xref: /openbmc/linux/drivers/hwmon/emc1403.c (revision 786baecf)
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 	/*
45 	 * Cache the hyst value so we don't keep re-reading it. In theory
46 	 * we could cache it forever as nobody else should be writing it.
47 	 */
48 	u8 cached_hyst;
49 	unsigned long hyst_valid;
50 };
51 
52 static ssize_t show_temp(struct device *dev,
53 			struct device_attribute *attr, char *buf)
54 {
55 	struct i2c_client *client = to_i2c_client(dev);
56 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
57 	int retval = i2c_smbus_read_byte_data(client, sda->index);
58 
59 	if (retval < 0)
60 		return retval;
61 	return sprintf(buf, "%d000\n", retval);
62 }
63 
64 static ssize_t show_bit(struct device *dev,
65 			struct device_attribute *attr, char *buf)
66 {
67 	struct i2c_client *client = to_i2c_client(dev);
68 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
69 	int retval = i2c_smbus_read_byte_data(client, sda->nr);
70 
71 	if (retval < 0)
72 		return retval;
73 	retval &= sda->index;
74 	return sprintf(buf, "%d\n", retval ? 1 : 0);
75 }
76 
77 static ssize_t store_temp(struct device *dev,
78 		struct device_attribute *attr, const char *buf, size_t count)
79 {
80 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
81 	struct i2c_client *client = to_i2c_client(dev);
82 	unsigned long val;
83 	int retval;
84 
85 	if (kstrtoul(buf, 10, &val))
86 		return -EINVAL;
87 	retval = i2c_smbus_write_byte_data(client, sda->index,
88 					DIV_ROUND_CLOSEST(val, 1000));
89 	if (retval < 0)
90 		return retval;
91 	return count;
92 }
93 
94 static ssize_t store_bit(struct device *dev,
95 		struct device_attribute *attr, const char *buf, size_t count)
96 {
97 	struct i2c_client *client = to_i2c_client(dev);
98 	struct thermal_data *data = i2c_get_clientdata(client);
99 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
100 	unsigned long val;
101 	int retval;
102 
103 	if (kstrtoul(buf, 10, &val))
104 		return -EINVAL;
105 
106 	mutex_lock(&data->mutex);
107 	retval = i2c_smbus_read_byte_data(client, sda->nr);
108 	if (retval < 0)
109 		goto fail;
110 
111 	retval &= ~sda->index;
112 	if (val)
113 		retval |= sda->index;
114 
115 	retval = i2c_smbus_write_byte_data(client, sda->index, retval);
116 	if (retval == 0)
117 		retval = count;
118 fail:
119 	mutex_unlock(&data->mutex);
120 	return retval;
121 }
122 
123 static ssize_t show_hyst(struct device *dev,
124 			struct device_attribute *attr, char *buf)
125 {
126 	struct i2c_client *client = to_i2c_client(dev);
127 	struct thermal_data *data = i2c_get_clientdata(client);
128 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
129 	int retval;
130 	int hyst;
131 
132 	retval = i2c_smbus_read_byte_data(client, sda->index);
133 	if (retval < 0)
134 		return retval;
135 
136 	if (time_after(jiffies, data->hyst_valid)) {
137 		hyst = i2c_smbus_read_byte_data(client, 0x21);
138 		if (hyst < 0)
139 			return retval;
140 		data->cached_hyst = hyst;
141 		data->hyst_valid = jiffies + HZ;
142 	}
143 	return sprintf(buf, "%d000\n", retval - data->cached_hyst);
144 }
145 
146 static ssize_t store_hyst(struct device *dev,
147 		struct device_attribute *attr, const char *buf, size_t count)
148 {
149 	struct i2c_client *client = to_i2c_client(dev);
150 	struct thermal_data *data = i2c_get_clientdata(client);
151 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
152 	int retval;
153 	int hyst;
154 	unsigned long val;
155 
156 	if (kstrtoul(buf, 10, &val))
157 		return -EINVAL;
158 
159 	mutex_lock(&data->mutex);
160 	retval = i2c_smbus_read_byte_data(client, sda->index);
161 	if (retval < 0)
162 		goto fail;
163 
164 	hyst = val - retval * 1000;
165 	hyst = DIV_ROUND_CLOSEST(hyst, 1000);
166 	if (hyst < 0 || hyst > 255) {
167 		retval = -ERANGE;
168 		goto fail;
169 	}
170 
171 	retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
172 	if (retval == 0) {
173 		retval = count;
174 		data->cached_hyst = hyst;
175 		data->hyst_valid = jiffies + HZ;
176 	}
177 fail:
178 	mutex_unlock(&data->mutex);
179 	return retval;
180 }
181 
182 /*
183  *	Sensors. We pass the actual i2c register to the methods.
184  */
185 
186 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
187 	show_temp, store_temp, 0x06);
188 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
189 	show_temp, store_temp, 0x05);
190 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
191 	show_temp, store_temp, 0x20);
192 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
193 static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
194 	show_bit, NULL, 0x36, 0x01);
195 static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
196 	show_bit, NULL, 0x35, 0x01);
197 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
198 	show_bit, NULL, 0x37, 0x01);
199 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
200 	show_hyst, store_hyst, 0x20);
201 
202 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
203 	show_temp, store_temp, 0x08);
204 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
205 	show_temp, store_temp, 0x07);
206 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
207 	show_temp, store_temp, 0x19);
208 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
209 static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
210 	show_bit, NULL, 0x36, 0x02);
211 static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
212 	show_bit, NULL, 0x35, 0x02);
213 static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
214 	show_bit, NULL, 0x37, 0x02);
215 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
216 	show_hyst, store_hyst, 0x19);
217 
218 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
219 	show_temp, store_temp, 0x16);
220 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
221 	show_temp, store_temp, 0x15);
222 static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
223 	show_temp, store_temp, 0x1A);
224 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
225 static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
226 	show_bit, NULL, 0x36, 0x04);
227 static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
228 	show_bit, NULL, 0x35, 0x04);
229 static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
230 	show_bit, NULL, 0x37, 0x04);
231 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
232 	show_hyst, store_hyst, 0x1A);
233 
234 static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
235 	show_bit, store_bit, 0x03, 0x40);
236 
237 static struct attribute *mid_att_thermal[] = {
238 	&sensor_dev_attr_temp1_min.dev_attr.attr,
239 	&sensor_dev_attr_temp1_max.dev_attr.attr,
240 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
241 	&sensor_dev_attr_temp1_input.dev_attr.attr,
242 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
243 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
244 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
245 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
246 	&sensor_dev_attr_temp2_min.dev_attr.attr,
247 	&sensor_dev_attr_temp2_max.dev_attr.attr,
248 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
249 	&sensor_dev_attr_temp2_input.dev_attr.attr,
250 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
251 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
252 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
253 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
254 	&sensor_dev_attr_temp3_min.dev_attr.attr,
255 	&sensor_dev_attr_temp3_max.dev_attr.attr,
256 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
257 	&sensor_dev_attr_temp3_input.dev_attr.attr,
258 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
259 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
260 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
261 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
262 	&sensor_dev_attr_power_state.dev_attr.attr,
263 	NULL
264 };
265 
266 static const struct attribute_group m_thermal_gr = {
267 	.attrs = mid_att_thermal
268 };
269 
270 static int emc1403_detect(struct i2c_client *client,
271 			struct i2c_board_info *info)
272 {
273 	int id;
274 	/* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
275 
276 	id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
277 	if (id != 0x5d)
278 		return -ENODEV;
279 
280 	id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
281 	switch (id) {
282 	case 0x21:
283 		strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
284 		break;
285 	case 0x23:
286 		strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
287 		break;
288 	/*
289 	 * Note: 0x25 is the 1404 which is very similar and this
290 	 * driver could be extended
291 	 */
292 	default:
293 		return -ENODEV;
294 	}
295 
296 	id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
297 	if (id != 0x01)
298 		return -ENODEV;
299 
300 	return 0;
301 }
302 
303 static int emc1403_probe(struct i2c_client *client,
304 			const struct i2c_device_id *id)
305 {
306 	int res;
307 	struct thermal_data *data;
308 
309 	data = kzalloc(sizeof(struct thermal_data), GFP_KERNEL);
310 	if (data == NULL) {
311 		dev_warn(&client->dev, "out of memory");
312 		return -ENOMEM;
313 	}
314 
315 	i2c_set_clientdata(client, data);
316 	mutex_init(&data->mutex);
317 	data->hyst_valid = jiffies - 1;		/* Expired */
318 
319 	res = sysfs_create_group(&client->dev.kobj, &m_thermal_gr);
320 	if (res) {
321 		dev_warn(&client->dev, "create group failed\n");
322 		goto thermal_error1;
323 	}
324 	data->hwmon_dev = hwmon_device_register(&client->dev);
325 	if (IS_ERR(data->hwmon_dev)) {
326 		res = PTR_ERR(data->hwmon_dev);
327 		dev_warn(&client->dev, "register hwmon dev failed\n");
328 		goto thermal_error2;
329 	}
330 	dev_info(&client->dev, "EMC1403 Thermal chip found\n");
331 	return res;
332 
333 thermal_error2:
334 	sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
335 thermal_error1:
336 	kfree(data);
337 	return res;
338 }
339 
340 static int emc1403_remove(struct i2c_client *client)
341 {
342 	struct thermal_data *data = i2c_get_clientdata(client);
343 
344 	hwmon_device_unregister(data->hwmon_dev);
345 	sysfs_remove_group(&client->dev.kobj, &m_thermal_gr);
346 	kfree(data);
347 	return 0;
348 }
349 
350 static const unsigned short emc1403_address_list[] = {
351 	0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
352 };
353 
354 static const struct i2c_device_id emc1403_idtable[] = {
355 	{ "emc1403", 0 },
356 	{ "emc1423", 0 },
357 	{ }
358 };
359 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
360 
361 static struct i2c_driver sensor_emc1403 = {
362 	.class = I2C_CLASS_HWMON,
363 	.driver = {
364 		.name = "emc1403",
365 	},
366 	.detect = emc1403_detect,
367 	.probe = emc1403_probe,
368 	.remove = emc1403_remove,
369 	.id_table = emc1403_idtable,
370 	.address_list = emc1403_address_list,
371 };
372 
373 module_i2c_driver(sensor_emc1403);
374 
375 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
376 MODULE_DESCRIPTION("emc1403 Thermal Driver");
377 MODULE_LICENSE("GPL v2");
378