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			break;
177
178		udelay(1);
179	}
180
181	if (timeout > abb->settling_time) {
182		dev_warn_ratelimited(dev,
183				     "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
184				     __func__, timeout, readl(abb->int_base));
185		return -ETIMEDOUT;
186	}
187
188	return 0;
189}
190
191/**
192 * ti_abb_clear_all_txdone() - clears ABB tranxdone event
193 * @dev:	device
194 * @abb:	pointer to the abb instance
195 *
196 * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
197 */
198static int ti_abb_clear_all_txdone(struct device *dev, const struct ti_abb *abb)
199{
200	int timeout = 0;
201	bool status;
202
203	while (timeout++ <= abb->settling_time) {
204		ti_abb_clear_txdone(abb);
205
206		status = ti_abb_check_txdone(abb);
207		if (!status)
208			break;
209
210		udelay(1);
211	}
212
213	if (timeout > abb->settling_time) {
214		dev_warn_ratelimited(dev,
215				     "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
216				     __func__, timeout, readl(abb->int_base));
217		return -ETIMEDOUT;
218	}
219
220	return 0;
221}
222
223/**
224 * ti_abb_program_ldovbb() - program LDOVBB register for override value
225 * @dev:	device
226 * @abb:	pointer to the abb instance
227 * @info:	ABB info to program
228 */
229static void ti_abb_program_ldovbb(struct device *dev, const struct ti_abb *abb,
230				  struct ti_abb_info *info)
231{
232	u32 val;
233
234	val = readl(abb->ldo_base);
235	/* clear up previous values */
236	val &= ~(abb->ldovbb_override_mask | abb->ldovbb_vset_mask);
237
238	switch (info->opp_sel) {
239	case TI_ABB_SLOW_OPP:
240	case TI_ABB_FAST_OPP:
241		val |= abb->ldovbb_override_mask;
242		val |= info->vset << __ffs(abb->ldovbb_vset_mask);
243		break;
244	}
245
246	writel(val, abb->ldo_base);
247}
248
249/**
250 * ti_abb_set_opp() - Setup ABB and LDO VBB for required bias
251 * @rdev:	regulator device
252 * @abb:	pointer to the abb instance
253 * @info:	ABB info to program
254 *
255 * Return: 0 on success or appropriate error value when fails
256 */
257static int ti_abb_set_opp(struct regulator_dev *rdev, struct ti_abb *abb,
258			  struct ti_abb_info *info)
259{
260	const struct ti_abb_reg *regs = abb->regs;
261	struct device *dev = &rdev->dev;
262	int ret;
263
264	ret = ti_abb_clear_all_txdone(dev, abb);
265	if (ret)
266		goto out;
267
268	ti_abb_rmw(regs->fbb_sel_mask | regs->rbb_sel_mask, 0, abb->setup_reg);
269
270	switch (info->opp_sel) {
271	case TI_ABB_SLOW_OPP:
272		ti_abb_rmw(regs->rbb_sel_mask, 1, abb->setup_reg);
273		break;
274	case TI_ABB_FAST_OPP:
275		ti_abb_rmw(regs->fbb_sel_mask, 1, abb->setup_reg);
276		break;
277	}
278
279	/* program next state of ABB ldo */
280	ti_abb_rmw(regs->opp_sel_mask, info->opp_sel, abb->control_reg);
281
282	/*
283	 * program LDO VBB vset override if needed for !bypass mode
284	 * XXX: Do not switch sequence - for !bypass, LDO override reset *must*
285	 * be performed *before* switch to bias mode else VBB glitches.
286	 */
287	if (abb->ldo_base && info->opp_sel != TI_ABB_NOMINAL_OPP)
288		ti_abb_program_ldovbb(dev, abb, info);
289
290	/* Initiate ABB ldo change */
291	ti_abb_rmw(regs->opp_change_mask, 1, abb->control_reg);
292
293	/* Wait for ABB LDO to complete transition to new Bias setting */
294	ret = ti_abb_wait_txdone(dev, abb);
295	if (ret)
296		goto out;
297
298	ret = ti_abb_clear_all_txdone(dev, abb);
299	if (ret)
300		goto out;
301
302	/*
303	 * Reset LDO VBB vset override bypass mode
304	 * XXX: Do not switch sequence - for bypass, LDO override reset *must*
305	 * be performed *after* switch to bypass else VBB glitches.
306	 */
307	if (abb->ldo_base && info->opp_sel == TI_ABB_NOMINAL_OPP)
308		ti_abb_program_ldovbb(dev, abb, info);
309
310out:
311	return ret;
312}
313
314/**
315 * ti_abb_set_voltage_sel() - regulator accessor function to set ABB LDO
316 * @rdev:	regulator device
317 * @sel:	selector to index into required ABB LDO settings (maps to
318 *		regulator descriptor's volt_table)
319 *
320 * Return: 0 on success or appropriate error value when fails
321 */
322static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel)
323{
324	const struct regulator_desc *desc = rdev->desc;
325	struct ti_abb *abb = rdev_get_drvdata(rdev);
326	struct device *dev = &rdev->dev;
327	struct ti_abb_info *info, *oinfo;
328	int ret = 0;
329
330	if (!abb) {
331		dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
332				    __func__);
333		return -ENODEV;
334	}
335
336	if (!desc->n_voltages || !abb->info) {
337		dev_err_ratelimited(dev,
338				    "%s: No valid voltage table entries?\n",
339				    __func__);
340		return -EINVAL;
341	}
342
343	if (sel >= desc->n_voltages) {
344		dev_err(dev, "%s: sel idx(%d) >= n_voltages(%d)\n", __func__,
345			sel, desc->n_voltages);
346		return -EINVAL;
347	}
348
349	/* If we are in the same index as we were, nothing to do here! */
350	if (sel == abb->current_info_idx) {
351		dev_dbg(dev, "%s: Already at sel=%d\n", __func__, sel);
352		return ret;
353	}
354
355	/* If data is exactly the same, then just update index, no change */
356	info = &abb->info[sel];
357	oinfo = &abb->info[abb->current_info_idx];
358	if (!memcmp(info, oinfo, sizeof(*info))) {
359		dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
360			sel, abb->current_info_idx);
361		goto out;
362	}
363
364	ret = ti_abb_set_opp(rdev, abb, info);
365
366out:
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 */
383static 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 */
418static 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 */
506static 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_kzalloc(dev, sizeof(*info) * num_entries, GFP_KERNEL);
536	if (!info)
537		return -ENOMEM;
538
539	abb->info = info;
540
541	volt_table = devm_kzalloc(dev, sizeof(unsigned int) * num_entries,
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);
611check_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
632static 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 */
640static 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
654static 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
667static 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
677static 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
684MODULE_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 */
696static 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		pname = "base-address";
729		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
730		abb->base = devm_ioremap_resource(dev, res);
731		if (IS_ERR(abb->base))
732			return PTR_ERR(abb->base);
733
734		abb->setup_reg = abb->base + abb->regs->setup_off;
735		abb->control_reg = abb->base + abb->regs->control_off;
736
737	} else {
738		pname = "control-address";
739		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
740		abb->control_reg = devm_ioremap_resource(dev, res);
741		if (IS_ERR(abb->control_reg))
742			return PTR_ERR(abb->control_reg);
743
744		pname = "setup-address";
745		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
746		abb->setup_reg = devm_ioremap_resource(dev, res);
747		if (IS_ERR(abb->setup_reg))
748			return PTR_ERR(abb->setup_reg);
749	}
750
751	pname = "int-address";
752	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
753	if (!res) {
754		dev_err(dev, "Missing '%s' IO resource\n", pname);
755		return -ENODEV;
756	}
757	/*
758	 * We may have shared interrupt register offsets which are
759	 * write-1-to-clear between domains ensuring exclusivity.
760	 */
761	abb->int_base = devm_ioremap_nocache(dev, res->start,
762					     resource_size(res));
763	if (!abb->int_base) {
764		dev_err(dev, "Unable to map '%s'\n", pname);
765		return -ENOMEM;
766	}
767
768	/* Map Optional resources */
769	pname = "efuse-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
777	/*
778	 * We may have shared efuse register offsets which are read-only
779	 * between domains
780	 */
781	abb->efuse_base = devm_ioremap_nocache(dev, res->start,
782					       resource_size(res));
783	if (!abb->efuse_base) {
784		dev_err(dev, "Unable to map '%s'\n", pname);
785		return -ENOMEM;
786	}
787
788	pname = "ldo-address";
789	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
790	if (!res) {
791		dev_dbg(dev, "Missing '%s' IO resource\n", pname);
792		ret = -ENODEV;
793		goto skip_opt;
794	}
795	abb->ldo_base = devm_ioremap_resource(dev, res);
796	if (IS_ERR(abb->ldo_base))
797		return PTR_ERR(abb->ldo_base);
798
799	/* IF ldo_base is set, the following are mandatory */
800	pname = "ti,ldovbb-override-mask";
801	ret =
802	    of_property_read_u32(pdev->dev.of_node, pname,
803				 &abb->ldovbb_override_mask);
804	if (ret) {
805		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
806		return ret;
807	}
808	if (!abb->ldovbb_override_mask) {
809		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
810		return -EINVAL;
811	}
812
813	pname = "ti,ldovbb-vset-mask";
814	ret =
815	    of_property_read_u32(pdev->dev.of_node, pname,
816				 &abb->ldovbb_vset_mask);
817	if (ret) {
818		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
819		return ret;
820	}
821	if (!abb->ldovbb_vset_mask) {
822		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
823		return -EINVAL;
824	}
825
826skip_opt:
827	pname = "ti,tranxdone-status-mask";
828	ret =
829	    of_property_read_u32(pdev->dev.of_node, pname,
830				 &abb->txdone_mask);
831	if (ret) {
832		dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
833		return ret;
834	}
835	if (!abb->txdone_mask) {
836		dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
837		return -EINVAL;
838	}
839
840	initdata = of_get_regulator_init_data(dev, pdev->dev.of_node,
841					      &abb->rdesc);
842	if (!initdata) {
843		dev_err(dev, "%s: Unable to alloc regulator init data\n",
844			__func__);
845		return -ENOMEM;
846	}
847
848	/* init ABB opp_sel table */
849	ret = ti_abb_init_table(dev, abb, initdata);
850	if (ret)
851		return ret;
852
853	/* init ABB timing */
854	ret = ti_abb_init_timings(dev, abb);
855	if (ret)
856		return ret;
857
858	desc = &abb->rdesc;
859	desc->name = dev_name(dev);
860	desc->owner = THIS_MODULE;
861	desc->type = REGULATOR_VOLTAGE;
862	desc->ops = &ti_abb_reg_ops;
863
864	c = &initdata->constraints;
865	if (desc->n_voltages > 1)
866		c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
867	c->always_on = true;
868
869	config.dev = dev;
870	config.init_data = initdata;
871	config.driver_data = abb;
872	config.of_node = pdev->dev.of_node;
873
874	rdev = devm_regulator_register(dev, desc, &config);
875	if (IS_ERR(rdev)) {
876		ret = PTR_ERR(rdev);
877		dev_err(dev, "%s: failed to register regulator(%d)\n",
878			__func__, ret);
879		return ret;
880	}
881	platform_set_drvdata(pdev, rdev);
882
883	/* Enable the ldo if not already done by bootloader */
884	ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->setup_reg);
885
886	return 0;
887}
888
889MODULE_ALIAS("platform:ti_abb");
890
891static struct platform_driver ti_abb_driver = {
892	.probe = ti_abb_probe,
893	.driver = {
894		   .name = "ti_abb",
895		   .of_match_table = of_match_ptr(ti_abb_of_match),
896		   },
897};
898module_platform_driver(ti_abb_driver);
899
900MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
901MODULE_AUTHOR("Texas Instruments Inc.");
902MODULE_LICENSE("GPL v2");
903