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/drivers/regulator/ad5398.c

http://github.com/mirrors/linux
C | 278 lines | 211 code | 56 blank | 11 comment | 19 complexity | 67ab51155e786c9d017c94292b9860d4 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Voltage and current regulation for AD5398 and AD5821
  4 *
  5 * Copyright 2010 Analog Devices Inc.
  6 *
  7 * Enter bugs at http://blackfin.uclinux.org/
  8 */
  9
 10#include <linux/module.h>
 11#include <linux/err.h>
 12#include <linux/i2c.h>
 13#include <linux/slab.h>
 14#include <linux/platform_device.h>
 15#include <linux/regulator/driver.h>
 16#include <linux/regulator/machine.h>
 17
 18#define AD5398_CURRENT_EN_MASK	0x8000
 19
 20struct ad5398_chip_info {
 21	struct i2c_client *client;
 22	int min_uA;
 23	int max_uA;
 24	unsigned int current_level;
 25	unsigned int current_mask;
 26	unsigned int current_offset;
 27	struct regulator_dev *rdev;
 28};
 29
 30static int ad5398_calc_current(struct ad5398_chip_info *chip,
 31	unsigned selector)
 32{
 33	unsigned range_uA = chip->max_uA - chip->min_uA;
 34
 35	return chip->min_uA + (selector * range_uA / chip->current_level);
 36}
 37
 38static int ad5398_read_reg(struct i2c_client *client, unsigned short *data)
 39{
 40	unsigned short val;
 41	int ret;
 42
 43	ret = i2c_master_recv(client, (char *)&val, 2);
 44	if (ret < 0) {
 45		dev_err(&client->dev, "I2C read error\n");
 46		return ret;
 47	}
 48	*data = be16_to_cpu(val);
 49
 50	return ret;
 51}
 52
 53static int ad5398_write_reg(struct i2c_client *client, const unsigned short data)
 54{
 55	unsigned short val;
 56	int ret;
 57
 58	val = cpu_to_be16(data);
 59	ret = i2c_master_send(client, (char *)&val, 2);
 60	if (ret != 2) {
 61		dev_err(&client->dev, "I2C write error\n");
 62		return ret < 0 ? ret : -EIO;
 63	}
 64
 65	return 0;
 66}
 67
 68static int ad5398_get_current_limit(struct regulator_dev *rdev)
 69{
 70	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
 71	struct i2c_client *client = chip->client;
 72	unsigned short data;
 73	int ret;
 74
 75	ret = ad5398_read_reg(client, &data);
 76	if (ret < 0)
 77		return ret;
 78
 79	ret = (data & chip->current_mask) >> chip->current_offset;
 80
 81	return ad5398_calc_current(chip, ret);
 82}
 83
 84static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
 85{
 86	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
 87	struct i2c_client *client = chip->client;
 88	unsigned range_uA = chip->max_uA - chip->min_uA;
 89	unsigned selector;
 90	unsigned short data;
 91	int ret;
 92
 93	if (min_uA < chip->min_uA)
 94		min_uA = chip->min_uA;
 95	if (max_uA > chip->max_uA)
 96		max_uA = chip->max_uA;
 97
 98	if (min_uA > chip->max_uA || max_uA < chip->min_uA)
 99		return -EINVAL;
100
101	selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level,
102				range_uA);
103	if (ad5398_calc_current(chip, selector) > max_uA)
104		return -EINVAL;
105
106	dev_dbg(&client->dev, "changing current %duA\n",
107		ad5398_calc_current(chip, selector));
108
109	/* read chip enable bit */
110	ret = ad5398_read_reg(client, &data);
111	if (ret < 0)
112		return ret;
113
114	/* prepare register data */
115	selector = (selector << chip->current_offset) & chip->current_mask;
116	data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK);
117
118	/* write the new current value back as well as enable bit */
119	ret = ad5398_write_reg(client, data);
120
121	return ret;
122}
123
124static int ad5398_is_enabled(struct regulator_dev *rdev)
125{
126	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
127	struct i2c_client *client = chip->client;
128	unsigned short data;
129	int ret;
130
131	ret = ad5398_read_reg(client, &data);
132	if (ret < 0)
133		return ret;
134
135	if (data & AD5398_CURRENT_EN_MASK)
136		return 1;
137	else
138		return 0;
139}
140
141static int ad5398_enable(struct regulator_dev *rdev)
142{
143	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
144	struct i2c_client *client = chip->client;
145	unsigned short data;
146	int ret;
147
148	ret = ad5398_read_reg(client, &data);
149	if (ret < 0)
150		return ret;
151
152	if (data & AD5398_CURRENT_EN_MASK)
153		return 0;
154
155	data |= AD5398_CURRENT_EN_MASK;
156
157	ret = ad5398_write_reg(client, data);
158
159	return ret;
160}
161
162static int ad5398_disable(struct regulator_dev *rdev)
163{
164	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
165	struct i2c_client *client = chip->client;
166	unsigned short data;
167	int ret;
168
169	ret = ad5398_read_reg(client, &data);
170	if (ret < 0)
171		return ret;
172
173	if (!(data & AD5398_CURRENT_EN_MASK))
174		return 0;
175
176	data &= ~AD5398_CURRENT_EN_MASK;
177
178	ret = ad5398_write_reg(client, data);
179
180	return ret;
181}
182
183static const struct regulator_ops ad5398_ops = {
184	.get_current_limit = ad5398_get_current_limit,
185	.set_current_limit = ad5398_set_current_limit,
186	.enable = ad5398_enable,
187	.disable = ad5398_disable,
188	.is_enabled = ad5398_is_enabled,
189};
190
191static const struct regulator_desc ad5398_reg = {
192	.name = "isink",
193	.id = 0,
194	.ops = &ad5398_ops,
195	.type = REGULATOR_CURRENT,
196	.owner = THIS_MODULE,
197};
198
199struct ad5398_current_data_format {
200	int current_bits;
201	int current_offset;
202	int min_uA;
203	int max_uA;
204};
205
206static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};
207
208static const struct i2c_device_id ad5398_id[] = {
209	{ "ad5398", (kernel_ulong_t)&df_10_4_120 },
210	{ "ad5821", (kernel_ulong_t)&df_10_4_120 },
211	{ }
212};
213MODULE_DEVICE_TABLE(i2c, ad5398_id);
214
215static int ad5398_probe(struct i2c_client *client,
216				const struct i2c_device_id *id)
217{
218	struct regulator_init_data *init_data = dev_get_platdata(&client->dev);
219	struct regulator_config config = { };
220	struct ad5398_chip_info *chip;
221	const struct ad5398_current_data_format *df =
222			(struct ad5398_current_data_format *)id->driver_data;
223
224	if (!init_data)
225		return -EINVAL;
226
227	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
228	if (!chip)
229		return -ENOMEM;
230
231	config.dev = &client->dev;
232	config.init_data = init_data;
233	config.driver_data = chip;
234
235	chip->client = client;
236
237	chip->min_uA = df->min_uA;
238	chip->max_uA = df->max_uA;
239	chip->current_level = 1 << df->current_bits;
240	chip->current_offset = df->current_offset;
241	chip->current_mask = (chip->current_level - 1) << chip->current_offset;
242
243	chip->rdev = devm_regulator_register(&client->dev, &ad5398_reg,
244					     &config);
245	if (IS_ERR(chip->rdev)) {
246		dev_err(&client->dev, "failed to register %s %s\n",
247			id->name, ad5398_reg.name);
248		return PTR_ERR(chip->rdev);
249	}
250
251	i2c_set_clientdata(client, chip);
252	dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
253	return 0;
254}
255
256static struct i2c_driver ad5398_driver = {
257	.probe = ad5398_probe,
258	.driver		= {
259		.name	= "ad5398",
260	},
261	.id_table	= ad5398_id,
262};
263
264static int __init ad5398_init(void)
265{
266	return i2c_add_driver(&ad5398_driver);
267}
268subsys_initcall(ad5398_init);
269
270static void __exit ad5398_exit(void)
271{
272	i2c_del_driver(&ad5398_driver);
273}
274module_exit(ad5398_exit);
275
276MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
277MODULE_AUTHOR("Sonic Zhang");
278MODULE_LICENSE("GPL");