463 					return ret;
464 				}
465 			}
466 		}
467 
468 		config.dev = pdev->dev.parent;
469 		config.driver_data = ri;
470 		config.regmap = tps65090_mfd->rmap;
471 		if (tps_pdata)
472 			config.init_data = tps_pdata->reg_init_data;
473 		else
474 			config.init_data = NULL;
475 		if (tps65090_reg_matches)
476 			config.of_node = tps65090_reg_matches[num].of_node;
477 		else
478 			config.of_node = NULL;
479 
480 		rdev = devm_regulator_register(&pdev->dev, ri->desc, &config);
481 		if (IS_ERR(rdev)) {
482 			dev_err(&pdev->dev, "failed to register regulator %s\n",
483 				ri->desc->name);
484 			return PTR_ERR(rdev);
485 		}
486 		ri->rdev = rdev;
487 
488 		if (ri->overcurrent_wait_valid) {
489 			ret = tps65090_reg_set_overcurrent_wait(ri, rdev);
490 			if (ret < 0)
491 				return ret;
492 		}
493 
494 		/* Enable external control if it is require */
495 		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data &&
496 				tps_pdata->enable_ext_control) {
497 			ret = tps65090_config_ext_control(ri, true);
498 			if (ret < 0)
499 				return ret;
500 		}
501 	}
502 
503 	platform_set_drvdata(pdev, pmic);
504 	return 0;
505 }
506 
507 static struct platform_driver tps65090_regulator_driver = {
508 	.driver	= {
509 		.name	= "tps65090-pmic",
510 		.owner	= THIS_MODULE,
511 	},
512 	.probe		= tps65090_regulator_probe,
513 };
514 
515 static int __init tps65090_regulator_init(void)
516 {
517 	return platform_driver_register(&tps65090_regulator_driver);
518 }
519 subsys_initcall(tps65090_regulator_init);
520 
521 static void __exit tps65090_regulator_exit(void)
522 {
523 	platform_driver_unregister(&tps65090_regulator_driver);
524 }
525 module_exit(tps65090_regulator_exit);
526 
527 MODULE_DESCRIPTION("tps65090 regulator driver");
528 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
529 MODULE_LICENSE("GPL v2");
530 MODULE_ALIAS("platform:tps65090-pmic");
531