xref: /openbmc/linux/drivers/hwmon/max1619.c (revision 87c2ce3b)
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 
37 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
38 					0x29, 0x2a, 0x2b,
39 					0x4c, 0x4d, 0x4e,
40 					I2C_CLIENT_END };
41 
42 /*
43  * Insmod parameters
44  */
45 
46 I2C_CLIENT_INSMOD_1(max1619);
47 
48 /*
49  * The MAX1619 registers
50  */
51 
52 #define MAX1619_REG_R_MAN_ID		0xFE
53 #define MAX1619_REG_R_CHIP_ID		0xFF
54 #define MAX1619_REG_R_CONFIG		0x03
55 #define MAX1619_REG_W_CONFIG		0x09
56 #define MAX1619_REG_R_CONVRATE		0x04
57 #define MAX1619_REG_W_CONVRATE		0x0A
58 #define MAX1619_REG_R_STATUS		0x02
59 #define MAX1619_REG_R_LOCAL_TEMP	0x00
60 #define MAX1619_REG_R_REMOTE_TEMP	0x01
61 #define MAX1619_REG_R_REMOTE_HIGH	0x07
62 #define MAX1619_REG_W_REMOTE_HIGH	0x0D
63 #define MAX1619_REG_R_REMOTE_LOW	0x08
64 #define MAX1619_REG_W_REMOTE_LOW	0x0E
65 #define MAX1619_REG_R_REMOTE_CRIT	0x10
66 #define MAX1619_REG_W_REMOTE_CRIT	0x12
67 #define MAX1619_REG_R_TCRIT_HYST	0x11
68 #define MAX1619_REG_W_TCRIT_HYST	0x13
69 
70 /*
71  * Conversions and various macros
72  */
73 
74 #define TEMP_FROM_REG(val)	((val & 0x80 ? val-0x100 : val) * 1000)
75 #define TEMP_TO_REG(val)	((val < 0 ? val+0x100*1000 : val) / 1000)
76 
77 /*
78  * Functions declaration
79  */
80 
81 static int max1619_attach_adapter(struct i2c_adapter *adapter);
82 static int max1619_detect(struct i2c_adapter *adapter, int address,
83 	int kind);
84 static void max1619_init_client(struct i2c_client *client);
85 static int max1619_detach_client(struct i2c_client *client);
86 static struct max1619_data *max1619_update_device(struct device *dev);
87 
88 /*
89  * Driver data (common to all clients)
90  */
91 
92 static struct i2c_driver max1619_driver = {
93 	.driver = {
94 		.name	= "max1619",
95 	},
96 	.attach_adapter	= max1619_attach_adapter,
97 	.detach_client	= max1619_detach_client,
98 };
99 
100 /*
101  * Client data (each client gets its own)
102  */
103 
104 struct max1619_data {
105 	struct i2c_client client;
106 	struct class_device *class_dev;
107 	struct semaphore update_lock;
108 	char valid; /* zero until following fields are valid */
109 	unsigned long last_updated; /* in jiffies */
110 
111 	/* registers values */
112 	u8 temp_input1; /* local */
113 	u8 temp_input2, temp_low2, temp_high2; /* remote */
114 	u8 temp_crit2;
115 	u8 temp_hyst2;
116 	u8 alarms;
117 };
118 
119 /*
120  * Sysfs stuff
121  */
122 
123 #define show_temp(value) \
124 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
125 { \
126 	struct max1619_data *data = max1619_update_device(dev); \
127 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
128 }
129 show_temp(temp_input1);
130 show_temp(temp_input2);
131 show_temp(temp_low2);
132 show_temp(temp_high2);
133 show_temp(temp_crit2);
134 show_temp(temp_hyst2);
135 
136 #define set_temp2(value, reg) \
137 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
138 	size_t count) \
139 { \
140 	struct i2c_client *client = to_i2c_client(dev); \
141 	struct max1619_data *data = i2c_get_clientdata(client); \
142 	long val = simple_strtol(buf, NULL, 10); \
143  \
144 	down(&data->update_lock); \
145 	data->value = TEMP_TO_REG(val); \
146 	i2c_smbus_write_byte_data(client, reg, data->value); \
147 	up(&data->update_lock); \
148 	return count; \
149 }
150 
151 set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
152 set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
153 set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
154 set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);
155 
156 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
157 {
158 	struct max1619_data *data = max1619_update_device(dev);
159 	return sprintf(buf, "%d\n", data->alarms);
160 }
161 
162 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
163 static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
164 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
165 	set_temp_low2);
166 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
167 	set_temp_high2);
168 static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
169 	set_temp_crit2);
170 static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
171 	set_temp_hyst2);
172 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
173 
174 /*
175  * Real code
176  */
177 
178 static int max1619_attach_adapter(struct i2c_adapter *adapter)
179 {
180 	if (!(adapter->class & I2C_CLASS_HWMON))
181 		return 0;
182 	return i2c_probe(adapter, &addr_data, max1619_detect);
183 }
184 
185 /*
186  * The following function does more than just detection. If detection
187  * succeeds, it also registers the new chip.
188  */
189 static int max1619_detect(struct i2c_adapter *adapter, int address, int kind)
190 {
191 	struct i2c_client *new_client;
192 	struct max1619_data *data;
193 	int err = 0;
194 	const char *name = "";
195 	u8 reg_config=0, reg_convrate=0, reg_status=0;
196 
197 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
198 		goto exit;
199 
200 	if (!(data = kzalloc(sizeof(struct max1619_data), GFP_KERNEL))) {
201 		err = -ENOMEM;
202 		goto exit;
203 	}
204 
205 	/* The common I2C client data is placed right before the
206 	   MAX1619-specific data. */
207 	new_client = &data->client;
208 	i2c_set_clientdata(new_client, data);
209 	new_client->addr = address;
210 	new_client->adapter = adapter;
211 	new_client->driver = &max1619_driver;
212 	new_client->flags = 0;
213 
214 	/*
215 	 * Now we do the remaining detection. A negative kind means that
216 	 * the driver was loaded with no force parameter (default), so we
217 	 * must both detect and identify the chip. A zero kind means that
218 	 * the driver was loaded with the force parameter, the detection
219 	 * step shall be skipped. A positive kind means that the driver
220 	 * was loaded with the force parameter and a given kind of chip is
221 	 * requested, so both the detection and the identification steps
222 	 * are skipped.
223 	 */
224 	if (kind < 0) { /* detection */
225 		reg_config = i2c_smbus_read_byte_data(new_client,
226 			      MAX1619_REG_R_CONFIG);
227 		reg_convrate = i2c_smbus_read_byte_data(new_client,
228 			       MAX1619_REG_R_CONVRATE);
229 		reg_status = i2c_smbus_read_byte_data(new_client,
230 				MAX1619_REG_R_STATUS);
231 		if ((reg_config & 0x03) != 0x00
232 		 || reg_convrate > 0x07 || (reg_status & 0x61 ) !=0x00) {
233 			dev_dbg(&adapter->dev,
234 				"MAX1619 detection failed at 0x%02x.\n",
235 				address);
236 			goto exit_free;
237 		}
238 	}
239 
240 	if (kind <= 0) { /* identification */
241 		u8 man_id, chip_id;
242 
243 		man_id = i2c_smbus_read_byte_data(new_client,
244 			 MAX1619_REG_R_MAN_ID);
245 		chip_id = i2c_smbus_read_byte_data(new_client,
246 			  MAX1619_REG_R_CHIP_ID);
247 
248 		if ((man_id == 0x4D) && (chip_id == 0x04))
249 			kind = max1619;
250 
251 		if (kind <= 0) { /* identification failed */
252 			dev_info(&adapter->dev,
253 			    "Unsupported chip (man_id=0x%02X, "
254 			    "chip_id=0x%02X).\n", man_id, chip_id);
255 			goto exit_free;
256 		}
257 	}
258 
259 	if (kind == max1619)
260 		name = "max1619";
261 
262 	/* We can fill in the remaining client fields */
263 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
264 	data->valid = 0;
265 	init_MUTEX(&data->update_lock);
266 
267 	/* Tell the I2C layer a new client has arrived */
268 	if ((err = i2c_attach_client(new_client)))
269 		goto exit_free;
270 
271 	/* Initialize the MAX1619 chip */
272 	max1619_init_client(new_client);
273 
274 	/* Register sysfs hooks */
275 	data->class_dev = hwmon_device_register(&new_client->dev);
276 	if (IS_ERR(data->class_dev)) {
277 		err = PTR_ERR(data->class_dev);
278 		goto exit_detach;
279 	}
280 
281 	device_create_file(&new_client->dev, &dev_attr_temp1_input);
282 	device_create_file(&new_client->dev, &dev_attr_temp2_input);
283 	device_create_file(&new_client->dev, &dev_attr_temp2_min);
284 	device_create_file(&new_client->dev, &dev_attr_temp2_max);
285 	device_create_file(&new_client->dev, &dev_attr_temp2_crit);
286 	device_create_file(&new_client->dev, &dev_attr_temp2_crit_hyst);
287 	device_create_file(&new_client->dev, &dev_attr_alarms);
288 
289 	return 0;
290 
291 exit_detach:
292 	i2c_detach_client(new_client);
293 exit_free:
294 	kfree(data);
295 exit:
296 	return err;
297 }
298 
299 static void max1619_init_client(struct i2c_client *client)
300 {
301 	u8 config;
302 
303 	/*
304 	 * Start the conversions.
305 	 */
306 	i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
307 				  5); /* 2 Hz */
308 	config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
309 	if (config & 0x40)
310 		i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
311 					  config & 0xBF); /* run */
312 }
313 
314 static int max1619_detach_client(struct i2c_client *client)
315 {
316 	struct max1619_data *data = i2c_get_clientdata(client);
317 	int err;
318 
319 	hwmon_device_unregister(data->class_dev);
320 
321 	if ((err = i2c_detach_client(client)))
322 		return err;
323 
324 	kfree(data);
325 	return 0;
326 }
327 
328 static struct max1619_data *max1619_update_device(struct device *dev)
329 {
330 	struct i2c_client *client = to_i2c_client(dev);
331 	struct max1619_data *data = i2c_get_clientdata(client);
332 
333 	down(&data->update_lock);
334 
335 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
336 		dev_dbg(&client->dev, "Updating max1619 data.\n");
337 		data->temp_input1 = i2c_smbus_read_byte_data(client,
338 					MAX1619_REG_R_LOCAL_TEMP);
339 		data->temp_input2 = i2c_smbus_read_byte_data(client,
340 					MAX1619_REG_R_REMOTE_TEMP);
341 		data->temp_high2 = i2c_smbus_read_byte_data(client,
342 					MAX1619_REG_R_REMOTE_HIGH);
343 		data->temp_low2 = i2c_smbus_read_byte_data(client,
344 					MAX1619_REG_R_REMOTE_LOW);
345 		data->temp_crit2 = i2c_smbus_read_byte_data(client,
346 					MAX1619_REG_R_REMOTE_CRIT);
347 		data->temp_hyst2 = i2c_smbus_read_byte_data(client,
348 					MAX1619_REG_R_TCRIT_HYST);
349 		data->alarms = i2c_smbus_read_byte_data(client,
350 					MAX1619_REG_R_STATUS);
351 
352 		data->last_updated = jiffies;
353 		data->valid = 1;
354 	}
355 
356 	up(&data->update_lock);
357 
358 	return data;
359 }
360 
361 static int __init sensors_max1619_init(void)
362 {
363 	return i2c_add_driver(&max1619_driver);
364 }
365 
366 static void __exit sensors_max1619_exit(void)
367 {
368 	i2c_del_driver(&max1619_driver);
369 }
370 
371 MODULE_AUTHOR("Alexey Fisher <fishor@mail.ru> and "
372 	"Jean Delvare <khali@linux-fr.org>");
373 MODULE_DESCRIPTION("MAX1619 sensor driver");
374 MODULE_LICENSE("GPL");
375 
376 module_init(sensors_max1619_init);
377 module_exit(sensors_max1619_exit);
378