xref: /openbmc/linux/drivers/hwmon/max1619.c (revision 643d1f7f)
1 /*
2  * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
3  *             monitoring
4  * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
5  *                         Jean Delvare <khali@linux-fr.org>
6  *
7  * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
8  * It reports up to two temperatures (its own plus up to
9  * one external one). Complete datasheet can be
10  * obtained from Maxim's website at:
11  *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
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.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/jiffies.h>
33 #include <linux/i2c.h>
34 #include <linux/hwmon.h>
35 #include <linux/err.h>
36 #include <linux/mutex.h>
37 #include <linux/sysfs.h>
38 
39 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
40 					0x29, 0x2a, 0x2b,
41 					0x4c, 0x4d, 0x4e,
42 					I2C_CLIENT_END };
43 
44 /*
45  * Insmod parameters
46  */
47 
48 I2C_CLIENT_INSMOD_1(max1619);
49 
50 /*
51  * The MAX1619 registers
52  */
53 
54 #define MAX1619_REG_R_MAN_ID		0xFE
55 #define MAX1619_REG_R_CHIP_ID		0xFF
56 #define MAX1619_REG_R_CONFIG		0x03
57 #define MAX1619_REG_W_CONFIG		0x09
58 #define MAX1619_REG_R_CONVRATE		0x04
59 #define MAX1619_REG_W_CONVRATE		0x0A
60 #define MAX1619_REG_R_STATUS		0x02
61 #define MAX1619_REG_R_LOCAL_TEMP	0x00
62 #define MAX1619_REG_R_REMOTE_TEMP	0x01
63 #define MAX1619_REG_R_REMOTE_HIGH	0x07
64 #define MAX1619_REG_W_REMOTE_HIGH	0x0D
65 #define MAX1619_REG_R_REMOTE_LOW	0x08
66 #define MAX1619_REG_W_REMOTE_LOW	0x0E
67 #define MAX1619_REG_R_REMOTE_CRIT	0x10
68 #define MAX1619_REG_W_REMOTE_CRIT	0x12
69 #define MAX1619_REG_R_TCRIT_HYST	0x11
70 #define MAX1619_REG_W_TCRIT_HYST	0x13
71 
72 /*
73  * Conversions and various macros
74  */
75 
76 #define TEMP_FROM_REG(val)	((val & 0x80 ? val-0x100 : val) * 1000)
77 #define TEMP_TO_REG(val)	((val < 0 ? val+0x100*1000 : val) / 1000)
78 
79 /*
80  * Functions declaration
81  */
82 
83 static int max1619_attach_adapter(struct i2c_adapter *adapter);
84 static int max1619_detect(struct i2c_adapter *adapter, int address,
85 	int kind);
86 static void max1619_init_client(struct i2c_client *client);
87 static int max1619_detach_client(struct i2c_client *client);
88 static struct max1619_data *max1619_update_device(struct device *dev);
89 
90 /*
91  * Driver data (common to all clients)
92  */
93 
94 static struct i2c_driver max1619_driver = {
95 	.driver = {
96 		.name	= "max1619",
97 	},
98 	.attach_adapter	= max1619_attach_adapter,
99 	.detach_client	= max1619_detach_client,
100 };
101 
102 /*
103  * Client data (each client gets its own)
104  */
105 
106 struct max1619_data {
107 	struct i2c_client client;
108 	struct device *hwmon_dev;
109 	struct mutex update_lock;
110 	char valid; /* zero until following fields are valid */
111 	unsigned long last_updated; /* in jiffies */
112 
113 	/* registers values */
114 	u8 temp_input1; /* local */
115 	u8 temp_input2, temp_low2, temp_high2; /* remote */
116 	u8 temp_crit2;
117 	u8 temp_hyst2;
118 	u8 alarms;
119 };
120 
121 /*
122  * Sysfs stuff
123  */
124 
125 #define show_temp(value) \
126 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
127 { \
128 	struct max1619_data *data = max1619_update_device(dev); \
129 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
130 }
131 show_temp(temp_input1);
132 show_temp(temp_input2);
133 show_temp(temp_low2);
134 show_temp(temp_high2);
135 show_temp(temp_crit2);
136 show_temp(temp_hyst2);
137 
138 #define set_temp2(value, reg) \
139 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
140 	size_t count) \
141 { \
142 	struct i2c_client *client = to_i2c_client(dev); \
143 	struct max1619_data *data = i2c_get_clientdata(client); \
144 	long val = simple_strtol(buf, NULL, 10); \
145  \
146 	mutex_lock(&data->update_lock); \
147 	data->value = TEMP_TO_REG(val); \
148 	i2c_smbus_write_byte_data(client, reg, data->value); \
149 	mutex_unlock(&data->update_lock); \
150 	return count; \
151 }
152 
153 set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
154 set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
155 set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
156 set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);
157 
158 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
159 {
160 	struct max1619_data *data = max1619_update_device(dev);
161 	return sprintf(buf, "%d\n", data->alarms);
162 }
163 
164 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
165 static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
166 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
167 	set_temp_low2);
168 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
169 	set_temp_high2);
170 static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
171 	set_temp_crit2);
172 static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
173 	set_temp_hyst2);
174 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
175 
176 static struct attribute *max1619_attributes[] = {
177 	&dev_attr_temp1_input.attr,
178 	&dev_attr_temp2_input.attr,
179 	&dev_attr_temp2_min.attr,
180 	&dev_attr_temp2_max.attr,
181 	&dev_attr_temp2_crit.attr,
182 	&dev_attr_temp2_crit_hyst.attr,
183 
184 	&dev_attr_alarms.attr,
185 	NULL
186 };
187 
188 static const struct attribute_group max1619_group = {
189 	.attrs = max1619_attributes,
190 };
191 
192 /*
193  * Real code
194  */
195 
196 static int max1619_attach_adapter(struct i2c_adapter *adapter)
197 {
198 	if (!(adapter->class & I2C_CLASS_HWMON))
199 		return 0;
200 	return i2c_probe(adapter, &addr_data, max1619_detect);
201 }
202 
203 /*
204  * The following function does more than just detection. If detection
205  * succeeds, it also registers the new chip.
206  */
207 static int max1619_detect(struct i2c_adapter *adapter, int address, int kind)
208 {
209 	struct i2c_client *new_client;
210 	struct max1619_data *data;
211 	int err = 0;
212 	const char *name = "";
213 	u8 reg_config=0, reg_convrate=0, reg_status=0;
214 
215 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
216 		goto exit;
217 
218 	if (!(data = kzalloc(sizeof(struct max1619_data), GFP_KERNEL))) {
219 		err = -ENOMEM;
220 		goto exit;
221 	}
222 
223 	/* The common I2C client data is placed right before the
224 	   MAX1619-specific data. */
225 	new_client = &data->client;
226 	i2c_set_clientdata(new_client, data);
227 	new_client->addr = address;
228 	new_client->adapter = adapter;
229 	new_client->driver = &max1619_driver;
230 	new_client->flags = 0;
231 
232 	/*
233 	 * Now we do the remaining detection. A negative kind means that
234 	 * the driver was loaded with no force parameter (default), so we
235 	 * must both detect and identify the chip. A zero kind means that
236 	 * the driver was loaded with the force parameter, the detection
237 	 * step shall be skipped. A positive kind means that the driver
238 	 * was loaded with the force parameter and a given kind of chip is
239 	 * requested, so both the detection and the identification steps
240 	 * are skipped.
241 	 */
242 	if (kind < 0) { /* detection */
243 		reg_config = i2c_smbus_read_byte_data(new_client,
244 			      MAX1619_REG_R_CONFIG);
245 		reg_convrate = i2c_smbus_read_byte_data(new_client,
246 			       MAX1619_REG_R_CONVRATE);
247 		reg_status = i2c_smbus_read_byte_data(new_client,
248 				MAX1619_REG_R_STATUS);
249 		if ((reg_config & 0x03) != 0x00
250 		 || reg_convrate > 0x07 || (reg_status & 0x61 ) !=0x00) {
251 			dev_dbg(&adapter->dev,
252 				"MAX1619 detection failed at 0x%02x.\n",
253 				address);
254 			goto exit_free;
255 		}
256 	}
257 
258 	if (kind <= 0) { /* identification */
259 		u8 man_id, chip_id;
260 
261 		man_id = i2c_smbus_read_byte_data(new_client,
262 			 MAX1619_REG_R_MAN_ID);
263 		chip_id = i2c_smbus_read_byte_data(new_client,
264 			  MAX1619_REG_R_CHIP_ID);
265 
266 		if ((man_id == 0x4D) && (chip_id == 0x04))
267 			kind = max1619;
268 
269 		if (kind <= 0) { /* identification failed */
270 			dev_info(&adapter->dev,
271 			    "Unsupported chip (man_id=0x%02X, "
272 			    "chip_id=0x%02X).\n", man_id, chip_id);
273 			goto exit_free;
274 		}
275 	}
276 
277 	if (kind == max1619)
278 		name = "max1619";
279 
280 	/* We can fill in the remaining client fields */
281 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
282 	data->valid = 0;
283 	mutex_init(&data->update_lock);
284 
285 	/* Tell the I2C layer a new client has arrived */
286 	if ((err = i2c_attach_client(new_client)))
287 		goto exit_free;
288 
289 	/* Initialize the MAX1619 chip */
290 	max1619_init_client(new_client);
291 
292 	/* Register sysfs hooks */
293 	if ((err = sysfs_create_group(&new_client->dev.kobj, &max1619_group)))
294 		goto exit_detach;
295 
296 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
297 	if (IS_ERR(data->hwmon_dev)) {
298 		err = PTR_ERR(data->hwmon_dev);
299 		goto exit_remove_files;
300 	}
301 
302 	return 0;
303 
304 exit_remove_files:
305 	sysfs_remove_group(&new_client->dev.kobj, &max1619_group);
306 exit_detach:
307 	i2c_detach_client(new_client);
308 exit_free:
309 	kfree(data);
310 exit:
311 	return err;
312 }
313 
314 static void max1619_init_client(struct i2c_client *client)
315 {
316 	u8 config;
317 
318 	/*
319 	 * Start the conversions.
320 	 */
321 	i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
322 				  5); /* 2 Hz */
323 	config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
324 	if (config & 0x40)
325 		i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
326 					  config & 0xBF); /* run */
327 }
328 
329 static int max1619_detach_client(struct i2c_client *client)
330 {
331 	struct max1619_data *data = i2c_get_clientdata(client);
332 	int err;
333 
334 	hwmon_device_unregister(data->hwmon_dev);
335 	sysfs_remove_group(&client->dev.kobj, &max1619_group);
336 
337 	if ((err = i2c_detach_client(client)))
338 		return err;
339 
340 	kfree(data);
341 	return 0;
342 }
343 
344 static struct max1619_data *max1619_update_device(struct device *dev)
345 {
346 	struct i2c_client *client = to_i2c_client(dev);
347 	struct max1619_data *data = i2c_get_clientdata(client);
348 
349 	mutex_lock(&data->update_lock);
350 
351 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
352 		dev_dbg(&client->dev, "Updating max1619 data.\n");
353 		data->temp_input1 = i2c_smbus_read_byte_data(client,
354 					MAX1619_REG_R_LOCAL_TEMP);
355 		data->temp_input2 = i2c_smbus_read_byte_data(client,
356 					MAX1619_REG_R_REMOTE_TEMP);
357 		data->temp_high2 = i2c_smbus_read_byte_data(client,
358 					MAX1619_REG_R_REMOTE_HIGH);
359 		data->temp_low2 = i2c_smbus_read_byte_data(client,
360 					MAX1619_REG_R_REMOTE_LOW);
361 		data->temp_crit2 = i2c_smbus_read_byte_data(client,
362 					MAX1619_REG_R_REMOTE_CRIT);
363 		data->temp_hyst2 = i2c_smbus_read_byte_data(client,
364 					MAX1619_REG_R_TCRIT_HYST);
365 		data->alarms = i2c_smbus_read_byte_data(client,
366 					MAX1619_REG_R_STATUS);
367 
368 		data->last_updated = jiffies;
369 		data->valid = 1;
370 	}
371 
372 	mutex_unlock(&data->update_lock);
373 
374 	return data;
375 }
376 
377 static int __init sensors_max1619_init(void)
378 {
379 	return i2c_add_driver(&max1619_driver);
380 }
381 
382 static void __exit sensors_max1619_exit(void)
383 {
384 	i2c_del_driver(&max1619_driver);
385 }
386 
387 MODULE_AUTHOR("Alexey Fisher <fishor@mail.ru> and "
388 	"Jean Delvare <khali@linux-fr.org>");
389 MODULE_DESCRIPTION("MAX1619 sensor driver");
390 MODULE_LICENSE("GPL");
391 
392 module_init(sensors_max1619_init);
393 module_exit(sensors_max1619_exit);
394