1 /*
2  * twl-regulator.c -- support regulators in twl4030/twl6030 family chips
3  *
4  * Copyright (C) 2008 David Brownell
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/err.h>
17 #include <linux/platform_device.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/regulator/driver.h>
21 #include <linux/regulator/machine.h>
22 #include <linux/regulator/of_regulator.h>
23 #include <linux/mfd/twl.h>
24 #include <linux/delay.h>
25 
26 /*
27  * The TWL4030/TW5030/TPS659x0 family chips include power management, a
28  * USB OTG transceiver, an RTC, ADC, PWM, and lots more.  Some versions
29  * include an audio codec, battery charger, and more voltage regulators.
30  * These chips are often used in OMAP-based systems.
31  *
32  * This driver implements software-based resource control for various
33  * voltage regulators.  This is usually augmented with state machine
34  * based control.
35  */
36 
37 struct twlreg_info {
38 	/* start of regulator's PM_RECEIVER control register bank */
39 	u8			base;
40 
41 	/* twl resource ID, for resource control state machine */
42 	u8			id;
43 
44 	/* voltage in mV = table[VSEL]; table_len must be a power-of-two */
45 	u8			table_len;
46 	const u16		*table;
47 
48 	/* State REMAP default configuration */
49 	u8			remap;
50 
51 	/* used by regulator core */
52 	struct regulator_desc	desc;
53 
54 	/* chip specific features */
55 	unsigned long		features;
56 
57 	/* data passed from board for external get/set voltage */
58 	void			*data;
59 };
60 
61 
62 /* LDO control registers ... offset is from the base of its register bank.
63  * The first three registers of all power resource banks help hardware to
64  * manage the various resource groups.
65  */
66 /* Common offset in TWL4030/6030 */
67 #define VREG_GRP		0
68 /* TWL4030 register offsets */
69 #define VREG_TYPE		1
70 #define VREG_REMAP		2
71 #define VREG_DEDICATED		3	/* LDO control */
72 #define VREG_VOLTAGE_SMPS_4030	9
73 /* TWL6030 register offsets */
74 #define VREG_TRANS		1
75 #define VREG_STATE		2
76 #define VREG_VOLTAGE		3
77 #define VREG_VOLTAGE_SMPS	4
78 
79 static inline int
80 twlreg_read(struct twlreg_info *info, unsigned slave_subgp, unsigned offset)
81 {
82 	u8 value;
83 	int status;
84 
85 	status = twl_i2c_read_u8(slave_subgp,
86 			&value, info->base + offset);
87 	return (status < 0) ? status : value;
88 }
89 
90 static inline int
91 twlreg_write(struct twlreg_info *info, unsigned slave_subgp, unsigned offset,
92 						 u8 value)
93 {
94 	return twl_i2c_write_u8(slave_subgp,
95 			value, info->base + offset);
96 }
97 
98 /*----------------------------------------------------------------------*/
99 
100 /* generic power resource operations, which work on all regulators */
101 
102 static int twlreg_grp(struct regulator_dev *rdev)
103 {
104 	return twlreg_read(rdev_get_drvdata(rdev), TWL_MODULE_PM_RECEIVER,
105 								 VREG_GRP);
106 }
107 
108 /*
109  * Enable/disable regulators by joining/leaving the P1 (processor) group.
110  * We assume nobody else is updating the DEV_GRP registers.
111  */
112 /* definition for 4030 family */
113 #define P3_GRP_4030	BIT(7)		/* "peripherals" */
114 #define P2_GRP_4030	BIT(6)		/* secondary processor, modem, etc */
115 #define P1_GRP_4030	BIT(5)		/* CPU/Linux */
116 /* definition for 6030 family */
117 #define P3_GRP_6030	BIT(2)		/* secondary processor, modem, etc */
118 #define P2_GRP_6030	BIT(1)		/* "peripherals" */
119 #define P1_GRP_6030	BIT(0)		/* CPU/Linux */
120 
121 static int twl4030reg_is_enabled(struct regulator_dev *rdev)
122 {
123 	int	state = twlreg_grp(rdev);
124 
125 	if (state < 0)
126 		return state;
127 
128 	return state & P1_GRP_4030;
129 }
130 
131 #define PB_I2C_BUSY	BIT(0)
132 #define PB_I2C_BWEN	BIT(1)
133 
134 /* Wait until buffer empty/ready to send a word on power bus. */
135 static int twl4030_wait_pb_ready(void)
136 {
137 
138 	int	ret;
139 	int	timeout = 10;
140 	u8	val;
141 
142 	do {
143 		ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
144 				      TWL4030_PM_MASTER_PB_CFG);
145 		if (ret < 0)
146 			return ret;
147 
148 		if (!(val & PB_I2C_BUSY))
149 			return 0;
150 
151 		mdelay(1);
152 		timeout--;
153 	} while (timeout);
154 
155 	return -ETIMEDOUT;
156 }
157 
158 /* Send a word over the powerbus */
159 static int twl4030_send_pb_msg(unsigned msg)
160 {
161 	u8	val;
162 	int	ret;
163 
164 	/* save powerbus configuration */
165 	ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
166 			      TWL4030_PM_MASTER_PB_CFG);
167 	if (ret < 0)
168 		return ret;
169 
170 	/* Enable i2c access to powerbus */
171 	ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val | PB_I2C_BWEN,
172 			       TWL4030_PM_MASTER_PB_CFG);
173 	if (ret < 0)
174 		return ret;
175 
176 	ret = twl4030_wait_pb_ready();
177 	if (ret < 0)
178 		return ret;
179 
180 	ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg >> 8,
181 			       TWL4030_PM_MASTER_PB_WORD_MSB);
182 	if (ret < 0)
183 		return ret;
184 
185 	ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg & 0xff,
186 			       TWL4030_PM_MASTER_PB_WORD_LSB);
187 	if (ret < 0)
188 		return ret;
189 
190 	ret = twl4030_wait_pb_ready();
191 	if (ret < 0)
192 		return ret;
193 
194 	/* Restore powerbus configuration */
195 	return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
196 				TWL4030_PM_MASTER_PB_CFG);
197 }
198 
199 static int twl4030reg_enable(struct regulator_dev *rdev)
200 {
201 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
202 	int			grp;
203 	int			ret;
204 
205 	grp = twlreg_grp(rdev);
206 	if (grp < 0)
207 		return grp;
208 
209 	grp |= P1_GRP_4030;
210 
211 	ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
212 
213 	return ret;
214 }
215 
216 static int twl4030reg_disable(struct regulator_dev *rdev)
217 {
218 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
219 	int			grp;
220 	int			ret;
221 
222 	grp = twlreg_grp(rdev);
223 	if (grp < 0)
224 		return grp;
225 
226 	grp &= ~(P1_GRP_4030 | P2_GRP_4030 | P3_GRP_4030);
227 
228 	ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
229 
230 	return ret;
231 }
232 
233 static int twl4030reg_get_status(struct regulator_dev *rdev)
234 {
235 	int	state = twlreg_grp(rdev);
236 
237 	if (state < 0)
238 		return state;
239 	state &= 0x0f;
240 
241 	/* assume state != WARM_RESET; we'd not be running...  */
242 	if (!state)
243 		return REGULATOR_STATUS_OFF;
244 	return (state & BIT(3))
245 		? REGULATOR_STATUS_NORMAL
246 		: REGULATOR_STATUS_STANDBY;
247 }
248 
249 static int twl4030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
250 {
251 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
252 	unsigned		message;
253 
254 	/* We can only set the mode through state machine commands... */
255 	switch (mode) {
256 	case REGULATOR_MODE_NORMAL:
257 		message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_ACTIVE);
258 		break;
259 	case REGULATOR_MODE_STANDBY:
260 		message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_SLEEP);
261 		break;
262 	default:
263 		return -EINVAL;
264 	}
265 
266 	return twl4030_send_pb_msg(message);
267 }
268 
269 static inline unsigned int twl4030reg_map_mode(unsigned int mode)
270 {
271 	switch (mode) {
272 	case RES_STATE_ACTIVE:
273 		return REGULATOR_MODE_NORMAL;
274 	case RES_STATE_SLEEP:
275 		return REGULATOR_MODE_STANDBY;
276 	default:
277 		return -EINVAL;
278 	}
279 }
280 
281 /*----------------------------------------------------------------------*/
282 
283 /*
284  * Support for adjustable-voltage LDOs uses a four bit (or less) voltage
285  * select field in its control register.   We use tables indexed by VSEL
286  * to record voltages in milliVolts.  (Accuracy is about three percent.)
287  *
288  * Note that VSEL values for VAUX2 changed in twl5030 and newer silicon;
289  * currently handled by listing two slightly different VAUX2 regulators,
290  * only one of which will be configured.
291  *
292  * VSEL values documented as "TI cannot support these values" are flagged
293  * in these tables as UNSUP() values; we normally won't assign them.
294  *
295  * VAUX3 at 3V is incorrectly listed in some TI manuals as unsupported.
296  * TI are revising the twl5030/tps659x0 specs to support that 3.0V setting.
297  */
298 #define UNSUP_MASK	0x8000
299 
300 #define UNSUP(x)	(UNSUP_MASK | (x))
301 #define IS_UNSUP(info, x)			\
302 	((UNSUP_MASK & (x)) &&			\
303 	 !((info)->features & TWL4030_ALLOW_UNSUPPORTED))
304 #define LDO_MV(x)	(~UNSUP_MASK & (x))
305 
306 
307 static const u16 VAUX1_VSEL_table[] = {
308 	UNSUP(1500), UNSUP(1800), 2500, 2800,
309 	3000, 3000, 3000, 3000,
310 };
311 static const u16 VAUX2_4030_VSEL_table[] = {
312 	UNSUP(1000), UNSUP(1000), UNSUP(1200), 1300,
313 	1500, 1800, UNSUP(1850), 2500,
314 	UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
315 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
316 };
317 static const u16 VAUX2_VSEL_table[] = {
318 	1700, 1700, 1900, 1300,
319 	1500, 1800, 2000, 2500,
320 	2100, 2800, 2200, 2300,
321 	2400, 2400, 2400, 2400,
322 };
323 static const u16 VAUX3_VSEL_table[] = {
324 	1500, 1800, 2500, 2800,
325 	3000, 3000, 3000, 3000,
326 };
327 static const u16 VAUX4_VSEL_table[] = {
328 	700, 1000, 1200, UNSUP(1300),
329 	1500, 1800, UNSUP(1850), 2500,
330 	UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
331 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
332 };
333 static const u16 VMMC1_VSEL_table[] = {
334 	1850, 2850, 3000, 3150,
335 };
336 static const u16 VMMC2_VSEL_table[] = {
337 	UNSUP(1000), UNSUP(1000), UNSUP(1200), UNSUP(1300),
338 	UNSUP(1500), UNSUP(1800), 1850, UNSUP(2500),
339 	2600, 2800, 2850, 3000,
340 	3150, 3150, 3150, 3150,
341 };
342 static const u16 VPLL1_VSEL_table[] = {
343 	1000, 1200, 1300, 1800,
344 	UNSUP(2800), UNSUP(3000), UNSUP(3000), UNSUP(3000),
345 };
346 static const u16 VPLL2_VSEL_table[] = {
347 	700, 1000, 1200, 1300,
348 	UNSUP(1500), 1800, UNSUP(1850), UNSUP(2500),
349 	UNSUP(2600), UNSUP(2800), UNSUP(2850), UNSUP(3000),
350 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
351 };
352 static const u16 VSIM_VSEL_table[] = {
353 	UNSUP(1000), UNSUP(1200), UNSUP(1300), 1800,
354 	2800, 3000, 3000, 3000,
355 };
356 static const u16 VDAC_VSEL_table[] = {
357 	1200, 1300, 1800, 1800,
358 };
359 static const u16 VIO_VSEL_table[] = {
360 	1800, 1850,
361 };
362 static const u16 VINTANA2_VSEL_table[] = {
363 	2500, 2750,
364 };
365 
366 static int twl4030ldo_list_voltage(struct regulator_dev *rdev, unsigned index)
367 {
368 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
369 	int			mV = info->table[index];
370 
371 	return IS_UNSUP(info, mV) ? 0 : (LDO_MV(mV) * 1000);
372 }
373 
374 static int
375 twl4030ldo_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
376 {
377 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
378 
379 	return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE,
380 			    selector);
381 }
382 
383 static int twl4030ldo_get_voltage_sel(struct regulator_dev *rdev)
384 {
385 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
386 	int vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE);
387 
388 	if (vsel < 0)
389 		return vsel;
390 
391 	vsel &= info->table_len - 1;
392 	return vsel;
393 }
394 
395 static struct regulator_ops twl4030ldo_ops = {
396 	.list_voltage	= twl4030ldo_list_voltage,
397 
398 	.set_voltage_sel = twl4030ldo_set_voltage_sel,
399 	.get_voltage_sel = twl4030ldo_get_voltage_sel,
400 
401 	.enable		= twl4030reg_enable,
402 	.disable	= twl4030reg_disable,
403 	.is_enabled	= twl4030reg_is_enabled,
404 
405 	.set_mode	= twl4030reg_set_mode,
406 
407 	.get_status	= twl4030reg_get_status,
408 };
409 
410 static int
411 twl4030smps_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
412 			unsigned *selector)
413 {
414 	struct twlreg_info *info = rdev_get_drvdata(rdev);
415 	int vsel = DIV_ROUND_UP(min_uV - 600000, 12500);
416 
417 	twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE_SMPS_4030, vsel);
418 
419 	return 0;
420 }
421 
422 static int twl4030smps_get_voltage(struct regulator_dev *rdev)
423 {
424 	struct twlreg_info *info = rdev_get_drvdata(rdev);
425 	int vsel;
426 
427 	vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER,
428 		VREG_VOLTAGE_SMPS_4030);
429 
430 	return vsel * 12500 + 600000;
431 }
432 
433 static struct regulator_ops twl4030smps_ops = {
434 	.set_voltage	= twl4030smps_set_voltage,
435 	.get_voltage	= twl4030smps_get_voltage,
436 };
437 
438 /*----------------------------------------------------------------------*/
439 
440 static struct regulator_ops twl4030fixed_ops = {
441 	.list_voltage	= regulator_list_voltage_linear,
442 
443 	.enable		= twl4030reg_enable,
444 	.disable	= twl4030reg_disable,
445 	.is_enabled	= twl4030reg_is_enabled,
446 
447 	.set_mode	= twl4030reg_set_mode,
448 
449 	.get_status	= twl4030reg_get_status,
450 };
451 
452 /*----------------------------------------------------------------------*/
453 
454 #define TWL4030_ADJUSTABLE_LDO(label, offset, num, turnon_delay, remap_conf) \
455 static const struct twlreg_info TWL4030_INFO_##label = { \
456 	.base = offset, \
457 	.id = num, \
458 	.table_len = ARRAY_SIZE(label##_VSEL_table), \
459 	.table = label##_VSEL_table, \
460 	.remap = remap_conf, \
461 	.desc = { \
462 		.name = #label, \
463 		.id = TWL4030_REG_##label, \
464 		.n_voltages = ARRAY_SIZE(label##_VSEL_table), \
465 		.ops = &twl4030ldo_ops, \
466 		.type = REGULATOR_VOLTAGE, \
467 		.owner = THIS_MODULE, \
468 		.enable_time = turnon_delay, \
469 		.of_map_mode = twl4030reg_map_mode, \
470 		}, \
471 	}
472 
473 #define TWL4030_ADJUSTABLE_SMPS(label, offset, num, turnon_delay, remap_conf) \
474 static const struct twlreg_info TWL4030_INFO_##label = { \
475 	.base = offset, \
476 	.id = num, \
477 	.remap = remap_conf, \
478 	.desc = { \
479 		.name = #label, \
480 		.id = TWL4030_REG_##label, \
481 		.ops = &twl4030smps_ops, \
482 		.type = REGULATOR_VOLTAGE, \
483 		.owner = THIS_MODULE, \
484 		.enable_time = turnon_delay, \
485 		.of_map_mode = twl4030reg_map_mode, \
486 		}, \
487 	}
488 
489 #define TWL4030_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
490 			remap_conf) \
491 static const struct twlreg_info TWLFIXED_INFO_##label = { \
492 	.base = offset, \
493 	.id = num, \
494 	.remap = remap_conf, \
495 	.desc = { \
496 		.name = #label, \
497 		.id = TWL4030##_REG_##label, \
498 		.n_voltages = 1, \
499 		.ops = &twl4030fixed_ops, \
500 		.type = REGULATOR_VOLTAGE, \
501 		.owner = THIS_MODULE, \
502 		.min_uV = mVolts * 1000, \
503 		.enable_time = turnon_delay, \
504 		.of_map_mode = twl4030reg_map_mode, \
505 		}, \
506 	}
507 
508 /*
509  * We list regulators here if systems need some level of
510  * software control over them after boot.
511  */
512 TWL4030_ADJUSTABLE_LDO(VAUX1, 0x17, 1, 100, 0x08);
513 TWL4030_ADJUSTABLE_LDO(VAUX2_4030, 0x1b, 2, 100, 0x08);
514 TWL4030_ADJUSTABLE_LDO(VAUX2, 0x1b, 2, 100, 0x08);
515 TWL4030_ADJUSTABLE_LDO(VAUX3, 0x1f, 3, 100, 0x08);
516 TWL4030_ADJUSTABLE_LDO(VAUX4, 0x23, 4, 100, 0x08);
517 TWL4030_ADJUSTABLE_LDO(VMMC1, 0x27, 5, 100, 0x08);
518 TWL4030_ADJUSTABLE_LDO(VMMC2, 0x2b, 6, 100, 0x08);
519 TWL4030_ADJUSTABLE_LDO(VPLL1, 0x2f, 7, 100, 0x00);
520 TWL4030_ADJUSTABLE_LDO(VPLL2, 0x33, 8, 100, 0x08);
521 TWL4030_ADJUSTABLE_LDO(VSIM, 0x37, 9, 100, 0x00);
522 TWL4030_ADJUSTABLE_LDO(VDAC, 0x3b, 10, 100, 0x08);
523 TWL4030_ADJUSTABLE_LDO(VINTANA2, 0x43, 12, 100, 0x08);
524 TWL4030_ADJUSTABLE_LDO(VIO, 0x4b, 14, 1000, 0x08);
525 TWL4030_ADJUSTABLE_SMPS(VDD1, 0x55, 15, 1000, 0x08);
526 TWL4030_ADJUSTABLE_SMPS(VDD2, 0x63, 16, 1000, 0x08);
527 /* VUSBCP is managed *only* by the USB subchip */
528 TWL4030_FIXED_LDO(VINTANA1, 0x3f, 1500, 11, 100, 0x08);
529 TWL4030_FIXED_LDO(VINTDIG, 0x47, 1500, 13, 100, 0x08);
530 TWL4030_FIXED_LDO(VUSB1V5, 0x71, 1500, 17, 100, 0x08);
531 TWL4030_FIXED_LDO(VUSB1V8, 0x74, 1800, 18, 100, 0x08);
532 TWL4030_FIXED_LDO(VUSB3V1, 0x77, 3100, 19, 150, 0x08);
533 
534 #define TWL_OF_MATCH(comp, family, label) \
535 	{ \
536 		.compatible = comp, \
537 		.data = &family##_INFO_##label, \
538 	}
539 
540 #define TWL4030_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL4030, label)
541 #define TWL6030_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL6030, label)
542 #define TWL6032_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWL6032, label)
543 #define TWLFIXED_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWLFIXED, label)
544 #define TWLSMPS_OF_MATCH(comp, label) TWL_OF_MATCH(comp, TWLSMPS, label)
545 
546 static const struct of_device_id twl_of_match[] = {
547 	TWL4030_OF_MATCH("ti,twl4030-vaux1", VAUX1),
548 	TWL4030_OF_MATCH("ti,twl4030-vaux2", VAUX2_4030),
549 	TWL4030_OF_MATCH("ti,twl5030-vaux2", VAUX2),
550 	TWL4030_OF_MATCH("ti,twl4030-vaux3", VAUX3),
551 	TWL4030_OF_MATCH("ti,twl4030-vaux4", VAUX4),
552 	TWL4030_OF_MATCH("ti,twl4030-vmmc1", VMMC1),
553 	TWL4030_OF_MATCH("ti,twl4030-vmmc2", VMMC2),
554 	TWL4030_OF_MATCH("ti,twl4030-vpll1", VPLL1),
555 	TWL4030_OF_MATCH("ti,twl4030-vpll2", VPLL2),
556 	TWL4030_OF_MATCH("ti,twl4030-vsim", VSIM),
557 	TWL4030_OF_MATCH("ti,twl4030-vdac", VDAC),
558 	TWL4030_OF_MATCH("ti,twl4030-vintana2", VINTANA2),
559 	TWL4030_OF_MATCH("ti,twl4030-vio", VIO),
560 	TWL4030_OF_MATCH("ti,twl4030-vdd1", VDD1),
561 	TWL4030_OF_MATCH("ti,twl4030-vdd2", VDD2),
562 	TWLFIXED_OF_MATCH("ti,twl4030-vintana1", VINTANA1),
563 	TWLFIXED_OF_MATCH("ti,twl4030-vintdig", VINTDIG),
564 	TWLFIXED_OF_MATCH("ti,twl4030-vusb1v5", VUSB1V5),
565 	TWLFIXED_OF_MATCH("ti,twl4030-vusb1v8", VUSB1V8),
566 	TWLFIXED_OF_MATCH("ti,twl4030-vusb3v1", VUSB3V1),
567 	{},
568 };
569 MODULE_DEVICE_TABLE(of, twl_of_match);
570 
571 static int twlreg_probe(struct platform_device *pdev)
572 {
573 	int id;
574 	struct twlreg_info		*info;
575 	const struct twlreg_info	*template;
576 	struct regulator_init_data	*initdata;
577 	struct regulation_constraints	*c;
578 	struct regulator_dev		*rdev;
579 	const struct of_device_id	*match;
580 	struct regulator_config		config = { };
581 
582 	match = of_match_device(twl_of_match, &pdev->dev);
583 	if (!match)
584 		return -ENODEV;
585 
586 	template = match->data;
587 	if (!template)
588 		return -ENODEV;
589 
590 	id = template->desc.id;
591 	initdata = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
592 						&template->desc);
593 	if (!initdata)
594 		return -EINVAL;
595 
596 	info = devm_kmemdup(&pdev->dev, template, sizeof(*info), GFP_KERNEL);
597 	if (!info)
598 		return -ENOMEM;
599 
600 	/* Constrain board-specific capabilities according to what
601 	 * this driver and the chip itself can actually do.
602 	 */
603 	c = &initdata->constraints;
604 	c->valid_modes_mask &= REGULATOR_MODE_NORMAL | REGULATOR_MODE_STANDBY;
605 	c->valid_ops_mask &= REGULATOR_CHANGE_VOLTAGE
606 				| REGULATOR_CHANGE_MODE
607 				| REGULATOR_CHANGE_STATUS;
608 	switch (id) {
609 	case TWL4030_REG_VIO:
610 	case TWL4030_REG_VDD1:
611 	case TWL4030_REG_VDD2:
612 	case TWL4030_REG_VPLL1:
613 	case TWL4030_REG_VINTANA1:
614 	case TWL4030_REG_VINTANA2:
615 	case TWL4030_REG_VINTDIG:
616 		c->always_on = true;
617 		break;
618 	default:
619 		break;
620 	}
621 
622 	config.dev = &pdev->dev;
623 	config.init_data = initdata;
624 	config.driver_data = info;
625 	config.of_node = pdev->dev.of_node;
626 
627 	rdev = devm_regulator_register(&pdev->dev, &info->desc, &config);
628 	if (IS_ERR(rdev)) {
629 		dev_err(&pdev->dev, "can't register %s, %ld\n",
630 				info->desc.name, PTR_ERR(rdev));
631 		return PTR_ERR(rdev);
632 	}
633 	platform_set_drvdata(pdev, rdev);
634 
635 	twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_REMAP, info->remap);
636 
637 	/* NOTE:  many regulators support short-circuit IRQs (presentable
638 	 * as REGULATOR_OVER_CURRENT notifications?) configured via:
639 	 *  - SC_CONFIG
640 	 *  - SC_DETECT1 (vintana2, vmmc1/2, vaux1/2/3/4)
641 	 *  - SC_DETECT2 (vusb, vdac, vio, vdd1/2, vpll2)
642 	 *  - IT_CONFIG
643 	 */
644 
645 	return 0;
646 }
647 
648 MODULE_ALIAS("platform:twl4030_reg");
649 
650 static struct platform_driver twlreg_driver = {
651 	.probe		= twlreg_probe,
652 	/* NOTE: short name, to work around driver model truncation of
653 	 * "twl_regulator.12" (and friends) to "twl_regulator.1".
654 	 */
655 	.driver  = {
656 		.name  = "twl4030_reg",
657 		.of_match_table = of_match_ptr(twl_of_match),
658 	},
659 };
660 
661 static int __init twlreg_init(void)
662 {
663 	return platform_driver_register(&twlreg_driver);
664 }
665 subsys_initcall(twlreg_init);
666 
667 static void __exit twlreg_exit(void)
668 {
669 	platform_driver_unregister(&twlreg_driver);
670 }
671 module_exit(twlreg_exit)
672 
673 MODULE_DESCRIPTION("TWL4030 regulator driver");
674 MODULE_LICENSE("GPL");
675