1/*
2 * Regulator driver for tps65090 power management chip.
3 *
4 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
5
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13 * more details.
14
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>
17 */
18
19#include <linux/module.h>
20#include <linux/delay.h>
21#include <linux/init.h>
22#include <linux/gpio.h>
23#include <linux/of_gpio.h>
24#include <linux/slab.h>
25#include <linux/err.h>
26#include <linux/platform_device.h>
27#include <linux/regulator/driver.h>
28#include <linux/regulator/machine.h>
29#include <linux/regulator/of_regulator.h>
30#include <linux/mfd/tps65090.h>
31
32#define MAX_CTRL_READ_TRIES	5
33#define MAX_FET_ENABLE_TRIES	1000
34
35#define CTRL_EN_BIT		0 /* Regulator enable bit, active high */
36#define CTRL_WT_BIT		2 /* Regulator wait time 0 bit */
37#define CTRL_PG_BIT		4 /* Regulator power good bit, 1=good */
38#define CTRL_TO_BIT		7 /* Regulator timeout bit, 1=wait */
39
40#define MAX_OVERCURRENT_WAIT	3 /* Overcurrent wait must be <= this */
41
42/**
43 * struct tps65090_regulator - Per-regulator data for a tps65090 regulator
44 *
45 * @dev: Pointer to our device.
46 * @desc: The struct regulator_desc for the regulator.
47 * @rdev: The struct regulator_dev for the regulator.
48 * @overcurrent_wait_valid: True if overcurrent_wait is valid.
49 * @overcurrent_wait: For FETs, the value to put in the WTFET bitfield.
50 */
51
52struct tps65090_regulator {
53	struct device		*dev;
54	struct regulator_desc	*desc;
55	struct regulator_dev	*rdev;
56	bool			overcurrent_wait_valid;
57	int			overcurrent_wait;
58};
59
60static struct regulator_ops tps65090_ext_control_ops = {
61};
62
63/**
64 * tps65090_reg_set_overcurrent_wait - Setup overcurrent wait
65 *
66 * This will set the overcurrent wait time based on what's in the regulator
67 * info.
68 *
69 * @ri:		Overall regulator data
70 * @rdev:	Regulator device
71 *
72 * Return: 0 if no error, non-zero if there was an error writing the register.
73 */
74static int tps65090_reg_set_overcurrent_wait(struct tps65090_regulator *ri,
75					     struct regulator_dev *rdev)
76{
77	int ret;
78
79	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
80				 MAX_OVERCURRENT_WAIT << CTRL_WT_BIT,
81				 ri->overcurrent_wait << CTRL_WT_BIT);
82	if (ret) {
83		dev_err(&rdev->dev, "Error updating overcurrent wait %#x\n",
84			rdev->desc->enable_reg);
85	}
86
87	return ret;
88}
89
90/**
91 * tps65090_try_enable_fet - Try to enable a FET
92 *
93 * @rdev:	Regulator device
94 *
95 * Return: 0 if ok, -ENOTRECOVERABLE if the FET power good bit did not get
96 * set, or some other -ve value if another error occurred (e.g. i2c error)
97 */
98static int tps65090_try_enable_fet(struct regulator_dev *rdev)
99{
100	unsigned int control;
101	int ret, i;
102
103	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
104				 rdev->desc->enable_mask,
105				 rdev->desc->enable_mask);
106	if (ret < 0) {
107		dev_err(&rdev->dev, "Error in updating reg %#x\n",
108			rdev->desc->enable_reg);
109		return ret;
110	}
111
112	for (i = 0; i < MAX_CTRL_READ_TRIES; i++) {
113		ret = regmap_read(rdev->regmap, rdev->desc->enable_reg,
114				  &control);
115		if (ret < 0)
116			return ret;
117
118		if (!(control & BIT(CTRL_TO_BIT)))
119			break;
120
121		usleep_range(1000, 1500);
122	}
123	if (!(control & BIT(CTRL_PG_BIT)))
124		return -ENOTRECOVERABLE;
125
126	return 0;
127}
128
129/**
130 * tps65090_fet_enable - Enable a FET, trying a few times if it fails
131 *
132 * Some versions of the tps65090 have issues when turning on the FETs.
133 * This function goes through several steps to ensure the best chance of the
134 * FET going on.  Specifically:
135 * - We'll make sure that we bump the "overcurrent wait" to the maximum, which
136 *   increases the chances that we'll turn on properly.
137 * - We'll retry turning the FET on multiple times (turning off in between).
138 *
139 * @rdev:	Regulator device
140 *
141 * Return: 0 if ok, non-zero if it fails.
142 */
143static int tps65090_fet_enable(struct regulator_dev *rdev)
144{
145	int ret, tries;
146
147	/*
148	 * Try enabling multiple times until we succeed since sometimes the
149	 * first try times out.
150	 */
151	tries = 0;
152	while (true) {
153		ret = tps65090_try_enable_fet(rdev);
154		if (!ret)
155			break;
156		if (ret != -ENOTRECOVERABLE || tries == MAX_FET_ENABLE_TRIES)
157			goto err;
158
159		/* Try turning the FET off (and then on again) */
160		ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
161					 rdev->desc->enable_mask, 0);
162		if (ret)
163			goto err;
164
165		tries++;
166	}
167
168	if (tries)
169		dev_warn(&rdev->dev, "reg %#x enable ok after %d tries\n",
170			 rdev->desc->enable_reg, tries);
171
172	return 0;
173err:
174	dev_warn(&rdev->dev, "reg %#x enable failed\n", rdev->desc->enable_reg);
175	WARN_ON(1);
176
177	return ret;
178}
179
180static struct regulator_ops tps65090_reg_control_ops = {
181	.enable		= regulator_enable_regmap,
182	.disable	= regulator_disable_regmap,
183	.is_enabled	= regulator_is_enabled_regmap,
184};
185
186static struct regulator_ops tps65090_fet_control_ops = {
187	.enable		= tps65090_fet_enable,
188	.disable	= regulator_disable_regmap,
189	.is_enabled	= regulator_is_enabled_regmap,
190};
191
192static struct regulator_ops tps65090_ldo_ops = {
193};
194
195#define tps65090_REG_DESC(_id, _sname, _en_reg, _en_bits, _nvolt, _volt, _ops) \
196{							\
197	.name = "TPS65090_RAILS"#_id,			\
198	.supply_name = _sname,				\
199	.id = TPS65090_REGULATOR_##_id,			\
200	.n_voltages = _nvolt,				\
201	.ops = &_ops,					\
202	.fixed_uV = _volt,				\
203	.enable_reg = _en_reg,				\
204	.enable_val = _en_bits,				\
205	.enable_mask = _en_bits,			\
206	.type = REGULATOR_VOLTAGE,			\
207	.owner = THIS_MODULE,				\
208}
209
210#define tps65090_REG_FIXEDV(_id, _sname, en_reg, _en_bits, _volt, _ops) \
211	tps65090_REG_DESC(_id, _sname, en_reg, _en_bits, 1, _volt, _ops)
212
213#define tps65090_REG_SWITCH(_id, _sname, en_reg, _en_bits, _ops) \
214	tps65090_REG_DESC(_id, _sname, en_reg, _en_bits, 0, 0, _ops)
215
216static struct regulator_desc tps65090_regulator_desc[] = {
217	tps65090_REG_FIXEDV(DCDC1, "vsys1",   0x0C, BIT(CTRL_EN_BIT), 5000000,
218			    tps65090_reg_control_ops),
219	tps65090_REG_FIXEDV(DCDC2, "vsys2",   0x0D, BIT(CTRL_EN_BIT), 3300000,
220			    tps65090_reg_control_ops),
221	tps65090_REG_SWITCH(DCDC3, "vsys3",   0x0E, BIT(CTRL_EN_BIT),
222			    tps65090_reg_control_ops),
223
224	tps65090_REG_SWITCH(FET1,  "infet1",  0x0F,
225			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
226			    tps65090_fet_control_ops),
227	tps65090_REG_SWITCH(FET2,  "infet2",  0x10,
228			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
229			    tps65090_fet_control_ops),
230	tps65090_REG_SWITCH(FET3,  "infet3",  0x11,
231			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
232			    tps65090_fet_control_ops),
233	tps65090_REG_SWITCH(FET4,  "infet4",  0x12,
234			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
235			    tps65090_fet_control_ops),
236	tps65090_REG_SWITCH(FET5,  "infet5",  0x13,
237			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
238			    tps65090_fet_control_ops),
239	tps65090_REG_SWITCH(FET6,  "infet6",  0x14,
240			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
241			    tps65090_fet_control_ops),
242	tps65090_REG_SWITCH(FET7,  "infet7",  0x15,
243			    BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT),
244			    tps65090_fet_control_ops),
245
246	tps65090_REG_FIXEDV(LDO1,  "vsys-l1", 0, 0, 5000000,
247			    tps65090_ldo_ops),
248	tps65090_REG_FIXEDV(LDO2,  "vsys-l2", 0, 0, 3300000,
249			    tps65090_ldo_ops),
250};
251
252static inline bool is_dcdc(int id)
253{
254	switch (id) {
255	case TPS65090_REGULATOR_DCDC1:
256	case TPS65090_REGULATOR_DCDC2:
257	case TPS65090_REGULATOR_DCDC3:
258		return true;
259	default:
260		return false;
261	}
262}
263
264static int tps65090_config_ext_control(
265	struct tps65090_regulator *ri, bool enable)
266{
267	int ret;
268	struct device *parent = ri->dev->parent;
269	unsigned int reg_en_reg = ri->desc->enable_reg;
270
271	if (enable)
272		ret = tps65090_set_bits(parent, reg_en_reg, 1);
273	else
274		ret =  tps65090_clr_bits(parent, reg_en_reg, 1);
275	if (ret < 0)
276		dev_err(ri->dev, "Error in updating reg 0x%x\n", reg_en_reg);
277	return ret;
278}
279
280static int tps65090_regulator_disable_ext_control(
281		struct tps65090_regulator *ri,
282		struct tps65090_regulator_plat_data *tps_pdata)
283{
284	int ret = 0;
285	struct device *parent = ri->dev->parent;
286	unsigned int reg_en_reg = ri->desc->enable_reg;
287
288	/*
289	 * First enable output for internal control if require.
290	 * And then disable external control.
291	 */
292	if (tps_pdata->reg_init_data->constraints.always_on ||
293			tps_pdata->reg_init_data->constraints.boot_on) {
294		ret =  tps65090_set_bits(parent, reg_en_reg, 0);
295		if (ret < 0) {
296			dev_err(ri->dev, "Error in set reg 0x%x\n", reg_en_reg);
297			return ret;
298		}
299	}
300	return tps65090_config_ext_control(ri, false);
301}
302
303static void tps65090_configure_regulator_config(
304		struct tps65090_regulator_plat_data *tps_pdata,
305		struct regulator_config *config)
306{
307	if (gpio_is_valid(tps_pdata->gpio)) {
308		int gpio_flag = GPIOF_OUT_INIT_LOW;
309
310		if (tps_pdata->reg_init_data->constraints.always_on ||
311				tps_pdata->reg_init_data->constraints.boot_on)
312			gpio_flag = GPIOF_OUT_INIT_HIGH;
313
314		config->ena_gpio = tps_pdata->gpio;
315		config->ena_gpio_initialized = true;
316		config->ena_gpio_flags = gpio_flag;
317	} else {
318		config->ena_gpio = -EINVAL;
319		config->ena_gpio_initialized = false;
320	}
321}
322
323#ifdef CONFIG_OF
324static struct of_regulator_match tps65090_matches[] = {
325	{ .name = "dcdc1", },
326	{ .name = "dcdc2", },
327	{ .name = "dcdc3", },
328	{ .name = "fet1",  },
329	{ .name = "fet2",  },
330	{ .name = "fet3",  },
331	{ .name = "fet4",  },
332	{ .name = "fet5",  },
333	{ .name = "fet6",  },
334	{ .name = "fet7",  },
335	{ .name = "ldo1",  },
336	{ .name = "ldo2",  },
337};
338
339static struct tps65090_platform_data *tps65090_parse_dt_reg_data(
340		struct platform_device *pdev,
341		struct of_regulator_match **tps65090_reg_matches)
342{
343	struct tps65090_platform_data *tps65090_pdata;
344	struct device_node *np = pdev->dev.parent->of_node;
345	struct device_node *regulators;
346	int idx = 0, ret;
347	struct tps65090_regulator_plat_data *reg_pdata;
348
349	tps65090_pdata = devm_kzalloc(&pdev->dev, sizeof(*tps65090_pdata),
350				GFP_KERNEL);
351	if (!tps65090_pdata)
352		return ERR_PTR(-ENOMEM);
353
354	reg_pdata = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX *
355				sizeof(*reg_pdata), GFP_KERNEL);
356	if (!reg_pdata)
357		return ERR_PTR(-ENOMEM);
358
359	regulators = of_get_child_by_name(np, "regulators");
360	if (!regulators) {
361		dev_err(&pdev->dev, "regulator node not found\n");
362		return ERR_PTR(-ENODEV);
363	}
364
365	ret = of_regulator_match(&pdev->dev, regulators, tps65090_matches,
366			ARRAY_SIZE(tps65090_matches));
367	of_node_put(regulators);
368	if (ret < 0) {
369		dev_err(&pdev->dev,
370			"Error parsing regulator init data: %d\n", ret);
371		return ERR_PTR(ret);
372	}
373
374	*tps65090_reg_matches = tps65090_matches;
375	for (idx = 0; idx < ARRAY_SIZE(tps65090_matches); idx++) {
376		struct regulator_init_data *ri_data;
377		struct tps65090_regulator_plat_data *rpdata;
378
379		rpdata = &reg_pdata[idx];
380		ri_data = tps65090_matches[idx].init_data;
381		if (!ri_data || !tps65090_matches[idx].of_node)
382			continue;
383
384		rpdata->reg_init_data = ri_data;
385		rpdata->enable_ext_control = of_property_read_bool(
386					tps65090_matches[idx].of_node,
387					"ti,enable-ext-control");
388		if (rpdata->enable_ext_control)
389			rpdata->gpio = of_get_named_gpio(np,
390					"dcdc-ext-control-gpios", 0);
391
392		if (of_property_read_u32(tps65090_matches[idx].of_node,
393					 "ti,overcurrent-wait",
394					 &rpdata->overcurrent_wait) == 0)
395			rpdata->overcurrent_wait_valid = true;
396
397		tps65090_pdata->reg_pdata[idx] = rpdata;
398	}
399	return tps65090_pdata;
400}
401#else
402static inline struct tps65090_platform_data *tps65090_parse_dt_reg_data(
403			struct platform_device *pdev,
404			struct of_regulator_match **tps65090_reg_matches)
405{
406	*tps65090_reg_matches = NULL;
407	return NULL;
408}
409#endif
410
411static int tps65090_regulator_probe(struct platform_device *pdev)
412{
413	struct tps65090 *tps65090_mfd = dev_get_drvdata(pdev->dev.parent);
414	struct tps65090_regulator *ri = NULL;
415	struct regulator_config config = { };
416	struct regulator_dev *rdev;
417	struct tps65090_regulator_plat_data *tps_pdata;
418	struct tps65090_regulator *pmic;
419	struct tps65090_platform_data *tps65090_pdata;
420	struct of_regulator_match *tps65090_reg_matches = NULL;
421	int num;
422	int ret;
423
424	dev_dbg(&pdev->dev, "Probing regulator\n");
425
426	tps65090_pdata = dev_get_platdata(pdev->dev.parent);
427	if (!tps65090_pdata && tps65090_mfd->dev->of_node)
428		tps65090_pdata = tps65090_parse_dt_reg_data(pdev,
429					&tps65090_reg_matches);
430	if (IS_ERR_OR_NULL(tps65090_pdata)) {
431		dev_err(&pdev->dev, "Platform data missing\n");
432		return tps65090_pdata ? PTR_ERR(tps65090_pdata) : -EINVAL;
433	}
434
435	pmic = devm_kzalloc(&pdev->dev, TPS65090_REGULATOR_MAX * sizeof(*pmic),
436			GFP_KERNEL);
437	if (!pmic)
438		return -ENOMEM;
439
440	for (num = 0; num < TPS65090_REGULATOR_MAX; num++) {
441		tps_pdata = tps65090_pdata->reg_pdata[num];
442
443		ri = &pmic[num];
444		ri->dev = &pdev->dev;
445		ri->desc = &tps65090_regulator_desc[num];
446		if (tps_pdata) {
447			ri->overcurrent_wait_valid =
448				tps_pdata->overcurrent_wait_valid;
449			ri->overcurrent_wait = tps_pdata->overcurrent_wait;
450		}
451
452		/*
453		 * TPS5090 DCDC support the control from external digital input.
454		 * Configure it as per platform data.
455		 */
456		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data) {
457			if (tps_pdata->enable_ext_control) {
458				tps65090_configure_regulator_config(
459						tps_pdata, &config);
460				ri->desc->ops = &tps65090_ext_control_ops;
461			} else {
462				ret = tps65090_regulator_disable_ext_control(
463						ri, tps_pdata);
464				if (ret < 0) {
465					dev_err(&pdev->dev,
466						"failed disable ext control\n");
467					return ret;
468				}
469			}
470		}
471
472		config.dev = pdev->dev.parent;
473		config.driver_data = ri;
474		config.regmap = tps65090_mfd->rmap;
475		if (tps_pdata)
476			config.init_data = tps_pdata->reg_init_data;
477		else
478			config.init_data = NULL;
479		if (tps65090_reg_matches)
480			config.of_node = tps65090_reg_matches[num].of_node;
481		else
482			config.of_node = NULL;
483
484		rdev = devm_regulator_register(&pdev->dev, ri->desc, &config);
485		if (IS_ERR(rdev)) {
486			dev_err(&pdev->dev, "failed to register regulator %s\n",
487				ri->desc->name);
488			return PTR_ERR(rdev);
489		}
490		ri->rdev = rdev;
491
492		if (ri->overcurrent_wait_valid) {
493			ret = tps65090_reg_set_overcurrent_wait(ri, rdev);
494			if (ret < 0)
495				return ret;
496		}
497
498		/* Enable external control if it is require */
499		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data &&
500				tps_pdata->enable_ext_control) {
501			ret = tps65090_config_ext_control(ri, true);
502			if (ret < 0)
503				return ret;
504		}
505	}
506
507	platform_set_drvdata(pdev, pmic);
508	return 0;
509}
510
511static struct platform_driver tps65090_regulator_driver = {
512	.driver	= {
513		.name	= "tps65090-pmic",
514	},
515	.probe		= tps65090_regulator_probe,
516};
517
518static int __init tps65090_regulator_init(void)
519{
520	return platform_driver_register(&tps65090_regulator_driver);
521}
522subsys_initcall(tps65090_regulator_init);
523
524static void __exit tps65090_regulator_exit(void)
525{
526	platform_driver_unregister(&tps65090_regulator_driver);
527}
528module_exit(tps65090_regulator_exit);
529
530MODULE_DESCRIPTION("tps65090 regulator driver");
531MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
532MODULE_LICENSE("GPL v2");
533MODULE_ALIAS("platform:tps65090-pmic");
534