1/*
2 * tps51632-regulator.c -- TI TPS51632
3 *
4 * Regulator driver for TPS51632 3-2-1 Phase D-Cap Step Down Driverless
5 * Controller with serial VID control and DVFS.
6 *
7 * Copyright (c) 2012, NVIDIA Corporation.
8 *
9 * Author: Laxman Dewangan <ldewangan@nvidia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
14 *
15 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
16 * whether express or implied; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 * 02111-1307, USA
24 */
25
26#include <linux/err.h>
27#include <linux/i2c.h>
28#include <linux/init.h>
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/of.h>
32#include <linux/of_device.h>
33#include <linux/platform_device.h>
34#include <linux/regmap.h>
35#include <linux/regulator/driver.h>
36#include <linux/regulator/machine.h>
37#include <linux/regulator/of_regulator.h>
38#include <linux/regulator/tps51632-regulator.h>
39#include <linux/slab.h>
40
41/* Register definitions */
42#define TPS51632_VOLTAGE_SELECT_REG		0x0
43#define TPS51632_VOLTAGE_BASE_REG		0x1
44#define TPS51632_OFFSET_REG			0x2
45#define TPS51632_IMON_REG			0x3
46#define TPS51632_VMAX_REG			0x4
47#define TPS51632_DVFS_CONTROL_REG		0x5
48#define TPS51632_POWER_STATE_REG		0x6
49#define TPS51632_SLEW_REGS			0x7
50#define TPS51632_FAULT_REG			0x14
51
52#define TPS51632_MAX_REG			0x15
53
54#define TPS51632_VOUT_MASK			0x7F
55#define TPS51632_VOUT_OFFSET_MASK		0x1F
56#define TPS51632_VMAX_MASK			0x7F
57#define TPS51632_VMAX_LOCK			0x80
58
59/* TPS51632_DVFS_CONTROL_REG */
60#define TPS51632_DVFS_PWMEN			0x1
61#define TPS51632_DVFS_STEP_20			0x2
62#define TPS51632_DVFS_VMAX_PG			0x4
63#define TPS51632_DVFS_PWMRST			0x8
64#define TPS51632_DVFS_OCA_EN			0x10
65#define TPS51632_DVFS_FCCM			0x20
66
67/* TPS51632_POWER_STATE_REG */
68#define TPS51632_POWER_STATE_MASK		0x03
69#define TPS51632_POWER_STATE_MULTI_PHASE_CCM	0x0
70#define TPS51632_POWER_STATE_SINGLE_PHASE_CCM	0x1
71#define TPS51632_POWER_STATE_SINGLE_PHASE_DCM	0x2
72
73#define TPS51632_MIN_VOLTAGE			500000
74#define TPS51632_MAX_VOLTAGE			1520000
75#define TPS51632_VOLTAGE_STEP_10mV		10000
76#define TPS51632_VOLTAGE_STEP_20mV		20000
77#define TPS51632_MAX_VSEL			0x7F
78#define TPS51632_MIN_VSEL			0x19
79#define TPS51632_DEFAULT_RAMP_DELAY		6000
80#define TPS51632_VOLT_VSEL(uV)					\
81		(DIV_ROUND_UP(uV - TPS51632_MIN_VOLTAGE,	\
82			TPS51632_VOLTAGE_STEP_10mV) +		\
83			TPS51632_MIN_VSEL)
84
85/* TPS51632 chip information */
86struct tps51632_chip {
87	struct device *dev;
88	struct regulator_desc desc;
89	struct regulator_dev *rdev;
90	struct regmap *regmap;
91};
92
93static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
94		int ramp_delay)
95{
96	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
97	int bit = ramp_delay/6000;
98	int ret;
99
100	if (bit)
101		bit--;
102	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
103	if (ret < 0)
104		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
105	return ret;
106}
107
108static struct regulator_ops tps51632_dcdc_ops = {
109	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
110	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
111	.list_voltage		= regulator_list_voltage_linear,
112	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
113	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
114};
115
116static int tps51632_init_dcdc(struct tps51632_chip *tps,
117		struct tps51632_regulator_platform_data *pdata)
118{
119	int ret;
120	uint8_t	control = 0;
121	int vsel;
122
123	if (!pdata->enable_pwm_dvfs)
124		goto skip_pwm_config;
125
126	control |= TPS51632_DVFS_PWMEN;
127	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
128	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
129	if (ret < 0) {
130		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
131		return ret;
132	}
133
134	if (pdata->dvfs_step_20mV)
135		control |= TPS51632_DVFS_STEP_20;
136
137	if (pdata->max_voltage_uV) {
138		unsigned int vmax;
139		/**
140		 * TPS51632 hw behavior: VMAX register can be write only
141		 * once as it get locked after first write. The lock get
142		 * reset only when device is power-reset.
143		 * Write register only when lock bit is not enabled.
144		 */
145		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
146		if (ret < 0) {
147			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
148			return ret;
149		}
150		if (!(vmax & TPS51632_VMAX_LOCK)) {
151			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
152			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
153					vsel);
154			if (ret < 0) {
155				dev_err(tps->dev,
156					"VMAX write failed, err %d\n", ret);
157				return ret;
158			}
159		}
160	}
161
162skip_pwm_config:
163	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
164	if (ret < 0)
165		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
166	return ret;
167}
168
169static bool is_volatile_reg(struct device *dev, unsigned int reg)
170{
171	switch (reg) {
172	case TPS51632_OFFSET_REG:
173	case TPS51632_FAULT_REG:
174	case TPS51632_IMON_REG:
175		return true;
176	default:
177		return false;
178	}
179}
180
181static bool is_read_reg(struct device *dev, unsigned int reg)
182{
183	switch (reg) {
184	case 0x08 ... 0x0F:
185		return false;
186	default:
187		return true;
188	}
189}
190
191static bool is_write_reg(struct device *dev, unsigned int reg)
192{
193	switch (reg) {
194	case TPS51632_VOLTAGE_SELECT_REG:
195	case TPS51632_VOLTAGE_BASE_REG:
196	case TPS51632_VMAX_REG:
197	case TPS51632_DVFS_CONTROL_REG:
198	case TPS51632_POWER_STATE_REG:
199	case TPS51632_SLEW_REGS:
200		return true;
201	default:
202		return false;
203	}
204}
205
206static const struct regmap_config tps51632_regmap_config = {
207	.reg_bits		= 8,
208	.val_bits		= 8,
209	.writeable_reg		= is_write_reg,
210	.readable_reg		= is_read_reg,
211	.volatile_reg		= is_volatile_reg,
212	.max_register		= TPS51632_MAX_REG - 1,
213	.cache_type		= REGCACHE_RBTREE,
214};
215
216#if defined(CONFIG_OF)
217static const struct of_device_id tps51632_of_match[] = {
218	{ .compatible = "ti,tps51632",},
219	{},
220};
221MODULE_DEVICE_TABLE(of, tps51632_of_match);
222
223static struct tps51632_regulator_platform_data *
224	of_get_tps51632_platform_data(struct device *dev,
225				      const struct regulator_desc *desc)
226{
227	struct tps51632_regulator_platform_data *pdata;
228	struct device_node *np = dev->of_node;
229
230	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
231	if (!pdata)
232		return NULL;
233
234	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node,
235							  desc);
236	if (!pdata->reg_init_data) {
237		dev_err(dev, "Not able to get OF regulator init data\n");
238		return NULL;
239	}
240
241	pdata->enable_pwm_dvfs =
242			of_property_read_bool(np, "ti,enable-pwm-dvfs");
243	pdata->dvfs_step_20mV = of_property_read_bool(np, "ti,dvfs-step-20mV");
244
245	pdata->base_voltage_uV = pdata->reg_init_data->constraints.min_uV ? :
246					TPS51632_MIN_VOLTAGE;
247	pdata->max_voltage_uV = pdata->reg_init_data->constraints.max_uV ? :
248					TPS51632_MAX_VOLTAGE;
249	return pdata;
250}
251#else
252static struct tps51632_regulator_platform_data *
253	of_get_tps51632_platform_data(struct device *dev,
254				      const struct regulator_desc *desc)
255{
256	return NULL;
257}
258#endif
259
260static int tps51632_probe(struct i2c_client *client,
261				const struct i2c_device_id *id)
262{
263	struct tps51632_regulator_platform_data *pdata;
264	struct regulator_dev *rdev;
265	struct tps51632_chip *tps;
266	int ret;
267	struct regulator_config config = { };
268
269	if (client->dev.of_node) {
270		const struct of_device_id *match;
271		match = of_match_device(of_match_ptr(tps51632_of_match),
272				&client->dev);
273		if (!match) {
274			dev_err(&client->dev, "Error: No device match found\n");
275			return -ENODEV;
276		}
277	}
278
279	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
280	if (!tps)
281		return -ENOMEM;
282
283	tps->dev = &client->dev;
284	tps->desc.name = client->name;
285	tps->desc.id = 0;
286	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
287	tps->desc.min_uV = TPS51632_MIN_VOLTAGE;
288	tps->desc.uV_step = TPS51632_VOLTAGE_STEP_10mV;
289	tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
290	tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
291	tps->desc.ops = &tps51632_dcdc_ops;
292	tps->desc.type = REGULATOR_VOLTAGE;
293	tps->desc.owner = THIS_MODULE;
294
295	pdata = dev_get_platdata(&client->dev);
296	if (!pdata && client->dev.of_node)
297		pdata = of_get_tps51632_platform_data(&client->dev, &tps->desc);
298	if (!pdata) {
299		dev_err(&client->dev, "No Platform data\n");
300		return -EINVAL;
301	}
302
303	if (pdata->enable_pwm_dvfs) {
304		if ((pdata->base_voltage_uV < TPS51632_MIN_VOLTAGE) ||
305		    (pdata->base_voltage_uV > TPS51632_MAX_VOLTAGE)) {
306			dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
307			return -EINVAL;
308		}
309
310		if ((pdata->max_voltage_uV) &&
311		    ((pdata->max_voltage_uV < TPS51632_MIN_VOLTAGE) ||
312		     (pdata->max_voltage_uV > TPS51632_MAX_VOLTAGE))) {
313			dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
314			return -EINVAL;
315		}
316	}
317
318	if (pdata->enable_pwm_dvfs)
319		tps->desc.vsel_reg = TPS51632_VOLTAGE_BASE_REG;
320	else
321		tps->desc.vsel_reg = TPS51632_VOLTAGE_SELECT_REG;
322	tps->desc.vsel_mask = TPS51632_VOUT_MASK;
323
324	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
325	if (IS_ERR(tps->regmap)) {
326		ret = PTR_ERR(tps->regmap);
327		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
328		return ret;
329	}
330	i2c_set_clientdata(client, tps);
331
332	ret = tps51632_init_dcdc(tps, pdata);
333	if (ret < 0) {
334		dev_err(tps->dev, "Init failed, err = %d\n", ret);
335		return ret;
336	}
337
338	/* Register the regulators */
339	config.dev = &client->dev;
340	config.init_data = pdata->reg_init_data;
341	config.driver_data = tps;
342	config.regmap = tps->regmap;
343	config.of_node = client->dev.of_node;
344
345	rdev = devm_regulator_register(&client->dev, &tps->desc, &config);
346	if (IS_ERR(rdev)) {
347		dev_err(tps->dev, "regulator register failed\n");
348		return PTR_ERR(rdev);
349	}
350
351	tps->rdev = rdev;
352	return 0;
353}
354
355static const struct i2c_device_id tps51632_id[] = {
356	{.name = "tps51632",},
357	{},
358};
359
360MODULE_DEVICE_TABLE(i2c, tps51632_id);
361
362static struct i2c_driver tps51632_i2c_driver = {
363	.driver = {
364		.name = "tps51632",
365		.owner = THIS_MODULE,
366		.of_match_table = of_match_ptr(tps51632_of_match),
367	},
368	.probe = tps51632_probe,
369	.id_table = tps51632_id,
370};
371
372static int __init tps51632_init(void)
373{
374	return i2c_add_driver(&tps51632_i2c_driver);
375}
376subsys_initcall(tps51632_init);
377
378static void __exit tps51632_cleanup(void)
379{
380	i2c_del_driver(&tps51632_i2c_driver);
381}
382module_exit(tps51632_cleanup);
383
384MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
385MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
386MODULE_LICENSE("GPL v2");
387