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/init.h>
14 #include <linux/err.h>
15 #include <linux/delay.h>
16 #include <linux/platform_device.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/regulator/machine.h>
19 #include <linux/i2c/twl.h>
20 
21 
22 /*
23  * The TWL4030/TW5030/TPS659x0/TWL6030 family chips include power management, a
24  * USB OTG transceiver, an RTC, ADC, PWM, and lots more.  Some versions
25  * include an audio codec, battery charger, and more voltage regulators.
26  * These chips are often used in OMAP-based systems.
27  *
28  * This driver implements software-based resource control for various
29  * voltage regulators.  This is usually augmented with state machine
30  * based control.
31  */
32 
33 struct twlreg_info {
34 	/* start of regulator's PM_RECEIVER control register bank */
35 	u8			base;
36 
37 	/* twl resource ID, for resource control state machine */
38 	u8			id;
39 
40 	/* voltage in mV = table[VSEL]; table_len must be a power-of-two */
41 	u8			table_len;
42 	const u16		*table;
43 
44 	/* regulator specific turn-on delay */
45 	u16			delay;
46 
47 	/* State REMAP default configuration */
48 	u8			remap;
49 
50 	/* chip constraints on regulator behavior */
51 	u16			min_mV;
52 
53 	/* used by regulator core */
54 	struct regulator_desc	desc;
55 };
56 
57 
58 /* LDO control registers ... offset is from the base of its register bank.
59  * The first three registers of all power resource banks help hardware to
60  * manage the various resource groups.
61  */
62 /* Common offset in TWL4030/6030 */
63 #define VREG_GRP		0
64 /* TWL4030 register offsets */
65 #define VREG_TYPE		1
66 #define VREG_REMAP		2
67 #define VREG_DEDICATED		3	/* LDO control */
68 /* TWL6030 register offsets */
69 #define VREG_TRANS		1
70 #define VREG_STATE		2
71 #define VREG_VOLTAGE		3
72 /* TWL6030 Misc register offsets */
73 #define VREG_BC_ALL		1
74 #define VREG_BC_REF		2
75 #define VREG_BC_PROC		3
76 #define VREG_BC_CLK_RST		4
77 
78 static inline int
79 twlreg_read(struct twlreg_info *info, unsigned slave_subgp, unsigned offset)
80 {
81 	u8 value;
82 	int status;
83 
84 	status = twl_i2c_read_u8(slave_subgp,
85 			&value, info->base + offset);
86 	return (status < 0) ? status : value;
87 }
88 
89 static inline int
90 twlreg_write(struct twlreg_info *info, unsigned slave_subgp, unsigned offset,
91 						 u8 value)
92 {
93 	return twl_i2c_write_u8(slave_subgp,
94 			value, info->base + offset);
95 }
96 
97 /*----------------------------------------------------------------------*/
98 
99 /* generic power resource operations, which work on all regulators */
100 
101 static int twlreg_grp(struct regulator_dev *rdev)
102 {
103 	return twlreg_read(rdev_get_drvdata(rdev), TWL_MODULE_PM_RECEIVER,
104 								 VREG_GRP);
105 }
106 
107 /*
108  * Enable/disable regulators by joining/leaving the P1 (processor) group.
109  * We assume nobody else is updating the DEV_GRP registers.
110  */
111 /* definition for 4030 family */
112 #define P3_GRP_4030	BIT(7)		/* "peripherals" */
113 #define P2_GRP_4030	BIT(6)		/* secondary processor, modem, etc */
114 #define P1_GRP_4030	BIT(5)		/* CPU/Linux */
115 /* definition for 6030 family */
116 #define P3_GRP_6030	BIT(2)		/* secondary processor, modem, etc */
117 #define P2_GRP_6030	BIT(1)		/* "peripherals" */
118 #define P1_GRP_6030	BIT(0)		/* CPU/Linux */
119 
120 static int twlreg_is_enabled(struct regulator_dev *rdev)
121 {
122 	int	state = twlreg_grp(rdev);
123 
124 	if (state < 0)
125 		return state;
126 
127 	if (twl_class_is_4030())
128 		state &= P1_GRP_4030;
129 	else
130 		state &= P1_GRP_6030;
131 	return state;
132 }
133 
134 static int twlreg_enable(struct regulator_dev *rdev)
135 {
136 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
137 	int			grp;
138 	int			ret;
139 
140 	grp = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_GRP);
141 	if (grp < 0)
142 		return grp;
143 
144 	if (twl_class_is_4030())
145 		grp |= P1_GRP_4030;
146 	else
147 		grp |= P1_GRP_6030;
148 
149 	ret = twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
150 
151 	udelay(info->delay);
152 
153 	return ret;
154 }
155 
156 static int twlreg_disable(struct regulator_dev *rdev)
157 {
158 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
159 	int			grp;
160 
161 	grp = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_GRP);
162 	if (grp < 0)
163 		return grp;
164 
165 	if (twl_class_is_4030())
166 		grp &= ~(P1_GRP_4030 | P2_GRP_4030 | P3_GRP_4030);
167 	else
168 		grp &= ~(P1_GRP_6030 | P2_GRP_6030 | P3_GRP_6030);
169 
170 	return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_GRP, grp);
171 }
172 
173 static int twlreg_get_status(struct regulator_dev *rdev)
174 {
175 	int	state = twlreg_grp(rdev);
176 
177 	if (twl_class_is_6030())
178 		return 0; /* FIXME return for 6030 regulator */
179 
180 	if (state < 0)
181 		return state;
182 	state &= 0x0f;
183 
184 	/* assume state != WARM_RESET; we'd not be running...  */
185 	if (!state)
186 		return REGULATOR_STATUS_OFF;
187 	return (state & BIT(3))
188 		? REGULATOR_STATUS_NORMAL
189 		: REGULATOR_STATUS_STANDBY;
190 }
191 
192 static int twlreg_set_mode(struct regulator_dev *rdev, unsigned mode)
193 {
194 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
195 	unsigned		message;
196 	int			status;
197 
198 	if (twl_class_is_6030())
199 		return 0; /* FIXME return for 6030 regulator */
200 
201 	/* We can only set the mode through state machine commands... */
202 	switch (mode) {
203 	case REGULATOR_MODE_NORMAL:
204 		message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_ACTIVE);
205 		break;
206 	case REGULATOR_MODE_STANDBY:
207 		message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_SLEEP);
208 		break;
209 	default:
210 		return -EINVAL;
211 	}
212 
213 	/* Ensure the resource is associated with some group */
214 	status = twlreg_grp(rdev);
215 	if (status < 0)
216 		return status;
217 	if (!(status & (P3_GRP_4030 | P2_GRP_4030 | P1_GRP_4030)))
218 		return -EACCES;
219 
220 	status = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
221 			message >> 8, 0x15 /* PB_WORD_MSB */ );
222 	if (status >= 0)
223 		return status;
224 
225 	return twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
226 			message, 0x16 /* PB_WORD_LSB */ );
227 }
228 
229 /*----------------------------------------------------------------------*/
230 
231 /*
232  * Support for adjustable-voltage LDOs uses a four bit (or less) voltage
233  * select field in its control register.   We use tables indexed by VSEL
234  * to record voltages in milliVolts.  (Accuracy is about three percent.)
235  *
236  * Note that VSEL values for VAUX2 changed in twl5030 and newer silicon;
237  * currently handled by listing two slightly different VAUX2 regulators,
238  * only one of which will be configured.
239  *
240  * VSEL values documented as "TI cannot support these values" are flagged
241  * in these tables as UNSUP() values; we normally won't assign them.
242  *
243  * VAUX3 at 3V is incorrectly listed in some TI manuals as unsupported.
244  * TI are revising the twl5030/tps659x0 specs to support that 3.0V setting.
245  */
246 #ifdef CONFIG_TWL4030_ALLOW_UNSUPPORTED
247 #define UNSUP_MASK	0x0000
248 #else
249 #define UNSUP_MASK	0x8000
250 #endif
251 
252 #define UNSUP(x)	(UNSUP_MASK | (x))
253 #define IS_UNSUP(x)	(UNSUP_MASK & (x))
254 #define LDO_MV(x)	(~UNSUP_MASK & (x))
255 
256 
257 static const u16 VAUX1_VSEL_table[] = {
258 	UNSUP(1500), UNSUP(1800), 2500, 2800,
259 	3000, 3000, 3000, 3000,
260 };
261 static const u16 VAUX2_4030_VSEL_table[] = {
262 	UNSUP(1000), UNSUP(1000), UNSUP(1200), 1300,
263 	1500, 1800, UNSUP(1850), 2500,
264 	UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
265 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
266 };
267 static const u16 VAUX2_VSEL_table[] = {
268 	1700, 1700, 1900, 1300,
269 	1500, 1800, 2000, 2500,
270 	2100, 2800, 2200, 2300,
271 	2400, 2400, 2400, 2400,
272 };
273 static const u16 VAUX3_VSEL_table[] = {
274 	1500, 1800, 2500, 2800,
275 	3000, 3000, 3000, 3000,
276 };
277 static const u16 VAUX4_VSEL_table[] = {
278 	700, 1000, 1200, UNSUP(1300),
279 	1500, 1800, UNSUP(1850), 2500,
280 	UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
281 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
282 };
283 static const u16 VMMC1_VSEL_table[] = {
284 	1850, 2850, 3000, 3150,
285 };
286 static const u16 VMMC2_VSEL_table[] = {
287 	UNSUP(1000), UNSUP(1000), UNSUP(1200), UNSUP(1300),
288 	UNSUP(1500), UNSUP(1800), 1850, UNSUP(2500),
289 	2600, 2800, 2850, 3000,
290 	3150, 3150, 3150, 3150,
291 };
292 static const u16 VPLL1_VSEL_table[] = {
293 	1000, 1200, 1300, 1800,
294 	UNSUP(2800), UNSUP(3000), UNSUP(3000), UNSUP(3000),
295 };
296 static const u16 VPLL2_VSEL_table[] = {
297 	700, 1000, 1200, 1300,
298 	UNSUP(1500), 1800, UNSUP(1850), UNSUP(2500),
299 	UNSUP(2600), UNSUP(2800), UNSUP(2850), UNSUP(3000),
300 	UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
301 };
302 static const u16 VSIM_VSEL_table[] = {
303 	UNSUP(1000), UNSUP(1200), UNSUP(1300), 1800,
304 	2800, 3000, 3000, 3000,
305 };
306 static const u16 VDAC_VSEL_table[] = {
307 	1200, 1300, 1800, 1800,
308 };
309 static const u16 VDD1_VSEL_table[] = {
310 	800, 1450,
311 };
312 static const u16 VDD2_VSEL_table[] = {
313 	800, 1450, 1500,
314 };
315 static const u16 VIO_VSEL_table[] = {
316 	1800, 1850,
317 };
318 static const u16 VINTANA2_VSEL_table[] = {
319 	2500, 2750,
320 };
321 static const u16 VAUX1_6030_VSEL_table[] = {
322 	1000, 1300, 1800, 2500,
323 	2800, 2900, 3000, 3000,
324 };
325 static const u16 VAUX2_6030_VSEL_table[] = {
326 	1200, 1800, 2500, 2750,
327 	2800, 2800, 2800, 2800,
328 };
329 static const u16 VAUX3_6030_VSEL_table[] = {
330 	1000, 1200, 1300, 1800,
331 	2500, 2800, 3000, 3000,
332 };
333 static const u16 VMMC_VSEL_table[] = {
334 	1200, 1800, 2800, 2900,
335 	3000, 3000, 3000, 3000,
336 };
337 static const u16 VPP_VSEL_table[] = {
338 	1800, 1900, 2000, 2100,
339 	2200, 2300, 2400, 2500,
340 };
341 static const u16 VUSIM_VSEL_table[] = {
342 	1200, 1800, 2500, 2900,
343 };
344 
345 static int twlldo_list_voltage(struct regulator_dev *rdev, unsigned index)
346 {
347 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
348 	int			mV = info->table[index];
349 
350 	return IS_UNSUP(mV) ? 0 : (LDO_MV(mV) * 1000);
351 }
352 
353 static int
354 twlldo_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV)
355 {
356 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
357 	int			vsel;
358 
359 	for (vsel = 0; vsel < info->table_len; vsel++) {
360 		int mV = info->table[vsel];
361 		int uV;
362 
363 		if (IS_UNSUP(mV))
364 			continue;
365 		uV = LDO_MV(mV) * 1000;
366 
367 		/* REVISIT for VAUX2, first match may not be best/lowest */
368 
369 		/* use the first in-range value */
370 		if (min_uV <= uV && uV <= max_uV)
371 			return twlreg_write(info, TWL_MODULE_PM_RECEIVER,
372 							VREG_VOLTAGE, vsel);
373 	}
374 
375 	return -EDOM;
376 }
377 
378 static int twlldo_get_voltage(struct regulator_dev *rdev)
379 {
380 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
381 	int		vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER,
382 								VREG_VOLTAGE);
383 
384 	if (vsel < 0)
385 		return vsel;
386 
387 	vsel &= info->table_len - 1;
388 	return LDO_MV(info->table[vsel]) * 1000;
389 }
390 
391 static struct regulator_ops twlldo_ops = {
392 	.list_voltage	= twlldo_list_voltage,
393 
394 	.set_voltage	= twlldo_set_voltage,
395 	.get_voltage	= twlldo_get_voltage,
396 
397 	.enable		= twlreg_enable,
398 	.disable	= twlreg_disable,
399 	.is_enabled	= twlreg_is_enabled,
400 
401 	.set_mode	= twlreg_set_mode,
402 
403 	.get_status	= twlreg_get_status,
404 };
405 
406 /*----------------------------------------------------------------------*/
407 
408 /*
409  * Fixed voltage LDOs don't have a VSEL field to update.
410  */
411 static int twlfixed_list_voltage(struct regulator_dev *rdev, unsigned index)
412 {
413 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
414 
415 	return info->min_mV * 1000;
416 }
417 
418 static int twlfixed_get_voltage(struct regulator_dev *rdev)
419 {
420 	struct twlreg_info	*info = rdev_get_drvdata(rdev);
421 
422 	return info->min_mV * 1000;
423 }
424 
425 static struct regulator_ops twlfixed_ops = {
426 	.list_voltage	= twlfixed_list_voltage,
427 
428 	.get_voltage	= twlfixed_get_voltage,
429 
430 	.enable		= twlreg_enable,
431 	.disable	= twlreg_disable,
432 	.is_enabled	= twlreg_is_enabled,
433 
434 	.set_mode	= twlreg_set_mode,
435 
436 	.get_status	= twlreg_get_status,
437 };
438 
439 /*----------------------------------------------------------------------*/
440 
441 #define TWL4030_ADJUSTABLE_LDO(label, offset, num, turnon_delay, remap_conf) \
442 		TWL_ADJUSTABLE_LDO(label, offset, num, turnon_delay, \
443 			remap_conf, TWL4030)
444 #define TWL4030_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
445 			remap_conf) \
446 		TWL_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
447 			remap_conf, TWL4030)
448 #define TWL6030_ADJUSTABLE_LDO(label, offset, num, turnon_delay, \
449 			remap_conf) \
450 		TWL_ADJUSTABLE_LDO(label, offset, num, turnon_delay, \
451 			remap_conf, TWL6030)
452 #define TWL6030_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
453 			remap_conf) \
454 		TWL_FIXED_LDO(label, offset, mVolts, num, turnon_delay, \
455 			remap_conf, TWL6030)
456 
457 #define TWL_ADJUSTABLE_LDO(label, offset, num, turnon_delay, remap_conf, \
458 		family) { \
459 	.base = offset, \
460 	.id = num, \
461 	.table_len = ARRAY_SIZE(label##_VSEL_table), \
462 	.table = label##_VSEL_table, \
463 	.delay = turnon_delay, \
464 	.remap = remap_conf, \
465 	.desc = { \
466 		.name = #label, \
467 		.id = family##_REG_##label, \
468 		.n_voltages = ARRAY_SIZE(label##_VSEL_table), \
469 		.ops = &twlldo_ops, \
470 		.type = REGULATOR_VOLTAGE, \
471 		.owner = THIS_MODULE, \
472 		}, \
473 	}
474 
475 #define TWL_FIXED_LDO(label, offset, mVolts, num, turnon_delay, remap_conf, \
476 		family) { \
477 	.base = offset, \
478 	.id = num, \
479 	.min_mV = mVolts, \
480 	.delay = turnon_delay, \
481 	.remap = remap_conf, \
482 	.desc = { \
483 		.name = #label, \
484 		.id = family##_REG_##label, \
485 		.n_voltages = 1, \
486 		.ops = &twlfixed_ops, \
487 		.type = REGULATOR_VOLTAGE, \
488 		.owner = THIS_MODULE, \
489 		}, \
490 	}
491 
492 /*
493  * We list regulators here if systems need some level of
494  * software control over them after boot.
495  */
496 static struct twlreg_info twl_regs[] = {
497 	TWL4030_ADJUSTABLE_LDO(VAUX1, 0x17, 1, 100, 0x08),
498 	TWL4030_ADJUSTABLE_LDO(VAUX2_4030, 0x1b, 2, 100, 0x08),
499 	TWL4030_ADJUSTABLE_LDO(VAUX2, 0x1b, 2, 100, 0x08),
500 	TWL4030_ADJUSTABLE_LDO(VAUX3, 0x1f, 3, 100, 0x08),
501 	TWL4030_ADJUSTABLE_LDO(VAUX4, 0x23, 4, 100, 0x08),
502 	TWL4030_ADJUSTABLE_LDO(VMMC1, 0x27, 5, 100, 0x08),
503 	TWL4030_ADJUSTABLE_LDO(VMMC2, 0x2b, 6, 100, 0x08),
504 	TWL4030_ADJUSTABLE_LDO(VPLL1, 0x2f, 7, 100, 0x00),
505 	TWL4030_ADJUSTABLE_LDO(VPLL2, 0x33, 8, 100, 0x08),
506 	TWL4030_ADJUSTABLE_LDO(VSIM, 0x37, 9, 100, 0x00),
507 	TWL4030_ADJUSTABLE_LDO(VDAC, 0x3b, 10, 100, 0x08),
508 	TWL4030_FIXED_LDO(VINTANA1, 0x3f, 1500, 11, 100, 0x08),
509 	TWL4030_ADJUSTABLE_LDO(VINTANA2, 0x43, 12, 100, 0x08),
510 	TWL4030_FIXED_LDO(VINTDIG, 0x47, 1500, 13, 100, 0x08),
511 	TWL4030_ADJUSTABLE_LDO(VIO, 0x4b, 14, 1000, 0x08),
512 	TWL4030_ADJUSTABLE_LDO(VDD1, 0x55, 15, 1000, 0x08),
513 	TWL4030_ADJUSTABLE_LDO(VDD2, 0x63, 16, 1000, 0x08),
514 	TWL4030_FIXED_LDO(VUSB1V5, 0x71, 1500, 17, 100, 0x08),
515 	TWL4030_FIXED_LDO(VUSB1V8, 0x74, 1800, 18, 100, 0x08),
516 	TWL4030_FIXED_LDO(VUSB3V1, 0x77, 3100, 19, 150, 0x08),
517 	/* VUSBCP is managed *only* by the USB subchip */
518 
519 	/* 6030 REG with base as PMC Slave Misc : 0x0030 */
520 	/* Turnon-delay and remap configuration values for 6030 are not
521 	   verified since the specification is not public */
522 	TWL6030_ADJUSTABLE_LDO(VAUX1_6030, 0x54, 1, 0, 0x08),
523 	TWL6030_ADJUSTABLE_LDO(VAUX2_6030, 0x58, 2, 0, 0x08),
524 	TWL6030_ADJUSTABLE_LDO(VAUX3_6030, 0x5c, 3, 0, 0x08),
525 	TWL6030_ADJUSTABLE_LDO(VMMC, 0x68, 4, 0, 0x08),
526 	TWL6030_ADJUSTABLE_LDO(VPP, 0x6c, 5, 0, 0x08),
527 	TWL6030_ADJUSTABLE_LDO(VUSIM, 0x74, 7, 0, 0x08),
528 	TWL6030_FIXED_LDO(VANA, 0x50, 2100, 15, 0, 0x08),
529 	TWL6030_FIXED_LDO(VCXIO, 0x60, 1800, 16, 0, 0x08),
530 	TWL6030_FIXED_LDO(VDAC, 0x64, 1800, 17, 0, 0x08),
531 	TWL6030_FIXED_LDO(VUSB, 0x70, 3300, 18, 0, 0x08)
532 };
533 
534 static int twlreg_probe(struct platform_device *pdev)
535 {
536 	int				i;
537 	struct twlreg_info		*info;
538 	struct regulator_init_data	*initdata;
539 	struct regulation_constraints	*c;
540 	struct regulator_dev		*rdev;
541 
542 	for (i = 0, info = NULL; i < ARRAY_SIZE(twl_regs); i++) {
543 		if (twl_regs[i].desc.id != pdev->id)
544 			continue;
545 		info = twl_regs + i;
546 		break;
547 	}
548 	if (!info)
549 		return -ENODEV;
550 
551 	initdata = pdev->dev.platform_data;
552 	if (!initdata)
553 		return -EINVAL;
554 
555 	/* Constrain board-specific capabilities according to what
556 	 * this driver and the chip itself can actually do.
557 	 */
558 	c = &initdata->constraints;
559 	c->valid_modes_mask &= REGULATOR_MODE_NORMAL | REGULATOR_MODE_STANDBY;
560 	c->valid_ops_mask &= REGULATOR_CHANGE_VOLTAGE
561 				| REGULATOR_CHANGE_MODE
562 				| REGULATOR_CHANGE_STATUS;
563 	switch (pdev->id) {
564 	case TWL4030_REG_VIO:
565 	case TWL4030_REG_VDD1:
566 	case TWL4030_REG_VDD2:
567 	case TWL4030_REG_VPLL1:
568 	case TWL4030_REG_VINTANA1:
569 	case TWL4030_REG_VINTANA2:
570 	case TWL4030_REG_VINTDIG:
571 		c->always_on = true;
572 		break;
573 	default:
574 		break;
575 	}
576 
577 	rdev = regulator_register(&info->desc, &pdev->dev, initdata, info);
578 	if (IS_ERR(rdev)) {
579 		dev_err(&pdev->dev, "can't register %s, %ld\n",
580 				info->desc.name, PTR_ERR(rdev));
581 		return PTR_ERR(rdev);
582 	}
583 	platform_set_drvdata(pdev, rdev);
584 
585 	twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_REMAP,
586 						info->remap);
587 
588 	/* NOTE:  many regulators support short-circuit IRQs (presentable
589 	 * as REGULATOR_OVER_CURRENT notifications?) configured via:
590 	 *  - SC_CONFIG
591 	 *  - SC_DETECT1 (vintana2, vmmc1/2, vaux1/2/3/4)
592 	 *  - SC_DETECT2 (vusb, vdac, vio, vdd1/2, vpll2)
593 	 *  - IT_CONFIG
594 	 */
595 
596 	return 0;
597 }
598 
599 static int __devexit twlreg_remove(struct platform_device *pdev)
600 {
601 	regulator_unregister(platform_get_drvdata(pdev));
602 	return 0;
603 }
604 
605 MODULE_ALIAS("platform:twl_reg");
606 
607 static struct platform_driver twlreg_driver = {
608 	.probe		= twlreg_probe,
609 	.remove		= __devexit_p(twlreg_remove),
610 	/* NOTE: short name, to work around driver model truncation of
611 	 * "twl_regulator.12" (and friends) to "twl_regulator.1".
612 	 */
613 	.driver.name	= "twl_reg",
614 	.driver.owner	= THIS_MODULE,
615 };
616 
617 static int __init twlreg_init(void)
618 {
619 	return platform_driver_register(&twlreg_driver);
620 }
621 subsys_initcall(twlreg_init);
622 
623 static void __exit twlreg_exit(void)
624 {
625 	platform_driver_unregister(&twlreg_driver);
626 }
627 module_exit(twlreg_exit)
628 
629 MODULE_DESCRIPTION("TWL regulator driver");
630 MODULE_LICENSE("GPL");
631