Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
/*
 * Copyright (C) ST-Ericsson 2010 - 2013
 * Author: Martin Persson <martin.persson@stericsson.com>
 *         Hongbo Zhang <hongbo.zhang@linaro.org>
 * License Terms: GNU General Public License v2
 *
 * ABX500 does not provide auto ADC, so to monitor the required temperatures,
 * a periodic work is used. It is more important to not wake up the CPU than
 * to perform this job, hence the use of a deferred delay.
 *
 * A deferred delay for thermal monitor is considered safe because:
 * If the chip gets too hot during a sleep state it's most likely due to
 * external factors, such as the surrounding temperature. I.e. no SW decisions
 * will make any difference.
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include "abx500.h"

#define DEFAULT_MONITOR_DELAY	HZ
#define DEFAULT_MAX_TEMP	130

static inline void schedule_monitor(struct abx500_temp *data)
{
	data->work_active = true;
	schedule_delayed_work(&data->work, DEFAULT_MONITOR_DELAY);
}

static void threshold_updated(struct abx500_temp *data)
{
	int i;
	for (i = 0; i < data->monitored_sensors; i++)
		if (data->max[i] != 0 || data->min[i] != 0) {
			schedule_monitor(data);
			return;
		}

	dev_dbg(&data->pdev->dev, "No active thresholds.\n");
	cancel_delayed_work_sync(&data->work);
	data->work_active = false;
}

static void gpadc_monitor(struct work_struct *work)
{
	int temp, i, ret;
	char alarm_node[30];
	bool updated_min_alarm, updated_max_alarm;
	struct abx500_temp *data;

	data = container_of(work, struct abx500_temp, work.work);
	mutex_lock(&data->lock);

	for (i = 0; i < data->monitored_sensors; i++) {
		/* Thresholds are considered inactive if set to 0 */
		if (data->max[i] == 0 && data->min[i] == 0)
			continue;

		if (data->max[i] < data->min[i])
			continue;

		ret = data->ops.read_sensor(data, data->gpadc_addr[i], &temp);
		if (ret < 0) {
			dev_err(&data->pdev->dev, "GPADC read failed\n");
			continue;
		}

		updated_min_alarm = false;
		updated_max_alarm = false;

		if (data->min[i] != 0) {
			if (temp < data->min[i]) {
				if (data->min_alarm[i] == false) {
					data->min_alarm[i] = true;
					updated_min_alarm = true;
				}
			} else {
				if (data->min_alarm[i] == true) {
					data->min_alarm[i] = false;
					updated_min_alarm = true;
				}
			}
		}
		if (data->max[i] != 0) {
			if (temp > data->max[i]) {
				if (data->max_alarm[i] == false) {
					data->max_alarm[i] = true;
					updated_max_alarm = true;
				}
			} else if (temp < data->max[i] - data->max_hyst[i]) {
				if (data->max_alarm[i] == true) {
					data->max_alarm[i] = false;
					updated_max_alarm = true;
				}
			}
		}

		if (updated_min_alarm) {
			ret = sprintf(alarm_node, "temp%d_min_alarm", i + 1);
			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
		}
		if (updated_max_alarm) {
			ret = sprintf(alarm_node, "temp%d_max_alarm", i + 1);
			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
		}
	}

	schedule_monitor(data);
	mutex_unlock(&data->lock);
}

/* HWMON sysfs interfaces */
static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
			 char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	/* Show chip name */
	return data->ops.show_name(dev, devattr, buf);
}

static ssize_t show_label(struct device *dev,
			  struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	/* Show each sensor label */
	return data->ops.show_label(dev, devattr, buf);
}

static ssize_t show_input(struct device *dev,
			  struct device_attribute *devattr, char *buf)
{
	int ret, temp;
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	u8 gpadc_addr = data->gpadc_addr[attr->index];

	ret = data->ops.read_sensor(data, gpadc_addr, &temp);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", temp);
}

/* Set functions (RW nodes) */
static ssize_t set_min(struct device *dev, struct device_attribute *devattr,
		       const char *buf, size_t count)
{
	unsigned long val;
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int res = kstrtol(buf, 10, &val);
	if (res < 0)
		return res;

	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);

	mutex_lock(&data->lock);
	data->min[attr->index] = val;
	threshold_updated(data);
	mutex_unlock(&data->lock);

	return count;
}

static ssize_t set_max(struct device *dev, struct device_attribute *devattr,
		       const char *buf, size_t count)
{
	unsigned long val;
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int res = kstrtol(buf, 10, &val);
	if (res < 0)
		return res;

	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);

	mutex_lock(&data->lock);
	data->max[attr->index] = val;
	threshold_updated(data);
	mutex_unlock(&data->lock);

	return count;
}

static ssize_t set_max_hyst(struct device *dev,
			    struct device_attribute *devattr,
			    const char *buf, size_t count)
{
	unsigned long val;
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int res = kstrtoul(buf, 10, &val);
	if (res < 0)
		return res;

	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);

	mutex_lock(&data->lock);
	data->max_hyst[attr->index] = val;
	threshold_updated(data);
	mutex_unlock(&data->lock);

	return count;
}

/* Show functions (RO nodes) */
static ssize_t show_min(struct device *dev,
			struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%lu\n", data->min[attr->index]);
}

static ssize_t show_max(struct device *dev,
			struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%lu\n", data->max[attr->index]);
}

static ssize_t show_max_hyst(struct device *dev,
			     struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%lu\n", data->max_hyst[attr->index]);
}

static ssize_t show_min_alarm(struct device *dev,
			      struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%d\n", data->min_alarm[attr->index]);
}

static ssize_t show_max_alarm(struct device *dev,
			      struct device_attribute *devattr, char *buf)
{
	struct abx500_temp *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%d\n", data->max_alarm[attr->index]);
}

static umode_t abx500_attrs_visible(struct kobject *kobj,
				   struct attribute *attr, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct abx500_temp *data = dev_get_drvdata(dev);

	if (data->ops.is_visible)
		return data->ops.is_visible(attr, n);

	return attr->mode;
}

/* Chip name, required by hwmon */
static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);

/* GPADC - SENSOR1 */
static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
			  show_max_hyst, set_max_hyst, 0);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);

/* GPADC - SENSOR2 */
static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min, 1);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max, 1);
static SENSOR_DEVICE_ATTR(temp2_max_hyst, S_IWUSR | S_IRUGO,
			  show_max_hyst, set_max_hyst, 1);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_min_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_max_alarm, NULL, 1);

/* GPADC - SENSOR3 */
static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, show_label, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min, 2);
static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max, 2);
static SENSOR_DEVICE_ATTR(temp3_max_hyst, S_IWUSR | S_IRUGO,
			  show_max_hyst, set_max_hyst, 2);
static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_min_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_max_alarm, NULL, 2);

/* GPADC - SENSOR4 */
static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, show_label, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_input, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_min, S_IWUSR | S_IRUGO, show_min, set_min, 3);
static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_max, set_max, 3);
static SENSOR_DEVICE_ATTR(temp4_max_hyst, S_IWUSR | S_IRUGO,
			  show_max_hyst, set_max_hyst, 3);
static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_min_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_max_alarm, NULL, 3);

static struct attribute *abx500_temp_attributes[] = {
	&sensor_dev_attr_name.dev_attr.attr,

	&sensor_dev_attr_temp1_label.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,

	&sensor_dev_attr_temp2_label.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,

	&sensor_dev_attr_temp3_label.dev_attr.attr,
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp3_min.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,

	&sensor_dev_attr_temp4_label.dev_attr.attr,
	&sensor_dev_attr_temp4_input.dev_attr.attr,
	&sensor_dev_attr_temp4_min.dev_attr.attr,
	&sensor_dev_attr_temp4_max.dev_attr.attr,
	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group abx500_temp_group = {
	.attrs = abx500_temp_attributes,
	.is_visible = abx500_attrs_visible,
};

static irqreturn_t abx500_temp_irq_handler(int irq, void *irq_data)
{
	struct platform_device *pdev = irq_data;
	struct abx500_temp *data = platform_get_drvdata(pdev);

	data->ops.irq_handler(irq, data);
	return IRQ_HANDLED;
}

static int setup_irqs(struct platform_device *pdev)
{
	int ret;
	int irq = platform_get_irq_byname(pdev, "ABX500_TEMP_WARM");

	if (irq < 0) {
		dev_err(&pdev->dev, "Get irq by name failed\n");
		return irq;
	}

	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
		abx500_temp_irq_handler, 0, "abx500-temp", pdev);
	if (ret < 0)
		dev_err(&pdev->dev, "Request threaded irq failed (%d)\n", ret);

	return ret;
}

static int abx500_temp_probe(struct platform_device *pdev)
{
	struct abx500_temp *data;
	int err;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->pdev = pdev;
	mutex_init(&data->lock);

	/* Chip specific initialization */
	err = abx500_hwmon_init(data);
	if (err	< 0 || !data->ops.read_sensor || !data->ops.show_name ||
			!data->ops.show_label)
		return err;

	INIT_DEFERRABLE_WORK(&data->work, gpadc_monitor);

	platform_set_drvdata(pdev, data);

	err = sysfs_create_group(&pdev->dev.kobj, &abx500_temp_group);
	if (err < 0) {
		dev_err(&pdev->dev, "Create sysfs group failed (%d)\n", err);
		return err;
	}

	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
		goto exit_sysfs_group;
	}

	if (data->ops.irq_handler) {
		err = setup_irqs(pdev);
		if (err < 0)
			goto exit_hwmon_reg;
	}
	return 0;

exit_hwmon_reg:
	hwmon_device_unregister(data->hwmon_dev);
exit_sysfs_group:
	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
	return err;
}

static int abx500_temp_remove(struct platform_device *pdev)
{
	struct abx500_temp *data = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&data->work);
	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);

	return 0;
}

static int abx500_temp_suspend(struct platform_device *pdev,
			       pm_message_t state)
{
	struct abx500_temp *data = platform_get_drvdata(pdev);

	if (data->work_active)
		cancel_delayed_work_sync(&data->work);

	return 0;
}

static int abx500_temp_resume(struct platform_device *pdev)
{
	struct abx500_temp *data = platform_get_drvdata(pdev);

	if (data->work_active)
		schedule_monitor(data);

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id abx500_temp_match[] = {
	{ .compatible = "stericsson,abx500-temp" },
	{},
};
MODULE_DEVICE_TABLE(of, abx500_temp_match);
#endif

static struct platform_driver abx500_temp_driver = {
	.driver = {
		.name = "abx500-temp",
		.of_match_table = of_match_ptr(abx500_temp_match),
	},
	.suspend = abx500_temp_suspend,
	.resume = abx500_temp_resume,
	.probe = abx500_temp_probe,
	.remove = abx500_temp_remove,
};

module_platform_driver(abx500_temp_driver);

MODULE_AUTHOR("Martin Persson <martin.persson@stericsson.com>");
MODULE_DESCRIPTION("ABX500 temperature driver");
MODULE_LICENSE("GPL");