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Andre Prendel94107002009-09-15 17:18:11 +02001/* tmp421.c
2 *
3 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
4 * Preliminary support by:
5 * Melvin Rook, Raymond Ng
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22/*
23 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
24 * Supported models: TMP421, TMP422, TMP423
25 */
26
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/slab.h>
30#include <linux/jiffies.h>
31#include <linux/i2c.h>
32#include <linux/hwmon.h>
33#include <linux/hwmon-sysfs.h>
34#include <linux/err.h>
35#include <linux/mutex.h>
36#include <linux/sysfs.h>
37
38/* Addresses to scan */
Jean Delvare918ee912010-10-28 20:31:50 +020039static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
40 I2C_CLIENT_END };
Andre Prendel94107002009-09-15 17:18:11 +020041
Jean Delvaree5e9f442009-12-14 21:17:27 +010042enum chips { tmp421, tmp422, tmp423 };
Andre Prendel94107002009-09-15 17:18:11 +020043
44/* The TMP421 registers */
45#define TMP421_CONFIG_REG_1 0x09
46#define TMP421_CONVERSION_RATE_REG 0x0B
47#define TMP421_MANUFACTURER_ID_REG 0xFE
48#define TMP421_DEVICE_ID_REG 0xFF
49
50static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
51static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
52
53/* Flags */
54#define TMP421_CONFIG_SHUTDOWN 0x40
55#define TMP421_CONFIG_RANGE 0x04
56
57/* Manufacturer / Device ID's */
58#define TMP421_MANUFACTURER_ID 0x55
59#define TMP421_DEVICE_ID 0x21
60#define TMP422_DEVICE_ID 0x22
61#define TMP423_DEVICE_ID 0x23
62
63static const struct i2c_device_id tmp421_id[] = {
Jean Delvare8d595822010-03-05 22:17:25 +010064 { "tmp421", 2 },
65 { "tmp422", 3 },
66 { "tmp423", 4 },
Andre Prendel94107002009-09-15 17:18:11 +020067 { }
68};
69MODULE_DEVICE_TABLE(i2c, tmp421_id);
70
71struct tmp421_data {
Guenter Roeck276dac82014-04-05 21:22:46 -070072 struct i2c_client *client;
Andre Prendel94107002009-09-15 17:18:11 +020073 struct mutex update_lock;
74 char valid;
75 unsigned long last_updated;
Jean Delvare8d595822010-03-05 22:17:25 +010076 int channels;
Andre Prendel94107002009-09-15 17:18:11 +020077 u8 config;
78 s16 temp[4];
79};
80
81static int temp_from_s16(s16 reg)
82{
Jean Delvarea44908d2010-03-05 22:17:25 +010083 /* Mask out status bits */
84 int temp = reg & ~0xf;
Andre Prendel94107002009-09-15 17:18:11 +020085
86 return (temp * 1000 + 128) / 256;
87}
88
89static int temp_from_u16(u16 reg)
90{
Jean Delvarea44908d2010-03-05 22:17:25 +010091 /* Mask out status bits */
92 int temp = reg & ~0xf;
Andre Prendel94107002009-09-15 17:18:11 +020093
94 /* Add offset for extended temperature range. */
95 temp -= 64 * 256;
96
97 return (temp * 1000 + 128) / 256;
98}
99
100static struct tmp421_data *tmp421_update_device(struct device *dev)
101{
Guenter Roeck276dac82014-04-05 21:22:46 -0700102 struct tmp421_data *data = dev_get_drvdata(dev);
103 struct i2c_client *client = data->client;
Andre Prendel94107002009-09-15 17:18:11 +0200104 int i;
105
106 mutex_lock(&data->update_lock);
107
108 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
109 data->config = i2c_smbus_read_byte_data(client,
110 TMP421_CONFIG_REG_1);
111
Jean Delvare8d595822010-03-05 22:17:25 +0100112 for (i = 0; i < data->channels; i++) {
Andre Prendel94107002009-09-15 17:18:11 +0200113 data->temp[i] = i2c_smbus_read_byte_data(client,
114 TMP421_TEMP_MSB[i]) << 8;
115 data->temp[i] |= i2c_smbus_read_byte_data(client,
116 TMP421_TEMP_LSB[i]);
117 }
118 data->last_updated = jiffies;
119 data->valid = 1;
120 }
121
122 mutex_unlock(&data->update_lock);
123
124 return data;
125}
126
127static ssize_t show_temp_value(struct device *dev,
128 struct device_attribute *devattr, char *buf)
129{
130 int index = to_sensor_dev_attr(devattr)->index;
131 struct tmp421_data *data = tmp421_update_device(dev);
132 int temp;
133
134 mutex_lock(&data->update_lock);
135 if (data->config & TMP421_CONFIG_RANGE)
136 temp = temp_from_u16(data->temp[index]);
137 else
138 temp = temp_from_s16(data->temp[index]);
139 mutex_unlock(&data->update_lock);
140
141 return sprintf(buf, "%d\n", temp);
142}
143
144static ssize_t show_fault(struct device *dev,
145 struct device_attribute *devattr, char *buf)
146{
147 int index = to_sensor_dev_attr(devattr)->index;
148 struct tmp421_data *data = tmp421_update_device(dev);
149
150 /*
151 * The OPEN bit signals a fault. This is bit 0 of the temperature
152 * register (low byte).
153 */
154 if (data->temp[index] & 0x01)
155 return sprintf(buf, "1\n");
156 else
157 return sprintf(buf, "0\n");
158}
159
Al Viro587a1f12011-07-23 23:11:19 -0400160static umode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
Andre Prendel94107002009-09-15 17:18:11 +0200161 int n)
162{
163 struct device *dev = container_of(kobj, struct device, kobj);
164 struct tmp421_data *data = dev_get_drvdata(dev);
165 struct device_attribute *devattr;
166 unsigned int index;
167
168 devattr = container_of(a, struct device_attribute, attr);
169 index = to_sensor_dev_attr(devattr)->index;
170
Jean Delvare8d595822010-03-05 22:17:25 +0100171 if (index < data->channels)
Andre Prendel94107002009-09-15 17:18:11 +0200172 return a->mode;
173
174 return 0;
175}
176
177static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
178static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
179static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
180static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
181static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
182static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
183static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
184
185static struct attribute *tmp421_attr[] = {
186 &sensor_dev_attr_temp1_input.dev_attr.attr,
187 &sensor_dev_attr_temp2_input.dev_attr.attr,
188 &sensor_dev_attr_temp2_fault.dev_attr.attr,
189 &sensor_dev_attr_temp3_input.dev_attr.attr,
190 &sensor_dev_attr_temp3_fault.dev_attr.attr,
191 &sensor_dev_attr_temp4_input.dev_attr.attr,
192 &sensor_dev_attr_temp4_fault.dev_attr.attr,
193 NULL
194};
195
196static const struct attribute_group tmp421_group = {
197 .attrs = tmp421_attr,
198 .is_visible = tmp421_is_visible,
199};
200
Guenter Roeck276dac82014-04-05 21:22:46 -0700201static const struct attribute_group *tmp421_groups[] = {
202 &tmp421_group,
203 NULL
204};
205
Andre Prendel94107002009-09-15 17:18:11 +0200206static int tmp421_init_client(struct i2c_client *client)
207{
208 int config, config_orig;
209
210 /* Set the conversion rate to 2 Hz */
211 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
212
213 /* Start conversions (disable shutdown if necessary) */
214 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
215 if (config < 0) {
Guenter Roeckb55f3752013-01-10 10:01:24 -0800216 dev_err(&client->dev,
217 "Could not read configuration register (%d)\n", config);
Sachin Kamat010a1662013-09-11 09:49:52 +0530218 return config;
Andre Prendel94107002009-09-15 17:18:11 +0200219 }
220
221 config_orig = config;
222 config &= ~TMP421_CONFIG_SHUTDOWN;
223
224 if (config != config_orig) {
225 dev_info(&client->dev, "Enable monitoring chip\n");
226 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
227 }
228
229 return 0;
230}
231
Jean Delvare310ec792009-12-14 21:17:23 +0100232static int tmp421_detect(struct i2c_client *client,
Andre Prendel94107002009-09-15 17:18:11 +0200233 struct i2c_board_info *info)
234{
Jean Delvaredbe73c82009-12-09 20:35:54 +0100235 enum chips kind;
Andre Prendel94107002009-09-15 17:18:11 +0200236 struct i2c_adapter *adapter = client->adapter;
237 const char *names[] = { "TMP421", "TMP422", "TMP423" };
Jean Delvaredbe73c82009-12-09 20:35:54 +0100238 u8 reg;
Andre Prendel94107002009-09-15 17:18:11 +0200239
240 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
241 return -ENODEV;
242
Jean Delvaredbe73c82009-12-09 20:35:54 +0100243 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
244 if (reg != TMP421_MANUFACTURER_ID)
245 return -ENODEV;
Andre Prendel94107002009-09-15 17:18:11 +0200246
Jean Delvaredbe73c82009-12-09 20:35:54 +0100247 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
248 switch (reg) {
249 case TMP421_DEVICE_ID:
250 kind = tmp421;
251 break;
252 case TMP422_DEVICE_ID:
253 kind = tmp422;
254 break;
255 case TMP423_DEVICE_ID:
256 kind = tmp423;
257 break;
258 default:
259 return -ENODEV;
Andre Prendel94107002009-09-15 17:18:11 +0200260 }
Jean Delvaredbe73c82009-12-09 20:35:54 +0100261
Jean Delvaredc71afe2010-03-05 22:17:26 +0100262 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
Andre Prendel94107002009-09-15 17:18:11 +0200263 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
Jean Delvaredc71afe2010-03-05 22:17:26 +0100264 names[kind], client->addr);
Andre Prendel94107002009-09-15 17:18:11 +0200265
266 return 0;
267}
268
269static int tmp421_probe(struct i2c_client *client,
270 const struct i2c_device_id *id)
271{
Guenter Roeck276dac82014-04-05 21:22:46 -0700272 struct device *dev = &client->dev;
273 struct device *hwmon_dev;
Andre Prendel94107002009-09-15 17:18:11 +0200274 struct tmp421_data *data;
275 int err;
276
Guenter Roeck276dac82014-04-05 21:22:46 -0700277 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
Andre Prendel94107002009-09-15 17:18:11 +0200278 if (!data)
279 return -ENOMEM;
280
Andre Prendel94107002009-09-15 17:18:11 +0200281 mutex_init(&data->update_lock);
Jean Delvare8d595822010-03-05 22:17:25 +0100282 data->channels = id->driver_data;
Guenter Roeck276dac82014-04-05 21:22:46 -0700283 data->client = client;
Andre Prendel94107002009-09-15 17:18:11 +0200284
285 err = tmp421_init_client(client);
286 if (err)
Guenter Roeckf625e0f2012-06-02 11:35:53 -0700287 return err;
Andre Prendel94107002009-09-15 17:18:11 +0200288
Guenter Roeck276dac82014-04-05 21:22:46 -0700289 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
290 data, tmp421_groups);
291 return PTR_ERR_OR_ZERO(hwmon_dev);
Andre Prendel94107002009-09-15 17:18:11 +0200292}
293
294static struct i2c_driver tmp421_driver = {
295 .class = I2C_CLASS_HWMON,
296 .driver = {
297 .name = "tmp421",
298 },
299 .probe = tmp421_probe,
Andre Prendel94107002009-09-15 17:18:11 +0200300 .id_table = tmp421_id,
301 .detect = tmp421_detect,
Jean Delvarec3813d62009-12-14 21:17:25 +0100302 .address_list = normal_i2c,
Andre Prendel94107002009-09-15 17:18:11 +0200303};
304
Axel Linf0967ee2012-01-20 15:38:18 +0800305module_i2c_driver(tmp421_driver);
Andre Prendel94107002009-09-15 17:18:11 +0200306
307MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
Guenter Roeckb55f3752013-01-10 10:01:24 -0800308MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor driver");
Andre Prendel94107002009-09-15 17:18:11 +0200309MODULE_LICENSE("GPL");