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74ba9207 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
83bffbce PD |
2 | /* |
3 | * Driver for +/-1 degree C, SMBus-Compatible Remote/Local Temperature Sensor | |
4 | * with Overtemperature Alarm | |
5 | * | |
6 | * Copyright (C) 2011 AppearTV AS | |
7 | * | |
8 | * Derived from: | |
9 | * | |
10 | * Based on the max1619 driver. | |
9292f055 | 11 | * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net> |
7c81c60f | 12 | * Jean Delvare <jdelvare@suse.de> |
83bffbce PD |
13 | * |
14 | * The MAX6642 is a sensor chip made by Maxim. | |
15 | * It reports up to two temperatures (its own plus up to | |
16 | * one external one). Complete datasheet can be | |
17 | * obtained from Maxim's website at: | |
18 | * http://datasheets.maxim-ic.com/en/ds/MAX6642.pdf | |
83bffbce PD |
19 | */ |
20 | ||
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/jiffies.h> | |
26 | #include <linux/i2c.h> | |
27 | #include <linux/hwmon.h> | |
28 | #include <linux/hwmon-sysfs.h> | |
29 | #include <linux/err.h> | |
30 | #include <linux/mutex.h> | |
31 | #include <linux/sysfs.h> | |
32 | ||
33 | static const unsigned short normal_i2c[] = { | |
34 | 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; | |
35 | ||
36 | /* | |
37 | * The MAX6642 registers | |
38 | */ | |
39 | ||
40 | #define MAX6642_REG_R_MAN_ID 0xFE | |
41 | #define MAX6642_REG_R_CONFIG 0x03 | |
42 | #define MAX6642_REG_W_CONFIG 0x09 | |
43 | #define MAX6642_REG_R_STATUS 0x02 | |
44 | #define MAX6642_REG_R_LOCAL_TEMP 0x00 | |
45 | #define MAX6642_REG_R_LOCAL_TEMPL 0x11 | |
46 | #define MAX6642_REG_R_LOCAL_HIGH 0x05 | |
47 | #define MAX6642_REG_W_LOCAL_HIGH 0x0B | |
48 | #define MAX6642_REG_R_REMOTE_TEMP 0x01 | |
49 | #define MAX6642_REG_R_REMOTE_TEMPL 0x10 | |
50 | #define MAX6642_REG_R_REMOTE_HIGH 0x07 | |
51 | #define MAX6642_REG_W_REMOTE_HIGH 0x0D | |
52 | ||
53 | /* | |
54 | * Conversions | |
55 | */ | |
56 | ||
57 | static int temp_from_reg10(int val) | |
58 | { | |
59 | return val * 250; | |
60 | } | |
61 | ||
62 | static int temp_from_reg(int val) | |
63 | { | |
64 | return val * 1000; | |
65 | } | |
66 | ||
67 | static int temp_to_reg(int val) | |
68 | { | |
69 | return val / 1000; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Client data (each client gets its own) | |
74 | */ | |
75 | ||
76 | struct max6642_data { | |
9bd024e9 | 77 | struct i2c_client *client; |
83bffbce PD |
78 | struct mutex update_lock; |
79 | bool valid; /* zero until following fields are valid */ | |
80 | unsigned long last_updated; /* in jiffies */ | |
81 | ||
82 | /* registers values */ | |
83 | u16 temp_input[2]; /* local/remote */ | |
84 | u16 temp_high[2]; /* local/remote */ | |
85 | u8 alarms; | |
86 | }; | |
87 | ||
88 | /* | |
89 | * Real code | |
90 | */ | |
91 | ||
9bd024e9 GR |
92 | static void max6642_init_client(struct max6642_data *data, |
93 | struct i2c_client *client) | |
83bffbce PD |
94 | { |
95 | u8 config; | |
83bffbce PD |
96 | |
97 | /* | |
98 | * Start the conversions. | |
99 | */ | |
100 | config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); | |
101 | if (config & 0x40) | |
102 | i2c_smbus_write_byte_data(client, MAX6642_REG_W_CONFIG, | |
103 | config & 0xBF); /* run */ | |
104 | ||
105 | data->temp_high[0] = i2c_smbus_read_byte_data(client, | |
106 | MAX6642_REG_R_LOCAL_HIGH); | |
107 | data->temp_high[1] = i2c_smbus_read_byte_data(client, | |
108 | MAX6642_REG_R_REMOTE_HIGH); | |
109 | } | |
110 | ||
111 | /* Return 0 if detection is successful, -ENODEV otherwise */ | |
112 | static int max6642_detect(struct i2c_client *client, | |
113 | struct i2c_board_info *info) | |
114 | { | |
115 | struct i2c_adapter *adapter = client->adapter; | |
116 | u8 reg_config, reg_status, man_id; | |
117 | ||
118 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
119 | return -ENODEV; | |
120 | ||
121 | /* identification */ | |
122 | man_id = i2c_smbus_read_byte_data(client, MAX6642_REG_R_MAN_ID); | |
123 | if (man_id != 0x4D) | |
124 | return -ENODEV; | |
125 | ||
942c1a92 PD |
126 | /* sanity check */ |
127 | if (i2c_smbus_read_byte_data(client, 0x04) != 0x4D | |
128 | || i2c_smbus_read_byte_data(client, 0x06) != 0x4D | |
129 | || i2c_smbus_read_byte_data(client, 0xff) != 0x4D) | |
130 | return -ENODEV; | |
131 | ||
83bffbce PD |
132 | /* |
133 | * We read the config and status register, the 4 lower bits in the | |
134 | * config register should be zero and bit 5, 3, 1 and 0 should be | |
135 | * zero in the status register. | |
136 | */ | |
137 | reg_config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); | |
942c1a92 PD |
138 | if ((reg_config & 0x0f) != 0x00) |
139 | return -ENODEV; | |
140 | ||
141 | /* in between, another round of sanity checks */ | |
142 | if (i2c_smbus_read_byte_data(client, 0x04) != reg_config | |
143 | || i2c_smbus_read_byte_data(client, 0x06) != reg_config | |
144 | || i2c_smbus_read_byte_data(client, 0xff) != reg_config) | |
145 | return -ENODEV; | |
146 | ||
83bffbce | 147 | reg_status = i2c_smbus_read_byte_data(client, MAX6642_REG_R_STATUS); |
942c1a92 | 148 | if ((reg_status & 0x2b) != 0x00) |
83bffbce PD |
149 | return -ENODEV; |
150 | ||
151 | strlcpy(info->type, "max6642", I2C_NAME_SIZE); | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static struct max6642_data *max6642_update_device(struct device *dev) | |
157 | { | |
9bd024e9 GR |
158 | struct max6642_data *data = dev_get_drvdata(dev); |
159 | struct i2c_client *client = data->client; | |
83bffbce PD |
160 | u16 val, tmp; |
161 | ||
162 | mutex_lock(&data->update_lock); | |
163 | ||
164 | if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { | |
9bd024e9 | 165 | dev_dbg(dev, "Updating max6642 data.\n"); |
83bffbce PD |
166 | val = i2c_smbus_read_byte_data(client, |
167 | MAX6642_REG_R_LOCAL_TEMPL); | |
168 | tmp = (val >> 6) & 3; | |
169 | val = i2c_smbus_read_byte_data(client, | |
170 | MAX6642_REG_R_LOCAL_TEMP); | |
171 | val = (val << 2) | tmp; | |
172 | data->temp_input[0] = val; | |
173 | val = i2c_smbus_read_byte_data(client, | |
174 | MAX6642_REG_R_REMOTE_TEMPL); | |
175 | tmp = (val >> 6) & 3; | |
176 | val = i2c_smbus_read_byte_data(client, | |
177 | MAX6642_REG_R_REMOTE_TEMP); | |
178 | val = (val << 2) | tmp; | |
179 | data->temp_input[1] = val; | |
180 | data->alarms = i2c_smbus_read_byte_data(client, | |
181 | MAX6642_REG_R_STATUS); | |
182 | ||
183 | data->last_updated = jiffies; | |
184 | data->valid = 1; | |
185 | } | |
186 | ||
187 | mutex_unlock(&data->update_lock); | |
188 | ||
189 | return data; | |
190 | } | |
191 | ||
192 | /* | |
193 | * Sysfs stuff | |
194 | */ | |
195 | ||
823b8678 | 196 | static ssize_t temp_max10_show(struct device *dev, |
83bffbce PD |
197 | struct device_attribute *dev_attr, char *buf) |
198 | { | |
83bffbce | 199 | struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr); |
9bd024e9 | 200 | struct max6642_data *data = max6642_update_device(dev); |
83bffbce PD |
201 | |
202 | return sprintf(buf, "%d\n", | |
203 | temp_from_reg10(data->temp_input[attr->index])); | |
204 | } | |
205 | ||
823b8678 GR |
206 | static ssize_t temp_max_show(struct device *dev, |
207 | struct device_attribute *attr, char *buf) | |
83bffbce | 208 | { |
83bffbce | 209 | struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); |
9bd024e9 | 210 | struct max6642_data *data = max6642_update_device(dev); |
83bffbce PD |
211 | |
212 | return sprintf(buf, "%d\n", temp_from_reg(data->temp_high[attr2->nr])); | |
213 | } | |
214 | ||
823b8678 GR |
215 | static ssize_t temp_max_store(struct device *dev, |
216 | struct device_attribute *attr, const char *buf, | |
217 | size_t count) | |
83bffbce | 218 | { |
9bd024e9 GR |
219 | struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); |
220 | struct max6642_data *data = dev_get_drvdata(dev); | |
83bffbce PD |
221 | unsigned long val; |
222 | int err; | |
83bffbce | 223 | |
179c4fdb | 224 | err = kstrtoul(buf, 10, &val); |
83bffbce PD |
225 | if (err < 0) |
226 | return err; | |
227 | ||
228 | mutex_lock(&data->update_lock); | |
2a844c14 | 229 | data->temp_high[attr2->nr] = clamp_val(temp_to_reg(val), 0, 255); |
9bd024e9 | 230 | i2c_smbus_write_byte_data(data->client, attr2->index, |
83bffbce PD |
231 | data->temp_high[attr2->nr]); |
232 | mutex_unlock(&data->update_lock); | |
233 | return count; | |
234 | } | |
235 | ||
823b8678 | 236 | static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, |
83bffbce PD |
237 | char *buf) |
238 | { | |
239 | int bitnr = to_sensor_dev_attr(attr)->index; | |
240 | struct max6642_data *data = max6642_update_device(dev); | |
241 | return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1); | |
242 | } | |
243 | ||
823b8678 GR |
244 | static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_max10, 0); |
245 | static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_max10, 1); | |
246 | static SENSOR_DEVICE_ATTR_2_RW(temp1_max, temp_max, 0, | |
247 | MAX6642_REG_W_LOCAL_HIGH); | |
248 | static SENSOR_DEVICE_ATTR_2_RW(temp2_max, temp_max, 1, | |
249 | MAX6642_REG_W_REMOTE_HIGH); | |
250 | static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2); | |
251 | static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6); | |
252 | static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4); | |
83bffbce | 253 | |
9bd024e9 | 254 | static struct attribute *max6642_attrs[] = { |
83bffbce PD |
255 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
256 | &sensor_dev_attr_temp2_input.dev_attr.attr, | |
257 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
258 | &sensor_dev_attr_temp2_max.dev_attr.attr, | |
259 | ||
614198bb | 260 | &sensor_dev_attr_temp2_fault.dev_attr.attr, |
83bffbce PD |
261 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, |
262 | &sensor_dev_attr_temp2_max_alarm.dev_attr.attr, | |
263 | NULL | |
264 | }; | |
9bd024e9 | 265 | ATTRIBUTE_GROUPS(max6642); |
83bffbce | 266 | |
9bd024e9 | 267 | static int max6642_probe(struct i2c_client *client, |
83bffbce PD |
268 | const struct i2c_device_id *id) |
269 | { | |
9bd024e9 | 270 | struct device *dev = &client->dev; |
83bffbce | 271 | struct max6642_data *data; |
9bd024e9 | 272 | struct device *hwmon_dev; |
83bffbce | 273 | |
9bd024e9 | 274 | data = devm_kzalloc(dev, sizeof(struct max6642_data), GFP_KERNEL); |
96f316c2 GR |
275 | if (!data) |
276 | return -ENOMEM; | |
83bffbce | 277 | |
9bd024e9 | 278 | data->client = client; |
83bffbce PD |
279 | mutex_init(&data->update_lock); |
280 | ||
281 | /* Initialize the MAX6642 chip */ | |
9bd024e9 | 282 | max6642_init_client(data, client); |
83bffbce | 283 | |
9bd024e9 GR |
284 | hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev, |
285 | client->name, data, | |
286 | max6642_groups); | |
e5840c78 | 287 | return PTR_ERR_OR_ZERO(hwmon_dev); |
83bffbce PD |
288 | } |
289 | ||
290 | /* | |
291 | * Driver data (common to all clients) | |
292 | */ | |
293 | ||
294 | static const struct i2c_device_id max6642_id[] = { | |
295 | { "max6642", 0 }, | |
296 | { } | |
297 | }; | |
298 | MODULE_DEVICE_TABLE(i2c, max6642_id); | |
299 | ||
300 | static struct i2c_driver max6642_driver = { | |
301 | .class = I2C_CLASS_HWMON, | |
302 | .driver = { | |
303 | .name = "max6642", | |
304 | }, | |
305 | .probe = max6642_probe, | |
83bffbce PD |
306 | .id_table = max6642_id, |
307 | .detect = max6642_detect, | |
308 | .address_list = normal_i2c, | |
309 | }; | |
310 | ||
f0967eea | 311 | module_i2c_driver(max6642_driver); |
83bffbce PD |
312 | |
313 | MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>"); | |
314 | MODULE_DESCRIPTION("MAX6642 sensor driver"); | |
315 | MODULE_LICENSE("GPL"); |