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_off:			setup register offset from base
58  * @control_off:		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_off;
68 	u32 control_off;
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  * @setup_reg:			setup register of ABB block
87  * @control_reg:		control register of ABB block
88  * @int_base:			interrupt register base address
89  * @efuse_base:			(optional) efuse base address for ABB modes
90  * @ldo_base:			(optional) LDOVBB vset override base address
91  * @regs:			pointer to struct ti_abb_reg for ABB block
92  * @txdone_mask:		mask on int_base for tranxdone interrupt
93  * @ldovbb_override_mask:	mask to ldo_base for overriding default LDO VBB
94  *				vset with value from efuse
95  * @ldovbb_vset_mask:		mask to ldo_base for providing the VSET override
96  * @info:			array to per voltage ABB configuration
97  * @current_info_idx:		current index to info
98  * @settling_time:		SoC specific settling time for LDO VBB
99  */
100 struct ti_abb {
101 	struct regulator_desc rdesc;
102 	struct clk *clk;
103 	void __iomem *base;
104 	void __iomem *setup_reg;
105 	void __iomem *control_reg;
106 	void __iomem *int_base;
107 	void __iomem *efuse_base;
108 	void __iomem *ldo_base;
109 
110 	const struct ti_abb_reg *regs;
111 	u32 txdone_mask;
112 	u32 ldovbb_override_mask;
113 	u32 ldovbb_vset_mask;
114 
115 	struct ti_abb_info *info;
116 	int current_info_idx;
117 
118 	u32 settling_time;
119 };
120 
121 /**
122  * ti_abb_rmw() - handy wrapper to set specific register bits
123  * @mask:	mask for register field
124  * @value:	value shifted to mask location and written
125  * @reg:	register address
126  *
127  * Return: final register value (may be unused)
128  */
129 static inline u32 ti_abb_rmw(u32 mask, u32 value, void __iomem *reg)
130 {
131 	u32 val;
132 
133 	val = readl(reg);
134 	val &= ~mask;
135 	val |= (value << __ffs(mask)) & mask;
136 	writel(val, reg);
137 
138 	return val;
139 }
140 
141 /**
142  * ti_abb_check_txdone() - handy wrapper to check ABB tranxdone status
143  * @abb:	pointer to the abb instance
144  *
145  * Return: true or false
146  */
147 static inline bool ti_abb_check_txdone(const struct ti_abb *abb)
148 {
149 	return !!(readl(abb->int_base) & abb->txdone_mask);
150 }
151 
152 /**
153  * ti_abb_clear_txdone() - handy wrapper to clear ABB tranxdone status
154  * @abb:	pointer to the abb instance
155  */
156 static inline void ti_abb_clear_txdone(const struct ti_abb *abb)
157 {
158 	writel(abb->txdone_mask, abb->int_base);
159 };
160 
161 /**
162  * ti_abb_wait_tranx() - waits for ABB tranxdone event
163  * @dev:	device
164  * @abb:	pointer to the abb instance
165  *
166  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
167  */
168 static int ti_abb_wait_txdone(struct device *dev, struct ti_abb *abb)
169 {
170 	int timeout = 0;
171 	bool status;
172 
173 	while (timeout++ <= abb->settling_time) {
174 		status = ti_abb_check_txdone(abb);
175 		if (status)
176 			return 0;
177 
178 		udelay(1);
179 	}
180 
181 	dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
182 			     __func__, timeout, readl(abb->int_base));
183 	return -ETIMEDOUT;
184 }
185 
186 /**
187  * ti_abb_clear_all_txdone() - clears ABB tranxdone event
188  * @dev:	device
189  * @abb:	pointer to the abb instance
190  *
191  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
192  */
193 static int ti_abb_clear_all_txdone(struct device *dev, const struct ti_abb *abb)
194 {
195 	int timeout = 0;
196 	bool status;
197 
198 	while (timeout++ <= abb->settling_time) {
199 		ti_abb_clear_txdone(abb);
200 
201 		status = ti_abb_check_txdone(abb);
202 		if (!status)
203 			return 0;
204 
205 		udelay(1);
206 	}
207 
208 	dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
209 			     __func__, timeout, readl(abb->int_base));
210 	return -ETIMEDOUT;
211 }
212 
213 /**
214  * ti_abb_program_ldovbb() - program LDOVBB register for override value
215  * @dev:	device
216  * @abb:	pointer to the abb instance
217  * @info:	ABB info to program
218  */
219 static void ti_abb_program_ldovbb(struct device *dev, const struct ti_abb *abb,
220 				  struct ti_abb_info *info)
221 {
222 	u32 val;
223 
224 	val = readl(abb->ldo_base);
225 	/* clear up previous values */
226 	val &= ~(abb->ldovbb_override_mask | abb->ldovbb_vset_mask);
227 
228 	switch (info->opp_sel) {
229 	case TI_ABB_SLOW_OPP:
230 	case TI_ABB_FAST_OPP:
231 		val |= abb->ldovbb_override_mask;
232 		val |= info->vset << __ffs(abb->ldovbb_vset_mask);
233 		break;
234 	}
235 
236 	writel(val, abb->ldo_base);
237 }
238 
239 /**
240  * ti_abb_set_opp() - Setup ABB and LDO VBB for required bias
241  * @rdev:	regulator device
242  * @abb:	pointer to the abb instance
243  * @info:	ABB info to program
244  *
245  * Return: 0 on success or appropriate error value when fails
246  */
247 static int ti_abb_set_opp(struct regulator_dev *rdev, struct ti_abb *abb,
248 			  struct ti_abb_info *info)
249 {
250 	const struct ti_abb_reg *regs = abb->regs;
251 	struct device *dev = &rdev->dev;
252 	int ret;
253 
254 	ret = ti_abb_clear_all_txdone(dev, abb);
255 	if (ret)
256 		goto out;
257 
258 	ti_abb_rmw(regs->fbb_sel_mask | regs->rbb_sel_mask, 0, abb->setup_reg);
259 
260 	switch (info->opp_sel) {
261 	case TI_ABB_SLOW_OPP:
262 		ti_abb_rmw(regs->rbb_sel_mask, 1, abb->setup_reg);
263 		break;
264 	case TI_ABB_FAST_OPP:
265 		ti_abb_rmw(regs->fbb_sel_mask, 1, abb->setup_reg);
266 		break;
267 	}
268 
269 	/* program next state of ABB ldo */
270 	ti_abb_rmw(regs->opp_sel_mask, info->opp_sel, abb->control_reg);
271 
272 	/*
273 	 * program LDO VBB vset override if needed for !bypass mode
274 	 * XXX: Do not switch sequence - for !bypass, LDO override reset *must*
275 	 * be performed *before* switch to bias mode else VBB glitches.
276 	 */
277 	if (abb->ldo_base && info->opp_sel != TI_ABB_NOMINAL_OPP)
278 		ti_abb_program_ldovbb(dev, abb, info);
279 
280 	/* Initiate ABB ldo change */
281 	ti_abb_rmw(regs->opp_change_mask, 1, abb->control_reg);
282 
283 	/* Wait for ABB LDO to complete transition to new Bias setting */
284 	ret = ti_abb_wait_txdone(dev, abb);
285 	if (ret)
286 		goto out;
287 
288 	ret = ti_abb_clear_all_txdone(dev, abb);
289 	if (ret)
290 		goto out;
291 
292 	/*
293 	 * Reset LDO VBB vset override bypass mode
294 	 * XXX: Do not switch sequence - for bypass, LDO override reset *must*
295 	 * be performed *after* switch to bypass else VBB glitches.
296 	 */
297 	if (abb->ldo_base && info->opp_sel == TI_ABB_NOMINAL_OPP)
298 		ti_abb_program_ldovbb(dev, abb, info);
299 
300 out:
301 	return ret;
302 }
303 
304 /**
305  * ti_abb_set_voltage_sel() - regulator accessor function to set ABB LDO
306  * @rdev:	regulator device
307  * @sel:	selector to index into required ABB LDO settings (maps to
308  *		regulator descriptor's volt_table)
309  *
310  * Return: 0 on success or appropriate error value when fails
311  */
312 static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel)
313 {
314 	const struct regulator_desc *desc = rdev->desc;
315 	struct ti_abb *abb = rdev_get_drvdata(rdev);
316 	struct device *dev = &rdev->dev;
317 	struct ti_abb_info *info, *oinfo;
318 	int ret = 0;
319 
320 	if (!abb) {
321 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
322 				    __func__);
323 		return -ENODEV;
324 	}
325 
326 	if (!desc->n_voltages || !abb->info) {
327 		dev_err_ratelimited(dev,
328 				    "%s: No valid voltage table entries?\n",
329 				    __func__);
330 		return -EINVAL;
331 	}
332 
333 	if (sel >= desc->n_voltages) {
334 		dev_err(dev, "%s: sel idx(%d) >= n_voltages(%d)\n", __func__,
335 			sel, desc->n_voltages);
336 		return -EINVAL;
337 	}
338 
339 	/* If we are in the same index as we were, nothing to do here! */
340 	if (sel == abb->current_info_idx) {
341 		dev_dbg(dev, "%s: Already at sel=%d\n", __func__, sel);
342 		return ret;
343 	}
344 
345 	info = &abb->info[sel];
346 	/*
347 	 * When Linux kernel is starting up, we are'nt sure of the
348 	 * Bias configuration that bootloader has configured.
349 	 * So, we get to know the actual setting the first time
350 	 * we are asked to transition.
351 	 */
352 	if (abb->current_info_idx == -EINVAL)
353 		goto just_set_abb;
354 
355 	/* If data is exactly the same, then just update index, no change */
356 	oinfo = &abb->info[abb->current_info_idx];
357 	if (!memcmp(info, oinfo, sizeof(*info))) {
358 		dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
359 			sel, abb->current_info_idx);
360 		goto out;
361 	}
362 
363 just_set_abb:
364 	ret = ti_abb_set_opp(rdev, abb, info);
365 
366 out:
367 	if (!ret)
368 		abb->current_info_idx = sel;
369 	else
370 		dev_err_ratelimited(dev,
371 				    "%s: Volt[%d] idx[%d] mode[%d] Fail(%d)\n",
372 				    __func__, desc->volt_table[sel], sel,
373 				    info->opp_sel, ret);
374 	return ret;
375 }
376 
377 /**
378  * ti_abb_get_voltage_sel() - Regulator accessor to get current ABB LDO setting
379  * @rdev:	regulator device
380  *
381  * Return: 0 on success or appropriate error value when fails
382  */
383 static int ti_abb_get_voltage_sel(struct regulator_dev *rdev)
384 {
385 	const struct regulator_desc *desc = rdev->desc;
386 	struct ti_abb *abb = rdev_get_drvdata(rdev);
387 	struct device *dev = &rdev->dev;
388 
389 	if (!abb) {
390 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
391 				    __func__);
392 		return -ENODEV;
393 	}
394 
395 	if (!desc->n_voltages || !abb->info) {
396 		dev_err_ratelimited(dev,
397 				    "%s: No valid voltage table entries?\n",
398 				    __func__);
399 		return -EINVAL;
400 	}
401 
402 	if (abb->current_info_idx >= (int)desc->n_voltages) {
403 		dev_err(dev, "%s: Corrupted data? idx(%d) >= n_voltages(%d)\n",
404 			__func__, abb->current_info_idx, desc->n_voltages);
405 		return -EINVAL;
406 	}
407 
408 	return abb->current_info_idx;
409 }
410 
411 /**
412  * ti_abb_init_timings() - setup ABB clock timing for the current platform
413  * @dev:	device
414  * @abb:	pointer to the abb instance
415  *
416  * Return: 0 if timing is updated, else returns error result.
417  */
418 static int ti_abb_init_timings(struct device *dev, struct ti_abb *abb)
419 {
420 	u32 clock_cycles;
421 	u32 clk_rate, sr2_wt_cnt_val, cycle_rate;
422 	const struct ti_abb_reg *regs = abb->regs;
423 	int ret;
424 	char *pname = "ti,settling-time";
425 
426 	/* read device tree properties */
427 	ret = of_property_read_u32(dev->of_node, pname, &abb->settling_time);
428 	if (ret) {
429 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
430 		return ret;
431 	}
432 
433 	/* ABB LDO cannot be settle in 0 time */
434 	if (!abb->settling_time) {
435 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
436 		return -EINVAL;
437 	}
438 
439 	pname = "ti,clock-cycles";
440 	ret = of_property_read_u32(dev->of_node, pname, &clock_cycles);
441 	if (ret) {
442 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
443 		return ret;
444 	}
445 	/* ABB LDO cannot be settle in 0 clock cycles */
446 	if (!clock_cycles) {
447 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
448 		return -EINVAL;
449 	}
450 
451 	abb->clk = devm_clk_get(dev, NULL);
452 	if (IS_ERR(abb->clk)) {
453 		ret = PTR_ERR(abb->clk);
454 		dev_err(dev, "%s: Unable to get clk(%d)\n", __func__, ret);
455 		return ret;
456 	}
457 
458 	/*
459 	 * SR2_WTCNT_VALUE is the settling time for the ABB ldo after a
460 	 * transition and must be programmed with the correct time at boot.
461 	 * The value programmed into the register is the number of SYS_CLK
462 	 * clock cycles that match a given wall time profiled for the ldo.
463 	 * This value depends on:
464 	 * settling time of ldo in micro-seconds (varies per OMAP family)
465 	 * # of clock cycles per SYS_CLK period (varies per OMAP family)
466 	 * the SYS_CLK frequency in MHz (varies per board)
467 	 * The formula is:
468 	 *
469 	 *                      ldo settling time (in micro-seconds)
470 	 * SR2_WTCNT_VALUE = ------------------------------------------
471 	 *                   (# system clock cycles) * (sys_clk period)
472 	 *
473 	 * Put another way:
474 	 *
475 	 * SR2_WTCNT_VALUE = settling time / (# SYS_CLK cycles / SYS_CLK rate))
476 	 *
477 	 * To avoid dividing by zero multiply both "# clock cycles" and
478 	 * "settling time" by 10 such that the final result is the one we want.
479 	 */
480 
481 	/* Convert SYS_CLK rate to MHz & prevent divide by zero */
482 	clk_rate = DIV_ROUND_CLOSEST(clk_get_rate(abb->clk), 1000000);
483 
484 	/* Calculate cycle rate */
485 	cycle_rate = DIV_ROUND_CLOSEST(clock_cycles * 10, clk_rate);
486 
487 	/* Calulate SR2_WTCNT_VALUE */
488 	sr2_wt_cnt_val = DIV_ROUND_CLOSEST(abb->settling_time * 10, cycle_rate);
489 
490 	dev_dbg(dev, "%s: Clk_rate=%ld, sr2_cnt=0x%08x\n", __func__,
491 		clk_get_rate(abb->clk), sr2_wt_cnt_val);
492 
493 	ti_abb_rmw(regs->sr2_wtcnt_value_mask, sr2_wt_cnt_val, abb->setup_reg);
494 
495 	return 0;
496 }
497 
498 /**
499  * ti_abb_init_table() - Initialize ABB table from device tree
500  * @dev:	device
501  * @abb:	pointer to the abb instance
502  * @rinit_data:	regulator initdata
503  *
504  * Return: 0 on success or appropriate error value when fails
505  */
506 static int ti_abb_init_table(struct device *dev, struct ti_abb *abb,
507 			     struct regulator_init_data *rinit_data)
508 {
509 	struct ti_abb_info *info;
510 	const u32 num_values = 6;
511 	char *pname = "ti,abb_info";
512 	u32 i;
513 	unsigned int *volt_table;
514 	int num_entries, min_uV = INT_MAX, max_uV = 0;
515 	struct regulation_constraints *c = &rinit_data->constraints;
516 
517 	/*
518 	 * Each abb_info is a set of n-tuple, where n is num_values, consisting
519 	 * of voltage and a set of detection logic for ABB information for that
520 	 * voltage to apply.
521 	 */
522 	num_entries = of_property_count_u32_elems(dev->of_node, pname);
523 	if (num_entries < 0) {
524 		dev_err(dev, "No '%s' property?\n", pname);
525 		return num_entries;
526 	}
527 
528 	if (!num_entries || (num_entries % num_values)) {
529 		dev_err(dev, "All '%s' list entries need %d vals\n", pname,
530 			num_values);
531 		return -EINVAL;
532 	}
533 	num_entries /= num_values;
534 
535 	info = devm_kcalloc(dev, num_entries, sizeof(*info), GFP_KERNEL);
536 	if (!info)
537 		return -ENOMEM;
538 
539 	abb->info = info;
540 
541 	volt_table = devm_kcalloc(dev, num_entries, sizeof(unsigned int),
542 				  GFP_KERNEL);
543 	if (!volt_table)
544 		return -ENOMEM;
545 
546 	abb->rdesc.n_voltages = num_entries;
547 	abb->rdesc.volt_table = volt_table;
548 	/* We do not know where the OPP voltage is at the moment */
549 	abb->current_info_idx = -EINVAL;
550 
551 	for (i = 0; i < num_entries; i++, info++, volt_table++) {
552 		u32 efuse_offset, rbb_mask, fbb_mask, vset_mask;
553 		u32 efuse_val;
554 
555 		/* NOTE: num_values should equal to entries picked up here */
556 		of_property_read_u32_index(dev->of_node, pname, i * num_values,
557 					   volt_table);
558 		of_property_read_u32_index(dev->of_node, pname,
559 					   i * num_values + 1, &info->opp_sel);
560 		of_property_read_u32_index(dev->of_node, pname,
561 					   i * num_values + 2, &efuse_offset);
562 		of_property_read_u32_index(dev->of_node, pname,
563 					   i * num_values + 3, &rbb_mask);
564 		of_property_read_u32_index(dev->of_node, pname,
565 					   i * num_values + 4, &fbb_mask);
566 		of_property_read_u32_index(dev->of_node, pname,
567 					   i * num_values + 5, &vset_mask);
568 
569 		dev_dbg(dev,
570 			"[%d]v=%d ABB=%d ef=0x%x rbb=0x%x fbb=0x%x vset=0x%x\n",
571 			i, *volt_table, info->opp_sel, efuse_offset, rbb_mask,
572 			fbb_mask, vset_mask);
573 
574 		/* Find min/max for voltage set */
575 		if (min_uV > *volt_table)
576 			min_uV = *volt_table;
577 		if (max_uV < *volt_table)
578 			max_uV = *volt_table;
579 
580 		if (!abb->efuse_base) {
581 			/* Ignore invalid data, but warn to help cleanup */
582 			if (efuse_offset || rbb_mask || fbb_mask || vset_mask)
583 				dev_err(dev, "prop '%s': v=%d,bad efuse/mask\n",
584 					pname, *volt_table);
585 			goto check_abb;
586 		}
587 
588 		efuse_val = readl(abb->efuse_base + efuse_offset);
589 
590 		/* Use ABB recommendation from Efuse */
591 		if (efuse_val & rbb_mask)
592 			info->opp_sel = TI_ABB_SLOW_OPP;
593 		else if (efuse_val & fbb_mask)
594 			info->opp_sel = TI_ABB_FAST_OPP;
595 		else if (rbb_mask || fbb_mask)
596 			info->opp_sel = TI_ABB_NOMINAL_OPP;
597 
598 		dev_dbg(dev,
599 			"[%d]v=%d efusev=0x%x final ABB=%d\n",
600 			i, *volt_table, efuse_val, info->opp_sel);
601 
602 		/* Use recommended Vset bits from Efuse */
603 		if (!abb->ldo_base) {
604 			if (vset_mask)
605 				dev_err(dev, "prop'%s':v=%d vst=%x LDO base?\n",
606 					pname, *volt_table, vset_mask);
607 			continue;
608 		}
609 		info->vset = (efuse_val & vset_mask) >> __ffs(vset_mask);
610 		dev_dbg(dev, "[%d]v=%d vset=%x\n", i, *volt_table, info->vset);
611 check_abb:
612 		switch (info->opp_sel) {
613 		case TI_ABB_NOMINAL_OPP:
614 		case TI_ABB_FAST_OPP:
615 		case TI_ABB_SLOW_OPP:
616 			/* Valid values */
617 			break;
618 		default:
619 			dev_err(dev, "%s:[%d]v=%d, ABB=%d is invalid! Abort!\n",
620 				__func__, i, *volt_table, info->opp_sel);
621 			return -EINVAL;
622 		}
623 	}
624 
625 	/* Setup the min/max voltage constraints from the supported list */
626 	c->min_uV = min_uV;
627 	c->max_uV = max_uV;
628 
629 	return 0;
630 }
631 
632 static const struct regulator_ops ti_abb_reg_ops = {
633 	.list_voltage = regulator_list_voltage_table,
634 
635 	.set_voltage_sel = ti_abb_set_voltage_sel,
636 	.get_voltage_sel = ti_abb_get_voltage_sel,
637 };
638 
639 /* Default ABB block offsets, IF this changes in future, create new one */
640 static const struct ti_abb_reg abb_regs_v1 = {
641 	/* WARNING: registers are wrongly documented in TRM */
642 	.setup_off		= 0x04,
643 	.control_off		= 0x00,
644 
645 	.sr2_wtcnt_value_mask	= (0xff << 8),
646 	.fbb_sel_mask		= (0x01 << 2),
647 	.rbb_sel_mask		= (0x01 << 1),
648 	.sr2_en_mask		= (0x01 << 0),
649 
650 	.opp_change_mask	= (0x01 << 2),
651 	.opp_sel_mask		= (0x03 << 0),
652 };
653 
654 static const struct ti_abb_reg abb_regs_v2 = {
655 	.setup_off		= 0x00,
656 	.control_off		= 0x04,
657 
658 	.sr2_wtcnt_value_mask	= (0xff << 8),
659 	.fbb_sel_mask		= (0x01 << 2),
660 	.rbb_sel_mask		= (0x01 << 1),
661 	.sr2_en_mask		= (0x01 << 0),
662 
663 	.opp_change_mask	= (0x01 << 2),
664 	.opp_sel_mask		= (0x03 << 0),
665 };
666 
667 static const struct ti_abb_reg abb_regs_generic = {
668 	.sr2_wtcnt_value_mask	= (0xff << 8),
669 	.fbb_sel_mask		= (0x01 << 2),
670 	.rbb_sel_mask		= (0x01 << 1),
671 	.sr2_en_mask		= (0x01 << 0),
672 
673 	.opp_change_mask	= (0x01 << 2),
674 	.opp_sel_mask		= (0x03 << 0),
675 };
676 
677 static const struct of_device_id ti_abb_of_match[] = {
678 	{.compatible = "ti,abb-v1", .data = &abb_regs_v1},
679 	{.compatible = "ti,abb-v2", .data = &abb_regs_v2},
680 	{.compatible = "ti,abb-v3", .data = &abb_regs_generic},
681 	{ },
682 };
683 
684 MODULE_DEVICE_TABLE(of, ti_abb_of_match);
685 
686 /**
687  * ti_abb_probe() - Initialize an ABB ldo instance
688  * @pdev: ABB platform device
689  *
690  * Initializes an individual ABB LDO for required Body-Bias. ABB is used to
691  * addional bias supply to SoC modules for power savings or mandatory stability
692  * configuration at certain Operating Performance Points(OPPs).
693  *
694  * Return: 0 on success or appropriate error value when fails
695  */
696 static int ti_abb_probe(struct platform_device *pdev)
697 {
698 	struct device *dev = &pdev->dev;
699 	const struct of_device_id *match;
700 	struct resource *res;
701 	struct ti_abb *abb;
702 	struct regulator_init_data *initdata = NULL;
703 	struct regulator_dev *rdev = NULL;
704 	struct regulator_desc *desc;
705 	struct regulation_constraints *c;
706 	struct regulator_config config = { };
707 	char *pname;
708 	int ret = 0;
709 
710 	match = of_match_device(ti_abb_of_match, dev);
711 	if (!match) {
712 		/* We do not expect this to happen */
713 		dev_err(dev, "%s: Unable to match device\n", __func__);
714 		return -ENODEV;
715 	}
716 	if (!match->data) {
717 		dev_err(dev, "%s: Bad data in match\n", __func__);
718 		return -EINVAL;
719 	}
720 
721 	abb = devm_kzalloc(dev, sizeof(struct ti_abb), GFP_KERNEL);
722 	if (!abb)
723 		return -ENOMEM;
724 	abb->regs = match->data;
725 
726 	/* Map ABB resources */
727 	if (abb->regs->setup_off || abb->regs->control_off) {
728 		abb->base = devm_platform_ioremap_resource_byname(pdev, "base-address");
729 		if (IS_ERR(abb->base))
730 			return PTR_ERR(abb->base);
731 
732 		abb->setup_reg = abb->base + abb->regs->setup_off;
733 		abb->control_reg = abb->base + abb->regs->control_off;
734 
735 	} else {
736 		abb->control_reg = devm_platform_ioremap_resource_byname(pdev, "control-address");
737 		if (IS_ERR(abb->control_reg))
738 			return PTR_ERR(abb->control_reg);
739 
740 		abb->setup_reg = devm_platform_ioremap_resource_byname(pdev, "setup-address");
741 		if (IS_ERR(abb->setup_reg))
742 			return PTR_ERR(abb->setup_reg);
743 	}
744 
745 	abb->int_base = devm_platform_ioremap_resource_byname(pdev, "int-address");
746 	if (IS_ERR(abb->int_base))
747 		return PTR_ERR(abb->int_base);
748 
749 	/* Map Optional resources */
750 	pname = "efuse-address";
751 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
752 	if (!res) {
753 		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
754 		ret = -ENODEV;
755 		goto skip_opt;
756 	}
757 
758 	/*
759 	 * We may have shared efuse register offsets which are read-only
760 	 * between domains
761 	 */
762 	abb->efuse_base = devm_ioremap(dev, res->start,
763 					       resource_size(res));
764 	if (!abb->efuse_base) {
765 		dev_err(dev, "Unable to map '%s'\n", pname);
766 		return -ENOMEM;
767 	}
768 
769 	pname = "ldo-address";
770 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
771 	if (!res) {
772 		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
773 		ret = -ENODEV;
774 		goto skip_opt;
775 	}
776 	abb->ldo_base = devm_ioremap_resource(dev, res);
777 	if (IS_ERR(abb->ldo_base))
778 		return PTR_ERR(abb->ldo_base);
779 
780 	/* IF ldo_base is set, the following are mandatory */
781 	pname = "ti,ldovbb-override-mask";
782 	ret =
783 	    of_property_read_u32(pdev->dev.of_node, pname,
784 				 &abb->ldovbb_override_mask);
785 	if (ret) {
786 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
787 		return ret;
788 	}
789 	if (!abb->ldovbb_override_mask) {
790 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
791 		return -EINVAL;
792 	}
793 
794 	pname = "ti,ldovbb-vset-mask";
795 	ret =
796 	    of_property_read_u32(pdev->dev.of_node, pname,
797 				 &abb->ldovbb_vset_mask);
798 	if (ret) {
799 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
800 		return ret;
801 	}
802 	if (!abb->ldovbb_vset_mask) {
803 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
804 		return -EINVAL;
805 	}
806 
807 skip_opt:
808 	pname = "ti,tranxdone-status-mask";
809 	ret =
810 	    of_property_read_u32(pdev->dev.of_node, pname,
811 				 &abb->txdone_mask);
812 	if (ret) {
813 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
814 		return ret;
815 	}
816 	if (!abb->txdone_mask) {
817 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
818 		return -EINVAL;
819 	}
820 
821 	initdata = of_get_regulator_init_data(dev, pdev->dev.of_node,
822 					      &abb->rdesc);
823 	if (!initdata) {
824 		dev_err(dev, "%s: Unable to alloc regulator init data\n",
825 			__func__);
826 		return -ENOMEM;
827 	}
828 
829 	/* init ABB opp_sel table */
830 	ret = ti_abb_init_table(dev, abb, initdata);
831 	if (ret)
832 		return ret;
833 
834 	/* init ABB timing */
835 	ret = ti_abb_init_timings(dev, abb);
836 	if (ret)
837 		return ret;
838 
839 	desc = &abb->rdesc;
840 	desc->name = dev_name(dev);
841 	desc->owner = THIS_MODULE;
842 	desc->type = REGULATOR_VOLTAGE;
843 	desc->ops = &ti_abb_reg_ops;
844 
845 	c = &initdata->constraints;
846 	if (desc->n_voltages > 1)
847 		c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
848 	c->always_on = true;
849 
850 	config.dev = dev;
851 	config.init_data = initdata;
852 	config.driver_data = abb;
853 	config.of_node = pdev->dev.of_node;
854 
855 	rdev = devm_regulator_register(dev, desc, &config);
856 	if (IS_ERR(rdev)) {
857 		ret = PTR_ERR(rdev);
858 		dev_err(dev, "%s: failed to register regulator(%d)\n",
859 			__func__, ret);
860 		return ret;
861 	}
862 	platform_set_drvdata(pdev, rdev);
863 
864 	/* Enable the ldo if not already done by bootloader */
865 	ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->setup_reg);
866 
867 	return 0;
868 }
869 
870 MODULE_ALIAS("platform:ti_abb");
871 
872 static struct platform_driver ti_abb_driver = {
873 	.probe = ti_abb_probe,
874 	.driver = {
875 		   .name = "ti_abb",
876 		   .of_match_table = of_match_ptr(ti_abb_of_match),
877 		   },
878 };
879 module_platform_driver(ti_abb_driver);
880 
881 MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
882 MODULE_AUTHOR("Texas Instruments Inc.");
883 MODULE_LICENSE("GPL v2");
884