1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Texas Instruments SoC Adaptive Body Bias(ABB) Regulator
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Mike Turquette <mturquette@ti.com>
7  *
8  * Copyright (C) 2012-2013 Texas Instruments, Inc.
9  * Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
10  * Nishanth Menon <nm@ti.com>
11  */
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/err.h>
15 #include <linux/io.h>
16 #include <linux/module.h>
17 #include <linux/of_device.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/driver.h>
21 #include <linux/regulator/machine.h>
22 #include <linux/regulator/of_regulator.h>
23 
24 /*
25  * ABB LDO operating states:
26  * NOMINAL_OPP:	bypasses the ABB LDO
27  * FAST_OPP:	sets ABB LDO to Forward Body-Bias
28  * SLOW_OPP:	sets ABB LDO to Reverse Body-Bias
29  */
30 #define TI_ABB_NOMINAL_OPP	0
31 #define TI_ABB_FAST_OPP		1
32 #define TI_ABB_SLOW_OPP		3
33 
34 /**
35  * struct ti_abb_info - ABB information per voltage setting
36  * @opp_sel:	one of TI_ABB macro
37  * @vset:	(optional) vset value that LDOVBB needs to be overridden with.
38  *
39  * Array of per voltage entries organized in the same order as regulator_desc's
40  * volt_table list. (selector is used to index from this array)
41  */
42 struct ti_abb_info {
43 	u32 opp_sel;
44 	u32 vset;
45 };
46 
47 /**
48  * struct ti_abb_reg - Register description for ABB block
49  * @setup_off:			setup register offset from base
50  * @control_off:		control register offset from base
51  * @sr2_wtcnt_value_mask:	setup register- sr2_wtcnt_value mask
52  * @fbb_sel_mask:		setup register- FBB sel mask
53  * @rbb_sel_mask:		setup register- RBB sel mask
54  * @sr2_en_mask:		setup register- enable mask
55  * @opp_change_mask:		control register - mask to trigger LDOVBB change
56  * @opp_sel_mask:		control register - mask for mode to operate
57  */
58 struct ti_abb_reg {
59 	u32 setup_off;
60 	u32 control_off;
61 
62 	/* Setup register fields */
63 	u32 sr2_wtcnt_value_mask;
64 	u32 fbb_sel_mask;
65 	u32 rbb_sel_mask;
66 	u32 sr2_en_mask;
67 
68 	/* Control register fields */
69 	u32 opp_change_mask;
70 	u32 opp_sel_mask;
71 };
72 
73 /**
74  * struct ti_abb - ABB instance data
75  * @rdesc:			regulator descriptor
76  * @clk:			clock(usually sysclk) supplying ABB block
77  * @base:			base address of ABB block
78  * @setup_reg:			setup register of ABB block
79  * @control_reg:		control register of ABB block
80  * @int_base:			interrupt register base address
81  * @efuse_base:			(optional) efuse base address for ABB modes
82  * @ldo_base:			(optional) LDOVBB vset override base address
83  * @regs:			pointer to struct ti_abb_reg for ABB block
84  * @txdone_mask:		mask on int_base for tranxdone interrupt
85  * @ldovbb_override_mask:	mask to ldo_base for overriding default LDO VBB
86  *				vset with value from efuse
87  * @ldovbb_vset_mask:		mask to ldo_base for providing the VSET override
88  * @info:			array to per voltage ABB configuration
89  * @current_info_idx:		current index to info
90  * @settling_time:		SoC specific settling time for LDO VBB
91  */
92 struct ti_abb {
93 	struct regulator_desc rdesc;
94 	struct clk *clk;
95 	void __iomem *base;
96 	void __iomem *setup_reg;
97 	void __iomem *control_reg;
98 	void __iomem *int_base;
99 	void __iomem *efuse_base;
100 	void __iomem *ldo_base;
101 
102 	const struct ti_abb_reg *regs;
103 	u32 txdone_mask;
104 	u32 ldovbb_override_mask;
105 	u32 ldovbb_vset_mask;
106 
107 	struct ti_abb_info *info;
108 	int current_info_idx;
109 
110 	u32 settling_time;
111 };
112 
113 /**
114  * ti_abb_rmw() - handy wrapper to set specific register bits
115  * @mask:	mask for register field
116  * @value:	value shifted to mask location and written
117  * @reg:	register address
118  *
119  * Return: final register value (may be unused)
120  */
121 static inline u32 ti_abb_rmw(u32 mask, u32 value, void __iomem *reg)
122 {
123 	u32 val;
124 
125 	val = readl(reg);
126 	val &= ~mask;
127 	val |= (value << __ffs(mask)) & mask;
128 	writel(val, reg);
129 
130 	return val;
131 }
132 
133 /**
134  * ti_abb_check_txdone() - handy wrapper to check ABB tranxdone status
135  * @abb:	pointer to the abb instance
136  *
137  * Return: true or false
138  */
139 static inline bool ti_abb_check_txdone(const struct ti_abb *abb)
140 {
141 	return !!(readl(abb->int_base) & abb->txdone_mask);
142 }
143 
144 /**
145  * ti_abb_clear_txdone() - handy wrapper to clear ABB tranxdone status
146  * @abb:	pointer to the abb instance
147  */
148 static inline void ti_abb_clear_txdone(const struct ti_abb *abb)
149 {
150 	writel(abb->txdone_mask, abb->int_base);
151 };
152 
153 /**
154  * ti_abb_wait_txdone() - waits for ABB tranxdone event
155  * @dev:	device
156  * @abb:	pointer to the abb instance
157  *
158  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
159  */
160 static int ti_abb_wait_txdone(struct device *dev, struct ti_abb *abb)
161 {
162 	int timeout = 0;
163 	bool status;
164 
165 	while (timeout++ <= abb->settling_time) {
166 		status = ti_abb_check_txdone(abb);
167 		if (status)
168 			return 0;
169 
170 		udelay(1);
171 	}
172 
173 	dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
174 			     __func__, timeout, readl(abb->int_base));
175 	return -ETIMEDOUT;
176 }
177 
178 /**
179  * ti_abb_clear_all_txdone() - clears ABB tranxdone event
180  * @dev:	device
181  * @abb:	pointer to the abb instance
182  *
183  * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
184  */
185 static int ti_abb_clear_all_txdone(struct device *dev, const struct ti_abb *abb)
186 {
187 	int timeout = 0;
188 	bool status;
189 
190 	while (timeout++ <= abb->settling_time) {
191 		ti_abb_clear_txdone(abb);
192 
193 		status = ti_abb_check_txdone(abb);
194 		if (!status)
195 			return 0;
196 
197 		udelay(1);
198 	}
199 
200 	dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
201 			     __func__, timeout, readl(abb->int_base));
202 	return -ETIMEDOUT;
203 }
204 
205 /**
206  * ti_abb_program_ldovbb() - program LDOVBB register for override value
207  * @dev:	device
208  * @abb:	pointer to the abb instance
209  * @info:	ABB info to program
210  */
211 static void ti_abb_program_ldovbb(struct device *dev, const struct ti_abb *abb,
212 				  struct ti_abb_info *info)
213 {
214 	u32 val;
215 
216 	val = readl(abb->ldo_base);
217 	/* clear up previous values */
218 	val &= ~(abb->ldovbb_override_mask | abb->ldovbb_vset_mask);
219 
220 	switch (info->opp_sel) {
221 	case TI_ABB_SLOW_OPP:
222 	case TI_ABB_FAST_OPP:
223 		val |= abb->ldovbb_override_mask;
224 		val |= info->vset << __ffs(abb->ldovbb_vset_mask);
225 		break;
226 	}
227 
228 	writel(val, abb->ldo_base);
229 }
230 
231 /**
232  * ti_abb_set_opp() - Setup ABB and LDO VBB for required bias
233  * @rdev:	regulator device
234  * @abb:	pointer to the abb instance
235  * @info:	ABB info to program
236  *
237  * Return: 0 on success or appropriate error value when fails
238  */
239 static int ti_abb_set_opp(struct regulator_dev *rdev, struct ti_abb *abb,
240 			  struct ti_abb_info *info)
241 {
242 	const struct ti_abb_reg *regs = abb->regs;
243 	struct device *dev = &rdev->dev;
244 	int ret;
245 
246 	ret = ti_abb_clear_all_txdone(dev, abb);
247 	if (ret)
248 		goto out;
249 
250 	ti_abb_rmw(regs->fbb_sel_mask | regs->rbb_sel_mask, 0, abb->setup_reg);
251 
252 	switch (info->opp_sel) {
253 	case TI_ABB_SLOW_OPP:
254 		ti_abb_rmw(regs->rbb_sel_mask, 1, abb->setup_reg);
255 		break;
256 	case TI_ABB_FAST_OPP:
257 		ti_abb_rmw(regs->fbb_sel_mask, 1, abb->setup_reg);
258 		break;
259 	}
260 
261 	/* program next state of ABB ldo */
262 	ti_abb_rmw(regs->opp_sel_mask, info->opp_sel, abb->control_reg);
263 
264 	/*
265 	 * program LDO VBB vset override if needed for !bypass mode
266 	 * XXX: Do not switch sequence - for !bypass, LDO override reset *must*
267 	 * be performed *before* switch to bias mode else VBB glitches.
268 	 */
269 	if (abb->ldo_base && info->opp_sel != TI_ABB_NOMINAL_OPP)
270 		ti_abb_program_ldovbb(dev, abb, info);
271 
272 	/* Initiate ABB ldo change */
273 	ti_abb_rmw(regs->opp_change_mask, 1, abb->control_reg);
274 
275 	/* Wait for ABB LDO to complete transition to new Bias setting */
276 	ret = ti_abb_wait_txdone(dev, abb);
277 	if (ret)
278 		goto out;
279 
280 	ret = ti_abb_clear_all_txdone(dev, abb);
281 	if (ret)
282 		goto out;
283 
284 	/*
285 	 * Reset LDO VBB vset override bypass mode
286 	 * XXX: Do not switch sequence - for bypass, LDO override reset *must*
287 	 * be performed *after* switch to bypass else VBB glitches.
288 	 */
289 	if (abb->ldo_base && info->opp_sel == TI_ABB_NOMINAL_OPP)
290 		ti_abb_program_ldovbb(dev, abb, info);
291 
292 out:
293 	return ret;
294 }
295 
296 /**
297  * ti_abb_set_voltage_sel() - regulator accessor function to set ABB LDO
298  * @rdev:	regulator device
299  * @sel:	selector to index into required ABB LDO settings (maps to
300  *		regulator descriptor's volt_table)
301  *
302  * Return: 0 on success or appropriate error value when fails
303  */
304 static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
305 {
306 	const struct regulator_desc *desc = rdev->desc;
307 	struct ti_abb *abb = rdev_get_drvdata(rdev);
308 	struct device *dev = &rdev->dev;
309 	struct ti_abb_info *info, *oinfo;
310 	int ret = 0;
311 
312 	if (!abb) {
313 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
314 				    __func__);
315 		return -ENODEV;
316 	}
317 
318 	if (!desc->n_voltages || !abb->info) {
319 		dev_err_ratelimited(dev,
320 				    "%s: No valid voltage table entries?\n",
321 				    __func__);
322 		return -EINVAL;
323 	}
324 
325 	if (sel >= desc->n_voltages) {
326 		dev_err(dev, "%s: sel idx(%d) >= n_voltages(%d)\n", __func__,
327 			sel, desc->n_voltages);
328 		return -EINVAL;
329 	}
330 
331 	/* If we are in the same index as we were, nothing to do here! */
332 	if (sel == abb->current_info_idx) {
333 		dev_dbg(dev, "%s: Already at sel=%d\n", __func__, sel);
334 		return ret;
335 	}
336 
337 	info = &abb->info[sel];
338 	/*
339 	 * When Linux kernel is starting up, we aren't sure of the
340 	 * Bias configuration that bootloader has configured.
341 	 * So, we get to know the actual setting the first time
342 	 * we are asked to transition.
343 	 */
344 	if (abb->current_info_idx == -EINVAL)
345 		goto just_set_abb;
346 
347 	/* If data is exactly the same, then just update index, no change */
348 	oinfo = &abb->info[abb->current_info_idx];
349 	if (!memcmp(info, oinfo, sizeof(*info))) {
350 		dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
351 			sel, abb->current_info_idx);
352 		goto out;
353 	}
354 
355 just_set_abb:
356 	ret = ti_abb_set_opp(rdev, abb, info);
357 
358 out:
359 	if (!ret)
360 		abb->current_info_idx = sel;
361 	else
362 		dev_err_ratelimited(dev,
363 				    "%s: Volt[%d] idx[%d] mode[%d] Fail(%d)\n",
364 				    __func__, desc->volt_table[sel], sel,
365 				    info->opp_sel, ret);
366 	return ret;
367 }
368 
369 /**
370  * ti_abb_get_voltage_sel() - Regulator accessor to get current ABB LDO setting
371  * @rdev:	regulator device
372  *
373  * Return: 0 on success or appropriate error value when fails
374  */
375 static int ti_abb_get_voltage_sel(struct regulator_dev *rdev)
376 {
377 	const struct regulator_desc *desc = rdev->desc;
378 	struct ti_abb *abb = rdev_get_drvdata(rdev);
379 	struct device *dev = &rdev->dev;
380 
381 	if (!abb) {
382 		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
383 				    __func__);
384 		return -ENODEV;
385 	}
386 
387 	if (!desc->n_voltages || !abb->info) {
388 		dev_err_ratelimited(dev,
389 				    "%s: No valid voltage table entries?\n",
390 				    __func__);
391 		return -EINVAL;
392 	}
393 
394 	if (abb->current_info_idx >= (int)desc->n_voltages) {
395 		dev_err(dev, "%s: Corrupted data? idx(%d) >= n_voltages(%d)\n",
396 			__func__, abb->current_info_idx, desc->n_voltages);
397 		return -EINVAL;
398 	}
399 
400 	return abb->current_info_idx;
401 }
402 
403 /**
404  * ti_abb_init_timings() - setup ABB clock timing for the current platform
405  * @dev:	device
406  * @abb:	pointer to the abb instance
407  *
408  * Return: 0 if timing is updated, else returns error result.
409  */
410 static int ti_abb_init_timings(struct device *dev, struct ti_abb *abb)
411 {
412 	u32 clock_cycles;
413 	u32 clk_rate, sr2_wt_cnt_val, cycle_rate;
414 	const struct ti_abb_reg *regs = abb->regs;
415 	int ret;
416 	char *pname = "ti,settling-time";
417 
418 	/* read device tree properties */
419 	ret = of_property_read_u32(dev->of_node, pname, &abb->settling_time);
420 	if (ret) {
421 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
422 		return ret;
423 	}
424 
425 	/* ABB LDO cannot be settle in 0 time */
426 	if (!abb->settling_time) {
427 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
428 		return -EINVAL;
429 	}
430 
431 	pname = "ti,clock-cycles";
432 	ret = of_property_read_u32(dev->of_node, pname, &clock_cycles);
433 	if (ret) {
434 		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
435 		return ret;
436 	}
437 	/* ABB LDO cannot be settle in 0 clock cycles */
438 	if (!clock_cycles) {
439 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
440 		return -EINVAL;
441 	}
442 
443 	abb->clk = devm_clk_get(dev, NULL);
444 	if (IS_ERR(abb->clk)) {
445 		ret = PTR_ERR(abb->clk);
446 		dev_err(dev, "%s: Unable to get clk(%d)\n", __func__, ret);
447 		return ret;
448 	}
449 
450 	/*
451 	 * SR2_WTCNT_VALUE is the settling time for the ABB ldo after a
452 	 * transition and must be programmed with the correct time at boot.
453 	 * The value programmed into the register is the number of SYS_CLK
454 	 * clock cycles that match a given wall time profiled for the ldo.
455 	 * This value depends on:
456 	 * settling time of ldo in micro-seconds (varies per OMAP family)
457 	 * # of clock cycles per SYS_CLK period (varies per OMAP family)
458 	 * the SYS_CLK frequency in MHz (varies per board)
459 	 * The formula is:
460 	 *
461 	 *                      ldo settling time (in micro-seconds)
462 	 * SR2_WTCNT_VALUE = ------------------------------------------
463 	 *                   (# system clock cycles) * (sys_clk period)
464 	 *
465 	 * Put another way:
466 	 *
467 	 * SR2_WTCNT_VALUE = settling time / (# SYS_CLK cycles / SYS_CLK rate))
468 	 *
469 	 * To avoid dividing by zero multiply both "# clock cycles" and
470 	 * "settling time" by 10 such that the final result is the one we want.
471 	 */
472 
473 	/* Convert SYS_CLK rate to MHz & prevent divide by zero */
474 	clk_rate = DIV_ROUND_CLOSEST(clk_get_rate(abb->clk), 1000000);
475 
476 	/* Calculate cycle rate */
477 	cycle_rate = DIV_ROUND_CLOSEST(clock_cycles * 10, clk_rate);
478 
479 	/* Calculate SR2_WTCNT_VALUE */
480 	sr2_wt_cnt_val = DIV_ROUND_CLOSEST(abb->settling_time * 10, cycle_rate);
481 
482 	dev_dbg(dev, "%s: Clk_rate=%ld, sr2_cnt=0x%08x\n", __func__,
483 		clk_get_rate(abb->clk), sr2_wt_cnt_val);
484 
485 	ti_abb_rmw(regs->sr2_wtcnt_value_mask, sr2_wt_cnt_val, abb->setup_reg);
486 
487 	return 0;
488 }
489 
490 /**
491  * ti_abb_init_table() - Initialize ABB table from device tree
492  * @dev:	device
493  * @abb:	pointer to the abb instance
494  * @rinit_data:	regulator initdata
495  *
496  * Return: 0 on success or appropriate error value when fails
497  */
498 static int ti_abb_init_table(struct device *dev, struct ti_abb *abb,
499 			     struct regulator_init_data *rinit_data)
500 {
501 	struct ti_abb_info *info;
502 	const u32 num_values = 6;
503 	char *pname = "ti,abb_info";
504 	u32 i;
505 	unsigned int *volt_table;
506 	int num_entries, min_uV = INT_MAX, max_uV = 0;
507 	struct regulation_constraints *c = &rinit_data->constraints;
508 
509 	/*
510 	 * Each abb_info is a set of n-tuple, where n is num_values, consisting
511 	 * of voltage and a set of detection logic for ABB information for that
512 	 * voltage to apply.
513 	 */
514 	num_entries = of_property_count_u32_elems(dev->of_node, pname);
515 	if (num_entries < 0) {
516 		dev_err(dev, "No '%s' property?\n", pname);
517 		return num_entries;
518 	}
519 
520 	if (!num_entries || (num_entries % num_values)) {
521 		dev_err(dev, "All '%s' list entries need %d vals\n", pname,
522 			num_values);
523 		return -EINVAL;
524 	}
525 	num_entries /= num_values;
526 
527 	info = devm_kcalloc(dev, num_entries, sizeof(*info), GFP_KERNEL);
528 	if (!info)
529 		return -ENOMEM;
530 
531 	abb->info = info;
532 
533 	volt_table = devm_kcalloc(dev, num_entries, sizeof(unsigned int),
534 				  GFP_KERNEL);
535 	if (!volt_table)
536 		return -ENOMEM;
537 
538 	abb->rdesc.n_voltages = num_entries;
539 	abb->rdesc.volt_table = volt_table;
540 	/* We do not know where the OPP voltage is at the moment */
541 	abb->current_info_idx = -EINVAL;
542 
543 	for (i = 0; i < num_entries; i++, info++, volt_table++) {
544 		u32 efuse_offset, rbb_mask, fbb_mask, vset_mask;
545 		u32 efuse_val;
546 
547 		/* NOTE: num_values should equal to entries picked up here */
548 		of_property_read_u32_index(dev->of_node, pname, i * num_values,
549 					   volt_table);
550 		of_property_read_u32_index(dev->of_node, pname,
551 					   i * num_values + 1, &info->opp_sel);
552 		of_property_read_u32_index(dev->of_node, pname,
553 					   i * num_values + 2, &efuse_offset);
554 		of_property_read_u32_index(dev->of_node, pname,
555 					   i * num_values + 3, &rbb_mask);
556 		of_property_read_u32_index(dev->of_node, pname,
557 					   i * num_values + 4, &fbb_mask);
558 		of_property_read_u32_index(dev->of_node, pname,
559 					   i * num_values + 5, &vset_mask);
560 
561 		dev_dbg(dev,
562 			"[%d]v=%d ABB=%d ef=0x%x rbb=0x%x fbb=0x%x vset=0x%x\n",
563 			i, *volt_table, info->opp_sel, efuse_offset, rbb_mask,
564 			fbb_mask, vset_mask);
565 
566 		/* Find min/max for voltage set */
567 		if (min_uV > *volt_table)
568 			min_uV = *volt_table;
569 		if (max_uV < *volt_table)
570 			max_uV = *volt_table;
571 
572 		if (!abb->efuse_base) {
573 			/* Ignore invalid data, but warn to help cleanup */
574 			if (efuse_offset || rbb_mask || fbb_mask || vset_mask)
575 				dev_err(dev, "prop '%s': v=%d,bad efuse/mask\n",
576 					pname, *volt_table);
577 			goto check_abb;
578 		}
579 
580 		efuse_val = readl(abb->efuse_base + efuse_offset);
581 
582 		/* Use ABB recommendation from Efuse */
583 		if (efuse_val & rbb_mask)
584 			info->opp_sel = TI_ABB_SLOW_OPP;
585 		else if (efuse_val & fbb_mask)
586 			info->opp_sel = TI_ABB_FAST_OPP;
587 		else if (rbb_mask || fbb_mask)
588 			info->opp_sel = TI_ABB_NOMINAL_OPP;
589 
590 		dev_dbg(dev,
591 			"[%d]v=%d efusev=0x%x final ABB=%d\n",
592 			i, *volt_table, efuse_val, info->opp_sel);
593 
594 		/* Use recommended Vset bits from Efuse */
595 		if (!abb->ldo_base) {
596 			if (vset_mask)
597 				dev_err(dev, "prop'%s':v=%d vst=%x LDO base?\n",
598 					pname, *volt_table, vset_mask);
599 			continue;
600 		}
601 		info->vset = (efuse_val & vset_mask) >> __ffs(vset_mask);
602 		dev_dbg(dev, "[%d]v=%d vset=%x\n", i, *volt_table, info->vset);
603 check_abb:
604 		switch (info->opp_sel) {
605 		case TI_ABB_NOMINAL_OPP:
606 		case TI_ABB_FAST_OPP:
607 		case TI_ABB_SLOW_OPP:
608 			/* Valid values */
609 			break;
610 		default:
611 			dev_err(dev, "%s:[%d]v=%d, ABB=%d is invalid! Abort!\n",
612 				__func__, i, *volt_table, info->opp_sel);
613 			return -EINVAL;
614 		}
615 	}
616 
617 	/* Setup the min/max voltage constraints from the supported list */
618 	c->min_uV = min_uV;
619 	c->max_uV = max_uV;
620 
621 	return 0;
622 }
623 
624 static const struct regulator_ops ti_abb_reg_ops = {
625 	.list_voltage = regulator_list_voltage_table,
626 
627 	.set_voltage_sel = ti_abb_set_voltage_sel,
628 	.get_voltage_sel = ti_abb_get_voltage_sel,
629 };
630 
631 /* Default ABB block offsets, IF this changes in future, create new one */
632 static const struct ti_abb_reg abb_regs_v1 = {
633 	/* WARNING: registers are wrongly documented in TRM */
634 	.setup_off		= 0x04,
635 	.control_off		= 0x00,
636 
637 	.sr2_wtcnt_value_mask	= (0xff << 8),
638 	.fbb_sel_mask		= (0x01 << 2),
639 	.rbb_sel_mask		= (0x01 << 1),
640 	.sr2_en_mask		= (0x01 << 0),
641 
642 	.opp_change_mask	= (0x01 << 2),
643 	.opp_sel_mask		= (0x03 << 0),
644 };
645 
646 static const struct ti_abb_reg abb_regs_v2 = {
647 	.setup_off		= 0x00,
648 	.control_off		= 0x04,
649 
650 	.sr2_wtcnt_value_mask	= (0xff << 8),
651 	.fbb_sel_mask		= (0x01 << 2),
652 	.rbb_sel_mask		= (0x01 << 1),
653 	.sr2_en_mask		= (0x01 << 0),
654 
655 	.opp_change_mask	= (0x01 << 2),
656 	.opp_sel_mask		= (0x03 << 0),
657 };
658 
659 static const struct ti_abb_reg abb_regs_generic = {
660 	.sr2_wtcnt_value_mask	= (0xff << 8),
661 	.fbb_sel_mask		= (0x01 << 2),
662 	.rbb_sel_mask		= (0x01 << 1),
663 	.sr2_en_mask		= (0x01 << 0),
664 
665 	.opp_change_mask	= (0x01 << 2),
666 	.opp_sel_mask		= (0x03 << 0),
667 };
668 
669 static const struct of_device_id ti_abb_of_match[] = {
670 	{.compatible = "ti,abb-v1", .data = &abb_regs_v1},
671 	{.compatible = "ti,abb-v2", .data = &abb_regs_v2},
672 	{.compatible = "ti,abb-v3", .data = &abb_regs_generic},
673 	{ },
674 };
675 
676 MODULE_DEVICE_TABLE(of, ti_abb_of_match);
677 
678 /**
679  * ti_abb_probe() - Initialize an ABB ldo instance
680  * @pdev: ABB platform device
681  *
682  * Initializes an individual ABB LDO for required Body-Bias. ABB is used to
683  * additional bias supply to SoC modules for power savings or mandatory stability
684  * configuration at certain Operating Performance Points(OPPs).
685  *
686  * Return: 0 on success or appropriate error value when fails
687  */
688 static int ti_abb_probe(struct platform_device *pdev)
689 {
690 	struct device *dev = &pdev->dev;
691 	const struct of_device_id *match;
692 	struct resource *res;
693 	struct ti_abb *abb;
694 	struct regulator_init_data *initdata = NULL;
695 	struct regulator_dev *rdev = NULL;
696 	struct regulator_desc *desc;
697 	struct regulation_constraints *c;
698 	struct regulator_config config = { };
699 	char *pname;
700 	int ret = 0;
701 
702 	match = of_match_device(ti_abb_of_match, dev);
703 	if (!match) {
704 		/* We do not expect this to happen */
705 		dev_err(dev, "%s: Unable to match device\n", __func__);
706 		return -ENODEV;
707 	}
708 	if (!match->data) {
709 		dev_err(dev, "%s: Bad data in match\n", __func__);
710 		return -EINVAL;
711 	}
712 
713 	abb = devm_kzalloc(dev, sizeof(struct ti_abb), GFP_KERNEL);
714 	if (!abb)
715 		return -ENOMEM;
716 	abb->regs = match->data;
717 
718 	/* Map ABB resources */
719 	if (abb->regs->setup_off || abb->regs->control_off) {
720 		abb->base = devm_platform_ioremap_resource_byname(pdev, "base-address");
721 		if (IS_ERR(abb->base))
722 			return PTR_ERR(abb->base);
723 
724 		abb->setup_reg = abb->base + abb->regs->setup_off;
725 		abb->control_reg = abb->base + abb->regs->control_off;
726 
727 	} else {
728 		abb->control_reg = devm_platform_ioremap_resource_byname(pdev, "control-address");
729 		if (IS_ERR(abb->control_reg))
730 			return PTR_ERR(abb->control_reg);
731 
732 		abb->setup_reg = devm_platform_ioremap_resource_byname(pdev, "setup-address");
733 		if (IS_ERR(abb->setup_reg))
734 			return PTR_ERR(abb->setup_reg);
735 	}
736 
737 	abb->int_base = devm_platform_ioremap_resource_byname(pdev, "int-address");
738 	if (IS_ERR(abb->int_base))
739 		return PTR_ERR(abb->int_base);
740 
741 	/* Map Optional resources */
742 	pname = "efuse-address";
743 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
744 	if (!res) {
745 		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
746 		ret = -ENODEV;
747 		goto skip_opt;
748 	}
749 
750 	/*
751 	 * We may have shared efuse register offsets which are read-only
752 	 * between domains
753 	 */
754 	abb->efuse_base = devm_ioremap(dev, res->start,
755 					       resource_size(res));
756 	if (!abb->efuse_base) {
757 		dev_err(dev, "Unable to map '%s'\n", pname);
758 		return -ENOMEM;
759 	}
760 
761 	pname = "ldo-address";
762 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
763 	if (!res) {
764 		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
765 		ret = -ENODEV;
766 		goto skip_opt;
767 	}
768 	abb->ldo_base = devm_ioremap_resource(dev, res);
769 	if (IS_ERR(abb->ldo_base))
770 		return PTR_ERR(abb->ldo_base);
771 
772 	/* IF ldo_base is set, the following are mandatory */
773 	pname = "ti,ldovbb-override-mask";
774 	ret =
775 	    of_property_read_u32(pdev->dev.of_node, pname,
776 				 &abb->ldovbb_override_mask);
777 	if (ret) {
778 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
779 		return ret;
780 	}
781 	if (!abb->ldovbb_override_mask) {
782 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
783 		return -EINVAL;
784 	}
785 
786 	pname = "ti,ldovbb-vset-mask";
787 	ret =
788 	    of_property_read_u32(pdev->dev.of_node, pname,
789 				 &abb->ldovbb_vset_mask);
790 	if (ret) {
791 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
792 		return ret;
793 	}
794 	if (!abb->ldovbb_vset_mask) {
795 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
796 		return -EINVAL;
797 	}
798 
799 skip_opt:
800 	pname = "ti,tranxdone-status-mask";
801 	ret =
802 	    of_property_read_u32(pdev->dev.of_node, pname,
803 				 &abb->txdone_mask);
804 	if (ret) {
805 		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
806 		return ret;
807 	}
808 	if (!abb->txdone_mask) {
809 		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
810 		return -EINVAL;
811 	}
812 
813 	initdata = of_get_regulator_init_data(dev, pdev->dev.of_node,
814 					      &abb->rdesc);
815 	if (!initdata) {
816 		dev_err(dev, "%s: Unable to alloc regulator init data\n",
817 			__func__);
818 		return -ENOMEM;
819 	}
820 
821 	/* init ABB opp_sel table */
822 	ret = ti_abb_init_table(dev, abb, initdata);
823 	if (ret)
824 		return ret;
825 
826 	/* init ABB timing */
827 	ret = ti_abb_init_timings(dev, abb);
828 	if (ret)
829 		return ret;
830 
831 	desc = &abb->rdesc;
832 	desc->name = dev_name(dev);
833 	desc->owner = THIS_MODULE;
834 	desc->type = REGULATOR_VOLTAGE;
835 	desc->ops = &ti_abb_reg_ops;
836 
837 	c = &initdata->constraints;
838 	if (desc->n_voltages > 1)
839 		c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
840 	c->always_on = true;
841 
842 	config.dev = dev;
843 	config.init_data = initdata;
844 	config.driver_data = abb;
845 	config.of_node = pdev->dev.of_node;
846 
847 	rdev = devm_regulator_register(dev, desc, &config);
848 	if (IS_ERR(rdev)) {
849 		ret = PTR_ERR(rdev);
850 		dev_err(dev, "%s: failed to register regulator(%d)\n",
851 			__func__, ret);
852 		return ret;
853 	}
854 	platform_set_drvdata(pdev, rdev);
855 
856 	/* Enable the ldo if not already done by bootloader */
857 	ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->setup_reg);
858 
859 	return 0;
860 }
861 
862 MODULE_ALIAS("platform:ti_abb");
863 
864 static struct platform_driver ti_abb_driver = {
865 	.probe = ti_abb_probe,
866 	.driver = {
867 		   .name = "ti_abb",
868 		   .probe_type = PROBE_PREFER_ASYNCHRONOUS,
869 		   .of_match_table = of_match_ptr(ti_abb_of_match),
870 		   },
871 };
872 module_platform_driver(ti_abb_driver);
873 
874 MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
875 MODULE_AUTHOR("Texas Instruments Inc.");
876 MODULE_LICENSE("GPL v2");
877