1 /*
2  * Texas Instruments SoC Adaptive Body Bias(ABB) Regulator
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Mike Turquette <mturquette@ti.com>
6  *
7  * Copyright (C) 2012-2013 Texas Instruments, Inc.
8  * Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
9  * Nishanth Menon <nm@ti.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  *
15  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
16  * kind, whether express or implied; without even the implied warranty
17  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  */
20 #include <linux/clk.h>
21 #include <linux/delay.h>
22 #include <linux/err.h>
23 #include <linux/io.h>
24 #include <linux/module.h>
25 #include <linux/of_device.h>
26 #include <linux/of.h>
27 #include <linux/platform_device.h>
28 #include <linux/regulator/driver.h>
29 #include <linux/regulator/machine.h>
30 #include <linux/regulator/of_regulator.h>
31 
32 /*
33  * ABB LDO operating states:
34  * NOMINAL_OPP:	bypasses the ABB LDO
35  * FAST_OPP:	sets ABB LDO to Forward Body-Bias
36  * SLOW_OPP:	sets ABB LDO to Reverse Body-Bias
37  */
38 #define TI_ABB_NOMINAL_OPP	0
39 #define TI_ABB_FAST_OPP		1
40 #define TI_ABB_SLOW_OPP		3
41 
42 /**
43  * struct ti_abb_info - ABB information per voltage setting
44  * @opp_sel:	one of TI_ABB macro
45  * @vset:	(optional) vset value that LDOVBB needs to be overriden with.
46  *
47  * Array of per voltage entries organized in the same order as regulator_desc's
48  * volt_table list. (selector is used to index from this array)
49  */
50 struct ti_abb_info {
51 	u32 opp_sel;
52 	u32 vset;
53 };
54 
55 /**
56  * struct ti_abb_reg - Register description for ABB block
57  * @setup_reg:			setup register offset from base
58  * @control_reg:		control register offset from base
59  * @sr2_wtcnt_value_mask:	setup register- sr2_wtcnt_value mask
60  * @fbb_sel_mask:		setup register- FBB sel mask
61  * @rbb_sel_mask:		setup register- RBB sel mask
62  * @sr2_en_mask:		setup register- enable mask
63  * @opp_change_mask:		control register - mask to trigger LDOVBB change
64  * @opp_sel_mask:		control register - mask for mode to operate
65  */
66 struct ti_abb_reg {
67 	u32 setup_reg;
68 	u32 control_reg;
69 
70 	/* Setup register fields */
71 	u32 sr2_wtcnt_value_mask;
72 	u32 fbb_sel_mask;
73 	u32 rbb_sel_mask;
74 	u32 sr2_en_mask;
75 
76 	/* Control register fields */
77 	u32 opp_change_mask;
78 	u32 opp_sel_mask;
79 };
80 
81 /**
82  * struct ti_abb - ABB instance data
83  * @rdesc:			regulator descriptor
84  * @clk:			clock(usually sysclk) supplying ABB block
85  * @base:			base address of ABB block
86  * @int_base:			interrupt register base address
87  * @efuse_base:			(optional) efuse base address for ABB modes
88  * @ldo_base:			(optional) LDOVBB vset override base address
89  * @regs:			pointer to struct ti_abb_reg for ABB block
90  * @txdone_mask:		mask on int_base for tranxdone interrupt
91  * @ldovbb_override_mask:	mask to ldo_base for overriding default LDO VBB
92  *				vset with value from efuse
93  * @ldovbb_vset_mask:		mask to ldo_base for providing the VSET override
94  * @info:			array to per voltage ABB configuration
95  * @current_info_idx:		current index to info
96  * @settling_time:		SoC specific settling time for LDO VBB
97  */
98 struct ti_abb {
99 	struct regulator_desc rdesc;
100 	struct clk *clk;
101 	void __iomem *base;
102 	void __iomem *int_base;
103 	void __iomem *efuse_base;
104 	void __iomem *ldo_base;
105 
106 	const struct ti_abb_reg *regs;
107 	u32 txdone_mask;
108 	u32 ldovbb_override_mask;
109 	u32 ldovbb_vset_mask;
110 
111 	struct ti_abb_info *info;
112 	int current_info_idx;
113 
114 	u32 settling_time;
115 };
116 
117 /**
118  * ti_abb_rmw() - handy wrapper to set specific register bits
119  * @mask:	mask for register field
120  * @value:	value shifted to mask location and written
121  * @offset:	offset of register
122  * @base:	base address
123  *
124  * Return: final register value (may be unused)
125  */
126 static inline u32 ti_abb_rmw(u32 mask, u32 value, u32 offset,
127 			     void __iomem *base)
128 {
129 	u32 val;
130 
131 	val = readl(base + offset);
132 	val &= ~mask;
133 	val |= (value << __ffs(mask)) & mask;
134 	writel(val, base + offset);
135 
136 	return val;
137 }
138 
139 /**
140  * ti_abb_check_txdone() - handy wrapper to check ABB tranxdone status
141  * @abb:	pointer to the abb instance
142  *
143  * Return: true or false
144  */
145 static inline bool ti_abb_check_txdone(const struct ti_abb *abb)
146 {
147 	return !!(readl(abb->int_base) & abb->txdone_mask);
148 }
149 
150 /**
151  * ti_abb_clear_txdone() - handy wrapper to clear ABB tranxdone status
152  * @abb:	pointer to the abb instance
153  */
154 static inline void ti_abb_clear_txdone(const struct ti_abb *abb)
155 {
156 	writel(abb->txdone_mask, abb->int_base);
157 };
158 
159 /**
160  * ti_abb_wait_tranx() - waits for ABB tranxdone event
161  * @dev:	device
162  * @abb:	pointer to the abb instance
163  *
164  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
165  */
166 static int ti_abb_wait_txdone(struct device *dev, struct ti_abb *abb)
167 {
168 	int timeout = 0;
169 	bool status;
170 
171 	while (timeout++ <= abb->settling_time) {
172 		status = ti_abb_check_txdone(abb);
173 		if (status)
174 			break;
175 
176 		udelay(1);
177 	}
178 
179 	if (timeout > abb->settling_time) {
180 		dev_warn_ratelimited(dev,
181 				     "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
182 				     __func__, timeout, readl(abb->int_base));
183 		return -ETIMEDOUT;
184 	}
185 
186 	return 0;
187 }
188 
189 /**
190  * ti_abb_clear_all_txdone() - clears ABB tranxdone event
191  * @dev:	device
192  * @abb:	pointer to the abb instance
193  *
194  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
195  */
196 static int ti_abb_clear_all_txdone(struct device *dev, const struct ti_abb *abb)
197 {
198 	int timeout = 0;
199 	bool status;
200 
201 	while (timeout++ <= abb->settling_time) {
202 		ti_abb_clear_txdone(abb);
203 
204 		status = ti_abb_check_txdone(abb);
205 		if (!status)
206 			break;
207 
208 		udelay(1);
209 	}
210 
211 	if (timeout > abb->settling_time) {
212 		dev_warn_ratelimited(dev,
213 				     "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
214 				     __func__, timeout, readl(abb->int_base));
215 		return -ETIMEDOUT;
216 	}
217 
218 	return 0;
219 }
220 
221 /**
222  * ti_abb_program_ldovbb() - program LDOVBB register for override value
223  * @dev:	device
224  * @abb:	pointer to the abb instance
225  * @info:	ABB info to program
226  */
227 static void ti_abb_program_ldovbb(struct device *dev, const struct ti_abb *abb,
228 				  struct ti_abb_info *info)
229 {
230 	u32 val;
231 
232 	val = readl(abb->ldo_base);
233 	/* clear up previous values */
234 	val &= ~(abb->ldovbb_override_mask | abb->ldovbb_vset_mask);
235 
236 	switch (info->opp_sel) {
237 	case TI_ABB_SLOW_OPP:
238 	case TI_ABB_FAST_OPP:
239 		val |= abb->ldovbb_override_mask;
240 		val |= info->vset << __ffs(abb->ldovbb_vset_mask);
241 		break;
242 	}
243 
244 	writel(val, abb->ldo_base);
245 }
246 
247 /**
248  * ti_abb_set_opp() - Setup ABB and LDO VBB for required bias
249  * @rdev:	regulator device
250  * @abb:	pointer to the abb instance
251  * @info:	ABB info to program
252  *
253  * Return: 0 on success or appropriate error value when fails
254  */
255 static int ti_abb_set_opp(struct regulator_dev *rdev, struct ti_abb *abb,
256 			  struct ti_abb_info *info)
257 {
258 	const struct ti_abb_reg *regs = abb->regs;
259 	struct device *dev = &rdev->dev;
260 	int ret;
261 
262 	ret = ti_abb_clear_all_txdone(dev, abb);
263 	if (ret)
264 		goto out;
265 
266 	ti_abb_rmw(regs->fbb_sel_mask | regs->rbb_sel_mask, 0, regs->setup_reg,
267 		   abb->base);
268 
269 	switch (info->opp_sel) {
270 	case TI_ABB_SLOW_OPP:
271 		ti_abb_rmw(regs->rbb_sel_mask, 1, regs->setup_reg, abb->base);
272 		break;
273 	case TI_ABB_FAST_OPP:
274 		ti_abb_rmw(regs->fbb_sel_mask, 1, regs->setup_reg, abb->base);
275 		break;
276 	}
277 
278 	/* program next state of ABB ldo */
279 	ti_abb_rmw(regs->opp_sel_mask, info->opp_sel, regs->control_reg,
280 		   abb->base);
281 
282 	/* program LDO VBB vset override if needed */
283 	if (abb->ldo_base)
284 		ti_abb_program_ldovbb(dev, abb, info);
285 
286 	/* Initiate ABB ldo change */
287 	ti_abb_rmw(regs->opp_change_mask, 1, regs->control_reg, abb->base);
288 
289 	/* Wait for ABB LDO to complete transition to new Bias setting */
290 	ret = ti_abb_wait_txdone(dev, abb);
291 	if (ret)
292 		goto out;
293 
294 	ret = ti_abb_clear_all_txdone(dev, abb);
295 	if (ret)
296 		goto out;
297 
298 out:
299 	return ret;
300 }
301 
302 /**
303  * ti_abb_set_voltage_sel() - regulator accessor function to set ABB LDO
304  * @rdev:	regulator device
305  * @sel:	selector to index into required ABB LDO settings (maps to
306  *		regulator descriptor's volt_table)
307  *
308  * Return: 0 on success or appropriate error value when fails
309  */
310 static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel)
311 {
312 	const struct regulator_desc *desc = rdev->desc;
313 	struct ti_abb *abb = rdev_get_drvdata(rdev);
314 	struct device *dev = &rdev->dev;
315 	struct ti_abb_info *info, *oinfo;
316 	int ret = 0;
317 
318 	if (!abb) {
319 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
320 				    __func__);
321 		return -ENODEV;
322 	}
323 
324 	if (!desc->n_voltages || !abb->info) {
325 		dev_err_ratelimited(dev,
326 				    "%s: No valid voltage table entries?\n",
327 				    __func__);
328 		return -EINVAL;
329 	}
330 
331 	if (sel >= desc->n_voltages) {
332 		dev_err(dev, "%s: sel idx(%d) >= n_voltages(%d)\n", __func__,
333 			sel, desc->n_voltages);
334 		return -EINVAL;
335 	}
336 
337 	/* If we are in the same index as we were, nothing to do here! */
338 	if (sel == abb->current_info_idx) {
339 		dev_dbg(dev, "%s: Already at sel=%d\n", __func__, sel);
340 		return ret;
341 	}
342 
343 	/* If data is exactly the same, then just update index, no change */
344 	info = &abb->info[sel];
345 	oinfo = &abb->info[abb->current_info_idx];
346 	if (!memcmp(info, oinfo, sizeof(*info))) {
347 		dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
348 			sel, abb->current_info_idx);
349 		goto out;
350 	}
351 
352 	ret = ti_abb_set_opp(rdev, abb, info);
353 
354 out:
355 	if (!ret)
356 		abb->current_info_idx = sel;
357 	else
358 		dev_err_ratelimited(dev,
359 				    "%s: Volt[%d] idx[%d] mode[%d] Fail(%d)\n",
360 				    __func__, desc->volt_table[sel], sel,
361 				    info->opp_sel, ret);
362 	return ret;
363 }
364 
365 /**
366  * ti_abb_get_voltage_sel() - Regulator accessor to get current ABB LDO setting
367  * @rdev:	regulator device
368  *
369  * Return: 0 on success or appropriate error value when fails
370  */
371 static int ti_abb_get_voltage_sel(struct regulator_dev *rdev)
372 {
373 	const struct regulator_desc *desc = rdev->desc;
374 	struct ti_abb *abb = rdev_get_drvdata(rdev);
375 	struct device *dev = &rdev->dev;
376 
377 	if (!abb) {
378 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
379 				    __func__);
380 		return -ENODEV;
381 	}
382 
383 	if (!desc->n_voltages || !abb->info) {
384 		dev_err_ratelimited(dev,
385 				    "%s: No valid voltage table entries?\n",
386 				    __func__);
387 		return -EINVAL;
388 	}
389 
390 	if (abb->current_info_idx >= (int)desc->n_voltages) {
391 		dev_err(dev, "%s: Corrupted data? idx(%d) >= n_voltages(%d)\n",
392 			__func__, abb->current_info_idx, desc->n_voltages);
393 		return -EINVAL;
394 	}
395 
396 	return abb->current_info_idx;
397 }
398 
399 /**
400  * ti_abb_init_timings() - setup ABB clock timing for the current platform
401  * @dev:	device
402  * @abb:	pointer to the abb instance
403  *
404  * Return: 0 if timing is updated, else returns error result.
405  */
406 static int ti_abb_init_timings(struct device *dev, struct ti_abb *abb)
407 {
408 	u32 clock_cycles;
409 	u32 clk_rate, sr2_wt_cnt_val, cycle_rate;
410 	const struct ti_abb_reg *regs = abb->regs;
411 	int ret;
412 	char *pname = "ti,settling-time";
413 
414 	/* read device tree properties */
415 	ret = of_property_read_u32(dev->of_node, pname, &abb->settling_time);
416 	if (ret) {
417 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
418 		return ret;
419 	}
420 
421 	/* ABB LDO cannot be settle in 0 time */
422 	if (!abb->settling_time) {
423 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
424 		return -EINVAL;
425 	}
426 
427 	pname = "ti,clock-cycles";
428 	ret = of_property_read_u32(dev->of_node, pname, &clock_cycles);
429 	if (ret) {
430 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
431 		return ret;
432 	}
433 	/* ABB LDO cannot be settle in 0 clock cycles */
434 	if (!clock_cycles) {
435 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
436 		return -EINVAL;
437 	}
438 
439 	abb->clk = devm_clk_get(dev, NULL);
440 	if (IS_ERR(abb->clk)) {
441 		ret = PTR_ERR(abb->clk);
442 		dev_err(dev, "%s: Unable to get clk(%d)\n", __func__, ret);
443 		return ret;
444 	}
445 
446 	/*
447 	 * SR2_WTCNT_VALUE is the settling time for the ABB ldo after a
448 	 * transition and must be programmed with the correct time at boot.
449 	 * The value programmed into the register is the number of SYS_CLK
450 	 * clock cycles that match a given wall time profiled for the ldo.
451 	 * This value depends on:
452 	 * settling time of ldo in micro-seconds (varies per OMAP family)
453 	 * # of clock cycles per SYS_CLK period (varies per OMAP family)
454 	 * the SYS_CLK frequency in MHz (varies per board)
455 	 * The formula is:
456 	 *
457 	 *                      ldo settling time (in micro-seconds)
458 	 * SR2_WTCNT_VALUE = ------------------------------------------
459 	 *                   (# system clock cycles) * (sys_clk period)
460 	 *
461 	 * Put another way:
462 	 *
463 	 * SR2_WTCNT_VALUE = settling time / (# SYS_CLK cycles / SYS_CLK rate))
464 	 *
465 	 * To avoid dividing by zero multiply both "# clock cycles" and
466 	 * "settling time" by 10 such that the final result is the one we want.
467 	 */
468 
469 	/* Convert SYS_CLK rate to MHz & prevent divide by zero */
470 	clk_rate = DIV_ROUND_CLOSEST(clk_get_rate(abb->clk), 1000000);
471 
472 	/* Calculate cycle rate */
473 	cycle_rate = DIV_ROUND_CLOSEST(clock_cycles * 10, clk_rate);
474 
475 	/* Calulate SR2_WTCNT_VALUE */
476 	sr2_wt_cnt_val = DIV_ROUND_CLOSEST(abb->settling_time * 10, cycle_rate);
477 
478 	dev_dbg(dev, "%s: Clk_rate=%ld, sr2_cnt=0x%08x\n", __func__,
479 		clk_get_rate(abb->clk), sr2_wt_cnt_val);
480 
481 	ti_abb_rmw(regs->sr2_wtcnt_value_mask, sr2_wt_cnt_val, regs->setup_reg,
482 		   abb->base);
483 
484 	return 0;
485 }
486 
487 /**
488  * ti_abb_init_table() - Initialize ABB table from device tree
489  * @dev:	device
490  * @abb:	pointer to the abb instance
491  * @rinit_data:	regulator initdata
492  *
493  * Return: 0 on success or appropriate error value when fails
494  */
495 static int ti_abb_init_table(struct device *dev, struct ti_abb *abb,
496 			     struct regulator_init_data *rinit_data)
497 {
498 	struct ti_abb_info *info;
499 	const struct property *prop;
500 	const __be32 *abb_info;
501 	const u32 num_values = 6;
502 	char *pname = "ti,abb_info";
503 	u32 num_entries, i;
504 	unsigned int *volt_table;
505 	int min_uV = INT_MAX, max_uV = 0;
506 	struct regulation_constraints *c = &rinit_data->constraints;
507 
508 	prop = of_find_property(dev->of_node, pname, NULL);
509 	if (!prop) {
510 		dev_err(dev, "No '%s' property?\n", pname);
511 		return -ENODEV;
512 	}
513 
514 	if (!prop->value) {
515 		dev_err(dev, "Empty '%s' property?\n", pname);
516 		return -ENODATA;
517 	}
518 
519 	/*
520 	 * Each abb_info is a set of n-tuple, where n is num_values, consisting
521 	 * of voltage and a set of detection logic for ABB information for that
522 	 * voltage to apply.
523 	 */
524 	num_entries = prop->length / sizeof(u32);
525 	if (!num_entries || (num_entries % num_values)) {
526 		dev_err(dev, "All '%s' list entries need %d vals\n", pname,
527 			num_values);
528 		return -EINVAL;
529 	}
530 	num_entries /= num_values;
531 
532 	info = devm_kzalloc(dev, sizeof(*info) * num_entries, GFP_KERNEL);
533 	if (!info) {
534 		dev_err(dev, "Can't allocate info table for '%s' property\n",
535 			pname);
536 		return -ENOMEM;
537 	}
538 	abb->info = info;
539 
540 	volt_table = devm_kzalloc(dev, sizeof(unsigned int) * num_entries,
541 				  GFP_KERNEL);
542 	if (!volt_table) {
543 		dev_err(dev, "Can't allocate voltage table for '%s' property\n",
544 			pname);
545 		return -ENOMEM;
546 	}
547 
548 	abb->rdesc.n_voltages = num_entries;
549 	abb->rdesc.volt_table = volt_table;
550 	/* We do not know where the OPP voltage is at the moment */
551 	abb->current_info_idx = -EINVAL;
552 
553 	abb_info = prop->value;
554 	for (i = 0; i < num_entries; i++, info++, volt_table++) {
555 		u32 efuse_offset, rbb_mask, fbb_mask, vset_mask;
556 		u32 efuse_val;
557 
558 		/* NOTE: num_values should equal to entries picked up here */
559 		*volt_table = be32_to_cpup(abb_info++);
560 		info->opp_sel = be32_to_cpup(abb_info++);
561 		efuse_offset = be32_to_cpup(abb_info++);
562 		rbb_mask = be32_to_cpup(abb_info++);
563 		fbb_mask = be32_to_cpup(abb_info++);
564 		vset_mask = be32_to_cpup(abb_info++);
565 
566 		dev_dbg(dev,
567 			"[%d]v=%d ABB=%d ef=0x%x rbb=0x%x fbb=0x%x vset=0x%x\n",
568 			i, *volt_table, info->opp_sel, efuse_offset, rbb_mask,
569 			fbb_mask, vset_mask);
570 
571 		/* Find min/max for voltage set */
572 		if (min_uV > *volt_table)
573 			min_uV = *volt_table;
574 		if (max_uV < *volt_table)
575 			max_uV = *volt_table;
576 
577 		if (!abb->efuse_base) {
578 			/* Ignore invalid data, but warn to help cleanup */
579 			if (efuse_offset || rbb_mask || fbb_mask || vset_mask)
580 				dev_err(dev, "prop '%s': v=%d,bad efuse/mask\n",
581 					pname, *volt_table);
582 			goto check_abb;
583 		}
584 
585 		efuse_val = readl(abb->efuse_base + efuse_offset);
586 
587 		/* Use ABB recommendation from Efuse */
588 		if (efuse_val & rbb_mask)
589 			info->opp_sel = TI_ABB_SLOW_OPP;
590 		else if (efuse_val & fbb_mask)
591 			info->opp_sel = TI_ABB_FAST_OPP;
592 		else if (rbb_mask || fbb_mask)
593 			info->opp_sel = TI_ABB_NOMINAL_OPP;
594 
595 		dev_dbg(dev,
596 			"[%d]v=%d efusev=0x%x final ABB=%d\n",
597 			i, *volt_table, efuse_val, info->opp_sel);
598 
599 		/* Use recommended Vset bits from Efuse */
600 		if (!abb->ldo_base) {
601 			if (vset_mask)
602 				dev_err(dev, "prop'%s':v=%d vst=%x LDO base?\n",
603 					pname, *volt_table, vset_mask);
604 			continue;
605 		}
606 		info->vset = efuse_val & vset_mask >> __ffs(vset_mask);
607 		dev_dbg(dev, "[%d]v=%d vset=%x\n", i, *volt_table, info->vset);
608 check_abb:
609 		switch (info->opp_sel) {
610 		case TI_ABB_NOMINAL_OPP:
611 		case TI_ABB_FAST_OPP:
612 		case TI_ABB_SLOW_OPP:
613 			/* Valid values */
614 			break;
615 		default:
616 			dev_err(dev, "%s:[%d]v=%d, ABB=%d is invalid! Abort!\n",
617 				__func__, i, *volt_table, info->opp_sel);
618 			return -EINVAL;
619 		}
620 	}
621 
622 	/* Setup the min/max voltage constraints from the supported list */
623 	c->min_uV = min_uV;
624 	c->max_uV = max_uV;
625 
626 	return 0;
627 }
628 
629 static struct regulator_ops ti_abb_reg_ops = {
630 	.list_voltage = regulator_list_voltage_table,
631 
632 	.set_voltage_sel = ti_abb_set_voltage_sel,
633 	.get_voltage_sel = ti_abb_get_voltage_sel,
634 };
635 
636 /* Default ABB block offsets, IF this changes in future, create new one */
637 static const struct ti_abb_reg abb_regs_v1 = {
638 	/* WARNING: registers are wrongly documented in TRM */
639 	.setup_reg		= 0x04,
640 	.control_reg		= 0x00,
641 
642 	.sr2_wtcnt_value_mask	= (0xff << 8),
643 	.fbb_sel_mask		= (0x01 << 2),
644 	.rbb_sel_mask		= (0x01 << 1),
645 	.sr2_en_mask		= (0x01 << 0),
646 
647 	.opp_change_mask	= (0x01 << 2),
648 	.opp_sel_mask		= (0x03 << 0),
649 };
650 
651 static const struct ti_abb_reg abb_regs_v2 = {
652 	.setup_reg		= 0x00,
653 	.control_reg		= 0x04,
654 
655 	.sr2_wtcnt_value_mask	= (0xff << 8),
656 	.fbb_sel_mask		= (0x01 << 2),
657 	.rbb_sel_mask		= (0x01 << 1),
658 	.sr2_en_mask		= (0x01 << 0),
659 
660 	.opp_change_mask	= (0x01 << 2),
661 	.opp_sel_mask		= (0x03 << 0),
662 };
663 
664 static const struct of_device_id ti_abb_of_match[] = {
665 	{.compatible = "ti,abb-v1", .data = &abb_regs_v1},
666 	{.compatible = "ti,abb-v2", .data = &abb_regs_v2},
667 	{ },
668 };
669 
670 MODULE_DEVICE_TABLE(of, ti_abb_of_match);
671 
672 /**
673  * ti_abb_probe() - Initialize an ABB ldo instance
674  * @pdev: ABB platform device
675  *
676  * Initializes an individual ABB LDO for required Body-Bias. ABB is used to
677  * addional bias supply to SoC modules for power savings or mandatory stability
678  * configuration at certain Operating Performance Points(OPPs).
679  *
680  * Return: 0 on success or appropriate error value when fails
681  */
682 static int ti_abb_probe(struct platform_device *pdev)
683 {
684 	struct device *dev = &pdev->dev;
685 	const struct of_device_id *match;
686 	struct resource *res;
687 	struct ti_abb *abb;
688 	struct regulator_init_data *initdata = NULL;
689 	struct regulator_dev *rdev = NULL;
690 	struct regulator_desc *desc;
691 	struct regulation_constraints *c;
692 	struct regulator_config config = { };
693 	char *pname;
694 	int ret = 0;
695 
696 	match = of_match_device(ti_abb_of_match, dev);
697 	if (!match) {
698 		/* We do not expect this to happen */
699 		ret = -ENODEV;
700 		dev_err(dev, "%s: Unable to match device\n", __func__);
701 		goto err;
702 	}
703 	if (!match->data) {
704 		ret = -EINVAL;
705 		dev_err(dev, "%s: Bad data in match\n", __func__);
706 		goto err;
707 	}
708 
709 	abb = devm_kzalloc(dev, sizeof(struct ti_abb), GFP_KERNEL);
710 	if (!abb) {
711 		dev_err(dev, "%s: Unable to allocate ABB struct\n", __func__);
712 		ret = -ENOMEM;
713 		goto err;
714 	}
715 	abb->regs = match->data;
716 
717 	/* Map ABB resources */
718 	pname = "base-address";
719 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
720 	abb->base = devm_ioremap_resource(dev, res);
721 	if (IS_ERR(abb->base)) {
722 		ret = PTR_ERR(abb->base);
723 		goto err;
724 	}
725 
726 	pname = "int-address";
727 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
728 	if (!res) {
729 		dev_err(dev, "Missing '%s' IO resource\n", pname);
730 		ret = -ENODEV;
731 		goto err;
732 	}
733 	/*
734 	 * We may have shared interrupt register offsets which are
735 	 * write-1-to-clear between domains ensuring exclusivity.
736 	 */
737 	abb->int_base = devm_ioremap_nocache(dev, res->start,
738 					     resource_size(res));
739 	if (!abb->int_base) {
740 		dev_err(dev, "Unable to map '%s'\n", pname);
741 		ret = -ENOMEM;
742 		goto err;
743 	}
744 
745 	/* Map Optional resources */
746 	pname = "efuse-address";
747 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
748 	if (!res) {
749 		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
750 		ret = -ENODEV;
751 		goto skip_opt;
752 	}
753 
754 	/*
755 	 * We may have shared efuse register offsets which are read-only
756 	 * between domains
757 	 */
758 	abb->efuse_base = devm_ioremap_nocache(dev, res->start,
759 					       resource_size(res));
760 	if (!abb->efuse_base) {
761 		dev_err(dev, "Unable to map '%s'\n", pname);
762 		ret = -ENOMEM;
763 		goto err;
764 	}
765 
766 	pname = "ldo-address";
767 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
768 	abb->ldo_base = devm_ioremap_resource(dev, res);
769 	if (IS_ERR(abb->ldo_base)) {
770 		ret = PTR_ERR(abb->ldo_base);
771 		goto err;
772 	}
773 
774 	/* IF ldo_base is set, the following are mandatory */
775 	pname = "ti,ldovbb-override-mask";
776 	ret =
777 	    of_property_read_u32(pdev->dev.of_node, pname,
778 				 &abb->ldovbb_override_mask);
779 	if (ret) {
780 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
781 		goto err;
782 	}
783 	if (!abb->ldovbb_override_mask) {
784 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
785 		ret = -EINVAL;
786 		goto err;
787 	}
788 
789 	pname = "ti,ldovbb-vset-mask";
790 	ret =
791 	    of_property_read_u32(pdev->dev.of_node, pname,
792 				 &abb->ldovbb_vset_mask);
793 	if (ret) {
794 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
795 		goto err;
796 	}
797 	if (!abb->ldovbb_vset_mask) {
798 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
799 		ret = -EINVAL;
800 		goto err;
801 	}
802 
803 skip_opt:
804 	pname = "ti,tranxdone-status-mask";
805 	ret =
806 	    of_property_read_u32(pdev->dev.of_node, pname,
807 				 &abb->txdone_mask);
808 	if (ret) {
809 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
810 		goto err;
811 	}
812 	if (!abb->txdone_mask) {
813 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
814 		ret = -EINVAL;
815 		goto err;
816 	}
817 
818 	initdata = of_get_regulator_init_data(dev, pdev->dev.of_node);
819 	if (!initdata) {
820 		ret = -ENOMEM;
821 		dev_err(dev, "%s: Unable to alloc regulator init data\n",
822 			__func__);
823 		goto err;
824 	}
825 
826 	/* init ABB opp_sel table */
827 	ret = ti_abb_init_table(dev, abb, initdata);
828 	if (ret)
829 		goto err;
830 
831 	/* init ABB timing */
832 	ret = ti_abb_init_timings(dev, abb);
833 	if (ret)
834 		goto err;
835 
836 	desc = &abb->rdesc;
837 	desc->name = dev_name(dev);
838 	desc->owner = THIS_MODULE;
839 	desc->type = REGULATOR_VOLTAGE;
840 	desc->ops = &ti_abb_reg_ops;
841 
842 	c = &initdata->constraints;
843 	if (desc->n_voltages > 1)
844 		c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
845 	c->always_on = true;
846 
847 	config.dev = dev;
848 	config.init_data = initdata;
849 	config.driver_data = abb;
850 	config.of_node = pdev->dev.of_node;
851 
852 	rdev = regulator_register(desc, &config);
853 	if (IS_ERR(rdev)) {
854 		ret = PTR_ERR(rdev);
855 		dev_err(dev, "%s: failed to register regulator(%d)\n",
856 			__func__, ret);
857 		goto err;
858 	}
859 	platform_set_drvdata(pdev, rdev);
860 
861 	/* Enable the ldo if not already done by bootloader */
862 	ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->regs->setup_reg, abb->base);
863 
864 	return 0;
865 
866 err:
867 	dev_err(dev, "%s: Failed to initialize(%d)\n", __func__, ret);
868 	return ret;
869 }
870 
871 /**
872  * ti_abb_remove() - cleanups
873  * @pdev: ABB platform device
874  *
875  * Return: 0
876  */
877 static int ti_abb_remove(struct platform_device *pdev)
878 {
879 	struct regulator_dev *rdev = platform_get_drvdata(pdev);
880 
881 	regulator_unregister(rdev);
882 	return 0;
883 }
884 
885 MODULE_ALIAS("platform:ti_abb");
886 
887 static struct platform_driver ti_abb_driver = {
888 	.probe = ti_abb_probe,
889 	.remove = ti_abb_remove,
890 	.driver = {
891 		   .name = "ti_abb",
892 		   .owner = THIS_MODULE,
893 		   .of_match_table = of_match_ptr(ti_abb_of_match),
894 		   },
895 };
896 module_platform_driver(ti_abb_driver);
897 
898 MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
899 MODULE_AUTHOR("Texas Instruments Inc.");
900 MODULE_LICENSE("GPL v2");
901