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1/* 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 */
39static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
40 I2C_CLIENT_END };
41
42enum chips { tmp421, tmp422, tmp423 };
43
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[] = {
64 { "tmp421", 2 },
65 { "tmp422", 3 },
66 { "tmp423", 4 },
67 { }
68};
69MODULE_DEVICE_TABLE(i2c, tmp421_id);
70
71struct tmp421_data {
72 struct device *hwmon_dev;
73 struct mutex update_lock;
74 char valid;
75 unsigned long last_updated;
76 int channels;
77 u8 config;
78 s16 temp[4];
79};
80
81static int temp_from_s16(s16 reg)
82{
83 /* Mask out status bits */
84 int temp = reg & ~0xf;
85
86 return (temp * 1000 + 128) / 256;
87}
88
89static int temp_from_u16(u16 reg)
90{
91 /* Mask out status bits */
92 int temp = reg & ~0xf;
93
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{
102 struct i2c_client *client = to_i2c_client(dev);
103 struct tmp421_data *data = i2c_get_clientdata(client);
104 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
112 for (i = 0; i < data->channels; i++) {
113 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
160static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
161 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
171 if (index < data->channels)
172 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
201static int tmp421_init_client(struct i2c_client *client)
202{
203 int config, config_orig;
204
205 /* Set the conversion rate to 2 Hz */
206 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
207
208 /* Start conversions (disable shutdown if necessary) */
209 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
210 if (config < 0) {
211 dev_err(&client->dev, "Could not read configuration"
212 " register (%d)\n", config);
213 return -ENODEV;
214 }
215
216 config_orig = config;
217 config &= ~TMP421_CONFIG_SHUTDOWN;
218
219 if (config != config_orig) {
220 dev_info(&client->dev, "Enable monitoring chip\n");
221 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
222 }
223
224 return 0;
225}
226
227static int tmp421_detect(struct i2c_client *client,
228 struct i2c_board_info *info)
229{
230 enum chips kind;
231 struct i2c_adapter *adapter = client->adapter;
232 const char *names[] = { "TMP421", "TMP422", "TMP423" };
233 u8 reg;
234
235 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
236 return -ENODEV;
237
238 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
239 if (reg != TMP421_MANUFACTURER_ID)
240 return -ENODEV;
241
242 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
243 switch (reg) {
244 case TMP421_DEVICE_ID:
245 kind = tmp421;
246 break;
247 case TMP422_DEVICE_ID:
248 kind = tmp422;
249 break;
250 case TMP423_DEVICE_ID:
251 kind = tmp423;
252 break;
253 default:
254 return -ENODEV;
255 }
256
257 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
258 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
259 names[kind], client->addr);
260
261 return 0;
262}
263
264static int tmp421_probe(struct i2c_client *client,
265 const struct i2c_device_id *id)
266{
267 struct tmp421_data *data;
268 int err;
269
270 data = kzalloc(sizeof(struct tmp421_data), GFP_KERNEL);
271 if (!data)
272 return -ENOMEM;
273
274 i2c_set_clientdata(client, data);
275 mutex_init(&data->update_lock);
276 data->channels = id->driver_data;
277
278 err = tmp421_init_client(client);
279 if (err)
280 goto exit_free;
281
282 err = sysfs_create_group(&client->dev.kobj, &tmp421_group);
283 if (err)
284 goto exit_free;
285
286 data->hwmon_dev = hwmon_device_register(&client->dev);
287 if (IS_ERR(data->hwmon_dev)) {
288 err = PTR_ERR(data->hwmon_dev);
289 data->hwmon_dev = NULL;
290 goto exit_remove;
291 }
292 return 0;
293
294exit_remove:
295 sysfs_remove_group(&client->dev.kobj, &tmp421_group);
296
297exit_free:
298 kfree(data);
299
300 return err;
301}
302
303static int tmp421_remove(struct i2c_client *client)
304{
305 struct tmp421_data *data = i2c_get_clientdata(client);
306
307 hwmon_device_unregister(data->hwmon_dev);
308 sysfs_remove_group(&client->dev.kobj, &tmp421_group);
309
310 kfree(data);
311
312 return 0;
313}
314
315static struct i2c_driver tmp421_driver = {
316 .class = I2C_CLASS_HWMON,
317 .driver = {
318 .name = "tmp421",
319 },
320 .probe = tmp421_probe,
321 .remove = tmp421_remove,
322 .id_table = tmp421_id,
323 .detect = tmp421_detect,
324 .address_list = normal_i2c,
325};
326
327static int __init tmp421_init(void)
328{
329 return i2c_add_driver(&tmp421_driver);
330}
331
332static void __exit tmp421_exit(void)
333{
334 i2c_del_driver(&tmp421_driver);
335}
336
337MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
338MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor"
339 " driver");
340MODULE_LICENSE("GPL");
341
342module_init(tmp421_init);
343module_exit(tmp421_exit);
1/* 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
18/*
19 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
20 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
21 */
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/jiffies.h>
27#include <linux/i2c.h>
28#include <linux/hwmon.h>
29#include <linux/hwmon-sysfs.h>
30#include <linux/err.h>
31#include <linux/mutex.h>
32#include <linux/of_device.h>
33#include <linux/sysfs.h>
34
35/* Addresses to scan */
36static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
37 I2C_CLIENT_END };
38
39enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
40
41/* The TMP421 registers */
42#define TMP421_STATUS_REG 0x08
43#define TMP421_CONFIG_REG_1 0x09
44#define TMP421_CONVERSION_RATE_REG 0x0B
45#define TMP421_MANUFACTURER_ID_REG 0xFE
46#define TMP421_DEVICE_ID_REG 0xFF
47
48static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
49static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
50
51/* Flags */
52#define TMP421_CONFIG_SHUTDOWN 0x40
53#define TMP421_CONFIG_RANGE 0x04
54
55/* Manufacturer / Device ID's */
56#define TMP421_MANUFACTURER_ID 0x55
57#define TMP421_DEVICE_ID 0x21
58#define TMP422_DEVICE_ID 0x22
59#define TMP423_DEVICE_ID 0x23
60#define TMP441_DEVICE_ID 0x41
61#define TMP442_DEVICE_ID 0x42
62
63static const struct i2c_device_id tmp421_id[] = {
64 { "tmp421", 2 },
65 { "tmp422", 3 },
66 { "tmp423", 4 },
67 { "tmp441", 2 },
68 { "tmp442", 3 },
69 { }
70};
71MODULE_DEVICE_TABLE(i2c, tmp421_id);
72
73static const struct of_device_id tmp421_of_match[] = {
74 {
75 .compatible = "ti,tmp421",
76 .data = (void *)2
77 },
78 {
79 .compatible = "ti,tmp422",
80 .data = (void *)3
81 },
82 {
83 .compatible = "ti,tmp423",
84 .data = (void *)4
85 },
86 {
87 .compatible = "ti,tmp441",
88 .data = (void *)2
89 },
90 {
91 .compatible = "ti,tmp422",
92 .data = (void *)3
93 },
94 { },
95};
96MODULE_DEVICE_TABLE(of, tmp421_of_match);
97
98struct tmp421_data {
99 struct i2c_client *client;
100 struct mutex update_lock;
101 u32 temp_config[5];
102 struct hwmon_channel_info temp_info;
103 const struct hwmon_channel_info *info[2];
104 struct hwmon_chip_info chip;
105 char valid;
106 unsigned long last_updated;
107 unsigned long channels;
108 u8 config;
109 s16 temp[4];
110};
111
112static int temp_from_s16(s16 reg)
113{
114 /* Mask out status bits */
115 int temp = reg & ~0xf;
116
117 return (temp * 1000 + 128) / 256;
118}
119
120static int temp_from_u16(u16 reg)
121{
122 /* Mask out status bits */
123 int temp = reg & ~0xf;
124
125 /* Add offset for extended temperature range. */
126 temp -= 64 * 256;
127
128 return (temp * 1000 + 128) / 256;
129}
130
131static struct tmp421_data *tmp421_update_device(struct device *dev)
132{
133 struct tmp421_data *data = dev_get_drvdata(dev);
134 struct i2c_client *client = data->client;
135 int i;
136
137 mutex_lock(&data->update_lock);
138
139 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
140 data->config = i2c_smbus_read_byte_data(client,
141 TMP421_CONFIG_REG_1);
142
143 for (i = 0; i < data->channels; i++) {
144 data->temp[i] = i2c_smbus_read_byte_data(client,
145 TMP421_TEMP_MSB[i]) << 8;
146 data->temp[i] |= i2c_smbus_read_byte_data(client,
147 TMP421_TEMP_LSB[i]);
148 }
149 data->last_updated = jiffies;
150 data->valid = 1;
151 }
152
153 mutex_unlock(&data->update_lock);
154
155 return data;
156}
157
158static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
159 u32 attr, int channel, long *val)
160{
161 struct tmp421_data *tmp421 = tmp421_update_device(dev);
162
163 switch (attr) {
164 case hwmon_temp_input:
165 if (tmp421->config & TMP421_CONFIG_RANGE)
166 *val = temp_from_u16(tmp421->temp[channel]);
167 else
168 *val = temp_from_s16(tmp421->temp[channel]);
169 return 0;
170 case hwmon_temp_fault:
171 /*
172 * The OPEN bit signals a fault. This is bit 0 of the temperature
173 * register (low byte).
174 */
175 *val = tmp421->temp[channel] & 0x01;
176 return 0;
177 default:
178 return -EOPNOTSUPP;
179 }
180
181}
182
183static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
184 u32 attr, int channel)
185{
186 switch (attr) {
187 case hwmon_temp_fault:
188 if (channel == 0)
189 return 0;
190 return S_IRUGO;
191 case hwmon_temp_input:
192 return S_IRUGO;
193 default:
194 return 0;
195 }
196}
197
198static int tmp421_init_client(struct i2c_client *client)
199{
200 int config, config_orig;
201
202 /* Set the conversion rate to 2 Hz */
203 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
204
205 /* Start conversions (disable shutdown if necessary) */
206 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
207 if (config < 0) {
208 dev_err(&client->dev,
209 "Could not read configuration register (%d)\n", config);
210 return config;
211 }
212
213 config_orig = config;
214 config &= ~TMP421_CONFIG_SHUTDOWN;
215
216 if (config != config_orig) {
217 dev_info(&client->dev, "Enable monitoring chip\n");
218 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
219 }
220
221 return 0;
222}
223
224static int tmp421_detect(struct i2c_client *client,
225 struct i2c_board_info *info)
226{
227 enum chips kind;
228 struct i2c_adapter *adapter = client->adapter;
229 const char * const names[] = { "TMP421", "TMP422", "TMP423",
230 "TMP441", "TMP442" };
231 int addr = client->addr;
232 u8 reg;
233
234 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
235 return -ENODEV;
236
237 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
238 if (reg != TMP421_MANUFACTURER_ID)
239 return -ENODEV;
240
241 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
242 if (reg & 0xf8)
243 return -ENODEV;
244
245 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
246 if (reg & 0x7f)
247 return -ENODEV;
248
249 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
250 switch (reg) {
251 case TMP421_DEVICE_ID:
252 kind = tmp421;
253 break;
254 case TMP422_DEVICE_ID:
255 if (addr == 0x2a)
256 return -ENODEV;
257 kind = tmp422;
258 break;
259 case TMP423_DEVICE_ID:
260 if (addr != 0x4c && addr != 0x4d)
261 return -ENODEV;
262 kind = tmp423;
263 break;
264 case TMP441_DEVICE_ID:
265 kind = tmp441;
266 break;
267 case TMP442_DEVICE_ID:
268 if (addr != 0x4c && addr != 0x4d)
269 return -ENODEV;
270 kind = tmp442;
271 break;
272 default:
273 return -ENODEV;
274 }
275
276 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
277 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
278 names[kind], client->addr);
279
280 return 0;
281}
282
283static const struct hwmon_ops tmp421_ops = {
284 .is_visible = tmp421_is_visible,
285 .read = tmp421_read,
286};
287
288static int tmp421_probe(struct i2c_client *client,
289 const struct i2c_device_id *id)
290{
291 struct device *dev = &client->dev;
292 struct device *hwmon_dev;
293 struct tmp421_data *data;
294 int i, err;
295
296 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
297 if (!data)
298 return -ENOMEM;
299
300 mutex_init(&data->update_lock);
301 if (client->dev.of_node)
302 data->channels = (unsigned long)
303 of_device_get_match_data(&client->dev);
304 else
305 data->channels = id->driver_data;
306 data->client = client;
307
308 err = tmp421_init_client(client);
309 if (err)
310 return err;
311
312 for (i = 0; i < data->channels; i++)
313 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
314
315 data->chip.ops = &tmp421_ops;
316 data->chip.info = data->info;
317
318 data->info[0] = &data->temp_info;
319
320 data->temp_info.type = hwmon_temp;
321 data->temp_info.config = data->temp_config;
322
323 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
324 data,
325 &data->chip,
326 NULL);
327 return PTR_ERR_OR_ZERO(hwmon_dev);
328}
329
330static struct i2c_driver tmp421_driver = {
331 .class = I2C_CLASS_HWMON,
332 .driver = {
333 .name = "tmp421",
334 .of_match_table = of_match_ptr(tmp421_of_match),
335 },
336 .probe = tmp421_probe,
337 .id_table = tmp421_id,
338 .detect = tmp421_detect,
339 .address_list = normal_i2c,
340};
341
342module_i2c_driver(tmp421_driver);
343
344MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
345MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
346MODULE_LICENSE("GPL");