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 */
 50struct 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 */
 66struct 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 */
100struct 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 */
129static 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 */
147static 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 */
156static 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 */
168static 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 */
193static 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 */
219static 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 */
247static 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
300out:
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 */
312static 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	/* If data is exactly the same, then just update index, no change */
346	info = &abb->info[sel];
347	oinfo = &abb->info[abb->current_info_idx];
348	if (!memcmp(info, oinfo, sizeof(*info))) {
349		dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
350			sel, abb->current_info_idx);
351		goto out;
352	}
353
354	ret = ti_abb_set_opp(rdev, abb, info);
355
356out:
357	if (!ret)
358		abb->current_info_idx = sel;
359	else
360		dev_err_ratelimited(dev,
361				    "%s: Volt[%d] idx[%d] mode[%d] Fail(%d)\n",
362				    __func__, desc->volt_table[sel], sel,
363				    info->opp_sel, ret);
364	return ret;
365}
366
367/**
368 * ti_abb_get_voltage_sel() - Regulator accessor to get current ABB LDO setting
369 * @rdev:	regulator device
370 *
371 * Return: 0 on success or appropriate error value when fails
372 */
373static int ti_abb_get_voltage_sel(struct regulator_dev *rdev)
374{
375	const struct regulator_desc *desc = rdev->desc;
376	struct ti_abb *abb = rdev_get_drvdata(rdev);
377	struct device *dev = &rdev->dev;
378
379	if (!abb) {
380		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
381				    __func__);
382		return -ENODEV;
383	}
384
385	if (!desc->n_voltages || !abb->info) {
386		dev_err_ratelimited(dev,
387				    "%s: No valid voltage table entries?\n",
388				    __func__);
389		return -EINVAL;
390	}
391
392	if (abb->current_info_idx >= (int)desc->n_voltages) {
393		dev_err(dev, "%s: Corrupted data? idx(%d) >= n_voltages(%d)\n",
394			__func__, abb->current_info_idx, desc->n_voltages);
395		return -EINVAL;
396	}
397
398	return abb->current_info_idx;
399}
400
401/**
402 * ti_abb_init_timings() - setup ABB clock timing for the current platform
403 * @dev:	device
404 * @abb:	pointer to the abb instance
405 *
406 * Return: 0 if timing is updated, else returns error result.
407 */
408static int ti_abb_init_timings(struct device *dev, struct ti_abb *abb)
409{
410	u32 clock_cycles;
411	u32 clk_rate, sr2_wt_cnt_val, cycle_rate;
412	const struct ti_abb_reg *regs = abb->regs;
413	int ret;
414	char *pname = "ti,settling-time";
415
416	/* read device tree properties */
417	ret = of_property_read_u32(dev->of_node, pname, &abb->settling_time);
418	if (ret) {
419		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
420		return ret;
421	}
422
423	/* ABB LDO cannot be settle in 0 time */
424	if (!abb->settling_time) {
425		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
426		return -EINVAL;
427	}
428
429	pname = "ti,clock-cycles";
430	ret = of_property_read_u32(dev->of_node, pname, &clock_cycles);
431	if (ret) {
432		dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
433		return ret;
434	}
435	/* ABB LDO cannot be settle in 0 clock cycles */
436	if (!clock_cycles) {
437		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
438		return -EINVAL;
439	}
440
441	abb->clk = devm_clk_get(dev, NULL);
442	if (IS_ERR(abb->clk)) {
443		ret = PTR_ERR(abb->clk);
444		dev_err(dev, "%s: Unable to get clk(%d)\n", __func__, ret);
445		return ret;
446	}
447
448	/*
449	 * SR2_WTCNT_VALUE is the settling time for the ABB ldo after a
450	 * transition and must be programmed with the correct time at boot.
451	 * The value programmed into the register is the number of SYS_CLK
452	 * clock cycles that match a given wall time profiled for the ldo.
453	 * This value depends on:
454	 * settling time of ldo in micro-seconds (varies per OMAP family)
455	 * # of clock cycles per SYS_CLK period (varies per OMAP family)
456	 * the SYS_CLK frequency in MHz (varies per board)
457	 * The formula is:
458	 *
459	 *                      ldo settling time (in micro-seconds)
460	 * SR2_WTCNT_VALUE = ------------------------------------------
461	 *                   (# system clock cycles) * (sys_clk period)
462	 *
463	 * Put another way:
464	 *
465	 * SR2_WTCNT_VALUE = settling time / (# SYS_CLK cycles / SYS_CLK rate))
466	 *
467	 * To avoid dividing by zero multiply both "# clock cycles" and
468	 * "settling time" by 10 such that the final result is the one we want.
469	 */
470
471	/* Convert SYS_CLK rate to MHz & prevent divide by zero */
472	clk_rate = DIV_ROUND_CLOSEST(clk_get_rate(abb->clk), 1000000);
473
474	/* Calculate cycle rate */
475	cycle_rate = DIV_ROUND_CLOSEST(clock_cycles * 10, clk_rate);
476
477	/* Calulate SR2_WTCNT_VALUE */
478	sr2_wt_cnt_val = DIV_ROUND_CLOSEST(abb->settling_time * 10, cycle_rate);
479
480	dev_dbg(dev, "%s: Clk_rate=%ld, sr2_cnt=0x%08x\n", __func__,
481		clk_get_rate(abb->clk), sr2_wt_cnt_val);
482
483	ti_abb_rmw(regs->sr2_wtcnt_value_mask, sr2_wt_cnt_val, abb->setup_reg);
484
485	return 0;
486}
487
488/**
489 * ti_abb_init_table() - Initialize ABB table from device tree
490 * @dev:	device
491 * @abb:	pointer to the abb instance
492 * @rinit_data:	regulator initdata
493 *
494 * Return: 0 on success or appropriate error value when fails
495 */
496static int ti_abb_init_table(struct device *dev, struct ti_abb *abb,
497			     struct regulator_init_data *rinit_data)
498{
499	struct ti_abb_info *info;
500	const u32 num_values = 6;
501	char *pname = "ti,abb_info";
502	u32 i;
503	unsigned int *volt_table;
504	int num_entries, min_uV = INT_MAX, max_uV = 0;
505	struct regulation_constraints *c = &rinit_data->constraints;
506
507	/*
508	 * Each abb_info is a set of n-tuple, where n is num_values, consisting
509	 * of voltage and a set of detection logic for ABB information for that
510	 * voltage to apply.
511	 */
512	num_entries = of_property_count_u32_elems(dev->of_node, pname);
513	if (num_entries < 0) {
514		dev_err(dev, "No '%s' property?\n", pname);
515		return num_entries;
516	}
517
518	if (!num_entries || (num_entries % num_values)) {
519		dev_err(dev, "All '%s' list entries need %d vals\n", pname,
520			num_values);
521		return -EINVAL;
522	}
523	num_entries /= num_values;
524
525	info = devm_kcalloc(dev, num_entries, sizeof(*info), GFP_KERNEL);
526	if (!info)
527		return -ENOMEM;
528
529	abb->info = info;
530
531	volt_table = devm_kcalloc(dev, num_entries, sizeof(unsigned int),
532				  GFP_KERNEL);
533	if (!volt_table)
534		return -ENOMEM;
535
536	abb->rdesc.n_voltages = num_entries;
537	abb->rdesc.volt_table = volt_table;
538	/* We do not know where the OPP voltage is at the moment */
539	abb->current_info_idx = -EINVAL;
540
541	for (i = 0; i < num_entries; i++, info++, volt_table++) {
542		u32 efuse_offset, rbb_mask, fbb_mask, vset_mask;
543		u32 efuse_val;
544
545		/* NOTE: num_values should equal to entries picked up here */
546		of_property_read_u32_index(dev->of_node, pname, i * num_values,
547					   volt_table);
548		of_property_read_u32_index(dev->of_node, pname,
549					   i * num_values + 1, &info->opp_sel);
550		of_property_read_u32_index(dev->of_node, pname,
551					   i * num_values + 2, &efuse_offset);
552		of_property_read_u32_index(dev->of_node, pname,
553					   i * num_values + 3, &rbb_mask);
554		of_property_read_u32_index(dev->of_node, pname,
555					   i * num_values + 4, &fbb_mask);
556		of_property_read_u32_index(dev->of_node, pname,
557					   i * num_values + 5, &vset_mask);
558
559		dev_dbg(dev,
560			"[%d]v=%d ABB=%d ef=0x%x rbb=0x%x fbb=0x%x vset=0x%x\n",
561			i, *volt_table, info->opp_sel, efuse_offset, rbb_mask,
562			fbb_mask, vset_mask);
563
564		/* Find min/max for voltage set */
565		if (min_uV > *volt_table)
566			min_uV = *volt_table;
567		if (max_uV < *volt_table)
568			max_uV = *volt_table;
569
570		if (!abb->efuse_base) {
571			/* Ignore invalid data, but warn to help cleanup */
572			if (efuse_offset || rbb_mask || fbb_mask || vset_mask)
573				dev_err(dev, "prop '%s': v=%d,bad efuse/mask\n",
574					pname, *volt_table);
575			goto check_abb;
576		}
577
578		efuse_val = readl(abb->efuse_base + efuse_offset);
579
580		/* Use ABB recommendation from Efuse */
581		if (efuse_val & rbb_mask)
582			info->opp_sel = TI_ABB_SLOW_OPP;
583		else if (efuse_val & fbb_mask)
584			info->opp_sel = TI_ABB_FAST_OPP;
585		else if (rbb_mask || fbb_mask)
586			info->opp_sel = TI_ABB_NOMINAL_OPP;
587
588		dev_dbg(dev,
589			"[%d]v=%d efusev=0x%x final ABB=%d\n",
590			i, *volt_table, efuse_val, info->opp_sel);
591
592		/* Use recommended Vset bits from Efuse */
593		if (!abb->ldo_base) {
594			if (vset_mask)
595				dev_err(dev, "prop'%s':v=%d vst=%x LDO base?\n",
596					pname, *volt_table, vset_mask);
597			continue;
598		}
599		info->vset = (efuse_val & vset_mask) >> __ffs(vset_mask);
600		dev_dbg(dev, "[%d]v=%d vset=%x\n", i, *volt_table, info->vset);
601check_abb:
602		switch (info->opp_sel) {
603		case TI_ABB_NOMINAL_OPP:
604		case TI_ABB_FAST_OPP:
605		case TI_ABB_SLOW_OPP:
606			/* Valid values */
607			break;
608		default:
609			dev_err(dev, "%s:[%d]v=%d, ABB=%d is invalid! Abort!\n",
610				__func__, i, *volt_table, info->opp_sel);
611			return -EINVAL;
612		}
613	}
614
615	/* Setup the min/max voltage constraints from the supported list */
616	c->min_uV = min_uV;
617	c->max_uV = max_uV;
618
619	return 0;
620}
621
622static struct regulator_ops ti_abb_reg_ops = {
623	.list_voltage = regulator_list_voltage_table,
624
625	.set_voltage_sel = ti_abb_set_voltage_sel,
626	.get_voltage_sel = ti_abb_get_voltage_sel,
627};
628
629/* Default ABB block offsets, IF this changes in future, create new one */
630static const struct ti_abb_reg abb_regs_v1 = {
631	/* WARNING: registers are wrongly documented in TRM */
632	.setup_off		= 0x04,
633	.control_off		= 0x00,
634
635	.sr2_wtcnt_value_mask	= (0xff << 8),
636	.fbb_sel_mask		= (0x01 << 2),
637	.rbb_sel_mask		= (0x01 << 1),
638	.sr2_en_mask		= (0x01 << 0),
639
640	.opp_change_mask	= (0x01 << 2),
641	.opp_sel_mask		= (0x03 << 0),
642};
643
644static const struct ti_abb_reg abb_regs_v2 = {
645	.setup_off		= 0x00,
646	.control_off		= 0x04,
647
648	.sr2_wtcnt_value_mask	= (0xff << 8),
649	.fbb_sel_mask		= (0x01 << 2),
650	.rbb_sel_mask		= (0x01 << 1),
651	.sr2_en_mask		= (0x01 << 0),
652
653	.opp_change_mask	= (0x01 << 2),
654	.opp_sel_mask		= (0x03 << 0),
655};
656
657static const struct ti_abb_reg abb_regs_generic = {
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
667static const struct of_device_id ti_abb_of_match[] = {
668	{.compatible = "ti,abb-v1", .data = &abb_regs_v1},
669	{.compatible = "ti,abb-v2", .data = &abb_regs_v2},
670	{.compatible = "ti,abb-v3", .data = &abb_regs_generic},
671	{ },
672};
673
674MODULE_DEVICE_TABLE(of, ti_abb_of_match);
675
676/**
677 * ti_abb_probe() - Initialize an ABB ldo instance
678 * @pdev: ABB platform device
679 *
680 * Initializes an individual ABB LDO for required Body-Bias. ABB is used to
681 * addional bias supply to SoC modules for power savings or mandatory stability
682 * configuration at certain Operating Performance Points(OPPs).
683 *
684 * Return: 0 on success or appropriate error value when fails
685 */
686static int ti_abb_probe(struct platform_device *pdev)
687{
688	struct device *dev = &pdev->dev;
689	const struct of_device_id *match;
690	struct resource *res;
691	struct ti_abb *abb;
692	struct regulator_init_data *initdata = NULL;
693	struct regulator_dev *rdev = NULL;
694	struct regulator_desc *desc;
695	struct regulation_constraints *c;
696	struct regulator_config config = { };
697	char *pname;
698	int ret = 0;
699
700	match = of_match_device(ti_abb_of_match, dev);
701	if (!match) {
702		/* We do not expect this to happen */
703		dev_err(dev, "%s: Unable to match device\n", __func__);
704		return -ENODEV;
705	}
706	if (!match->data) {
707		dev_err(dev, "%s: Bad data in match\n", __func__);
708		return -EINVAL;
709	}
710
711	abb = devm_kzalloc(dev, sizeof(struct ti_abb), GFP_KERNEL);
712	if (!abb)
713		return -ENOMEM;
714	abb->regs = match->data;
715
716	/* Map ABB resources */
717	if (abb->regs->setup_off || abb->regs->control_off) {
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			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		pname = "control-address";
729		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
730		abb->control_reg = devm_ioremap_resource(dev, res);
731		if (IS_ERR(abb->control_reg))
732			return PTR_ERR(abb->control_reg);
733
734		pname = "setup-address";
735		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
736		abb->setup_reg = devm_ioremap_resource(dev, res);
737		if (IS_ERR(abb->setup_reg))
738			return PTR_ERR(abb->setup_reg);
739	}
740
741	pname = "int-address";
742	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
743	if (!res) {
744		dev_err(dev, "Missing '%s' IO resource\n", pname);
745		return -ENODEV;
746	}
747	/*
748	 * We may have shared interrupt register offsets which are
749	 * write-1-to-clear between domains ensuring exclusivity.
750	 */
751	abb->int_base = devm_ioremap(dev, res->start,
752					     resource_size(res));
753	if (!abb->int_base) {
754		dev_err(dev, "Unable to map '%s'\n", pname);
755		return -ENOMEM;
756	}
757
758	/* Map Optional resources */
759	pname = "efuse-address";
760	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
761	if (!res) {
762		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
763		ret = -ENODEV;
764		goto skip_opt;
765	}
766
767	/*
768	 * We may have shared efuse register offsets which are read-only
769	 * between domains
770	 */
771	abb->efuse_base = devm_ioremap(dev, res->start,
772					       resource_size(res));
773	if (!abb->efuse_base) {
774		dev_err(dev, "Unable to map '%s'\n", pname);
775		return -ENOMEM;
776	}
777
778	pname = "ldo-address";
779	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
780	if (!res) {
781		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
782		ret = -ENODEV;
783		goto skip_opt;
784	}
785	abb->ldo_base = devm_ioremap_resource(dev, res);
786	if (IS_ERR(abb->ldo_base))
787		return PTR_ERR(abb->ldo_base);
788
789	/* IF ldo_base is set, the following are mandatory */
790	pname = "ti,ldovbb-override-mask";
791	ret =
792	    of_property_read_u32(pdev->dev.of_node, pname,
793				 &abb->ldovbb_override_mask);
794	if (ret) {
795		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
796		return ret;
797	}
798	if (!abb->ldovbb_override_mask) {
799		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
800		return -EINVAL;
801	}
802
803	pname = "ti,ldovbb-vset-mask";
804	ret =
805	    of_property_read_u32(pdev->dev.of_node, pname,
806				 &abb->ldovbb_vset_mask);
807	if (ret) {
808		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
809		return ret;
810	}
811	if (!abb->ldovbb_vset_mask) {
812		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
813		return -EINVAL;
814	}
815
816skip_opt:
817	pname = "ti,tranxdone-status-mask";
818	ret =
819	    of_property_read_u32(pdev->dev.of_node, pname,
820				 &abb->txdone_mask);
821	if (ret) {
822		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
823		return ret;
824	}
825	if (!abb->txdone_mask) {
826		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
827		return -EINVAL;
828	}
829
830	initdata = of_get_regulator_init_data(dev, pdev->dev.of_node,
831					      &abb->rdesc);
832	if (!initdata) {
833		dev_err(dev, "%s: Unable to alloc regulator init data\n",
834			__func__);
835		return -ENOMEM;
836	}
837
838	/* init ABB opp_sel table */
839	ret = ti_abb_init_table(dev, abb, initdata);
840	if (ret)
841		return ret;
842
843	/* init ABB timing */
844	ret = ti_abb_init_timings(dev, abb);
845	if (ret)
846		return ret;
847
848	desc = &abb->rdesc;
849	desc->name = dev_name(dev);
850	desc->owner = THIS_MODULE;
851	desc->type = REGULATOR_VOLTAGE;
852	desc->ops = &ti_abb_reg_ops;
853
854	c = &initdata->constraints;
855	if (desc->n_voltages > 1)
856		c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
857	c->always_on = true;
858
859	config.dev = dev;
860	config.init_data = initdata;
861	config.driver_data = abb;
862	config.of_node = pdev->dev.of_node;
863
864	rdev = devm_regulator_register(dev, desc, &config);
865	if (IS_ERR(rdev)) {
866		ret = PTR_ERR(rdev);
867		dev_err(dev, "%s: failed to register regulator(%d)\n",
868			__func__, ret);
869		return ret;
870	}
871	platform_set_drvdata(pdev, rdev);
872
873	/* Enable the ldo if not already done by bootloader */
874	ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->setup_reg);
875
876	return 0;
877}
878
879MODULE_ALIAS("platform:ti_abb");
880
881static struct platform_driver ti_abb_driver = {
882	.probe = ti_abb_probe,
883	.driver = {
884		   .name = "ti_abb",
885		   .of_match_table = of_match_ptr(ti_abb_of_match),
886		   },
887};
888module_platform_driver(ti_abb_driver);
889
890MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
891MODULE_AUTHOR("Texas Instruments Inc.");
892MODULE_LICENSE("GPL v2");