1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (c) 2020, The Linux Foundation. All rights reserved.
3 
4 #include <linux/module.h>
5 #include <linux/of_irq.h>
6 #include <linux/of.h>
7 #include <linux/of_device.h>
8 #include <linux/platform_device.h>
9 #include <linux/regmap.h>
10 #include <linux/regulator/driver.h>
11 #include <linux/regulator/of_regulator.h>
12 
13 #define REG_PERPH_TYPE                  0x04
14 
15 #define QCOM_LAB_TYPE			0x24
16 #define QCOM_IBB_TYPE			0x20
17 
18 #define PMI8998_LAB_REG_BASE		0xde00
19 #define PMI8998_IBB_REG_BASE		0xdc00
20 #define PMI8998_IBB_LAB_REG_OFFSET	0x200
21 
22 #define REG_LABIBB_STATUS1		0x08
23  #define LABIBB_STATUS1_SC_BIT		BIT(6)
24  #define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
25 
26 #define REG_LABIBB_INT_SET_TYPE		0x11
27 #define REG_LABIBB_INT_POLARITY_HIGH	0x12
28 #define REG_LABIBB_INT_POLARITY_LOW	0x13
29 #define REG_LABIBB_INT_LATCHED_CLR	0x14
30 #define REG_LABIBB_INT_EN_SET		0x15
31 #define REG_LABIBB_INT_EN_CLR		0x16
32  #define LABIBB_INT_VREG_OK		BIT(0)
33  #define LABIBB_INT_VREG_TYPE_LEVEL	0
34 
35 #define REG_LABIBB_VOLTAGE		0x41
36  #define LABIBB_VOLTAGE_OVERRIDE_EN	BIT(7)
37  #define LAB_VOLTAGE_SET_MASK		GENMASK(3, 0)
38  #define IBB_VOLTAGE_SET_MASK		GENMASK(5, 0)
39 
40 #define REG_LABIBB_ENABLE_CTL		0x46
41  #define LABIBB_CONTROL_ENABLE		BIT(7)
42 
43 #define REG_LABIBB_PD_CTL		0x47
44  #define LAB_PD_CTL_MASK		GENMASK(1, 0)
45  #define IBB_PD_CTL_MASK		(BIT(0) | BIT(7))
46  #define LAB_PD_CTL_STRONG_PULL		BIT(0)
47  #define IBB_PD_CTL_HALF_STRENGTH	BIT(0)
48  #define IBB_PD_CTL_EN			BIT(7)
49 
50 #define REG_LABIBB_CURRENT_LIMIT	0x4b
51  #define LAB_CURRENT_LIMIT_MASK		GENMASK(2, 0)
52  #define IBB_CURRENT_LIMIT_MASK		GENMASK(4, 0)
53  #define LAB_CURRENT_LIMIT_OVERRIDE_EN	BIT(3)
54  #define LABIBB_CURRENT_LIMIT_EN	BIT(7)
55 
56 #define REG_IBB_PWRUP_PWRDN_CTL_1	0x58
57  #define IBB_CTL_1_DISCHARGE_EN		BIT(2)
58 
59 #define REG_LABIBB_SOFT_START_CTL	0x5f
60 #define REG_LABIBB_SEC_ACCESS		0xd0
61  #define LABIBB_SEC_UNLOCK_CODE		0xa5
62 
63 #define LAB_ENABLE_CTL_MASK		BIT(7)
64 #define IBB_ENABLE_CTL_MASK		(BIT(7) | BIT(6))
65 
66 #define LABIBB_OFF_ON_DELAY		1000
67 #define LAB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 2)
68 #define IBB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 10)
69 #define LABIBB_POLL_ENABLED_TIME	1000
70 #define OCP_RECOVERY_INTERVAL_MS	500
71 #define SC_RECOVERY_INTERVAL_MS		250
72 #define LABIBB_MAX_OCP_COUNT		4
73 #define LABIBB_MAX_SC_COUNT		3
74 #define LABIBB_MAX_FATAL_COUNT		2
75 
76 struct labibb_current_limits {
77 	u32				uA_min;
78 	u32				uA_step;
79 	u8				ovr_val;
80 };
81 
82 struct labibb_regulator {
83 	struct regulator_desc		desc;
84 	struct device			*dev;
85 	struct regmap			*regmap;
86 	struct regulator_dev		*rdev;
87 	struct labibb_current_limits	uA_limits;
88 	struct delayed_work		ocp_recovery_work;
89 	struct delayed_work		sc_recovery_work;
90 	u16				base;
91 	u8				type;
92 	u8				dischg_sel;
93 	u8				soft_start_sel;
94 	int				sc_irq;
95 	int				sc_count;
96 	int				ocp_irq;
97 	int				ocp_irq_count;
98 	int				fatal_count;
99 };
100 
101 struct labibb_regulator_data {
102 	const char			*name;
103 	u8				type;
104 	u16				base;
105 	const struct regulator_desc	*desc;
106 };
107 
108 static int qcom_labibb_ocp_hw_enable(struct regulator_dev *rdev)
109 {
110 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
111 	int ret;
112 
113 	/* Clear irq latch status to avoid spurious event */
114 	ret = regmap_update_bits(rdev->regmap,
115 				 vreg->base + REG_LABIBB_INT_LATCHED_CLR,
116 				 LABIBB_INT_VREG_OK, 1);
117 	if (ret)
118 		return ret;
119 
120 	/* Enable OCP HW interrupt */
121 	return regmap_update_bits(rdev->regmap,
122 				  vreg->base + REG_LABIBB_INT_EN_SET,
123 				  LABIBB_INT_VREG_OK, 1);
124 }
125 
126 static int qcom_labibb_ocp_hw_disable(struct regulator_dev *rdev)
127 {
128 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
129 
130 	return regmap_update_bits(rdev->regmap,
131 				  vreg->base + REG_LABIBB_INT_EN_CLR,
132 				  LABIBB_INT_VREG_OK, 1);
133 }
134 
135 /**
136  * qcom_labibb_check_ocp_status - Check the Over-Current Protection status
137  * @vreg: Main driver structure
138  *
139  * This function checks the STATUS1 register for the VREG_OK bit: if it is
140  * set, then there is no Over-Current event.
141  *
142  * Returns: Zero if there is no over-current, 1 if in over-current or
143  *          negative number for error
144  */
145 static int qcom_labibb_check_ocp_status(struct labibb_regulator *vreg)
146 {
147 	u32 cur_status;
148 	int ret;
149 
150 	ret = regmap_read(vreg->rdev->regmap, vreg->base + REG_LABIBB_STATUS1,
151 			  &cur_status);
152 	if (ret)
153 		return ret;
154 
155 	return !(cur_status & LABIBB_STATUS1_VREG_OK_BIT);
156 }
157 
158 /**
159  * qcom_labibb_ocp_recovery_worker - Handle OCP event
160  * @work: OCP work structure
161  *
162  * This is the worker function to handle the Over Current Protection
163  * hardware event; This will check if the hardware is still
164  * signaling an over-current condition and will eventually stop
165  * the regulator if such condition is still signaled after
166  * LABIBB_MAX_OCP_COUNT times.
167  *
168  * If the driver that is consuming the regulator did not take action
169  * for the OCP condition, or the hardware did not stabilize, a cut
170  * of the LAB and IBB regulators will be forced (regulators will be
171  * disabled).
172  *
173  * As last, if the writes to shut down the LAB/IBB regulators fail
174  * for more than LABIBB_MAX_FATAL_COUNT, then a kernel panic will be
175  * triggered, as a last resort to protect the hardware from burning;
176  * this, however, is expected to never happen, but this is kept to
177  * try to further ensure that we protect the hardware at all costs.
178  */
179 static void qcom_labibb_ocp_recovery_worker(struct work_struct *work)
180 {
181 	struct labibb_regulator *vreg;
182 	const struct regulator_ops *ops;
183 	int ret;
184 
185 	vreg = container_of(work, struct labibb_regulator,
186 			    ocp_recovery_work.work);
187 	ops = vreg->rdev->desc->ops;
188 
189 	if (vreg->ocp_irq_count >= LABIBB_MAX_OCP_COUNT) {
190 		/*
191 		 * If we tried to disable the regulator multiple times but
192 		 * we kept failing, there's only one last hope to save our
193 		 * hardware from the death: raise a kernel bug, reboot and
194 		 * hope that the bootloader kindly saves us. This, though
195 		 * is done only as paranoid checking, because failing the
196 		 * regmap write to disable the vreg is almost impossible,
197 		 * since we got here after multiple regmap R/W.
198 		 */
199 		BUG_ON(vreg->fatal_count > LABIBB_MAX_FATAL_COUNT);
200 		dev_err(&vreg->rdev->dev, "LABIBB: CRITICAL: Disabling regulator\n");
201 
202 		/* Disable the regulator immediately to avoid damage */
203 		ret = ops->disable(vreg->rdev);
204 		if (ret) {
205 			vreg->fatal_count++;
206 			goto reschedule;
207 		}
208 		enable_irq(vreg->ocp_irq);
209 		vreg->fatal_count = 0;
210 		return;
211 	}
212 
213 	ret = qcom_labibb_check_ocp_status(vreg);
214 	if (ret != 0) {
215 		vreg->ocp_irq_count++;
216 		goto reschedule;
217 	}
218 
219 	ret = qcom_labibb_ocp_hw_enable(vreg->rdev);
220 	if (ret) {
221 		/* We cannot trust it without OCP enabled. */
222 		dev_err(vreg->dev, "Cannot enable OCP IRQ\n");
223 		vreg->ocp_irq_count++;
224 		goto reschedule;
225 	}
226 
227 	enable_irq(vreg->ocp_irq);
228 	/* Everything went fine: reset the OCP count! */
229 	vreg->ocp_irq_count = 0;
230 	return;
231 
232 reschedule:
233 	mod_delayed_work(system_wq, &vreg->ocp_recovery_work,
234 			 msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS));
235 }
236 
237 /**
238  * qcom_labibb_ocp_isr - Interrupt routine for OverCurrent Protection
239  * @irq:  Interrupt number
240  * @chip: Main driver structure
241  *
242  * Over Current Protection (OCP) will signal to the client driver
243  * that an over-current event has happened and then will schedule
244  * a recovery worker.
245  *
246  * Disabling and eventually re-enabling the regulator is expected
247  * to be done by the driver, as some hardware may be triggering an
248  * over-current condition only at first initialization or it may
249  * be expected only for a very brief amount of time, after which
250  * the attached hardware may be expected to stabilize its current
251  * draw.
252  *
253  * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
254  */
255 static irqreturn_t qcom_labibb_ocp_isr(int irq, void *chip)
256 {
257 	struct labibb_regulator *vreg = chip;
258 	const struct regulator_ops *ops = vreg->rdev->desc->ops;
259 	int ret;
260 
261 	/* If the regulator is not enabled, this is a fake event */
262 	if (!ops->is_enabled(vreg->rdev))
263 		return IRQ_HANDLED;
264 
265 	/* If we tried to recover for too many times it's not getting better */
266 	if (vreg->ocp_irq_count > LABIBB_MAX_OCP_COUNT)
267 		return IRQ_NONE;
268 
269 	/*
270 	 * If we (unlikely) can't read this register, to prevent hardware
271 	 * damage at all costs, we assume that the overcurrent event was
272 	 * real; Moreover, if the status register is not signaling OCP,
273 	 * it was a spurious event, so it's all ok.
274 	 */
275 	ret = qcom_labibb_check_ocp_status(vreg);
276 	if (ret == 0) {
277 		vreg->ocp_irq_count = 0;
278 		goto end;
279 	}
280 	vreg->ocp_irq_count++;
281 
282 	/*
283 	 * Disable the interrupt temporarily, or it will fire continuously;
284 	 * we will re-enable it in the recovery worker function.
285 	 */
286 	disable_irq_nosync(irq);
287 
288 	/* Warn the user for overcurrent */
289 	dev_warn(vreg->dev, "Over-Current interrupt fired!\n");
290 
291 	/* Disable the interrupt to avoid hogging */
292 	ret = qcom_labibb_ocp_hw_disable(vreg->rdev);
293 	if (ret)
294 		goto end;
295 
296 	/* Signal overcurrent event to drivers */
297 	regulator_notifier_call_chain(vreg->rdev,
298 				      REGULATOR_EVENT_OVER_CURRENT, NULL);
299 
300 end:
301 	/* Schedule the recovery work */
302 	schedule_delayed_work(&vreg->ocp_recovery_work,
303 			      msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS));
304 	if (ret)
305 		return IRQ_NONE;
306 
307 	return IRQ_HANDLED;
308 }
309 
310 static int qcom_labibb_set_ocp(struct regulator_dev *rdev, int lim,
311 			       int severity, bool enable)
312 {
313 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
314 	char *ocp_irq_name;
315 	u32 irq_flags = IRQF_ONESHOT;
316 	int irq_trig_low, ret;
317 
318 	/*
319 	 * labibb supports only protection - and does not support setting
320 	 * limit. Furthermore, we don't support disabling protection.
321 	 */
322 	if (lim || severity != REGULATOR_SEVERITY_PROT || !enable)
323 		return -EINVAL;
324 
325 	/* If there is no OCP interrupt, there's nothing to set */
326 	if (vreg->ocp_irq <= 0)
327 		return -EINVAL;
328 
329 	ocp_irq_name = devm_kasprintf(vreg->dev, GFP_KERNEL, "%s-over-current",
330 				      vreg->desc.name);
331 	if (!ocp_irq_name)
332 		return -ENOMEM;
333 
334 	/* IRQ polarities - LAB: trigger-low, IBB: trigger-high */
335 	switch (vreg->type) {
336 	case QCOM_LAB_TYPE:
337 		irq_flags |= IRQF_TRIGGER_LOW;
338 		irq_trig_low = 1;
339 		break;
340 	case QCOM_IBB_TYPE:
341 		irq_flags |= IRQF_TRIGGER_HIGH;
342 		irq_trig_low = 0;
343 		break;
344 	default:
345 		return -EINVAL;
346 	}
347 
348 	/* Activate OCP HW level interrupt */
349 	ret = regmap_update_bits(rdev->regmap,
350 				 vreg->base + REG_LABIBB_INT_SET_TYPE,
351 				 LABIBB_INT_VREG_OK,
352 				 LABIBB_INT_VREG_TYPE_LEVEL);
353 	if (ret)
354 		return ret;
355 
356 	/* Set OCP interrupt polarity */
357 	ret = regmap_update_bits(rdev->regmap,
358 				 vreg->base + REG_LABIBB_INT_POLARITY_HIGH,
359 				 LABIBB_INT_VREG_OK, !irq_trig_low);
360 	if (ret)
361 		return ret;
362 	ret = regmap_update_bits(rdev->regmap,
363 				 vreg->base + REG_LABIBB_INT_POLARITY_LOW,
364 				 LABIBB_INT_VREG_OK, irq_trig_low);
365 	if (ret)
366 		return ret;
367 
368 	ret = qcom_labibb_ocp_hw_enable(rdev);
369 	if (ret)
370 		return ret;
371 
372 	return devm_request_threaded_irq(vreg->dev, vreg->ocp_irq, NULL,
373 					 qcom_labibb_ocp_isr, irq_flags,
374 					 ocp_irq_name, vreg);
375 }
376 
377 /**
378  * qcom_labibb_check_sc_status - Check the Short Circuit Protection status
379  * @vreg: Main driver structure
380  *
381  * This function checks the STATUS1 register on both LAB and IBB regulators
382  * for the ShortCircuit bit: if it is set on *any* of them, then we have
383  * experienced a short-circuit event.
384  *
385  * Returns: Zero if there is no short-circuit, 1 if in short-circuit or
386  *          negative number for error
387  */
388 static int qcom_labibb_check_sc_status(struct labibb_regulator *vreg)
389 {
390 	u32 ibb_status, ibb_reg, lab_status, lab_reg;
391 	int ret;
392 
393 	/* We have to work on both regulators due to PBS... */
394 	lab_reg = ibb_reg = vreg->base + REG_LABIBB_STATUS1;
395 	if (vreg->type == QCOM_LAB_TYPE)
396 		ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET;
397 	else
398 		lab_reg += PMI8998_IBB_LAB_REG_OFFSET;
399 
400 	ret = regmap_read(vreg->rdev->regmap, lab_reg, &lab_status);
401 	if (ret)
402 		return ret;
403 	ret = regmap_read(vreg->rdev->regmap, ibb_reg, &ibb_status);
404 	if (ret)
405 		return ret;
406 
407 	return !!(lab_status & LABIBB_STATUS1_SC_BIT) ||
408 	       !!(ibb_status & LABIBB_STATUS1_SC_BIT);
409 }
410 
411 /**
412  * qcom_labibb_sc_recovery_worker - Handle Short Circuit event
413  * @work: SC work structure
414  *
415  * This is the worker function to handle the Short Circuit Protection
416  * hardware event; This will check if the hardware is still
417  * signaling a short-circuit condition and will eventually never
418  * re-enable the regulator if such condition is still signaled after
419  * LABIBB_MAX_SC_COUNT times.
420  *
421  * If the driver that is consuming the regulator did not take action
422  * for the SC condition, or the hardware did not stabilize, this
423  * worker will stop rescheduling, leaving the regulators disabled
424  * as already done by the Portable Batch System (PBS).
425  *
426  * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
427  */
428 static void qcom_labibb_sc_recovery_worker(struct work_struct *work)
429 {
430 	struct labibb_regulator *vreg;
431 	const struct regulator_ops *ops;
432 	u32 lab_reg, ibb_reg, lab_val, ibb_val, val;
433 	bool pbs_cut = false;
434 	int i, sc, ret;
435 
436 	vreg = container_of(work, struct labibb_regulator,
437 			    sc_recovery_work.work);
438 	ops = vreg->rdev->desc->ops;
439 
440 	/*
441 	 * If we tried to check the regulator status multiple times but we
442 	 * kept failing, then just bail out, as the Portable Batch System
443 	 * (PBS) will disable the vregs for us, preventing hardware damage.
444 	 */
445 	if (vreg->fatal_count > LABIBB_MAX_FATAL_COUNT)
446 		return;
447 
448 	/* Too many short-circuit events. Throw in the towel. */
449 	if (vreg->sc_count > LABIBB_MAX_SC_COUNT)
450 		return;
451 
452 	/*
453 	 * The Portable Batch System (PBS) automatically disables LAB
454 	 * and IBB when a short-circuit event is detected, so we have to
455 	 * check and work on both of them at the same time.
456 	 */
457 	lab_reg = ibb_reg = vreg->base + REG_LABIBB_ENABLE_CTL;
458 	if (vreg->type == QCOM_LAB_TYPE)
459 		ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET;
460 	else
461 		lab_reg += PMI8998_IBB_LAB_REG_OFFSET;
462 
463 	sc = qcom_labibb_check_sc_status(vreg);
464 	if (sc)
465 		goto reschedule;
466 
467 	for (i = 0; i < LABIBB_MAX_SC_COUNT; i++) {
468 		ret = regmap_read(vreg->regmap, lab_reg, &lab_val);
469 		if (ret) {
470 			vreg->fatal_count++;
471 			goto reschedule;
472 		}
473 
474 		ret = regmap_read(vreg->regmap, ibb_reg, &ibb_val);
475 		if (ret) {
476 			vreg->fatal_count++;
477 			goto reschedule;
478 		}
479 		val = lab_val & ibb_val;
480 
481 		if (!(val & LABIBB_CONTROL_ENABLE)) {
482 			pbs_cut = true;
483 			break;
484 		}
485 		usleep_range(5000, 6000);
486 	}
487 	if (pbs_cut)
488 		goto reschedule;
489 
490 
491 	/*
492 	 * If we have reached this point, we either have successfully
493 	 * recovered from the SC condition or we had a spurious SC IRQ,
494 	 * which means that we can re-enable the regulators, if they
495 	 * have ever been disabled by the PBS.
496 	 */
497 	ret = ops->enable(vreg->rdev);
498 	if (ret)
499 		goto reschedule;
500 
501 	/* Everything went fine: reset the OCP count! */
502 	vreg->sc_count = 0;
503 	enable_irq(vreg->sc_irq);
504 	return;
505 
506 reschedule:
507 	/*
508 	 * Now that we have done basic handling of the short-circuit,
509 	 * reschedule this worker in the regular system workqueue, as
510 	 * taking action is not truly urgent anymore.
511 	 */
512 	vreg->sc_count++;
513 	mod_delayed_work(system_wq, &vreg->sc_recovery_work,
514 			 msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS));
515 }
516 
517 /**
518  * qcom_labibb_sc_isr - Interrupt routine for Short Circuit Protection
519  * @irq:  Interrupt number
520  * @chip: Main driver structure
521  *
522  * Short Circuit Protection (SCP) will signal to the client driver
523  * that a regulation-out event has happened and then will schedule
524  * a recovery worker.
525  *
526  * The LAB and IBB regulators will be automatically disabled by the
527  * Portable Batch System (PBS) and they will be enabled again by
528  * the worker function if the hardware stops signaling the short
529  * circuit event.
530  *
531  * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
532  */
533 static irqreturn_t qcom_labibb_sc_isr(int irq, void *chip)
534 {
535 	struct labibb_regulator *vreg = chip;
536 
537 	if (vreg->sc_count > LABIBB_MAX_SC_COUNT)
538 		return IRQ_NONE;
539 
540 	/* Warn the user for short circuit */
541 	dev_warn(vreg->dev, "Short-Circuit interrupt fired!\n");
542 
543 	/*
544 	 * Disable the interrupt temporarily, or it will fire continuously;
545 	 * we will re-enable it in the recovery worker function.
546 	 */
547 	disable_irq_nosync(irq);
548 
549 	/* Signal out of regulation event to drivers */
550 	regulator_notifier_call_chain(vreg->rdev,
551 				      REGULATOR_EVENT_REGULATION_OUT, NULL);
552 
553 	/* Schedule the short-circuit handling as high-priority work */
554 	mod_delayed_work(system_highpri_wq, &vreg->sc_recovery_work,
555 			 msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS));
556 	return IRQ_HANDLED;
557 }
558 
559 
560 static int qcom_labibb_set_current_limit(struct regulator_dev *rdev,
561 					 int min_uA, int max_uA)
562 {
563 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
564 	struct regulator_desc *desc = &vreg->desc;
565 	struct labibb_current_limits *lim = &vreg->uA_limits;
566 	u32 mask, val;
567 	int i, ret, sel = -1;
568 
569 	if (min_uA < lim->uA_min || max_uA < lim->uA_min)
570 		return -EINVAL;
571 
572 	for (i = 0; i < desc->n_current_limits; i++) {
573 		int uA_limit = (lim->uA_step * i) + lim->uA_min;
574 
575 		if (max_uA >= uA_limit && min_uA <= uA_limit)
576 			sel = i;
577 	}
578 	if (sel < 0)
579 		return -EINVAL;
580 
581 	/* Current limit setting needs secure access */
582 	ret = regmap_write(vreg->regmap, vreg->base + REG_LABIBB_SEC_ACCESS,
583 			   LABIBB_SEC_UNLOCK_CODE);
584 	if (ret)
585 		return ret;
586 
587 	mask = desc->csel_mask | lim->ovr_val;
588 	mask |= LABIBB_CURRENT_LIMIT_EN;
589 	val = (u32)sel | lim->ovr_val;
590 	val |= LABIBB_CURRENT_LIMIT_EN;
591 
592 	return regmap_update_bits(vreg->regmap, desc->csel_reg, mask, val);
593 }
594 
595 static int qcom_labibb_get_current_limit(struct regulator_dev *rdev)
596 {
597 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
598 	struct regulator_desc *desc = &vreg->desc;
599 	struct labibb_current_limits *lim = &vreg->uA_limits;
600 	unsigned int cur_step;
601 	int ret;
602 
603 	ret = regmap_read(vreg->regmap, desc->csel_reg, &cur_step);
604 	if (ret)
605 		return ret;
606 	cur_step &= desc->csel_mask;
607 
608 	return (cur_step * lim->uA_step) + lim->uA_min;
609 }
610 
611 static int qcom_labibb_set_soft_start(struct regulator_dev *rdev)
612 {
613 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
614 	u32 val = 0;
615 
616 	if (vreg->type == QCOM_IBB_TYPE)
617 		val = vreg->dischg_sel;
618 	else
619 		val = vreg->soft_start_sel;
620 
621 	return regmap_write(rdev->regmap, rdev->desc->soft_start_reg, val);
622 }
623 
624 static int qcom_labibb_get_table_sel(const int *table, int sz, u32 value)
625 {
626 	int i;
627 
628 	for (i = 0; i < sz; i++)
629 		if (table[i] == value)
630 			return i;
631 	return -EINVAL;
632 }
633 
634 /* IBB discharge resistor values in KOhms */
635 static const int dischg_resistor_values[] = { 300, 64, 32, 16 };
636 
637 /* Soft start time in microseconds */
638 static const int soft_start_values[] = { 200, 400, 600, 800 };
639 
640 static int qcom_labibb_of_parse_cb(struct device_node *np,
641 				   const struct regulator_desc *desc,
642 				   struct regulator_config *config)
643 {
644 	struct labibb_regulator *vreg = config->driver_data;
645 	u32 dischg_kohms, soft_start_time;
646 	int ret;
647 
648 	ret = of_property_read_u32(np, "qcom,discharge-resistor-kohms",
649 				       &dischg_kohms);
650 	if (ret)
651 		dischg_kohms = 300;
652 
653 	ret = qcom_labibb_get_table_sel(dischg_resistor_values,
654 					ARRAY_SIZE(dischg_resistor_values),
655 					dischg_kohms);
656 	if (ret < 0)
657 		return ret;
658 	vreg->dischg_sel = (u8)ret;
659 
660 	ret = of_property_read_u32(np, "qcom,soft-start-us",
661 				   &soft_start_time);
662 	if (ret)
663 		soft_start_time = 200;
664 
665 	ret = qcom_labibb_get_table_sel(soft_start_values,
666 					ARRAY_SIZE(soft_start_values),
667 					soft_start_time);
668 	if (ret < 0)
669 		return ret;
670 	vreg->soft_start_sel = (u8)ret;
671 
672 	return 0;
673 }
674 
675 static const struct regulator_ops qcom_labibb_ops = {
676 	.enable			= regulator_enable_regmap,
677 	.disable		= regulator_disable_regmap,
678 	.is_enabled		= regulator_is_enabled_regmap,
679 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
680 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
681 	.list_voltage		= regulator_list_voltage_linear,
682 	.map_voltage		= regulator_map_voltage_linear,
683 	.set_active_discharge	= regulator_set_active_discharge_regmap,
684 	.set_pull_down		= regulator_set_pull_down_regmap,
685 	.set_current_limit	= qcom_labibb_set_current_limit,
686 	.get_current_limit	= qcom_labibb_get_current_limit,
687 	.set_soft_start		= qcom_labibb_set_soft_start,
688 	.set_over_current_protection = qcom_labibb_set_ocp,
689 };
690 
691 static const struct regulator_desc pmi8998_lab_desc = {
692 	.enable_mask		= LAB_ENABLE_CTL_MASK,
693 	.enable_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_ENABLE_CTL),
694 	.enable_val		= LABIBB_CONTROL_ENABLE,
695 	.enable_time		= LAB_ENABLE_TIME,
696 	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
697 	.soft_start_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
698 	.pull_down_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_PD_CTL),
699 	.pull_down_mask		= LAB_PD_CTL_MASK,
700 	.pull_down_val_on	= LAB_PD_CTL_STRONG_PULL,
701 	.vsel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
702 	.vsel_mask		= LAB_VOLTAGE_SET_MASK,
703 	.apply_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
704 	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
705 	.csel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
706 	.csel_mask		= LAB_CURRENT_LIMIT_MASK,
707 	.n_current_limits	= 8,
708 	.off_on_delay		= LABIBB_OFF_ON_DELAY,
709 	.owner			= THIS_MODULE,
710 	.type			= REGULATOR_VOLTAGE,
711 	.min_uV			= 4600000,
712 	.uV_step		= 100000,
713 	.n_voltages		= 16,
714 	.ops			= &qcom_labibb_ops,
715 	.of_parse_cb		= qcom_labibb_of_parse_cb,
716 };
717 
718 static const struct regulator_desc pmi8998_ibb_desc = {
719 	.enable_mask		= IBB_ENABLE_CTL_MASK,
720 	.enable_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_ENABLE_CTL),
721 	.enable_val		= LABIBB_CONTROL_ENABLE,
722 	.enable_time		= IBB_ENABLE_TIME,
723 	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
724 	.soft_start_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
725 	.active_discharge_off	= 0,
726 	.active_discharge_on	= IBB_CTL_1_DISCHARGE_EN,
727 	.active_discharge_mask	= IBB_CTL_1_DISCHARGE_EN,
728 	.active_discharge_reg	= (PMI8998_IBB_REG_BASE + REG_IBB_PWRUP_PWRDN_CTL_1),
729 	.pull_down_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_PD_CTL),
730 	.pull_down_mask		= IBB_PD_CTL_MASK,
731 	.pull_down_val_on	= IBB_PD_CTL_HALF_STRENGTH | IBB_PD_CTL_EN,
732 	.vsel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
733 	.vsel_mask		= IBB_VOLTAGE_SET_MASK,
734 	.apply_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
735 	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
736 	.csel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
737 	.csel_mask		= IBB_CURRENT_LIMIT_MASK,
738 	.n_current_limits	= 32,
739 	.off_on_delay		= LABIBB_OFF_ON_DELAY,
740 	.owner			= THIS_MODULE,
741 	.type			= REGULATOR_VOLTAGE,
742 	.min_uV			= 1400000,
743 	.uV_step		= 100000,
744 	.n_voltages		= 64,
745 	.ops			= &qcom_labibb_ops,
746 	.of_parse_cb		= qcom_labibb_of_parse_cb,
747 };
748 
749 static const struct labibb_regulator_data pmi8998_labibb_data[] = {
750 	{"lab", QCOM_LAB_TYPE, PMI8998_LAB_REG_BASE, &pmi8998_lab_desc},
751 	{"ibb", QCOM_IBB_TYPE, PMI8998_IBB_REG_BASE, &pmi8998_ibb_desc},
752 	{ },
753 };
754 
755 static const struct of_device_id qcom_labibb_match[] = {
756 	{ .compatible = "qcom,pmi8998-lab-ibb", .data = &pmi8998_labibb_data},
757 	{ },
758 };
759 MODULE_DEVICE_TABLE(of, qcom_labibb_match);
760 
761 static int qcom_labibb_regulator_probe(struct platform_device *pdev)
762 {
763 	struct labibb_regulator *vreg;
764 	struct device *dev = &pdev->dev;
765 	struct regulator_config cfg = {};
766 	struct device_node *reg_node;
767 	const struct of_device_id *match;
768 	const struct labibb_regulator_data *reg_data;
769 	struct regmap *reg_regmap;
770 	unsigned int type;
771 	int ret;
772 
773 	reg_regmap = dev_get_regmap(pdev->dev.parent, NULL);
774 	if (!reg_regmap) {
775 		dev_err(&pdev->dev, "Couldn't get parent's regmap\n");
776 		return -ENODEV;
777 	}
778 
779 	match = of_match_device(qcom_labibb_match, &pdev->dev);
780 	if (!match)
781 		return -ENODEV;
782 
783 	for (reg_data = match->data; reg_data->name; reg_data++) {
784 		char *sc_irq_name;
785 		int irq = 0;
786 
787 		/* Validate if the type of regulator is indeed
788 		 * what's mentioned in DT.
789 		 */
790 		ret = regmap_read(reg_regmap, reg_data->base + REG_PERPH_TYPE,
791 				  &type);
792 		if (ret < 0) {
793 			dev_err(dev,
794 				"Peripheral type read failed ret=%d\n",
795 				ret);
796 			return -EINVAL;
797 		}
798 
799 		if (WARN_ON((type != QCOM_LAB_TYPE) && (type != QCOM_IBB_TYPE)) ||
800 		    WARN_ON(type != reg_data->type))
801 			return -EINVAL;
802 
803 		vreg  = devm_kzalloc(&pdev->dev, sizeof(*vreg),
804 					   GFP_KERNEL);
805 		if (!vreg)
806 			return -ENOMEM;
807 
808 		sc_irq_name = devm_kasprintf(dev, GFP_KERNEL,
809 					     "%s-short-circuit",
810 					     reg_data->name);
811 		if (!sc_irq_name)
812 			return -ENOMEM;
813 
814 		reg_node = of_get_child_by_name(pdev->dev.of_node,
815 						reg_data->name);
816 		if (!reg_node)
817 			return -EINVAL;
818 
819 		/* The Short Circuit interrupt is critical */
820 		irq = of_irq_get_byname(reg_node, "sc-err");
821 		if (irq <= 0) {
822 			if (irq == 0)
823 				irq = -EINVAL;
824 
825 			of_node_put(reg_node);
826 			return dev_err_probe(vreg->dev, irq,
827 					     "Short-circuit irq not found.\n");
828 		}
829 		vreg->sc_irq = irq;
830 
831 		/* OverCurrent Protection IRQ is optional */
832 		irq = of_irq_get_byname(reg_node, "ocp");
833 		vreg->ocp_irq = irq;
834 		vreg->ocp_irq_count = 0;
835 		of_node_put(reg_node);
836 
837 		vreg->regmap = reg_regmap;
838 		vreg->dev = dev;
839 		vreg->base = reg_data->base;
840 		vreg->type = reg_data->type;
841 		INIT_DELAYED_WORK(&vreg->sc_recovery_work,
842 				  qcom_labibb_sc_recovery_worker);
843 
844 		if (vreg->ocp_irq > 0)
845 			INIT_DELAYED_WORK(&vreg->ocp_recovery_work,
846 					  qcom_labibb_ocp_recovery_worker);
847 
848 		switch (vreg->type) {
849 		case QCOM_LAB_TYPE:
850 			/* LAB Limits: 200-1600mA */
851 			vreg->uA_limits.uA_min  = 200000;
852 			vreg->uA_limits.uA_step = 200000;
853 			vreg->uA_limits.ovr_val = LAB_CURRENT_LIMIT_OVERRIDE_EN;
854 			break;
855 		case QCOM_IBB_TYPE:
856 			/* IBB Limits: 0-1550mA */
857 			vreg->uA_limits.uA_min  = 0;
858 			vreg->uA_limits.uA_step = 50000;
859 			vreg->uA_limits.ovr_val = 0; /* No override bit */
860 			break;
861 		default:
862 			return -EINVAL;
863 		}
864 
865 		memcpy(&vreg->desc, reg_data->desc, sizeof(vreg->desc));
866 		vreg->desc.of_match = reg_data->name;
867 		vreg->desc.name = reg_data->name;
868 
869 		cfg.dev = vreg->dev;
870 		cfg.driver_data = vreg;
871 		cfg.regmap = vreg->regmap;
872 
873 		vreg->rdev = devm_regulator_register(vreg->dev, &vreg->desc,
874 							&cfg);
875 
876 		if (IS_ERR(vreg->rdev)) {
877 			dev_err(dev, "qcom_labibb: error registering %s : %d\n",
878 					reg_data->name, ret);
879 			return PTR_ERR(vreg->rdev);
880 		}
881 
882 		ret = devm_request_threaded_irq(vreg->dev, vreg->sc_irq, NULL,
883 						qcom_labibb_sc_isr,
884 						IRQF_ONESHOT |
885 						IRQF_TRIGGER_RISING,
886 						sc_irq_name, vreg);
887 		if (ret)
888 			return ret;
889 	}
890 
891 	return 0;
892 }
893 
894 static struct platform_driver qcom_labibb_regulator_driver = {
895 	.driver	= {
896 		.name = "qcom-lab-ibb-regulator",
897 		.of_match_table	= qcom_labibb_match,
898 	},
899 	.probe = qcom_labibb_regulator_probe,
900 };
901 module_platform_driver(qcom_labibb_regulator_driver);
902 
903 MODULE_DESCRIPTION("Qualcomm labibb driver");
904 MODULE_AUTHOR("Nisha Kumari <nishakumari@codeaurora.org>");
905 MODULE_AUTHOR("Sumit Semwal <sumit.semwal@linaro.org>");
906 MODULE_LICENSE("GPL v2");
907