xref: /openbmc/linux/drivers/hwmon/adt7x10.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * adt7x10.c - Part of lm_sensors, Linux kernel modules for hardware
4  *	 monitoring
5  * This driver handles the ADT7410 and compatible digital temperature sensors.
6  * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
7  * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
8  * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <linux/jiffies.h>
15 #include <linux/hwmon.h>
16 #include <linux/hwmon-sysfs.h>
17 #include <linux/err.h>
18 #include <linux/mutex.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 
22 #include "adt7x10.h"
23 
24 /*
25  * ADT7X10 status
26  */
27 #define ADT7X10_STAT_T_LOW		(1 << 4)
28 #define ADT7X10_STAT_T_HIGH		(1 << 5)
29 #define ADT7X10_STAT_T_CRIT		(1 << 6)
30 #define ADT7X10_STAT_NOT_RDY		(1 << 7)
31 
32 /*
33  * ADT7X10 config
34  */
35 #define ADT7X10_FAULT_QUEUE_MASK	(1 << 0 | 1 << 1)
36 #define ADT7X10_CT_POLARITY		(1 << 2)
37 #define ADT7X10_INT_POLARITY		(1 << 3)
38 #define ADT7X10_EVENT_MODE		(1 << 4)
39 #define ADT7X10_MODE_MASK		(1 << 5 | 1 << 6)
40 #define ADT7X10_FULL			(0 << 5 | 0 << 6)
41 #define ADT7X10_PD			(1 << 5 | 1 << 6)
42 #define ADT7X10_RESOLUTION		(1 << 7)
43 
44 /*
45  * ADT7X10 masks
46  */
47 #define ADT7X10_T13_VALUE_MASK		0xFFF8
48 #define ADT7X10_T_HYST_MASK		0xF
49 
50 /* straight from the datasheet */
51 #define ADT7X10_TEMP_MIN (-55000)
52 #define ADT7X10_TEMP_MAX 150000
53 
54 /* Each client has this additional data */
55 struct adt7x10_data {
56 	const struct adt7x10_ops *ops;
57 	const char		*name;
58 	struct device		*hwmon_dev;
59 	struct mutex		update_lock;
60 	u8			config;
61 	u8			oldconfig;
62 	bool			valid;		/* true if registers valid */
63 	unsigned long		last_updated;	/* In jiffies */
64 	s16			temp[4];	/* Register values,
65 						   0 = input
66 						   1 = high
67 						   2 = low
68 						   3 = critical */
69 	u8			hyst;		/* hysteresis offset */
70 };
71 
72 static int adt7x10_read_byte(struct device *dev, u8 reg)
73 {
74 	struct adt7x10_data *d = dev_get_drvdata(dev);
75 	return d->ops->read_byte(dev, reg);
76 }
77 
78 static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
79 {
80 	struct adt7x10_data *d = dev_get_drvdata(dev);
81 	return d->ops->write_byte(dev, reg, data);
82 }
83 
84 static int adt7x10_read_word(struct device *dev, u8 reg)
85 {
86 	struct adt7x10_data *d = dev_get_drvdata(dev);
87 	return d->ops->read_word(dev, reg);
88 }
89 
90 static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
91 {
92 	struct adt7x10_data *d = dev_get_drvdata(dev);
93 	return d->ops->write_word(dev, reg, data);
94 }
95 
96 static const u8 ADT7X10_REG_TEMP[4] = {
97 	ADT7X10_TEMPERATURE,		/* input */
98 	ADT7X10_T_ALARM_HIGH,		/* high */
99 	ADT7X10_T_ALARM_LOW,		/* low */
100 	ADT7X10_T_CRIT,			/* critical */
101 };
102 
103 static irqreturn_t adt7x10_irq_handler(int irq, void *private)
104 {
105 	struct device *dev = private;
106 	int status;
107 
108 	status = adt7x10_read_byte(dev, ADT7X10_STATUS);
109 	if (status < 0)
110 		return IRQ_HANDLED;
111 
112 	if (status & ADT7X10_STAT_T_HIGH)
113 		sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
114 	if (status & ADT7X10_STAT_T_LOW)
115 		sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
116 	if (status & ADT7X10_STAT_T_CRIT)
117 		sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");
118 
119 	return IRQ_HANDLED;
120 }
121 
122 static int adt7x10_temp_ready(struct device *dev)
123 {
124 	int i, status;
125 
126 	for (i = 0; i < 6; i++) {
127 		status = adt7x10_read_byte(dev, ADT7X10_STATUS);
128 		if (status < 0)
129 			return status;
130 		if (!(status & ADT7X10_STAT_NOT_RDY))
131 			return 0;
132 		msleep(60);
133 	}
134 	return -ETIMEDOUT;
135 }
136 
137 static int adt7x10_update_temp(struct device *dev)
138 {
139 	struct adt7x10_data *data = dev_get_drvdata(dev);
140 	int ret = 0;
141 
142 	mutex_lock(&data->update_lock);
143 
144 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
145 	    || !data->valid) {
146 		int temp;
147 
148 		dev_dbg(dev, "Starting update\n");
149 
150 		ret = adt7x10_temp_ready(dev); /* check for new value */
151 		if (ret)
152 			goto abort;
153 
154 		temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
155 		if (temp < 0) {
156 			ret = temp;
157 			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
158 				ADT7X10_REG_TEMP[0], ret);
159 			goto abort;
160 		}
161 		data->temp[0] = temp;
162 		data->last_updated = jiffies;
163 		data->valid = true;
164 	}
165 
166 abort:
167 	mutex_unlock(&data->update_lock);
168 	return ret;
169 }
170 
171 static int adt7x10_fill_cache(struct device *dev)
172 {
173 	struct adt7x10_data *data = dev_get_drvdata(dev);
174 	int ret;
175 	int i;
176 
177 	for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
178 		ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
179 		if (ret < 0) {
180 			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
181 				ADT7X10_REG_TEMP[i], ret);
182 			return ret;
183 		}
184 		data->temp[i] = ret;
185 	}
186 
187 	ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
188 	if (ret < 0) {
189 		dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
190 				ADT7X10_T_HYST, ret);
191 		return ret;
192 	}
193 	data->hyst = ret;
194 
195 	return 0;
196 }
197 
198 static s16 ADT7X10_TEMP_TO_REG(long temp)
199 {
200 	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
201 					       ADT7X10_TEMP_MAX) * 128, 1000);
202 }
203 
204 static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
205 {
206 	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
207 	if (!(data->config & ADT7X10_RESOLUTION))
208 		reg &= ADT7X10_T13_VALUE_MASK;
209 	/*
210 	 * temperature is stored in twos complement format, in steps of
211 	 * 1/128°C
212 	 */
213 	return DIV_ROUND_CLOSEST(reg * 1000, 128);
214 }
215 
216 /*-----------------------------------------------------------------------*/
217 
218 /* sysfs attributes for hwmon */
219 
220 static ssize_t adt7x10_temp_show(struct device *dev,
221 				 struct device_attribute *da, char *buf)
222 {
223 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
224 	struct adt7x10_data *data = dev_get_drvdata(dev);
225 
226 
227 	if (attr->index == 0) {
228 		int ret;
229 
230 		ret = adt7x10_update_temp(dev);
231 		if (ret)
232 			return ret;
233 	}
234 
235 	return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
236 		       data->temp[attr->index]));
237 }
238 
239 static ssize_t adt7x10_temp_store(struct device *dev,
240 				  struct device_attribute *da,
241 				  const char *buf, size_t count)
242 {
243 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
244 	struct adt7x10_data *data = dev_get_drvdata(dev);
245 	int nr = attr->index;
246 	long temp;
247 	int ret;
248 
249 	ret = kstrtol(buf, 10, &temp);
250 	if (ret)
251 		return ret;
252 
253 	mutex_lock(&data->update_lock);
254 	data->temp[nr] = ADT7X10_TEMP_TO_REG(temp);
255 	ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
256 	if (ret)
257 		count = ret;
258 	mutex_unlock(&data->update_lock);
259 	return count;
260 }
261 
262 static ssize_t adt7x10_t_hyst_show(struct device *dev,
263 				   struct device_attribute *da, char *buf)
264 {
265 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
266 	struct adt7x10_data *data = dev_get_drvdata(dev);
267 	int nr = attr->index;
268 	int hyst;
269 
270 	hyst = (data->hyst & ADT7X10_T_HYST_MASK) * 1000;
271 
272 	/*
273 	 * hysteresis is stored as a 4 bit offset in the device, convert it
274 	 * to an absolute value
275 	 */
276 	if (nr == 2)	/* min has positive offset, others have negative */
277 		hyst = -hyst;
278 	return sprintf(buf, "%d\n",
279 		       ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
280 }
281 
282 static ssize_t adt7x10_t_hyst_store(struct device *dev,
283 				    struct device_attribute *da,
284 				    const char *buf, size_t count)
285 {
286 	struct adt7x10_data *data = dev_get_drvdata(dev);
287 	int limit, ret;
288 	long hyst;
289 
290 	ret = kstrtol(buf, 10, &hyst);
291 	if (ret)
292 		return ret;
293 	/* convert absolute hysteresis value to a 4 bit delta value */
294 	limit = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
295 	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
296 	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
297 				   0, ADT7X10_T_HYST_MASK);
298 	ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
299 	if (ret)
300 		return ret;
301 
302 	return count;
303 }
304 
305 static ssize_t adt7x10_alarm_show(struct device *dev,
306 				  struct device_attribute *da, char *buf)
307 {
308 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
309 	int ret;
310 
311 	ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
312 	if (ret < 0)
313 		return ret;
314 
315 	return sprintf(buf, "%d\n", !!(ret & attr->index));
316 }
317 
318 static ssize_t name_show(struct device *dev, struct device_attribute *da,
319 			 char *buf)
320 {
321 	struct adt7x10_data *data = dev_get_drvdata(dev);
322 
323 	return sprintf(buf, "%s\n", data->name);
324 }
325 
326 static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
327 static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
328 static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
329 static SENSOR_DEVICE_ATTR_RW(temp1_crit, adt7x10_temp, 3);
330 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adt7x10_t_hyst, 1);
331 static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, adt7x10_t_hyst, 2);
332 static SENSOR_DEVICE_ATTR_RO(temp1_crit_hyst, adt7x10_t_hyst, 3);
333 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, adt7x10_alarm,
334 			     ADT7X10_STAT_T_LOW);
335 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
336 			     ADT7X10_STAT_T_HIGH);
337 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
338 			     ADT7X10_STAT_T_CRIT);
339 static DEVICE_ATTR_RO(name);
340 
341 static struct attribute *adt7x10_attributes[] = {
342 	&sensor_dev_attr_temp1_input.dev_attr.attr,
343 	&sensor_dev_attr_temp1_max.dev_attr.attr,
344 	&sensor_dev_attr_temp1_min.dev_attr.attr,
345 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
346 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
347 	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
348 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
349 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
350 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
351 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
352 	NULL
353 };
354 
355 static const struct attribute_group adt7x10_group = {
356 	.attrs = adt7x10_attributes,
357 };
358 
359 int adt7x10_probe(struct device *dev, const char *name, int irq,
360 		  const struct adt7x10_ops *ops)
361 {
362 	struct adt7x10_data *data;
363 	int ret;
364 
365 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
366 	if (!data)
367 		return -ENOMEM;
368 
369 	data->ops = ops;
370 	data->name = name;
371 
372 	dev_set_drvdata(dev, data);
373 	mutex_init(&data->update_lock);
374 
375 	/* configure as specified */
376 	ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
377 	if (ret < 0) {
378 		dev_dbg(dev, "Can't read config? %d\n", ret);
379 		return ret;
380 	}
381 	data->oldconfig = ret;
382 
383 	/*
384 	 * Set to 16 bit resolution, continous conversion and comparator mode.
385 	 */
386 	data->config = data->oldconfig;
387 	data->config &= ~(ADT7X10_MODE_MASK | ADT7X10_CT_POLARITY |
388 			ADT7X10_INT_POLARITY);
389 	data->config |= ADT7X10_FULL | ADT7X10_RESOLUTION | ADT7X10_EVENT_MODE;
390 
391 	if (data->config != data->oldconfig) {
392 		ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
393 		if (ret)
394 			return ret;
395 	}
396 	dev_dbg(dev, "Config %02x\n", data->config);
397 
398 	ret = adt7x10_fill_cache(dev);
399 	if (ret)
400 		goto exit_restore;
401 
402 	/* Register sysfs hooks */
403 	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
404 	if (ret)
405 		goto exit_restore;
406 
407 	/*
408 	 * The I2C device will already have it's own 'name' attribute, but for
409 	 * the SPI device we need to register it. name will only be non NULL if
410 	 * the device doesn't register the 'name' attribute on its own.
411 	 */
412 	if (name) {
413 		ret = device_create_file(dev, &dev_attr_name);
414 		if (ret)
415 			goto exit_remove;
416 	}
417 
418 	data->hwmon_dev = hwmon_device_register(dev);
419 	if (IS_ERR(data->hwmon_dev)) {
420 		ret = PTR_ERR(data->hwmon_dev);
421 		goto exit_remove_name;
422 	}
423 
424 	if (irq > 0) {
425 		ret = request_threaded_irq(irq, NULL, adt7x10_irq_handler,
426 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
427 				dev_name(dev), dev);
428 		if (ret)
429 			goto exit_hwmon_device_unregister;
430 	}
431 
432 	return 0;
433 
434 exit_hwmon_device_unregister:
435 	hwmon_device_unregister(data->hwmon_dev);
436 exit_remove_name:
437 	if (name)
438 		device_remove_file(dev, &dev_attr_name);
439 exit_remove:
440 	sysfs_remove_group(&dev->kobj, &adt7x10_group);
441 exit_restore:
442 	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
443 	return ret;
444 }
445 EXPORT_SYMBOL_GPL(adt7x10_probe);
446 
447 void adt7x10_remove(struct device *dev, int irq)
448 {
449 	struct adt7x10_data *data = dev_get_drvdata(dev);
450 
451 	if (irq > 0)
452 		free_irq(irq, dev);
453 
454 	hwmon_device_unregister(data->hwmon_dev);
455 	if (data->name)
456 		device_remove_file(dev, &dev_attr_name);
457 	sysfs_remove_group(&dev->kobj, &adt7x10_group);
458 	if (data->oldconfig != data->config)
459 		adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
460 }
461 EXPORT_SYMBOL_GPL(adt7x10_remove);
462 
463 #ifdef CONFIG_PM_SLEEP
464 
465 static int adt7x10_suspend(struct device *dev)
466 {
467 	struct adt7x10_data *data = dev_get_drvdata(dev);
468 
469 	return adt7x10_write_byte(dev, ADT7X10_CONFIG,
470 		data->config | ADT7X10_PD);
471 }
472 
473 static int adt7x10_resume(struct device *dev)
474 {
475 	struct adt7x10_data *data = dev_get_drvdata(dev);
476 
477 	return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
478 }
479 
480 SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
481 EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);
482 
483 #endif /* CONFIG_PM_SLEEP */
484 
485 MODULE_AUTHOR("Hartmut Knaack");
486 MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
487 MODULE_LICENSE("GPL");
488