1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An hwmon driver for the Analog Devices AD7416/17/18
4 * Copyright (C) 2006-07 Tower Technologies
5 *
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 *
8 * Based on lm75.c
9 * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
10 */
11
12#include <linux/module.h>
13#include <linux/jiffies.h>
14#include <linux/i2c.h>
15#include <linux/hwmon.h>
16#include <linux/hwmon-sysfs.h>
17#include <linux/err.h>
18#include <linux/mutex.h>
19#include <linux/of.h>
20#include <linux/delay.h>
21#include <linux/slab.h>
22
23#include "lm75.h"
24
25#define DRV_VERSION "0.4"
26
27enum chips { ad7416, ad7417, ad7418 };
28
29/* AD7418 registers */
30#define AD7418_REG_TEMP_IN	0x00
31#define AD7418_REG_CONF		0x01
32#define AD7418_REG_TEMP_HYST	0x02
33#define AD7418_REG_TEMP_OS	0x03
34#define AD7418_REG_ADC		0x04
35#define AD7418_REG_CONF2	0x05
36
37#define AD7418_REG_ADC_CH(x)	((x) << 5)
38#define AD7418_CH_TEMP		AD7418_REG_ADC_CH(0)
39
40static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
41					AD7418_REG_TEMP_HYST,
42					AD7418_REG_TEMP_OS };
43
44struct ad7418_data {
45	struct i2c_client	*client;
46	enum chips		type;
47	struct mutex		lock;
48	int			adc_max;	/* number of ADC channels */
49	bool			valid;
50	unsigned long		last_updated;	/* In jiffies */
51	s16			temp[3];	/* Register values */
52	u16			in[4];
53};
54
55static int ad7418_update_device(struct device *dev)
56{
57	struct ad7418_data *data = dev_get_drvdata(dev);
58	struct i2c_client *client = data->client;
59	s32 val;
60
61	mutex_lock(&data->lock);
62
63	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
64		|| !data->valid) {
65		u8 cfg;
66		int i, ch;
67
68		/* read config register and clear channel bits */
69		val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
70		if (val < 0)
71			goto abort;
72
73		cfg = val;
74		cfg &= 0x1F;
75
76		val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
77						cfg | AD7418_CH_TEMP);
78		if (val < 0)
79			goto abort;
80
81		udelay(30);
82
83		for (i = 0; i < 3; i++) {
84			val = i2c_smbus_read_word_swapped(client,
85							  AD7418_REG_TEMP[i]);
86			if (val < 0)
87				goto abort;
88
89			data->temp[i] = val;
90		}
91
92		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
93			val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
94					cfg | AD7418_REG_ADC_CH(ch));
95			if (val < 0)
96				goto abort;
97
98			udelay(15);
99			val = i2c_smbus_read_word_swapped(client,
100							  AD7418_REG_ADC);
101			if (val < 0)
102				goto abort;
103
104			data->in[data->adc_max - 1 - i] = val;
105		}
106
107		/* restore old configuration value */
108		val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF,
109						   cfg);
110		if (val < 0)
111			goto abort;
112
113		data->last_updated = jiffies;
114		data->valid = true;
115	}
116
117	mutex_unlock(&data->lock);
118	return 0;
119
120abort:
121	data->valid = false;
122	mutex_unlock(&data->lock);
123	return val;
124}
125
126static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
127			 char *buf)
128{
129	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
130	struct ad7418_data *data = dev_get_drvdata(dev);
131	int ret;
132
133	ret = ad7418_update_device(dev);
134	if (ret < 0)
135		return ret;
136
137	return sprintf(buf, "%d\n",
138		LM75_TEMP_FROM_REG(data->temp[attr->index]));
139}
140
141static ssize_t adc_show(struct device *dev, struct device_attribute *devattr,
142			char *buf)
143{
144	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
145	struct ad7418_data *data = dev_get_drvdata(dev);
146	int ret;
147
148	ret = ad7418_update_device(dev);
149	if (ret < 0)
150		return ret;
151
152	return sprintf(buf, "%d\n",
153		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
154}
155
156static ssize_t temp_store(struct device *dev,
157			  struct device_attribute *devattr, const char *buf,
158			  size_t count)
159{
160	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
161	struct ad7418_data *data = dev_get_drvdata(dev);
162	struct i2c_client *client = data->client;
163	long temp;
164	int ret = kstrtol(buf, 10, &temp);
165
166	if (ret < 0)
167		return ret;
168
169	mutex_lock(&data->lock);
170	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
171	i2c_smbus_write_word_swapped(client,
172				     AD7418_REG_TEMP[attr->index],
173				     data->temp[attr->index]);
174	mutex_unlock(&data->lock);
175	return count;
176}
177
178static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
179static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp, 1);
180static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
181
182static SENSOR_DEVICE_ATTR_RO(in1_input, adc, 0);
183static SENSOR_DEVICE_ATTR_RO(in2_input, adc, 1);
184static SENSOR_DEVICE_ATTR_RO(in3_input, adc, 2);
185static SENSOR_DEVICE_ATTR_RO(in4_input, adc, 3);
186
187static struct attribute *ad7416_attrs[] = {
188	&sensor_dev_attr_temp1_max.dev_attr.attr,
189	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
190	&sensor_dev_attr_temp1_input.dev_attr.attr,
191	NULL
192};
193ATTRIBUTE_GROUPS(ad7416);
194
195static struct attribute *ad7417_attrs[] = {
196	&sensor_dev_attr_temp1_max.dev_attr.attr,
197	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
198	&sensor_dev_attr_temp1_input.dev_attr.attr,
199	&sensor_dev_attr_in1_input.dev_attr.attr,
200	&sensor_dev_attr_in2_input.dev_attr.attr,
201	&sensor_dev_attr_in3_input.dev_attr.attr,
202	&sensor_dev_attr_in4_input.dev_attr.attr,
203	NULL
204};
205ATTRIBUTE_GROUPS(ad7417);
206
207static struct attribute *ad7418_attrs[] = {
208	&sensor_dev_attr_temp1_max.dev_attr.attr,
209	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
210	&sensor_dev_attr_temp1_input.dev_attr.attr,
211	&sensor_dev_attr_in1_input.dev_attr.attr,
212	NULL
213};
214ATTRIBUTE_GROUPS(ad7418);
215
216static void ad7418_init_client(struct i2c_client *client)
217{
218	struct ad7418_data *data = i2c_get_clientdata(client);
219
220	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
221	if (reg < 0) {
222		dev_err(&client->dev, "cannot read configuration register\n");
223	} else {
224		dev_info(&client->dev, "configuring for mode 1\n");
225		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
226
227		if (data->type == ad7417 || data->type == ad7418)
228			i2c_smbus_write_byte_data(client,
229						AD7418_REG_CONF2, 0x00);
230	}
231}
232
233static const struct i2c_device_id ad7418_id[];
234
235static int ad7418_probe(struct i2c_client *client)
236{
237	struct device *dev = &client->dev;
238	struct i2c_adapter *adapter = client->adapter;
239	struct ad7418_data *data;
240	struct device *hwmon_dev;
241	const struct attribute_group **attr_groups = NULL;
242
243	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
244					I2C_FUNC_SMBUS_WORD_DATA))
245		return -EOPNOTSUPP;
246
247	data = devm_kzalloc(dev, sizeof(struct ad7418_data), GFP_KERNEL);
248	if (!data)
249		return -ENOMEM;
250
251	i2c_set_clientdata(client, data);
252
253	mutex_init(&data->lock);
254	data->client = client;
255	if (dev->of_node)
256		data->type = (uintptr_t)of_device_get_match_data(dev);
257	else
258		data->type = i2c_match_id(ad7418_id, client)->driver_data;
259
260	switch (data->type) {
261	case ad7416:
262		data->adc_max = 0;
263		attr_groups = ad7416_groups;
264		break;
265
266	case ad7417:
267		data->adc_max = 4;
268		attr_groups = ad7417_groups;
269		break;
270
271	case ad7418:
272		data->adc_max = 1;
273		attr_groups = ad7418_groups;
274		break;
275	}
276
277	dev_info(dev, "%s chip found\n", client->name);
278
279	/* Initialize the AD7418 chip */
280	ad7418_init_client(client);
281
282	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
283							   client->name,
284							   data, attr_groups);
285	return PTR_ERR_OR_ZERO(hwmon_dev);
286}
287
288static const struct i2c_device_id ad7418_id[] = {
289	{ "ad7416", ad7416 },
290	{ "ad7417", ad7417 },
291	{ "ad7418", ad7418 },
292	{ }
293};
294MODULE_DEVICE_TABLE(i2c, ad7418_id);
295
296static const struct of_device_id ad7418_dt_ids[] = {
297	{ .compatible = "adi,ad7416", .data = (void *)ad7416, },
298	{ .compatible = "adi,ad7417", .data = (void *)ad7417, },
299	{ .compatible = "adi,ad7418", .data = (void *)ad7418, },
300	{ }
301};
302MODULE_DEVICE_TABLE(of, ad7418_dt_ids);
303
304static struct i2c_driver ad7418_driver = {
305	.driver = {
306		.name	= "ad7418",
307		.of_match_table = ad7418_dt_ids,
308	},
309	.probe		= ad7418_probe,
310	.id_table	= ad7418_id,
311};
312
313module_i2c_driver(ad7418_driver);
314
315MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
316MODULE_DESCRIPTION("AD7416/17/18 driver");
317MODULE_LICENSE("GPL");
318MODULE_VERSION(DRV_VERSION);
319