xref: /openbmc/linux/drivers/hwmon/max1619.c (revision 63dc02bd)
1 /*
2  * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
3  *             monitoring
4  * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
5  *                         Jean Delvare <khali@linux-fr.org>
6  *
7  * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
8  * It reports up to two temperatures (its own plus up to
9  * one external one). Complete datasheet can be
10  * obtained from Maxim's website at:
11  *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/jiffies.h>
33 #include <linux/i2c.h>
34 #include <linux/hwmon.h>
35 #include <linux/hwmon-sysfs.h>
36 #include <linux/err.h>
37 #include <linux/mutex.h>
38 #include <linux/sysfs.h>
39 
40 static const unsigned short normal_i2c[] = {
41 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
42 
43 /*
44  * The MAX1619 registers
45  */
46 
47 #define MAX1619_REG_R_MAN_ID		0xFE
48 #define MAX1619_REG_R_CHIP_ID		0xFF
49 #define MAX1619_REG_R_CONFIG		0x03
50 #define MAX1619_REG_W_CONFIG		0x09
51 #define MAX1619_REG_R_CONVRATE		0x04
52 #define MAX1619_REG_W_CONVRATE		0x0A
53 #define MAX1619_REG_R_STATUS		0x02
54 #define MAX1619_REG_R_LOCAL_TEMP	0x00
55 #define MAX1619_REG_R_REMOTE_TEMP	0x01
56 #define MAX1619_REG_R_REMOTE_HIGH	0x07
57 #define MAX1619_REG_W_REMOTE_HIGH	0x0D
58 #define MAX1619_REG_R_REMOTE_LOW	0x08
59 #define MAX1619_REG_W_REMOTE_LOW	0x0E
60 #define MAX1619_REG_R_REMOTE_CRIT	0x10
61 #define MAX1619_REG_W_REMOTE_CRIT	0x12
62 #define MAX1619_REG_R_TCRIT_HYST	0x11
63 #define MAX1619_REG_W_TCRIT_HYST	0x13
64 
65 /*
66  * Conversions
67  */
68 
69 static int temp_from_reg(int val)
70 {
71 	return (val & 0x80 ? val-0x100 : val) * 1000;
72 }
73 
74 static int temp_to_reg(int val)
75 {
76 	return (val < 0 ? val+0x100*1000 : val) / 1000;
77 }
78 
79 /*
80  * Functions declaration
81  */
82 
83 static int max1619_probe(struct i2c_client *client,
84 			 const struct i2c_device_id *id);
85 static int max1619_detect(struct i2c_client *client,
86 			  struct i2c_board_info *info);
87 static void max1619_init_client(struct i2c_client *client);
88 static int max1619_remove(struct i2c_client *client);
89 static struct max1619_data *max1619_update_device(struct device *dev);
90 
91 /*
92  * Driver data (common to all clients)
93  */
94 
95 static const struct i2c_device_id max1619_id[] = {
96 	{ "max1619", 0 },
97 	{ }
98 };
99 MODULE_DEVICE_TABLE(i2c, max1619_id);
100 
101 static struct i2c_driver max1619_driver = {
102 	.class		= I2C_CLASS_HWMON,
103 	.driver = {
104 		.name	= "max1619",
105 	},
106 	.probe		= max1619_probe,
107 	.remove		= max1619_remove,
108 	.id_table	= max1619_id,
109 	.detect		= max1619_detect,
110 	.address_list	= normal_i2c,
111 };
112 
113 /*
114  * Client data (each client gets its own)
115  */
116 
117 struct max1619_data {
118 	struct device *hwmon_dev;
119 	struct mutex update_lock;
120 	char valid; /* zero until following fields are valid */
121 	unsigned long last_updated; /* in jiffies */
122 
123 	/* registers values */
124 	u8 temp_input1; /* local */
125 	u8 temp_input2, temp_low2, temp_high2; /* remote */
126 	u8 temp_crit2;
127 	u8 temp_hyst2;
128 	u8 alarms;
129 };
130 
131 /*
132  * Sysfs stuff
133  */
134 
135 #define show_temp(value) \
136 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
137 			    char *buf) \
138 { \
139 	struct max1619_data *data = max1619_update_device(dev); \
140 	return sprintf(buf, "%d\n", temp_from_reg(data->value)); \
141 }
142 show_temp(temp_input1);
143 show_temp(temp_input2);
144 show_temp(temp_low2);
145 show_temp(temp_high2);
146 show_temp(temp_crit2);
147 show_temp(temp_hyst2);
148 
149 #define set_temp2(value, reg) \
150 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
151 			   const char *buf, \
152 	size_t count) \
153 { \
154 	struct i2c_client *client = to_i2c_client(dev); \
155 	struct max1619_data *data = i2c_get_clientdata(client); \
156 	long val; \
157 	int err = kstrtol(buf, 10, &val); \
158 	if (err) \
159 		return err; \
160 \
161 	mutex_lock(&data->update_lock); \
162 	data->value = temp_to_reg(val); \
163 	i2c_smbus_write_byte_data(client, reg, data->value); \
164 	mutex_unlock(&data->update_lock); \
165 	return count; \
166 }
167 
168 set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
169 set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
170 set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
171 set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);
172 
173 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
174 			   char *buf)
175 {
176 	struct max1619_data *data = max1619_update_device(dev);
177 	return sprintf(buf, "%d\n", data->alarms);
178 }
179 
180 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
181 			  char *buf)
182 {
183 	int bitnr = to_sensor_dev_attr(attr)->index;
184 	struct max1619_data *data = max1619_update_device(dev);
185 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
186 }
187 
188 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
189 static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
190 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
191 	set_temp_low2);
192 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
193 	set_temp_high2);
194 static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
195 	set_temp_crit2);
196 static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
197 	set_temp_hyst2);
198 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
199 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
200 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
201 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
202 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
203 
204 static struct attribute *max1619_attributes[] = {
205 	&dev_attr_temp1_input.attr,
206 	&dev_attr_temp2_input.attr,
207 	&dev_attr_temp2_min.attr,
208 	&dev_attr_temp2_max.attr,
209 	&dev_attr_temp2_crit.attr,
210 	&dev_attr_temp2_crit_hyst.attr,
211 
212 	&dev_attr_alarms.attr,
213 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
214 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
215 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
216 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
217 	NULL
218 };
219 
220 static const struct attribute_group max1619_group = {
221 	.attrs = max1619_attributes,
222 };
223 
224 /*
225  * Real code
226  */
227 
228 /* Return 0 if detection is successful, -ENODEV otherwise */
229 static int max1619_detect(struct i2c_client *client,
230 			  struct i2c_board_info *info)
231 {
232 	struct i2c_adapter *adapter = client->adapter;
233 	u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
234 
235 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
236 		return -ENODEV;
237 
238 	/* detection */
239 	reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
240 	reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
241 	reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
242 	if ((reg_config & 0x03) != 0x00
243 	 || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
244 		dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
245 			client->addr);
246 		return -ENODEV;
247 	}
248 
249 	/* identification */
250 	man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
251 	chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
252 	if (man_id != 0x4D || chip_id != 0x04) {
253 		dev_info(&adapter->dev,
254 			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
255 			 man_id, chip_id);
256 		return -ENODEV;
257 	}
258 
259 	strlcpy(info->type, "max1619", I2C_NAME_SIZE);
260 
261 	return 0;
262 }
263 
264 static int max1619_probe(struct i2c_client *new_client,
265 			 const struct i2c_device_id *id)
266 {
267 	struct max1619_data *data;
268 	int err;
269 
270 	data = kzalloc(sizeof(struct max1619_data), GFP_KERNEL);
271 	if (!data) {
272 		err = -ENOMEM;
273 		goto exit;
274 	}
275 
276 	i2c_set_clientdata(new_client, data);
277 	data->valid = 0;
278 	mutex_init(&data->update_lock);
279 
280 	/* Initialize the MAX1619 chip */
281 	max1619_init_client(new_client);
282 
283 	/* Register sysfs hooks */
284 	err = sysfs_create_group(&new_client->dev.kobj, &max1619_group);
285 	if (err)
286 		goto exit_free;
287 
288 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
289 	if (IS_ERR(data->hwmon_dev)) {
290 		err = PTR_ERR(data->hwmon_dev);
291 		goto exit_remove_files;
292 	}
293 
294 	return 0;
295 
296 exit_remove_files:
297 	sysfs_remove_group(&new_client->dev.kobj, &max1619_group);
298 exit_free:
299 	kfree(data);
300 exit:
301 	return err;
302 }
303 
304 static void max1619_init_client(struct i2c_client *client)
305 {
306 	u8 config;
307 
308 	/*
309 	 * Start the conversions.
310 	 */
311 	i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
312 				  5); /* 2 Hz */
313 	config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
314 	if (config & 0x40)
315 		i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
316 					  config & 0xBF); /* run */
317 }
318 
319 static int max1619_remove(struct i2c_client *client)
320 {
321 	struct max1619_data *data = i2c_get_clientdata(client);
322 
323 	hwmon_device_unregister(data->hwmon_dev);
324 	sysfs_remove_group(&client->dev.kobj, &max1619_group);
325 
326 	kfree(data);
327 	return 0;
328 }
329 
330 static struct max1619_data *max1619_update_device(struct device *dev)
331 {
332 	struct i2c_client *client = to_i2c_client(dev);
333 	struct max1619_data *data = i2c_get_clientdata(client);
334 
335 	mutex_lock(&data->update_lock);
336 
337 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
338 		dev_dbg(&client->dev, "Updating max1619 data.\n");
339 		data->temp_input1 = i2c_smbus_read_byte_data(client,
340 					MAX1619_REG_R_LOCAL_TEMP);
341 		data->temp_input2 = i2c_smbus_read_byte_data(client,
342 					MAX1619_REG_R_REMOTE_TEMP);
343 		data->temp_high2 = i2c_smbus_read_byte_data(client,
344 					MAX1619_REG_R_REMOTE_HIGH);
345 		data->temp_low2 = i2c_smbus_read_byte_data(client,
346 					MAX1619_REG_R_REMOTE_LOW);
347 		data->temp_crit2 = i2c_smbus_read_byte_data(client,
348 					MAX1619_REG_R_REMOTE_CRIT);
349 		data->temp_hyst2 = i2c_smbus_read_byte_data(client,
350 					MAX1619_REG_R_TCRIT_HYST);
351 		data->alarms = i2c_smbus_read_byte_data(client,
352 					MAX1619_REG_R_STATUS);
353 
354 		data->last_updated = jiffies;
355 		data->valid = 1;
356 	}
357 
358 	mutex_unlock(&data->update_lock);
359 
360 	return data;
361 }
362 
363 module_i2c_driver(max1619_driver);
364 
365 MODULE_AUTHOR("Alexey Fisher <fishor@mail.ru> and "
366 	"Jean Delvare <khali@linux-fr.org>");
367 MODULE_DESCRIPTION("MAX1619 sensor driver");
368 MODULE_LICENSE("GPL");
369