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_device.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 
23 #include "lm75.h"
24 
25 #define DRV_VERSION "0.4"
26 
27 enum 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 
40 static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
41 					AD7418_REG_TEMP_HYST,
42 					AD7418_REG_TEMP_OS };
43 
44 struct 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 
ad7418_update_device(struct device * dev)55 static 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 
120 abort:
121 	data->valid = false;
122 	mutex_unlock(&data->lock);
123 	return val;
124 }
125 
temp_show(struct device * dev,struct device_attribute * devattr,char * buf)126 static 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 
adc_show(struct device * dev,struct device_attribute * devattr,char * buf)141 static 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 
temp_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)156 static 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 
178 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
179 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp, 1);
180 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
181 
182 static SENSOR_DEVICE_ATTR_RO(in1_input, adc, 0);
183 static SENSOR_DEVICE_ATTR_RO(in2_input, adc, 1);
184 static SENSOR_DEVICE_ATTR_RO(in3_input, adc, 2);
185 static SENSOR_DEVICE_ATTR_RO(in4_input, adc, 3);
186 
187 static 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 };
193 ATTRIBUTE_GROUPS(ad7416);
194 
195 static 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 };
205 ATTRIBUTE_GROUPS(ad7417);
206 
207 static 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 };
214 ATTRIBUTE_GROUPS(ad7418);
215 
ad7418_init_client(struct i2c_client * client)216 static 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 
233 static const struct i2c_device_id ad7418_id[];
234 
ad7418_probe(struct i2c_client * client)235 static 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 = (enum chips)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 
288 static const struct i2c_device_id ad7418_id[] = {
289 	{ "ad7416", ad7416 },
290 	{ "ad7417", ad7417 },
291 	{ "ad7418", ad7418 },
292 	{ }
293 };
294 MODULE_DEVICE_TABLE(i2c, ad7418_id);
295 
296 static 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 };
302 MODULE_DEVICE_TABLE(of, ad7418_dt_ids);
303 
304 static struct i2c_driver ad7418_driver = {
305 	.driver = {
306 		.name	= "ad7418",
307 		.of_match_table = ad7418_dt_ids,
308 	},
309 	.probe_new	= ad7418_probe,
310 	.id_table	= ad7418_id,
311 };
312 
313 module_i2c_driver(ad7418_driver);
314 
315 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
316 MODULE_DESCRIPTION("AD7416/17/18 driver");
317 MODULE_LICENSE("GPL");
318 MODULE_VERSION(DRV_VERSION);
319