1/*
2 * Regulators driver for Maxim max8649
3 *
4 * Copyright (C) 2009-2010 Marvell International Ltd.
5 *      Haojian Zhuang <haojian.zhuang@marvell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/err.h>
14#include <linux/i2c.h>
15#include <linux/platform_device.h>
16#include <linux/regulator/driver.h>
17#include <linux/slab.h>
18#include <linux/regulator/max8649.h>
19#include <linux/regmap.h>
20
21#define MAX8649_DCDC_VMIN	750000		/* uV */
22#define MAX8649_DCDC_VMAX	1380000		/* uV */
23#define MAX8649_DCDC_STEP	10000		/* uV */
24#define MAX8649_VOL_MASK	0x3f
25
26/* Registers */
27#define MAX8649_MODE0		0x00
28#define MAX8649_MODE1		0x01
29#define MAX8649_MODE2		0x02
30#define MAX8649_MODE3		0x03
31#define MAX8649_CONTROL		0x04
32#define MAX8649_SYNC		0x05
33#define MAX8649_RAMP		0x06
34#define MAX8649_CHIP_ID1	0x08
35#define MAX8649_CHIP_ID2	0x09
36
37/* Bits */
38#define MAX8649_EN_PD		(1 << 7)
39#define MAX8649_VID0_PD		(1 << 6)
40#define MAX8649_VID1_PD		(1 << 5)
41#define MAX8649_VID_MASK	(3 << 5)
42
43#define MAX8649_FORCE_PWM	(1 << 7)
44#define MAX8649_SYNC_EXTCLK	(1 << 6)
45
46#define MAX8649_EXT_MASK	(3 << 6)
47
48#define MAX8649_RAMP_MASK	(7 << 5)
49#define MAX8649_RAMP_DOWN	(1 << 1)
50
51struct max8649_regulator_info {
52	struct device		*dev;
53	struct regmap		*regmap;
54
55	unsigned	mode:2;	/* bit[1:0] = VID1, VID0 */
56	unsigned	extclk_freq:2;
57	unsigned	extclk:1;
58	unsigned	ramp_timing:3;
59	unsigned	ramp_down:1;
60};
61
62static int max8649_enable_time(struct regulator_dev *rdev)
63{
64	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
65	int voltage, rate, ret;
66	unsigned int val;
67
68	/* get voltage */
69	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
70	if (ret != 0)
71		return ret;
72	val &= MAX8649_VOL_MASK;
73	voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
74
75	/* get rate */
76	ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
77	if (ret != 0)
78		return ret;
79	ret = (val & MAX8649_RAMP_MASK) >> 5;
80	rate = (32 * 1000) >> ret;	/* uV/uS */
81
82	return DIV_ROUND_UP(voltage, rate);
83}
84
85static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
86{
87	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
88
89	switch (mode) {
90	case REGULATOR_MODE_FAST:
91		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
92				   MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
93		break;
94	case REGULATOR_MODE_NORMAL:
95		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
96				   MAX8649_FORCE_PWM, 0);
97		break;
98	default:
99		return -EINVAL;
100	}
101	return 0;
102}
103
104static unsigned int max8649_get_mode(struct regulator_dev *rdev)
105{
106	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
107	unsigned int val;
108	int ret;
109
110	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
111	if (ret != 0)
112		return ret;
113	if (val & MAX8649_FORCE_PWM)
114		return REGULATOR_MODE_FAST;
115	return REGULATOR_MODE_NORMAL;
116}
117
118static struct regulator_ops max8649_dcdc_ops = {
119	.set_voltage_sel = regulator_set_voltage_sel_regmap,
120	.get_voltage_sel = regulator_get_voltage_sel_regmap,
121	.list_voltage	= regulator_list_voltage_linear,
122	.map_voltage	= regulator_map_voltage_linear,
123	.enable		= regulator_enable_regmap,
124	.disable	= regulator_disable_regmap,
125	.is_enabled	= regulator_is_enabled_regmap,
126	.enable_time	= max8649_enable_time,
127	.set_mode	= max8649_set_mode,
128	.get_mode	= max8649_get_mode,
129
130};
131
132static struct regulator_desc dcdc_desc = {
133	.name		= "max8649",
134	.ops		= &max8649_dcdc_ops,
135	.type		= REGULATOR_VOLTAGE,
136	.n_voltages	= 1 << 6,
137	.owner		= THIS_MODULE,
138	.vsel_mask	= MAX8649_VOL_MASK,
139	.min_uV		= MAX8649_DCDC_VMIN,
140	.uV_step	= MAX8649_DCDC_STEP,
141	.enable_reg	= MAX8649_CONTROL,
142	.enable_mask	= MAX8649_EN_PD,
143	.enable_is_inverted = true,
144};
145
146static struct regmap_config max8649_regmap_config = {
147	.reg_bits = 8,
148	.val_bits = 8,
149};
150
151static int max8649_regulator_probe(struct i2c_client *client,
152					     const struct i2c_device_id *id)
153{
154	struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
155	struct max8649_regulator_info *info = NULL;
156	struct regulator_dev *regulator;
157	struct regulator_config config = { };
158	unsigned int val;
159	unsigned char data;
160	int ret;
161
162	info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
163			    GFP_KERNEL);
164	if (!info)
165		return -ENOMEM;
166
167	info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
168	if (IS_ERR(info->regmap)) {
169		ret = PTR_ERR(info->regmap);
170		dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
171		return ret;
172	}
173
174	info->dev = &client->dev;
175	i2c_set_clientdata(client, info);
176
177	info->mode = pdata->mode;
178	switch (info->mode) {
179	case 0:
180		dcdc_desc.vsel_reg = MAX8649_MODE0;
181		break;
182	case 1:
183		dcdc_desc.vsel_reg = MAX8649_MODE1;
184		break;
185	case 2:
186		dcdc_desc.vsel_reg = MAX8649_MODE2;
187		break;
188	case 3:
189		dcdc_desc.vsel_reg = MAX8649_MODE3;
190		break;
191	default:
192		break;
193	}
194
195	ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
196	if (ret != 0) {
197		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
198			ret);
199		return ret;
200	}
201	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
202
203	/* enable VID0 & VID1 */
204	regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
205
206	/* enable/disable external clock synchronization */
207	info->extclk = pdata->extclk;
208	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
209	regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
210			   MAX8649_SYNC_EXTCLK, data);
211	if (info->extclk) {
212		/* set external clock frequency */
213		info->extclk_freq = pdata->extclk_freq;
214		regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
215				   info->extclk_freq << 6);
216	}
217
218	if (pdata->ramp_timing) {
219		info->ramp_timing = pdata->ramp_timing;
220		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
221				   info->ramp_timing << 5);
222	}
223
224	info->ramp_down = pdata->ramp_down;
225	if (info->ramp_down) {
226		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
227				   MAX8649_RAMP_DOWN);
228	}
229
230	config.dev = &client->dev;
231	config.init_data = pdata->regulator;
232	config.driver_data = info;
233	config.regmap = info->regmap;
234
235	regulator = devm_regulator_register(&client->dev, &dcdc_desc,
236						  &config);
237	if (IS_ERR(regulator)) {
238		dev_err(info->dev, "failed to register regulator %s\n",
239			dcdc_desc.name);
240		return PTR_ERR(regulator);
241	}
242
243	return 0;
244}
245
246static const struct i2c_device_id max8649_id[] = {
247	{ "max8649", 0 },
248	{ }
249};
250MODULE_DEVICE_TABLE(i2c, max8649_id);
251
252static struct i2c_driver max8649_driver = {
253	.probe		= max8649_regulator_probe,
254	.driver		= {
255		.name	= "max8649",
256	},
257	.id_table	= max8649_id,
258};
259
260static int __init max8649_init(void)
261{
262	return i2c_add_driver(&max8649_driver);
263}
264subsys_initcall(max8649_init);
265
266static void __exit max8649_exit(void)
267{
268	i2c_del_driver(&max8649_driver);
269}
270module_exit(max8649_exit);
271
272/* Module information */
273MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
274MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
275MODULE_LICENSE("GPL");
276