max8925-i2c.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * I2C driver for Maxim MAX8925
  4 *
  5 * Copyright (C) 2009 Marvell International Ltd.
  6 *	Haojian Zhuang <haojian.zhuang@marvell.com>
  7 */
  8#include <linux/kernel.h>
  9#include <linux/init.h>
 10#include <linux/platform_device.h>
 11#include <linux/i2c.h>
 12#include <linux/mfd/max8925.h>
 13#include <linux/slab.h>
 14
 15#define RTC_I2C_ADDR		0x68
 16#define ADC_I2C_ADDR		0x47
 17
 18static inline int max8925_read_device(struct i2c_client *i2c,
 19				      int reg, int bytes, void *dest)
 20{
 21	int ret;
 22
 23	if (bytes > 1)
 24		ret = i2c_smbus_read_i2c_block_data(i2c, reg, bytes, dest);
 25	else {
 26		ret = i2c_smbus_read_byte_data(i2c, reg);
 27		if (ret < 0)
 28			return ret;
 29		*(unsigned char *)dest = (unsigned char)ret;
 30	}
 31	return ret;
 32}
 33
 34static inline int max8925_write_device(struct i2c_client *i2c,
 35				       int reg, int bytes, void *src)
 36{
 37	unsigned char buf[9];
 38	int ret;
 39
 40	buf[0] = (unsigned char)reg;
 41	memcpy(&buf[1], src, bytes);
 42
 43	ret = i2c_master_send(i2c, buf, bytes + 1);
 44	if (ret < 0)
 45		return ret;
 46	return 0;
 47}
 48
 49int max8925_reg_read(struct i2c_client *i2c, int reg)
 50{
 51	struct max8925_chip *chip = i2c_get_clientdata(i2c);
 52	unsigned char data = 0;
 53	int ret;
 54
 55	mutex_lock(&chip->io_lock);
 56	ret = max8925_read_device(i2c, reg, 1, &data);
 57	mutex_unlock(&chip->io_lock);
 58
 59	if (ret < 0)
 60		return ret;
 61	else
 62		return (int)data;
 63}
 64EXPORT_SYMBOL(max8925_reg_read);
 65
 66int max8925_reg_write(struct i2c_client *i2c, int reg,
 67		unsigned char data)
 68{
 69	struct max8925_chip *chip = i2c_get_clientdata(i2c);
 70	int ret;
 71
 72	mutex_lock(&chip->io_lock);
 73	ret = max8925_write_device(i2c, reg, 1, &data);
 74	mutex_unlock(&chip->io_lock);
 75
 76	return ret;
 77}
 78EXPORT_SYMBOL(max8925_reg_write);
 79
 80int max8925_bulk_read(struct i2c_client *i2c, int reg,
 81		int count, unsigned char *buf)
 82{
 83	struct max8925_chip *chip = i2c_get_clientdata(i2c);
 84	int ret;
 85
 86	mutex_lock(&chip->io_lock);
 87	ret = max8925_read_device(i2c, reg, count, buf);
 88	mutex_unlock(&chip->io_lock);
 89
 90	return ret;
 91}
 92EXPORT_SYMBOL(max8925_bulk_read);
 93
 94int max8925_bulk_write(struct i2c_client *i2c, int reg,
 95		int count, unsigned char *buf)
 96{
 97	struct max8925_chip *chip = i2c_get_clientdata(i2c);
 98	int ret;
 99
100	mutex_lock(&chip->io_lock);
101	ret = max8925_write_device(i2c, reg, count, buf);
102	mutex_unlock(&chip->io_lock);
103
104	return ret;
105}
106EXPORT_SYMBOL(max8925_bulk_write);
107
108int max8925_set_bits(struct i2c_client *i2c, int reg,
109		unsigned char mask, unsigned char data)
110{
111	struct max8925_chip *chip = i2c_get_clientdata(i2c);
112	unsigned char value;
113	int ret;
114
115	mutex_lock(&chip->io_lock);
116	ret = max8925_read_device(i2c, reg, 1, &value);
117	if (ret < 0)
118		goto out;
119	value &= ~mask;
120	value |= data;
121	ret = max8925_write_device(i2c, reg, 1, &value);
122out:
123	mutex_unlock(&chip->io_lock);
124	return ret;
125}
126EXPORT_SYMBOL(max8925_set_bits);
127
128
129static const struct i2c_device_id max8925_id_table[] = {
130	{ "max8925" },
131	{ }
132};
133
134static int max8925_dt_init(struct device_node *np, struct device *dev,
135			   struct max8925_platform_data *pdata)
136{
137	int ret;
138
139	ret = of_property_read_u32(np, "maxim,tsc-irq", &pdata->tsc_irq);
140	if (ret) {
141		dev_err(dev, "Not found maxim,tsc-irq property\n");
142		return -EINVAL;
143	}
144	return 0;
145}
146
147static int max8925_probe(struct i2c_client *client)
148{
149	struct max8925_platform_data *pdata = dev_get_platdata(&client->dev);
150	struct max8925_chip *chip;
151	struct device_node *node = client->dev.of_node;
152
153	if (node && !pdata) {
154		/* parse DT to get platform data */
155		pdata = devm_kzalloc(&client->dev,
156				     sizeof(struct max8925_platform_data),
157				     GFP_KERNEL);
158		if (!pdata)
159			return -ENOMEM;
160
161		if (max8925_dt_init(node, &client->dev, pdata))
162			return -EINVAL;
163	} else if (!pdata) {
164		pr_info("%s: platform data is missing\n", __func__);
165		return -EINVAL;
166	}
167
168	chip = devm_kzalloc(&client->dev,
169			    sizeof(struct max8925_chip), GFP_KERNEL);
170	if (chip == NULL)
171		return -ENOMEM;
172	chip->i2c = client;
173	chip->dev = &client->dev;
174	i2c_set_clientdata(client, chip);
175	mutex_init(&chip->io_lock);
176
177	chip->rtc = i2c_new_dummy_device(chip->i2c->adapter, RTC_I2C_ADDR);
178	if (IS_ERR(chip->rtc)) {
179		dev_err(chip->dev, "Failed to allocate I2C device for RTC\n");
180		return PTR_ERR(chip->rtc);
181	}
182	i2c_set_clientdata(chip->rtc, chip);
183
184	chip->adc = i2c_new_dummy_device(chip->i2c->adapter, ADC_I2C_ADDR);
185	if (IS_ERR(chip->adc)) {
186		dev_err(chip->dev, "Failed to allocate I2C device for ADC\n");
187		i2c_unregister_device(chip->rtc);
188		return PTR_ERR(chip->adc);
189	}
190	i2c_set_clientdata(chip->adc, chip);
191
192	device_init_wakeup(&client->dev, 1);
193
194	max8925_device_init(chip, pdata);
195
196	return 0;
197}
198
199static void max8925_remove(struct i2c_client *client)
200{
201	struct max8925_chip *chip = i2c_get_clientdata(client);
202
203	max8925_device_exit(chip);
204	device_init_wakeup(&client->dev, false);
205	i2c_unregister_device(chip->adc);
206	i2c_unregister_device(chip->rtc);
207}
208
209static int max8925_suspend(struct device *dev)
210{
211	struct i2c_client *client = to_i2c_client(dev);
212	struct max8925_chip *chip = i2c_get_clientdata(client);
213
214	if (device_may_wakeup(dev) && chip->wakeup_flag)
215		enable_irq_wake(chip->core_irq);
216	return 0;
217}
218
219static int max8925_resume(struct device *dev)
220{
221	struct i2c_client *client = to_i2c_client(dev);
222	struct max8925_chip *chip = i2c_get_clientdata(client);
223
224	if (device_may_wakeup(dev) && chip->wakeup_flag)
225		disable_irq_wake(chip->core_irq);
226	return 0;
227}
228
229static DEFINE_SIMPLE_DEV_PM_OPS(max8925_pm_ops,
230				max8925_suspend, max8925_resume);
231
232static const struct of_device_id max8925_dt_ids[] = {
233	{ .compatible = "maxim,max8925", },
234	{},
235};
236
237static struct i2c_driver max8925_driver = {
238	.driver	= {
239		.name	= "max8925",
240		.pm     = pm_sleep_ptr(&max8925_pm_ops),
241		.of_match_table = max8925_dt_ids,
242	},
243	.probe		= max8925_probe,
244	.remove		= max8925_remove,
245	.id_table	= max8925_id_table,
246};
247
248static int __init max8925_i2c_init(void)
249{
250	int ret;
251
252	ret = i2c_add_driver(&max8925_driver);
253	if (ret != 0)
254		pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
255
256	return ret;
257}
258subsys_initcall(max8925_i2c_init);