1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LM73 Sensor driver
4 * Based on LM75
5 *
6 * Copyright (C) 2007, CenoSYS (www.cenosys.com).
7 * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
8 *
9 * Guillaume Ligneul <guillaume.ligneul@gmail.com>
10 * Adrien Demarez <adrien.demarez@bolloretelecom.eu>
11 * Jeremy Laine <jeremy.laine@bolloretelecom.eu>
12 * Chris Verges <kg4ysn@gmail.com>
13 */
14
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/i2c.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/err.h>
21
22
23 /* Addresses scanned */
24 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
25 0x4d, 0x4e, I2C_CLIENT_END };
26
27 /* LM73 registers */
28 #define LM73_REG_INPUT 0x00
29 #define LM73_REG_CONF 0x01
30 #define LM73_REG_MAX 0x02
31 #define LM73_REG_MIN 0x03
32 #define LM73_REG_CTRL 0x04
33 #define LM73_REG_ID 0x07
34
35 #define LM73_ID 0x9001 /* 0x0190, byte-swapped */
36 #define DRVNAME "lm73"
37 #define LM73_TEMP_MIN (-256000 / 250)
38 #define LM73_TEMP_MAX (255750 / 250)
39
40 #define LM73_CTRL_RES_SHIFT 5
41 #define LM73_CTRL_RES_MASK (BIT(5) | BIT(6))
42 #define LM73_CTRL_TO_MASK BIT(7)
43
44 #define LM73_CTRL_HI_SHIFT 2
45 #define LM73_CTRL_LO_SHIFT 1
46
47 static const unsigned short lm73_convrates[] = {
48 14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */
49 28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */
50 56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */
51 112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */
52 };
53
54 struct lm73_data {
55 struct i2c_client *client;
56 struct mutex lock;
57 u8 ctrl; /* control register value */
58 };
59
60 /*-----------------------------------------------------------------------*/
61
temp_store(struct device * dev,struct device_attribute * da,const char * buf,size_t count)62 static ssize_t temp_store(struct device *dev, struct device_attribute *da,
63 const char *buf, size_t count)
64 {
65 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
66 struct lm73_data *data = dev_get_drvdata(dev);
67 long temp;
68 short value;
69 s32 err;
70
71 int status = kstrtol(buf, 10, &temp);
72 if (status < 0)
73 return status;
74
75 /* Write value */
76 value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5;
77 err = i2c_smbus_write_word_swapped(data->client, attr->index, value);
78 return (err < 0) ? err : count;
79 }
80
temp_show(struct device * dev,struct device_attribute * da,char * buf)81 static ssize_t temp_show(struct device *dev, struct device_attribute *da,
82 char *buf)
83 {
84 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
85 struct lm73_data *data = dev_get_drvdata(dev);
86 int temp;
87
88 s32 err = i2c_smbus_read_word_swapped(data->client, attr->index);
89 if (err < 0)
90 return err;
91
92 /* use integer division instead of equivalent right shift to
93 guarantee arithmetic shift and preserve the sign */
94 temp = (((s16) err) * 250) / 32;
95 return sysfs_emit(buf, "%d\n", temp);
96 }
97
convrate_store(struct device * dev,struct device_attribute * da,const char * buf,size_t count)98 static ssize_t convrate_store(struct device *dev, struct device_attribute *da,
99 const char *buf, size_t count)
100 {
101 struct lm73_data *data = dev_get_drvdata(dev);
102 unsigned long convrate;
103 s32 err;
104 int res = 0;
105
106 err = kstrtoul(buf, 10, &convrate);
107 if (err < 0)
108 return err;
109
110 /*
111 * Convert the desired conversion rate into register bits.
112 * res is already initialized, and everything past the second-to-last
113 * value in the array is treated as belonging to the last value
114 * in the array.
115 */
116 while (res < (ARRAY_SIZE(lm73_convrates) - 1) &&
117 convrate > lm73_convrates[res])
118 res++;
119
120 mutex_lock(&data->lock);
121 data->ctrl &= LM73_CTRL_TO_MASK;
122 data->ctrl |= res << LM73_CTRL_RES_SHIFT;
123 err = i2c_smbus_write_byte_data(data->client, LM73_REG_CTRL,
124 data->ctrl);
125 mutex_unlock(&data->lock);
126
127 if (err < 0)
128 return err;
129
130 return count;
131 }
132
convrate_show(struct device * dev,struct device_attribute * da,char * buf)133 static ssize_t convrate_show(struct device *dev, struct device_attribute *da,
134 char *buf)
135 {
136 struct lm73_data *data = dev_get_drvdata(dev);
137 int res;
138
139 res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT;
140 return sysfs_emit(buf, "%hu\n", lm73_convrates[res]);
141 }
142
maxmin_alarm_show(struct device * dev,struct device_attribute * da,char * buf)143 static ssize_t maxmin_alarm_show(struct device *dev,
144 struct device_attribute *da, char *buf)
145 {
146 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
147 struct lm73_data *data = dev_get_drvdata(dev);
148 s32 ctrl;
149
150 mutex_lock(&data->lock);
151 ctrl = i2c_smbus_read_byte_data(data->client, LM73_REG_CTRL);
152 if (ctrl < 0)
153 goto abort;
154 data->ctrl = ctrl;
155 mutex_unlock(&data->lock);
156
157 return sysfs_emit(buf, "%d\n", (ctrl >> attr->index) & 1);
158
159 abort:
160 mutex_unlock(&data->lock);
161 return ctrl;
162 }
163
164 /*-----------------------------------------------------------------------*/
165
166 /* sysfs attributes for hwmon */
167
168 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, LM73_REG_MAX);
169 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, LM73_REG_MIN);
170 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, LM73_REG_INPUT);
171 static SENSOR_DEVICE_ATTR_RW(update_interval, convrate, 0);
172 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, maxmin_alarm,
173 LM73_CTRL_HI_SHIFT);
174 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, maxmin_alarm,
175 LM73_CTRL_LO_SHIFT);
176
177 static struct attribute *lm73_attrs[] = {
178 &sensor_dev_attr_temp1_input.dev_attr.attr,
179 &sensor_dev_attr_temp1_max.dev_attr.attr,
180 &sensor_dev_attr_temp1_min.dev_attr.attr,
181 &sensor_dev_attr_update_interval.dev_attr.attr,
182 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
183 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
184 NULL
185 };
186 ATTRIBUTE_GROUPS(lm73);
187
188 /*-----------------------------------------------------------------------*/
189
190 /* device probe and removal */
191
192 static int
lm73_probe(struct i2c_client * client)193 lm73_probe(struct i2c_client *client)
194 {
195 struct device *dev = &client->dev;
196 struct device *hwmon_dev;
197 struct lm73_data *data;
198 int ctrl;
199
200 data = devm_kzalloc(dev, sizeof(struct lm73_data), GFP_KERNEL);
201 if (!data)
202 return -ENOMEM;
203
204 data->client = client;
205 mutex_init(&data->lock);
206
207 ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL);
208 if (ctrl < 0)
209 return ctrl;
210 data->ctrl = ctrl;
211
212 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
213 data, lm73_groups);
214 if (IS_ERR(hwmon_dev))
215 return PTR_ERR(hwmon_dev);
216
217 dev_info(dev, "sensor '%s'\n", client->name);
218
219 return 0;
220 }
221
222 static const struct i2c_device_id lm73_ids[] = {
223 { "lm73", 0 },
224 { /* LIST END */ }
225 };
226 MODULE_DEVICE_TABLE(i2c, lm73_ids);
227
228 /* Return 0 if detection is successful, -ENODEV otherwise */
lm73_detect(struct i2c_client * new_client,struct i2c_board_info * info)229 static int lm73_detect(struct i2c_client *new_client,
230 struct i2c_board_info *info)
231 {
232 struct i2c_adapter *adapter = new_client->adapter;
233 int id, ctrl, conf;
234
235 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
236 I2C_FUNC_SMBUS_WORD_DATA))
237 return -ENODEV;
238
239 /*
240 * Do as much detection as possible with byte reads first, as word
241 * reads can confuse other devices.
242 */
243 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
244 if (ctrl < 0 || (ctrl & 0x10))
245 return -ENODEV;
246
247 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF);
248 if (conf < 0 || (conf & 0x0c))
249 return -ENODEV;
250
251 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID);
252 if (id < 0 || id != (LM73_ID & 0xff))
253 return -ENODEV;
254
255 /* Check device ID */
256 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
257 if (id < 0 || id != LM73_ID)
258 return -ENODEV;
259
260 strscpy(info->type, "lm73", I2C_NAME_SIZE);
261
262 return 0;
263 }
264
265 static const struct of_device_id lm73_of_match[] = {
266 {
267 .compatible = "ti,lm73",
268 },
269 { },
270 };
271
272 MODULE_DEVICE_TABLE(of, lm73_of_match);
273
274 static struct i2c_driver lm73_driver = {
275 .class = I2C_CLASS_HWMON,
276 .driver = {
277 .name = "lm73",
278 .of_match_table = lm73_of_match,
279 },
280 .probe_new = lm73_probe,
281 .id_table = lm73_ids,
282 .detect = lm73_detect,
283 .address_list = normal_i2c,
284 };
285
286 module_i2c_driver(lm73_driver);
287
288 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
289 MODULE_DESCRIPTION("LM73 driver");
290 MODULE_LICENSE("GPL");
291