drivers/hwmon/abx500.c

   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
  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
  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
  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 */
 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
 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
 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) */
 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
 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
 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) */
 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, "%ld\n", data->min[attr->index]);
 225 }
 226
 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, "%ld\n", data->max[attr->index]);
 234 }
 235
 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, "%ld\n", data->max_hyst[attr->index]);
 243 }
 244
 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
 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
 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 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
 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
 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, IRQF_NO_SUSPEND, "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
 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
 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
 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
 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 #endif
 474
 475 static struct platform_driver abx500_temp_driver = {
 476         .driver = {
 477                 .owner = THIS_MODULE,
 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");