1 /*
2  * Copyright (C) ST-Ericsson 2010 - 2013
3  * Author: Martin Persson <martin.persson@stericsson.com>
4  *         Hongbo Zhang <hongbo.zhang@linaro.org>
5  * License Terms: GNU General Public License v2
6  *
7  * ABX500 does not provide auto ADC, so to monitor the required temperatures,
8  * a periodic work is used. It is more important to not wake up the CPU than
9  * to perform this job, hence the use of a deferred delay.
10  *
11  * A deferred delay for thermal monitor is considered safe because:
12  * If the chip gets too hot during a sleep state it's most likely due to
13  * external factors, such as the surrounding temperature. I.e. no SW decisions
14  * will make any difference.
15  */
16 
17 #include <linux/err.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/interrupt.h>
21 #include <linux/jiffies.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/of.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm.h>
27 #include <linux/slab.h>
28 #include <linux/sysfs.h>
29 #include <linux/workqueue.h>
30 #include "abx500.h"
31 
32 #define DEFAULT_MONITOR_DELAY	HZ
33 #define DEFAULT_MAX_TEMP	130
34 
schedule_monitor(struct abx500_temp * data)35 static inline void schedule_monitor(struct abx500_temp *data)
36 {
37 	data->work_active = true;
38 	schedule_delayed_work(&data->work, DEFAULT_MONITOR_DELAY);
39 }
40 
threshold_updated(struct abx500_temp * data)41 static void threshold_updated(struct abx500_temp *data)
42 {
43 	int i;
44 	for (i = 0; i < data->monitored_sensors; i++)
45 		if (data->max[i] != 0 || data->min[i] != 0) {
46 			schedule_monitor(data);
47 			return;
48 		}
49 
50 	dev_dbg(&data->pdev->dev, "No active thresholds.\n");
51 	cancel_delayed_work_sync(&data->work);
52 	data->work_active = false;
53 }
54 
gpadc_monitor(struct work_struct * work)55 static void gpadc_monitor(struct work_struct *work)
56 {
57 	int temp, i, ret;
58 	char alarm_node[30];
59 	bool updated_min_alarm, updated_max_alarm;
60 	struct abx500_temp *data;
61 
62 	data = container_of(work, struct abx500_temp, work.work);
63 	mutex_lock(&data->lock);
64 
65 	for (i = 0; i < data->monitored_sensors; i++) {
66 		/* Thresholds are considered inactive if set to 0 */
67 		if (data->max[i] == 0 && data->min[i] == 0)
68 			continue;
69 
70 		if (data->max[i] < data->min[i])
71 			continue;
72 
73 		ret = data->ops.read_sensor(data, data->gpadc_addr[i], &temp);
74 		if (ret < 0) {
75 			dev_err(&data->pdev->dev, "GPADC read failed\n");
76 			continue;
77 		}
78 
79 		updated_min_alarm = false;
80 		updated_max_alarm = false;
81 
82 		if (data->min[i] != 0) {
83 			if (temp < data->min[i]) {
84 				if (data->min_alarm[i] == false) {
85 					data->min_alarm[i] = true;
86 					updated_min_alarm = true;
87 				}
88 			} else {
89 				if (data->min_alarm[i] == true) {
90 					data->min_alarm[i] = false;
91 					updated_min_alarm = true;
92 				}
93 			}
94 		}
95 		if (data->max[i] != 0) {
96 			if (temp > data->max[i]) {
97 				if (data->max_alarm[i] == false) {
98 					data->max_alarm[i] = true;
99 					updated_max_alarm = true;
100 				}
101 			} else if (temp < data->max[i] - data->max_hyst[i]) {
102 				if (data->max_alarm[i] == true) {
103 					data->max_alarm[i] = false;
104 					updated_max_alarm = true;
105 				}
106 			}
107 		}
108 
109 		if (updated_min_alarm) {
110 			ret = sprintf(alarm_node, "temp%d_min_alarm", i + 1);
111 			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
112 		}
113 		if (updated_max_alarm) {
114 			ret = sprintf(alarm_node, "temp%d_max_alarm", i + 1);
115 			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
116 		}
117 	}
118 
119 	schedule_monitor(data);
120 	mutex_unlock(&data->lock);
121 }
122 
123 /* HWMON sysfs interfaces */
show_name(struct device * dev,struct device_attribute * devattr,char * buf)124 static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
125 			 char *buf)
126 {
127 	struct abx500_temp *data = dev_get_drvdata(dev);
128 	/* Show chip name */
129 	return data->ops.show_name(dev, devattr, buf);
130 }
131 
show_label(struct device * dev,struct device_attribute * devattr,char * buf)132 static ssize_t show_label(struct device *dev,
133 			  struct device_attribute *devattr, char *buf)
134 {
135 	struct abx500_temp *data = dev_get_drvdata(dev);
136 	/* Show each sensor label */
137 	return data->ops.show_label(dev, devattr, buf);
138 }
139 
show_input(struct device * dev,struct device_attribute * devattr,char * buf)140 static ssize_t show_input(struct device *dev,
141 			  struct device_attribute *devattr, char *buf)
142 {
143 	int ret, temp;
144 	struct abx500_temp *data = dev_get_drvdata(dev);
145 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
146 	u8 gpadc_addr = data->gpadc_addr[attr->index];
147 
148 	ret = data->ops.read_sensor(data, gpadc_addr, &temp);
149 	if (ret < 0)
150 		return ret;
151 
152 	return sprintf(buf, "%d\n", temp);
153 }
154 
155 /* Set functions (RW nodes) */
set_min(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)156 static ssize_t set_min(struct device *dev, struct device_attribute *devattr,
157 		       const char *buf, size_t count)
158 {
159 	unsigned long val;
160 	struct abx500_temp *data = dev_get_drvdata(dev);
161 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
162 	int res = kstrtol(buf, 10, &val);
163 	if (res < 0)
164 		return res;
165 
166 	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
167 
168 	mutex_lock(&data->lock);
169 	data->min[attr->index] = val;
170 	threshold_updated(data);
171 	mutex_unlock(&data->lock);
172 
173 	return count;
174 }
175 
set_max(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)176 static ssize_t set_max(struct device *dev, struct device_attribute *devattr,
177 		       const char *buf, size_t count)
178 {
179 	unsigned long val;
180 	struct abx500_temp *data = dev_get_drvdata(dev);
181 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
182 	int res = kstrtol(buf, 10, &val);
183 	if (res < 0)
184 		return res;
185 
186 	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
187 
188 	mutex_lock(&data->lock);
189 	data->max[attr->index] = val;
190 	threshold_updated(data);
191 	mutex_unlock(&data->lock);
192 
193 	return count;
194 }
195 
set_max_hyst(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)196 static ssize_t set_max_hyst(struct device *dev,
197 			    struct device_attribute *devattr,
198 			    const char *buf, size_t count)
199 {
200 	unsigned long val;
201 	struct abx500_temp *data = dev_get_drvdata(dev);
202 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
203 	int res = kstrtoul(buf, 10, &val);
204 	if (res < 0)
205 		return res;
206 
207 	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
208 
209 	mutex_lock(&data->lock);
210 	data->max_hyst[attr->index] = val;
211 	threshold_updated(data);
212 	mutex_unlock(&data->lock);
213 
214 	return count;
215 }
216 
217 /* Show functions (RO nodes) */
show_min(struct device * dev,struct device_attribute * devattr,char * buf)218 static ssize_t show_min(struct device *dev,
219 			struct device_attribute *devattr, char *buf)
220 {
221 	struct abx500_temp *data = dev_get_drvdata(dev);
222 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
223 
224 	return sprintf(buf, "%lu\n", data->min[attr->index]);
225 }
226 
show_max(struct device * dev,struct device_attribute * devattr,char * buf)227 static ssize_t show_max(struct device *dev,
228 			struct device_attribute *devattr, char *buf)
229 {
230 	struct abx500_temp *data = dev_get_drvdata(dev);
231 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
232 
233 	return sprintf(buf, "%lu\n", data->max[attr->index]);
234 }
235 
show_max_hyst(struct device * dev,struct device_attribute * devattr,char * buf)236 static ssize_t show_max_hyst(struct device *dev,
237 			     struct device_attribute *devattr, char *buf)
238 {
239 	struct abx500_temp *data = dev_get_drvdata(dev);
240 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
241 
242 	return sprintf(buf, "%lu\n", data->max_hyst[attr->index]);
243 }
244 
show_min_alarm(struct device * dev,struct device_attribute * devattr,char * buf)245 static ssize_t show_min_alarm(struct device *dev,
246 			      struct device_attribute *devattr, char *buf)
247 {
248 	struct abx500_temp *data = dev_get_drvdata(dev);
249 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
250 
251 	return sprintf(buf, "%d\n", data->min_alarm[attr->index]);
252 }
253 
show_max_alarm(struct device * dev,struct device_attribute * devattr,char * buf)254 static ssize_t show_max_alarm(struct device *dev,
255 			      struct device_attribute *devattr, char *buf)
256 {
257 	struct abx500_temp *data = dev_get_drvdata(dev);
258 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
259 
260 	return sprintf(buf, "%d\n", data->max_alarm[attr->index]);
261 }
262 
abx500_attrs_visible(struct kobject * kobj,struct attribute * attr,int n)263 static umode_t abx500_attrs_visible(struct kobject *kobj,
264 				   struct attribute *attr, int n)
265 {
266 	struct device *dev = container_of(kobj, struct device, kobj);
267 	struct abx500_temp *data = dev_get_drvdata(dev);
268 
269 	if (data->ops.is_visible)
270 		return data->ops.is_visible(attr, n);
271 
272 	return attr->mode;
273 }
274 
275 /* Chip name, required by hwmon */
276 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
277 
278 /* GPADC - SENSOR1 */
279 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 0);
280 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
281 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
282 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
283 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
284 			  show_max_hyst, set_max_hyst, 0);
285 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
286 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);
287 
288 /* GPADC - SENSOR2 */
289 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL, 1);
290 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 1);
291 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min, 1);
292 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max, 1);
293 static SENSOR_DEVICE_ATTR(temp2_max_hyst, S_IWUSR | S_IRUGO,
294 			  show_max_hyst, set_max_hyst, 1);
295 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_min_alarm, NULL, 1);
296 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_max_alarm, NULL, 1);
297 
298 /* GPADC - SENSOR3 */
299 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, show_label, NULL, 2);
300 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 2);
301 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min, 2);
302 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max, 2);
303 static SENSOR_DEVICE_ATTR(temp3_max_hyst, S_IWUSR | S_IRUGO,
304 			  show_max_hyst, set_max_hyst, 2);
305 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_min_alarm, NULL, 2);
306 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_max_alarm, NULL, 2);
307 
308 /* GPADC - SENSOR4 */
309 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, show_label, NULL, 3);
310 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_input, NULL, 3);
311 static SENSOR_DEVICE_ATTR(temp4_min, S_IWUSR | S_IRUGO, show_min, set_min, 3);
312 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_max, set_max, 3);
313 static SENSOR_DEVICE_ATTR(temp4_max_hyst, S_IWUSR | S_IRUGO,
314 			  show_max_hyst, set_max_hyst, 3);
315 static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_min_alarm, NULL, 3);
316 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_max_alarm, NULL, 3);
317 
318 static struct attribute *abx500_temp_attributes[] = {
319 	&sensor_dev_attr_name.dev_attr.attr,
320 
321 	&sensor_dev_attr_temp1_label.dev_attr.attr,
322 	&sensor_dev_attr_temp1_input.dev_attr.attr,
323 	&sensor_dev_attr_temp1_min.dev_attr.attr,
324 	&sensor_dev_attr_temp1_max.dev_attr.attr,
325 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
326 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
327 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
328 
329 	&sensor_dev_attr_temp2_label.dev_attr.attr,
330 	&sensor_dev_attr_temp2_input.dev_attr.attr,
331 	&sensor_dev_attr_temp2_min.dev_attr.attr,
332 	&sensor_dev_attr_temp2_max.dev_attr.attr,
333 	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
334 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
335 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
336 
337 	&sensor_dev_attr_temp3_label.dev_attr.attr,
338 	&sensor_dev_attr_temp3_input.dev_attr.attr,
339 	&sensor_dev_attr_temp3_min.dev_attr.attr,
340 	&sensor_dev_attr_temp3_max.dev_attr.attr,
341 	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
342 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
343 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
344 
345 	&sensor_dev_attr_temp4_label.dev_attr.attr,
346 	&sensor_dev_attr_temp4_input.dev_attr.attr,
347 	&sensor_dev_attr_temp4_min.dev_attr.attr,
348 	&sensor_dev_attr_temp4_max.dev_attr.attr,
349 	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
350 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
351 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
352 	NULL
353 };
354 
355 static const struct attribute_group abx500_temp_group = {
356 	.attrs = abx500_temp_attributes,
357 	.is_visible = abx500_attrs_visible,
358 };
359 
abx500_temp_irq_handler(int irq,void * irq_data)360 static irqreturn_t abx500_temp_irq_handler(int irq, void *irq_data)
361 {
362 	struct platform_device *pdev = irq_data;
363 	struct abx500_temp *data = platform_get_drvdata(pdev);
364 
365 	data->ops.irq_handler(irq, data);
366 	return IRQ_HANDLED;
367 }
368 
setup_irqs(struct platform_device * pdev)369 static int setup_irqs(struct platform_device *pdev)
370 {
371 	int ret;
372 	int irq = platform_get_irq_byname(pdev, "ABX500_TEMP_WARM");
373 
374 	if (irq < 0) {
375 		dev_err(&pdev->dev, "Get irq by name failed\n");
376 		return irq;
377 	}
378 
379 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
380 		abx500_temp_irq_handler, 0, "abx500-temp", pdev);
381 	if (ret < 0)
382 		dev_err(&pdev->dev, "Request threaded irq failed (%d)\n", ret);
383 
384 	return ret;
385 }
386 
abx500_temp_probe(struct platform_device * pdev)387 static int abx500_temp_probe(struct platform_device *pdev)
388 {
389 	struct abx500_temp *data;
390 	int err;
391 
392 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
393 	if (!data)
394 		return -ENOMEM;
395 
396 	data->pdev = pdev;
397 	mutex_init(&data->lock);
398 
399 	/* Chip specific initialization */
400 	err = abx500_hwmon_init(data);
401 	if (err	< 0 || !data->ops.read_sensor || !data->ops.show_name ||
402 			!data->ops.show_label)
403 		return err;
404 
405 	INIT_DEFERRABLE_WORK(&data->work, gpadc_monitor);
406 
407 	platform_set_drvdata(pdev, data);
408 
409 	err = sysfs_create_group(&pdev->dev.kobj, &abx500_temp_group);
410 	if (err < 0) {
411 		dev_err(&pdev->dev, "Create sysfs group failed (%d)\n", err);
412 		return err;
413 	}
414 
415 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
416 	if (IS_ERR(data->hwmon_dev)) {
417 		err = PTR_ERR(data->hwmon_dev);
418 		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
419 		goto exit_sysfs_group;
420 	}
421 
422 	if (data->ops.irq_handler) {
423 		err = setup_irqs(pdev);
424 		if (err < 0)
425 			goto exit_hwmon_reg;
426 	}
427 	return 0;
428 
429 exit_hwmon_reg:
430 	hwmon_device_unregister(data->hwmon_dev);
431 exit_sysfs_group:
432 	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
433 	return err;
434 }
435 
abx500_temp_remove(struct platform_device * pdev)436 static int abx500_temp_remove(struct platform_device *pdev)
437 {
438 	struct abx500_temp *data = platform_get_drvdata(pdev);
439 
440 	cancel_delayed_work_sync(&data->work);
441 	hwmon_device_unregister(data->hwmon_dev);
442 	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
443 
444 	return 0;
445 }
446 
abx500_temp_suspend(struct platform_device * pdev,pm_message_t state)447 static int abx500_temp_suspend(struct platform_device *pdev,
448 			       pm_message_t state)
449 {
450 	struct abx500_temp *data = platform_get_drvdata(pdev);
451 
452 	if (data->work_active)
453 		cancel_delayed_work_sync(&data->work);
454 
455 	return 0;
456 }
457 
abx500_temp_resume(struct platform_device * pdev)458 static int abx500_temp_resume(struct platform_device *pdev)
459 {
460 	struct abx500_temp *data = platform_get_drvdata(pdev);
461 
462 	if (data->work_active)
463 		schedule_monitor(data);
464 
465 	return 0;
466 }
467 
468 #ifdef CONFIG_OF
469 static const struct of_device_id abx500_temp_match[] = {
470 	{ .compatible = "stericsson,abx500-temp" },
471 	{},
472 };
473 MODULE_DEVICE_TABLE(of, abx500_temp_match);
474 #endif
475 
476 static struct platform_driver abx500_temp_driver = {
477 	.driver = {
478 		.name = "abx500-temp",
479 		.of_match_table = of_match_ptr(abx500_temp_match),
480 	},
481 	.suspend = abx500_temp_suspend,
482 	.resume = abx500_temp_resume,
483 	.probe = abx500_temp_probe,
484 	.remove = abx500_temp_remove,
485 };
486 
487 module_platform_driver(abx500_temp_driver);
488 
489 MODULE_AUTHOR("Martin Persson <martin.persson@stericsson.com>");
490 MODULE_DESCRIPTION("ABX500 temperature driver");
491 MODULE_LICENSE("GPL");
492