1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Regulators driver for Maxim max8649
4 *
5 * Copyright (C) 2009-2010 Marvell International Ltd.
6 *      Haojian Zhuang <haojian.zhuang@marvell.com>
7 */
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/err.h>
11#include <linux/i2c.h>
12#include <linux/platform_device.h>
13#include <linux/regulator/driver.h>
14#include <linux/slab.h>
15#include <linux/regulator/max8649.h>
16#include <linux/regmap.h>
17
18#define MAX8649_DCDC_VMIN	750000		/* uV */
19#define MAX8649_DCDC_VMAX	1380000		/* uV */
20#define MAX8649_DCDC_STEP	10000		/* uV */
21#define MAX8649_VOL_MASK	0x3f
22
23/* Registers */
24#define MAX8649_MODE0		0x00
25#define MAX8649_MODE1		0x01
26#define MAX8649_MODE2		0x02
27#define MAX8649_MODE3		0x03
28#define MAX8649_CONTROL		0x04
29#define MAX8649_SYNC		0x05
30#define MAX8649_RAMP		0x06
31#define MAX8649_CHIP_ID1	0x08
32#define MAX8649_CHIP_ID2	0x09
33
34/* Bits */
35#define MAX8649_EN_PD		(1 << 7)
36#define MAX8649_VID0_PD		(1 << 6)
37#define MAX8649_VID1_PD		(1 << 5)
38#define MAX8649_VID_MASK	(3 << 5)
39
40#define MAX8649_FORCE_PWM	(1 << 7)
41#define MAX8649_SYNC_EXTCLK	(1 << 6)
42
43#define MAX8649_EXT_MASK	(3 << 6)
44
45#define MAX8649_RAMP_MASK	(7 << 5)
46#define MAX8649_RAMP_DOWN	(1 << 1)
47
48struct max8649_regulator_info {
49	struct device		*dev;
50	struct regmap		*regmap;
51
52	unsigned	mode:2;	/* bit[1:0] = VID1, VID0 */
53	unsigned	extclk_freq:2;
54	unsigned	extclk:1;
55	unsigned	ramp_timing:3;
56	unsigned	ramp_down:1;
57};
58
59static int max8649_enable_time(struct regulator_dev *rdev)
60{
61	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
62	int voltage, rate, ret;
63	unsigned int val;
64
65	/* get voltage */
66	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
67	if (ret != 0)
68		return ret;
69	val &= MAX8649_VOL_MASK;
70	voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
71
72	/* get rate */
73	ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
74	if (ret != 0)
75		return ret;
76	ret = (val & MAX8649_RAMP_MASK) >> 5;
77	rate = (32 * 1000) >> ret;	/* uV/uS */
78
79	return DIV_ROUND_UP(voltage, rate);
80}
81
82static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
83{
84	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
85
86	switch (mode) {
87	case REGULATOR_MODE_FAST:
88		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
89				   MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
90		break;
91	case REGULATOR_MODE_NORMAL:
92		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
93				   MAX8649_FORCE_PWM, 0);
94		break;
95	default:
96		return -EINVAL;
97	}
98	return 0;
99}
100
101static unsigned int max8649_get_mode(struct regulator_dev *rdev)
102{
103	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
104	unsigned int val;
105	int ret;
106
107	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
108	if (ret != 0)
109		return ret;
110	if (val & MAX8649_FORCE_PWM)
111		return REGULATOR_MODE_FAST;
112	return REGULATOR_MODE_NORMAL;
113}
114
115static const struct regulator_ops max8649_dcdc_ops = {
116	.set_voltage_sel = regulator_set_voltage_sel_regmap,
117	.get_voltage_sel = regulator_get_voltage_sel_regmap,
118	.list_voltage	= regulator_list_voltage_linear,
119	.map_voltage	= regulator_map_voltage_linear,
120	.enable		= regulator_enable_regmap,
121	.disable	= regulator_disable_regmap,
122	.is_enabled	= regulator_is_enabled_regmap,
123	.enable_time	= max8649_enable_time,
124	.set_mode	= max8649_set_mode,
125	.get_mode	= max8649_get_mode,
126
127};
128
129static struct regulator_desc dcdc_desc = {
130	.name		= "max8649",
131	.ops		= &max8649_dcdc_ops,
132	.type		= REGULATOR_VOLTAGE,
133	.n_voltages	= 1 << 6,
134	.owner		= THIS_MODULE,
135	.vsel_mask	= MAX8649_VOL_MASK,
136	.min_uV		= MAX8649_DCDC_VMIN,
137	.uV_step	= MAX8649_DCDC_STEP,
138	.enable_reg	= MAX8649_CONTROL,
139	.enable_mask	= MAX8649_EN_PD,
140	.enable_is_inverted = true,
141};
142
143static const struct regmap_config max8649_regmap_config = {
144	.reg_bits = 8,
145	.val_bits = 8,
146};
147
148static int max8649_regulator_probe(struct i2c_client *client)
149{
150	struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
151	struct max8649_regulator_info *info = NULL;
152	struct regulator_dev *regulator;
153	struct regulator_config config = { };
154	unsigned int val;
155	unsigned char data;
156	int ret;
157
158	info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
159			    GFP_KERNEL);
160	if (!info)
161		return -ENOMEM;
162
163	info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
164	if (IS_ERR(info->regmap)) {
165		ret = PTR_ERR(info->regmap);
166		dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
167		return ret;
168	}
169
170	info->dev = &client->dev;
171	i2c_set_clientdata(client, info);
172
173	info->mode = pdata->mode;
174	switch (info->mode) {
175	case 0:
176		dcdc_desc.vsel_reg = MAX8649_MODE0;
177		break;
178	case 1:
179		dcdc_desc.vsel_reg = MAX8649_MODE1;
180		break;
181	case 2:
182		dcdc_desc.vsel_reg = MAX8649_MODE2;
183		break;
184	case 3:
185		dcdc_desc.vsel_reg = MAX8649_MODE3;
186		break;
187	default:
188		break;
189	}
190
191	ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
192	if (ret != 0) {
193		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
194			ret);
195		return ret;
196	}
197	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
198
199	/* enable VID0 & VID1 */
200	regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
201
202	/* enable/disable external clock synchronization */
203	info->extclk = pdata->extclk;
204	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
205	regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
206			   MAX8649_SYNC_EXTCLK, data);
207	if (info->extclk) {
208		/* set external clock frequency */
209		info->extclk_freq = pdata->extclk_freq;
210		regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
211				   info->extclk_freq << 6);
212	}
213
214	if (pdata->ramp_timing) {
215		info->ramp_timing = pdata->ramp_timing;
216		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
217				   info->ramp_timing << 5);
218	}
219
220	info->ramp_down = pdata->ramp_down;
221	if (info->ramp_down) {
222		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
223				   MAX8649_RAMP_DOWN);
224	}
225
226	config.dev = &client->dev;
227	config.init_data = pdata->regulator;
228	config.driver_data = info;
229	config.regmap = info->regmap;
230
231	regulator = devm_regulator_register(&client->dev, &dcdc_desc,
232						  &config);
233	if (IS_ERR(regulator)) {
234		dev_err(info->dev, "failed to register regulator %s\n",
235			dcdc_desc.name);
236		return PTR_ERR(regulator);
237	}
238
239	return 0;
240}
241
242static const struct i2c_device_id max8649_id[] = {
243	{ "max8649", 0 },
244	{ }
245};
246MODULE_DEVICE_TABLE(i2c, max8649_id);
247
248static struct i2c_driver max8649_driver = {
249	.probe		= max8649_regulator_probe,
250	.driver		= {
251		.name	= "max8649",
252		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
253	},
254	.id_table	= max8649_id,
255};
256
257static int __init max8649_init(void)
258{
259	return i2c_add_driver(&max8649_driver);
260}
261subsys_initcall(max8649_init);
262
263static void __exit max8649_exit(void)
264{
265	i2c_del_driver(&max8649_driver);
266}
267module_exit(max8649_exit);
268
269/* Module information */
270MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
271MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
272MODULE_LICENSE("GPL");
273