blob: 69b05cc2f60e504886b681cfa856ada12fa54c17 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Guenter Roeck02fe2fd2012-01-14 13:42:20 -08002 * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring
4 *
5 * Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
6 *
7 * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
8 * is a temperature sensor and thermal window comparator with 0.5 deg
9 * resolution made by National Semiconductor. Complete datasheet can be
10 * obtained at their site:
11 * http://www.national.com/pf/LM/LM77.html
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.
Guenter Roeck02fe2fd2012-01-14 13:42:20 -080022 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/i2c.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040029#include <linux/hwmon.h>
Jean Delvare1f52af02008-01-03 23:35:33 +010030#include <linux/hwmon-sysfs.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040031#include <linux/err.h>
Ingo Molnar9a61bf62006-01-18 23:19:26 +010032#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34/* Addresses to scan */
Mark M. Hoffman25e9c862008-02-17 22:28:03 -050035static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
36 I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Linus Torvalds1da177e2005-04-16 15:20:36 -070038/* The LM77 registers */
39#define LM77_REG_TEMP 0x00
40#define LM77_REG_CONF 0x01
41#define LM77_REG_TEMP_HYST 0x02
42#define LM77_REG_TEMP_CRIT 0x03
43#define LM77_REG_TEMP_MIN 0x04
44#define LM77_REG_TEMP_MAX 0x05
45
Guenter Roeck48dbd6f2014-04-12 09:17:37 -070046enum temp_index {
47 t_input = 0,
48 t_crit,
49 t_min,
50 t_max,
51 t_hyst,
52 t_num_temp
53};
54
55static const u8 temp_regs[t_num_temp] = {
56 [t_input] = LM77_REG_TEMP,
57 [t_min] = LM77_REG_TEMP_MIN,
58 [t_max] = LM77_REG_TEMP_MAX,
59 [t_crit] = LM77_REG_TEMP_CRIT,
60 [t_hyst] = LM77_REG_TEMP_HYST,
61};
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063/* Each client has this additional data */
64struct lm77_data {
Guenter Roeck5975dfb2014-04-12 09:25:25 -070065 struct i2c_client *client;
Ingo Molnar9a61bf62006-01-18 23:19:26 +010066 struct mutex update_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 char valid;
68 unsigned long last_updated; /* In jiffies */
Guenter Roeck48dbd6f2014-04-12 09:17:37 -070069 int temp[t_num_temp]; /* index using temp_index */
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 u8 alarms;
71};
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073/* straight from the datasheet */
74#define LM77_TEMP_MIN (-55000)
75#define LM77_TEMP_MAX 125000
76
Guenter Roeck02fe2fd2012-01-14 13:42:20 -080077/*
78 * In the temperature registers, the low 3 bits are not part of the
79 * temperature values; they are the status bits.
80 */
Jean Delvare413b6452006-01-09 22:43:08 +010081static inline s16 LM77_TEMP_TO_REG(int temp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082{
Axel Lin99765db2014-07-31 22:58:04 +080083 return (temp / 500) * 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
Jean Delvare413b6452006-01-09 22:43:08 +010086static inline int LM77_TEMP_FROM_REG(s16 reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Jean Delvare413b6452006-01-09 22:43:08 +010088 return (reg / 8) * 500;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90
Guenter Roeck9f9edcd2014-04-12 08:45:20 -070091/*
92 * All registers are word-sized, except for the configuration register.
93 * The LM77 uses the high-byte first convention.
94 */
95static u16 lm77_read_value(struct i2c_client *client, u8 reg)
96{
97 if (reg == LM77_REG_CONF)
98 return i2c_smbus_read_byte_data(client, reg);
99 else
100 return i2c_smbus_read_word_swapped(client, reg);
101}
102
103static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
104{
105 if (reg == LM77_REG_CONF)
106 return i2c_smbus_write_byte_data(client, reg, value);
107 else
108 return i2c_smbus_write_word_swapped(client, reg, value);
109}
110
111static struct lm77_data *lm77_update_device(struct device *dev)
112{
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700113 struct lm77_data *data = dev_get_drvdata(dev);
114 struct i2c_client *client = data->client;
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700115 int i;
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700116
117 mutex_lock(&data->update_lock);
118
119 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
120 || !data->valid) {
121 dev_dbg(&client->dev, "Starting lm77 update\n");
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700122 for (i = 0; i < t_num_temp; i++) {
123 data->temp[i] =
124 LM77_TEMP_FROM_REG(lm77_read_value(client,
125 temp_regs[i]));
126 }
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700127 data->alarms =
128 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
129 data->last_updated = jiffies;
130 data->valid = 1;
131 }
132
133 mutex_unlock(&data->update_lock);
134
135 return data;
136}
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138/* sysfs stuff */
139
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700140static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
141 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700143 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 struct lm77_data *data = lm77_update_device(dev);
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700145
146 return sprintf(buf, "%d\n", data->temp[attr->index]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147}
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700148
149static ssize_t show_temp_hyst(struct device *dev,
150 struct device_attribute *devattr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700152 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 struct lm77_data *data = lm77_update_device(dev);
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700154 int nr = attr->index;
155 int temp;
156
157 temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] :
158 data->temp[nr] - data->temp[t_hyst];
159
160 return sprintf(buf, "%d\n", temp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161}
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700162
163static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
164 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700166 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700167 struct lm77_data *data = dev_get_drvdata(dev);
168 struct i2c_client *client = data->client;
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700169 int nr = attr->index;
170 long val;
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800171 int err;
172
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700173 err = kstrtol(buf, 10, &val);
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800174 if (err)
175 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Axel Lin99765db2014-07-31 22:58:04 +0800177 val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100178 mutex_lock(&data->update_lock);
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700179 data->temp[nr] = val;
180 lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100181 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return count;
183}
184
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700185/*
186 * hysteresis is stored as a relative value on the chip, so it has to be
187 * converted first.
188 */
189static ssize_t set_temp_hyst(struct device *dev,
190 struct device_attribute *devattr,
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800191 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700193 struct lm77_data *data = dev_get_drvdata(dev);
194 struct i2c_client *client = data->client;
Axel Lin99765db2014-07-31 22:58:04 +0800195 long val;
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800196 int err;
197
Axel Lin99765db2014-07-31 22:58:04 +0800198 err = kstrtol(buf, 10, &val);
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800199 if (err)
200 return err;
201
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100202 mutex_lock(&data->update_lock);
Axel Lin99765db2014-07-31 22:58:04 +0800203 val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX);
204 data->temp[t_hyst] = val;
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700205 lm77_write_value(client, LM77_REG_TEMP_HYST,
206 LM77_TEMP_TO_REG(data->temp[t_hyst]));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100207 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 return count;
209}
210
Jean Delvare1f52af02008-01-03 23:35:33 +0100211static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
212 char *buf)
213{
214 int bitnr = to_sensor_dev_attr(attr)->index;
215 struct lm77_data *data = lm77_update_device(dev);
216 return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
217}
218
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700219static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
220static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
221 t_crit);
222static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
223 t_min);
224static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
225 t_max);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700227static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst,
228 set_temp_hyst, t_crit);
229static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_hyst, NULL, t_min);
230static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Jean Delvare1f52af02008-01-03 23:35:33 +0100232static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
233static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
234static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700236static struct attribute *lm77_attrs[] = {
Guenter Roeck48dbd6f2014-04-12 09:17:37 -0700237 &sensor_dev_attr_temp1_input.dev_attr.attr,
238 &sensor_dev_attr_temp1_crit.dev_attr.attr,
239 &sensor_dev_attr_temp1_min.dev_attr.attr,
240 &sensor_dev_attr_temp1_max.dev_attr.attr,
241 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
242 &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
243 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
Jean Delvare1f52af02008-01-03 23:35:33 +0100244 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
245 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
246 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200247 NULL
248};
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700249ATTRIBUTE_GROUPS(lm77);
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200250
Jean Delvarea189dd62008-07-16 19:30:13 +0200251/* Return 0 if detection is successful, -ENODEV otherwise */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700252static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
Guenter Roeckefd2d112012-06-02 09:58:09 -0700254 struct i2c_adapter *adapter = client->adapter;
Jean Delvare747d9be2009-12-09 20:35:52 +0100255 int i, cur, conf, hyst, crit, min, max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
258 I2C_FUNC_SMBUS_WORD_DATA))
Jean Delvarea189dd62008-07-16 19:30:13 +0200259 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800261 /*
262 * Here comes the remaining detection. Since the LM77 has no
263 * register dedicated to identification, we have to rely on the
264 * following tricks:
265 *
266 * 1. the high 4 bits represent the sign and thus they should
267 * always be the same
268 * 2. the high 3 bits are unused in the configuration register
269 * 3. addresses 0x06 and 0x07 return the last read value
270 * 4. registers cycling over 8-address boundaries
271 *
272 * Word-sized registers are high-byte first.
273 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
Jean Delvare747d9be2009-12-09 20:35:52 +0100275 /* addresses cycling */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700276 cur = i2c_smbus_read_word_data(client, 0);
277 conf = i2c_smbus_read_byte_data(client, 1);
278 hyst = i2c_smbus_read_word_data(client, 2);
279 crit = i2c_smbus_read_word_data(client, 3);
280 min = i2c_smbus_read_word_data(client, 4);
281 max = i2c_smbus_read_word_data(client, 5);
Jean Delvare747d9be2009-12-09 20:35:52 +0100282 for (i = 8; i <= 0xff; i += 8) {
Guenter Roeckefd2d112012-06-02 09:58:09 -0700283 if (i2c_smbus_read_byte_data(client, i + 1) != conf
284 || i2c_smbus_read_word_data(client, i + 2) != hyst
285 || i2c_smbus_read_word_data(client, i + 3) != crit
286 || i2c_smbus_read_word_data(client, i + 4) != min
287 || i2c_smbus_read_word_data(client, i + 5) != max)
Jean Delvarea189dd62008-07-16 19:30:13 +0200288 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 }
290
Jean Delvare747d9be2009-12-09 20:35:52 +0100291 /* sign bits */
292 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
293 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
294 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
295 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
296 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
297 return -ENODEV;
298
299 /* unused bits */
300 if (conf & 0xe0)
301 return -ENODEV;
302
303 /* 0x06 and 0x07 return the last read value */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700304 cur = i2c_smbus_read_word_data(client, 0);
305 if (i2c_smbus_read_word_data(client, 6) != cur
306 || i2c_smbus_read_word_data(client, 7) != cur)
Jean Delvare747d9be2009-12-09 20:35:52 +0100307 return -ENODEV;
Guenter Roeckefd2d112012-06-02 09:58:09 -0700308 hyst = i2c_smbus_read_word_data(client, 2);
309 if (i2c_smbus_read_word_data(client, 6) != hyst
310 || i2c_smbus_read_word_data(client, 7) != hyst)
Jean Delvare747d9be2009-12-09 20:35:52 +0100311 return -ENODEV;
Guenter Roeckefd2d112012-06-02 09:58:09 -0700312 min = i2c_smbus_read_word_data(client, 4);
313 if (i2c_smbus_read_word_data(client, 6) != min
314 || i2c_smbus_read_word_data(client, 7) != min)
Jean Delvare747d9be2009-12-09 20:35:52 +0100315 return -ENODEV;
316
Jean Delvarea189dd62008-07-16 19:30:13 +0200317 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Jean Delvarea189dd62008-07-16 19:30:13 +0200319 return 0;
320}
321
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700322static void lm77_init_client(struct i2c_client *client)
323{
324 /* Initialize the LM77 chip - turn off shutdown mode */
325 int conf = lm77_read_value(client, LM77_REG_CONF);
326 if (conf & 1)
327 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
328}
329
Guenter Roeckefd2d112012-06-02 09:58:09 -0700330static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id)
Jean Delvarea189dd62008-07-16 19:30:13 +0200331{
Guenter Roeckefd2d112012-06-02 09:58:09 -0700332 struct device *dev = &client->dev;
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700333 struct device *hwmon_dev;
Jean Delvarea189dd62008-07-16 19:30:13 +0200334 struct lm77_data *data;
Jean Delvarea189dd62008-07-16 19:30:13 +0200335
Guenter Roeck52714c02012-06-16 18:24:02 -0700336 data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
337 if (!data)
338 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700340 data->client = client;
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100341 mutex_init(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 /* Initialize the LM77 chip */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700344 lm77_init_client(client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
Guenter Roeck5975dfb2014-04-12 09:25:25 -0700346 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
347 data, lm77_groups);
348 return PTR_ERR_OR_ZERO(hwmon_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349}
350
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700351static const struct i2c_device_id lm77_id[] = {
352 { "lm77", 0 },
353 { }
354};
355MODULE_DEVICE_TABLE(i2c, lm77_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700357/* This is the driver that will be inserted */
358static struct i2c_driver lm77_driver = {
359 .class = I2C_CLASS_HWMON,
360 .driver = {
361 .name = "lm77",
362 },
363 .probe = lm77_probe,
Guenter Roeck9f9edcd2014-04-12 08:45:20 -0700364 .id_table = lm77_id,
365 .detect = lm77_detect,
366 .address_list = normal_i2c,
367};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
Axel Linf0967ee2012-01-20 15:38:18 +0800369module_i2c_driver(lm77_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
372MODULE_DESCRIPTION("LM77 driver");
373MODULE_LICENSE("GPL");