1/*
2 * da9210-regulator.c - Regulator device driver for DA9210
3 * Copyright (C) 2013  Dialog Semiconductor Ltd.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA  02110-1301, USA.
19 */
20
21#include <linux/err.h>
22#include <linux/i2c.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/regulator/driver.h>
27#include <linux/regulator/machine.h>
28#include <linux/regulator/of_regulator.h>
29#include <linux/regmap.h>
30
31#include "da9210-regulator.h"
32
33struct da9210 {
34	struct regulator_dev *rdev;
35	struct regmap *regmap;
36};
37
38static const struct regmap_config da9210_regmap_config = {
39	.reg_bits = 8,
40	.val_bits = 8,
41};
42
43static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
44				    int max_uA);
45static int da9210_get_current_limit(struct regulator_dev *rdev);
46
47static struct regulator_ops da9210_buck_ops = {
48	.enable = regulator_enable_regmap,
49	.disable = regulator_disable_regmap,
50	.is_enabled = regulator_is_enabled_regmap,
51	.set_voltage_sel = regulator_set_voltage_sel_regmap,
52	.get_voltage_sel = regulator_get_voltage_sel_regmap,
53	.list_voltage = regulator_list_voltage_linear,
54	.set_current_limit = da9210_set_current_limit,
55	.get_current_limit = da9210_get_current_limit,
56};
57
58/* Default limits measured in millivolts and milliamps */
59#define DA9210_MIN_MV		300
60#define DA9210_MAX_MV		1570
61#define DA9210_STEP_MV		10
62
63/* Current limits for buck (uA) indices corresponds with register values */
64static const int da9210_buck_limits[] = {
65	1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
66	3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
67};
68
69static const struct regulator_desc da9210_reg = {
70	.name = "DA9210",
71	.id = 0,
72	.ops = &da9210_buck_ops,
73	.type = REGULATOR_VOLTAGE,
74	.n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
75	.min_uV = (DA9210_MIN_MV * 1000),
76	.uV_step = (DA9210_STEP_MV * 1000),
77	.vsel_reg = DA9210_REG_VBUCK_A,
78	.vsel_mask = DA9210_VBUCK_MASK,
79	.enable_reg = DA9210_REG_BUCK_CONT,
80	.enable_mask = DA9210_BUCK_EN,
81	.owner = THIS_MODULE,
82};
83
84static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
85				    int max_uA)
86{
87	struct da9210 *chip = rdev_get_drvdata(rdev);
88	unsigned int sel;
89	int i;
90
91	/* search for closest to maximum */
92	for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
93		if (min_uA <= da9210_buck_limits[i] &&
94		    max_uA >= da9210_buck_limits[i]) {
95			sel = i;
96			sel = sel << DA9210_BUCK_ILIM_SHIFT;
97			return regmap_update_bits(chip->regmap,
98						  DA9210_REG_BUCK_ILIM,
99						  DA9210_BUCK_ILIM_MASK, sel);
100		}
101	}
102
103	return -EINVAL;
104}
105
106static int da9210_get_current_limit(struct regulator_dev *rdev)
107{
108	struct da9210 *chip = rdev_get_drvdata(rdev);
109	unsigned int data;
110	unsigned int sel;
111	int ret;
112
113	ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
114	if (ret < 0)
115		return ret;
116
117	/* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
118	sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
119
120	return da9210_buck_limits[sel];
121}
122
123/*
124 * I2C driver interface functions
125 */
126static int da9210_i2c_probe(struct i2c_client *i2c,
127			    const struct i2c_device_id *id)
128{
129	struct da9210 *chip;
130	struct device *dev = &i2c->dev;
131	struct da9210_pdata *pdata = dev_get_platdata(dev);
132	struct regulator_dev *rdev = NULL;
133	struct regulator_config config = { };
134	int error;
135
136	chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
137	if (!chip)
138		return -ENOMEM;
139
140	chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
141	if (IS_ERR(chip->regmap)) {
142		error = PTR_ERR(chip->regmap);
143		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
144			error);
145		return error;
146	}
147
148	config.dev = &i2c->dev;
149	config.init_data = pdata ? &pdata->da9210_constraints :
150		of_get_regulator_init_data(dev, dev->of_node);
151	config.driver_data = chip;
152	config.regmap = chip->regmap;
153	config.of_node = dev->of_node;
154
155	rdev = devm_regulator_register(&i2c->dev, &da9210_reg, &config);
156	if (IS_ERR(rdev)) {
157		dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
158		return PTR_ERR(rdev);
159	}
160
161	chip->rdev = rdev;
162
163	i2c_set_clientdata(i2c, chip);
164
165	return 0;
166}
167
168static const struct i2c_device_id da9210_i2c_id[] = {
169	{"da9210", 0},
170	{},
171};
172
173MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
174
175static struct i2c_driver da9210_regulator_driver = {
176	.driver = {
177		.name = "da9210",
178		.owner = THIS_MODULE,
179	},
180	.probe = da9210_i2c_probe,
181	.id_table = da9210_i2c_id,
182};
183
184module_i2c_driver(da9210_regulator_driver);
185
186MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
187MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
188MODULE_LICENSE("GPL v2");
189