xref: /openbmc/linux/drivers/hwmon/emc1403.c (revision 7fe2f639)
1 /*
2  * emc1403.c - SMSC Thermal Driver
3  *
4  * Copyright (C) 2008 Intel Corp
5  *
6  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, write to the Free Software Foundation, Inc.,
19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21  *
22  * TODO
23  *	-	cache alarm and critical limit registers
24  *	-	add emc1404 support
25  */
26 
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/i2c.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/err.h>
34 #include <linux/sysfs.h>
35 #include <linux/mutex.h>
36 
37 #define THERMAL_PID_REG		0xfd
38 #define THERMAL_SMSC_ID_REG	0xfe
39 #define THERMAL_REVISION_REG	0xff
40 
41 struct thermal_data {
42 	struct device *hwmon_dev;
43 	struct mutex mutex;
44 	/* Cache the hyst value so we don't keep re-reading it. In theory
45 	   we could cache it forever as nobody else should be writing it. */
46 	u8 cached_hyst;
47 	unsigned long hyst_valid;
48 };
49 
50 static ssize_t show_temp(struct device *dev,
51 			struct device_attribute *attr, char *buf)
52 {
53 	struct i2c_client *client = to_i2c_client(dev);
54 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
55 	int retval = i2c_smbus_read_byte_data(client, sda->index);
56 
57 	if (retval < 0)
58 		return retval;
59 	return sprintf(buf, "%d000\n", retval);
60 }
61 
62 static ssize_t show_bit(struct device *dev,
63 			struct device_attribute *attr, char *buf)
64 {
65 	struct i2c_client *client = to_i2c_client(dev);
66 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
67 	int retval = i2c_smbus_read_byte_data(client, sda->nr);
68 
69 	if (retval < 0)
70 		return retval;
71 	retval &= sda->index;
72 	return sprintf(buf, "%d\n", retval ? 1 : 0);
73 }
74 
75 static ssize_t store_temp(struct device *dev,
76 		struct device_attribute *attr, const char *buf, size_t count)
77 {
78 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
79 	struct i2c_client *client = to_i2c_client(dev);
80 	unsigned long val;
81 	int retval;
82 
83 	if (strict_strtoul(buf, 10, &val))
84 		return -EINVAL;
85 	retval = i2c_smbus_write_byte_data(client, sda->index,
86 					DIV_ROUND_CLOSEST(val, 1000));
87 	if (retval < 0)
88 		return retval;
89 	return count;
90 }
91 
92 static ssize_t store_bit(struct device *dev,
93 		struct device_attribute *attr, const char *buf, size_t count)
94 {
95 	struct i2c_client *client = to_i2c_client(dev);
96 	struct thermal_data *data = i2c_get_clientdata(client);
97 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
98 	unsigned long val;
99 	int retval;
100 
101 	if (strict_strtoul(buf, 10, &val))
102 		return -EINVAL;
103 
104 	mutex_lock(&data->mutex);
105 	retval = i2c_smbus_read_byte_data(client, sda->nr);
106 	if (retval < 0)
107 		goto fail;
108 
109 	retval &= ~sda->index;
110 	if (val)
111 		retval |= sda->index;
112 
113 	retval = i2c_smbus_write_byte_data(client, sda->index, retval);
114 	if (retval == 0)
115 		retval = count;
116 fail:
117 	mutex_unlock(&data->mutex);
118 	return retval;
119 }
120 
121 static ssize_t show_hyst(struct device *dev,
122 			struct device_attribute *attr, char *buf)
123 {
124 	struct i2c_client *client = to_i2c_client(dev);
125 	struct thermal_data *data = i2c_get_clientdata(client);
126 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
127 	int retval;
128 	int hyst;
129 
130 	retval = i2c_smbus_read_byte_data(client, sda->index);
131 	if (retval < 0)
132 		return retval;
133 
134 	if (time_after(jiffies, data->hyst_valid)) {
135 		hyst = i2c_smbus_read_byte_data(client, 0x21);
136 		if (hyst < 0)
137 			return retval;
138 		data->cached_hyst = hyst;
139 		data->hyst_valid = jiffies + HZ;
140 	}
141 	return sprintf(buf, "%d000\n", retval - data->cached_hyst);
142 }
143 
144 static ssize_t store_hyst(struct device *dev,
145 		struct device_attribute *attr, const char *buf, size_t count)
146 {
147 	struct i2c_client *client = to_i2c_client(dev);
148 	struct thermal_data *data = i2c_get_clientdata(client);
149 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
150 	int retval;
151 	int hyst;
152 	unsigned long val;
153 
154 	if (strict_strtoul(buf, 10, &val))
155 		return -EINVAL;
156 
157 	mutex_lock(&data->mutex);
158 	retval = i2c_smbus_read_byte_data(client, sda->index);
159 	if (retval < 0)
160 		goto fail;
161 
162 	hyst = val - retval * 1000;
163 	hyst = DIV_ROUND_CLOSEST(hyst, 1000);
164 	if (hyst < 0 || hyst > 255) {
165 		retval = -ERANGE;
166 		goto fail;
167 	}
168 
169 	retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
170 	if (retval == 0) {
171 		retval = count;
172 		data->cached_hyst = hyst;
173 		data->hyst_valid = jiffies + HZ;
174 	}
175 fail:
176 	mutex_unlock(&data->mutex);
177 	return retval;
178 }
179 
180 /*
181  *	Sensors. We pass the actual i2c register to the methods.
182  */
183 
184 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
185 	show_temp, store_temp, 0x06);
186 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
187 	show_temp, store_temp, 0x05);
188 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
189 	show_temp, store_temp, 0x20);
190 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
191 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
192 	show_bit, NULL, 0x36, 0x01);
193 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
194 	show_bit, NULL, 0x35, 0x01);
195 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
196 	show_bit, NULL, 0x37, 0x01);
197 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
198 	show_hyst, store_hyst, 0x20);
199 
200 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
201 	show_temp, store_temp, 0x08);
202 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
203 	show_temp, store_temp, 0x07);
204 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
205 	show_temp, store_temp, 0x19);
206 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
207 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
208 	show_bit, NULL, 0x36, 0x02);
209 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
210 	show_bit, NULL, 0x35, 0x02);
211 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
212 	show_bit, NULL, 0x37, 0x02);
213 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
214 	show_hyst, store_hyst, 0x19);
215 
216 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
217 	show_temp, store_temp, 0x16);
218 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
219 	show_temp, store_temp, 0x15);
220 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
221 	show_temp, store_temp, 0x1A);
222 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
223 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
224 	show_bit, NULL, 0x36, 0x04);
225 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
226 	show_bit, NULL, 0x35, 0x04);
227 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
228 	show_bit, NULL, 0x37, 0x04);
229 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
230 	show_hyst, store_hyst, 0x1A);
231 
232 static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
233 	show_bit, store_bit, 0x03, 0x40);
234 
235 static struct attribute *mid_att_thermal[] = {
236 	&sensor_dev_attr_temp1_min.dev_attr.attr,
237 	&sensor_dev_attr_temp1_max.dev_attr.attr,
238 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
239 	&sensor_dev_attr_temp1_input.dev_attr.attr,
240 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
241 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
242 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
243 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
244 	&sensor_dev_attr_temp2_min.dev_attr.attr,
245 	&sensor_dev_attr_temp2_max.dev_attr.attr,
246 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
247 	&sensor_dev_attr_temp2_input.dev_attr.attr,
248 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
249 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
250 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
251 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
252 	&sensor_dev_attr_temp3_min.dev_attr.attr,
253 	&sensor_dev_attr_temp3_max.dev_attr.attr,
254 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
255 	&sensor_dev_attr_temp3_input.dev_attr.attr,
256 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
257 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
258 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
259 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
260 	&sensor_dev_attr_power_state.dev_attr.attr,
261 	NULL
262 };
263 
264 static const struct attribute_group m_thermal_gr = {
265 	.attrs = mid_att_thermal
266 };
267 
268 static int emc1403_detect(struct i2c_client *client,
269 			struct i2c_board_info *info)
270 {
271 	int id;
272 	/* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
273 
274 	id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
275 	if (id != 0x5d)
276 		return -ENODEV;
277 
278 	id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
279 	switch (id) {
280 	case 0x21:
281 		strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
282 		break;
283 	case 0x23:
284 		strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
285 		break;
286 	/* Note: 0x25 is the 1404 which is very similar and this
287 	   driver could be extended */
288 	default:
289 		return -ENODEV;
290 	}
291 
292 	id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
293 	if (id != 0x01)
294 		return -ENODEV;
295 
296 	return 0;
297 }
298 
299 static int emc1403_probe(struct i2c_client *client,
300 			const struct i2c_device_id *id)
301 {
302 	int res;
303 	struct thermal_data *data;
304 
305 	data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
306 	if (data == NULL) {
307 		dev_warn(&client->dev, "out of memory");
308 		return -ENOMEM;
309 	}
310 
311 	i2c_set_clientdata(client, data);
312 	mutex_init(&data->mutex);
313 	data->hyst_valid = jiffies - 1;		/* Expired */
314 
315 	res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
316 	if (res) {
317 		dev_warn(&client->dev, "create group failed\n");
318 		goto thermal_error1;
319 	}
320 	data->hwmon_dev = hwmon_device_register(&client->dev);
321 	if (IS_ERR(data->hwmon_dev)) {
322 		res = PTR_ERR(data->hwmon_dev);
323 		dev_warn(&client->dev, "register hwmon dev failed\n");
324 		goto thermal_error2;
325 	}
326 	dev_info(&client->dev, "EMC1403 Thermal chip found\n");
327 	return res;
328 
329 thermal_error2:
330 	sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
331 thermal_error1:
332 	kfree(data);
333 	return res;
334 }
335 
336 static int emc1403_remove(struct i2c_client *client)
337 {
338 	struct thermal_data *data = i2c_get_clientdata(client);
339 
340 	hwmon_device_unregister(data->hwmon_dev);
341 	sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
342 	kfree(data);
343 	return 0;
344 }
345 
346 static const unsigned short emc1403_address_list[] = {
347 	0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
348 };
349 
350 static const struct i2c_device_id emc1403_idtable[] = {
351 	{ "emc1403", 0 },
352 	{ "emc1423", 0 },
353 	{ }
354 };
355 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
356 
357 static struct i2c_driver sensor_emc1403 = {
358 	.class = I2C_CLASS_HWMON,
359 	.driver = {
360 		.name = "emc1403",
361 	},
362 	.detect = emc1403_detect,
363 	.probe = emc1403_probe,
364 	.remove = emc1403_remove,
365 	.id_table = emc1403_idtable,
366 	.address_list = emc1403_address_list,
367 };
368 
369 static int __init sensor_emc1403_init(void)
370 {
371 	return i2c_add_driver(&sensor_emc1403);
372 }
373 
374 static void  __exit sensor_emc1403_exit(void)
375 {
376 	i2c_del_driver(&sensor_emc1403);
377 }
378 
379 module_init(sensor_emc1403_init);
380 module_exit(sensor_emc1403_exit);
381 
382 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
383 MODULE_DESCRIPTION("emc1403 Thermal Driver");
384 MODULE_LICENSE("GPL v2");
385