kernel/drivers/thermal/int340x_thermal/acpi_thermal_rel.c

   1 /* acpi_thermal_rel.c driver for exporting ACPI thermal relationship
   2  *
   3  * Copyright (c) 2014 Intel Corp
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  */
  10
  11 /*
  12  * Two functionalities included:
  13  * 1. Export _TRT, _ART, via misc device interface to the userspace.
  14  * 2. Provide parsing result to kernel drivers
  15  *
  16  */
  17 #include <linux/init.h>
  18 #include <linux/export.h>
  19 #include <linux/module.h>
  20 #include <linux/device.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/io.h>
  23 #include <linux/acpi.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/miscdevice.h>
  26 #include "acpi_thermal_rel.h"
  27
  28 static acpi_handle acpi_thermal_rel_handle;
  29 static DEFINE_SPINLOCK(acpi_thermal_rel_chrdev_lock);
  30 static int acpi_thermal_rel_chrdev_count;       /* #times opened */
  31 static int acpi_thermal_rel_chrdev_exclu;       /* already open exclusive? */
  32
  33 static int acpi_thermal_rel_open(struct inode *inode, struct file *file)
  34 {
  35         spin_lock(&acpi_thermal_rel_chrdev_lock);
  36         if (acpi_thermal_rel_chrdev_exclu ||
  37             (acpi_thermal_rel_chrdev_count && (file->f_flags & O_EXCL))) {
  38                 spin_unlock(&acpi_thermal_rel_chrdev_lock);
  39                 return -EBUSY;
  40         }
  41
  42         if (file->f_flags & O_EXCL)
  43                 acpi_thermal_rel_chrdev_exclu = 1;
  44         acpi_thermal_rel_chrdev_count++;
  45
  46         spin_unlock(&acpi_thermal_rel_chrdev_lock);
  47
  48         return nonseekable_open(inode, file);
  49 }
  50
  51 static int acpi_thermal_rel_release(struct inode *inode, struct file *file)
  52 {
  53         spin_lock(&acpi_thermal_rel_chrdev_lock);
  54         acpi_thermal_rel_chrdev_count--;
  55         acpi_thermal_rel_chrdev_exclu = 0;
  56         spin_unlock(&acpi_thermal_rel_chrdev_lock);
  57
  58         return 0;
  59 }
  60
  61 /**
  62  * acpi_parse_trt - Thermal Relationship Table _TRT for passive cooling
  63  *
  64  * @handle: ACPI handle of the device contains _TRT
  65  * @art_count: the number of valid entries resulted from parsing _TRT
  66  * @artp: pointer to pointer of array of art entries in parsing result
  67  * @create_dev: whether to create platform devices for target and source
  68  *
  69  */
  70 int acpi_parse_trt(acpi_handle handle, int *trt_count, struct trt **trtp,
  71                 bool create_dev)
  72 {
  73         acpi_status status;
  74         int result = 0;
  75         int i;
  76         int nr_bad_entries = 0;
  77         struct trt *trts;
  78         struct acpi_device *adev;
  79         union acpi_object *p;
  80         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  81         struct acpi_buffer element = { 0, NULL };
  82         struct acpi_buffer trt_format = { sizeof("RRNNNNNN"), "RRNNNNNN" };
  83
  84         if (!acpi_has_method(handle, "_TRT"))
  85                 return -ENODEV;
  86
  87         status = acpi_evaluate_object(handle, "_TRT", NULL, &buffer);
  88         if (ACPI_FAILURE(status))
  89                 return -ENODEV;
  90
  91         p = buffer.pointer;
  92         if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
  93                 pr_err("Invalid _TRT data\n");
  94                 result = -EFAULT;
  95                 goto end;
  96         }
  97
  98         *trt_count = p->package.count;
  99         trts = kzalloc(*trt_count * sizeof(struct trt), GFP_KERNEL);
 100         if (!trts) {
 101                 result = -ENOMEM;
 102                 goto end;
 103         }
 104
 105         for (i = 0; i < *trt_count; i++) {
 106                 struct trt *trt = &trts[i - nr_bad_entries];
 107
 108                 element.length = sizeof(struct trt);
 109                 element.pointer = trt;
 110
 111                 status = acpi_extract_package(&(p->package.elements[i]),
 112                                               &trt_format, &element);
 113                 if (ACPI_FAILURE(status)) {
 114                         nr_bad_entries++;
 115                         pr_warn("_TRT package %d is invalid, ignored\n", i);
 116                         continue;
 117                 }
 118                 if (!create_dev)
 119                         continue;
 120
 121                 result = acpi_bus_get_device(trt->source, &adev);
 122                 if (result)
 123                         pr_warn("Failed to get source ACPI device\n");
 124
 125                 result = acpi_bus_get_device(trt->target, &adev);
 126                 if (result)
 127                         pr_warn("Failed to get target ACPI device\n");
 128         }
 129
 130         result = 0;
 131
 132         *trtp = trts;
 133         /* don't count bad entries */
 134         *trt_count -= nr_bad_entries;
 135 end:
 136         kfree(buffer.pointer);
 137         return result;
 138 }
 139 EXPORT_SYMBOL(acpi_parse_trt);
 140
 141 /**
 142  * acpi_parse_art - Parse Active Relationship Table _ART
 143  *
 144  * @handle: ACPI handle of the device contains _ART
 145  * @art_count: the number of valid entries resulted from parsing _ART
 146  * @artp: pointer to pointer of array of art entries in parsing result
 147  * @create_dev: whether to create platform devices for target and source
 148  *
 149  */
 150 int acpi_parse_art(acpi_handle handle, int *art_count, struct art **artp,
 151                 bool create_dev)
 152 {
 153         acpi_status status;
 154         int result = 0;
 155         int i;
 156         int nr_bad_entries = 0;
 157         struct art *arts;
 158         struct acpi_device *adev;
 159         union acpi_object *p;
 160         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 161         struct acpi_buffer element = { 0, NULL };
 162         struct acpi_buffer art_format = {
 163                 sizeof("RRNNNNNNNNNNN"), "RRNNNNNNNNNNN" };
 164
 165         if (!acpi_has_method(handle, "_ART"))
 166                 return -ENODEV;
 167
 168         status = acpi_evaluate_object(handle, "_ART", NULL, &buffer);
 169         if (ACPI_FAILURE(status))
 170                 return -ENODEV;
 171
 172         p = buffer.pointer;
 173         if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
 174                 pr_err("Invalid _ART data\n");
 175                 result = -EFAULT;
 176                 goto end;
 177         }
 178
 179         /* ignore p->package.elements[0], as this is _ART Revision field */
 180         *art_count = p->package.count - 1;
 181         arts = kzalloc(*art_count * sizeof(struct art), GFP_KERNEL);
 182         if (!arts) {
 183                 result = -ENOMEM;
 184                 goto end;
 185         }
 186
 187         for (i = 0; i < *art_count; i++) {
 188                 struct art *art = &arts[i - nr_bad_entries];
 189
 190                 element.length = sizeof(struct art);
 191                 element.pointer = art;
 192
 193                 status = acpi_extract_package(&(p->package.elements[i + 1]),
 194                                               &art_format, &element);
 195                 if (ACPI_FAILURE(status)) {
 196                         pr_warn("_ART package %d is invalid, ignored", i);
 197                         nr_bad_entries++;
 198                         continue;
 199                 }
 200                 if (!create_dev)
 201                         continue;
 202
 203                 if (art->source) {
 204                         result = acpi_bus_get_device(art->source, &adev);
 205                         if (result)
 206                                 pr_warn("Failed to get source ACPI device\n");
 207                 }
 208                 if (art->target) {
 209                         result = acpi_bus_get_device(art->target, &adev);
 210                         if (result)
 211                                 pr_warn("Failed to get source ACPI device\n");
 212                 }
 213         }
 214
 215         *artp = arts;
 216         /* don't count bad entries */
 217         *art_count -= nr_bad_entries;
 218 end:
 219         kfree(buffer.pointer);
 220         return result;
 221 }
 222 EXPORT_SYMBOL(acpi_parse_art);
 223
 224
 225 /* get device name from acpi handle */
 226 static void get_single_name(acpi_handle handle, char *name)
 227 {
 228         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
 229
 230         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)))
 231                 pr_warn("Failed get name from handle\n");
 232         else {
 233                 memcpy(name, buffer.pointer, ACPI_NAME_SIZE);
 234                 kfree(buffer.pointer);
 235         }
 236 }
 237
 238 static int fill_art(char __user *ubuf)
 239 {
 240         int i;
 241         int ret;
 242         int count;
 243         int art_len;
 244         struct art *arts = NULL;
 245         union art_object *art_user;
 246
 247         ret = acpi_parse_art(acpi_thermal_rel_handle, &count, &arts, false);
 248         if (ret)
 249                 goto free_art;
 250         art_len = count * sizeof(union art_object);
 251         art_user = kzalloc(art_len, GFP_KERNEL);
 252         if (!art_user) {
 253                 ret = -ENOMEM;
 254                 goto free_art;
 255         }
 256         /* now fill in user art data */
 257         for (i = 0; i < count; i++) {
 258                 /* userspace art needs device name instead of acpi reference */
 259                 get_single_name(arts[i].source, art_user[i].source_device);
 260                 get_single_name(arts[i].target, art_user[i].target_device);
 261                 /* copy the rest int data in addition to source and target */
 262                 memcpy(&art_user[i].weight, &arts[i].weight,
 263                         sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
 264         }
 265
 266         if (copy_to_user(ubuf, art_user, art_len))
 267                 ret = -EFAULT;
 268         kfree(art_user);
 269 free_art:
 270         kfree(arts);
 271         return ret;
 272 }
 273
 274 static int fill_trt(char __user *ubuf)
 275 {
 276         int i;
 277         int ret;
 278         int count;
 279         int trt_len;
 280         struct trt *trts = NULL;
 281         union trt_object *trt_user;
 282
 283         ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, &trts, false);
 284         if (ret)
 285                 goto free_trt;
 286         trt_len = count * sizeof(union trt_object);
 287         trt_user = kzalloc(trt_len, GFP_KERNEL);
 288         if (!trt_user) {
 289                 ret = -ENOMEM;
 290                 goto free_trt;
 291         }
 292         /* now fill in user trt data */
 293         for (i = 0; i < count; i++) {
 294                 /* userspace trt needs device name instead of acpi reference */
 295                 get_single_name(trts[i].source, trt_user[i].source_device);
 296                 get_single_name(trts[i].target, trt_user[i].target_device);
 297                 trt_user[i].sample_period = trts[i].sample_period;
 298                 trt_user[i].influence = trts[i].influence;
 299         }
 300
 301         if (copy_to_user(ubuf, trt_user, trt_len))
 302                 ret = -EFAULT;
 303         kfree(trt_user);
 304 free_trt:
 305         kfree(trts);
 306         return ret;
 307 }
 308
 309 static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd,
 310                                    unsigned long __arg)
 311 {
 312         int ret = 0;
 313         unsigned long length = 0;
 314         int count = 0;
 315         char __user *arg = (void __user *)__arg;
 316         struct trt *trts = NULL;
 317         struct art *arts = NULL;
 318
 319         switch (cmd) {
 320         case ACPI_THERMAL_GET_TRT_COUNT:
 321                 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
 322                                 &trts, false);
 323                 kfree(trts);
 324                 if (!ret)
 325                         return put_user(count, (unsigned long __user *)__arg);
 326                 return ret;
 327         case ACPI_THERMAL_GET_TRT_LEN:
 328                 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
 329                                 &trts, false);
 330                 kfree(trts);
 331                 length = count * sizeof(union trt_object);
 332                 if (!ret)
 333                         return put_user(length, (unsigned long __user *)__arg);
 334                 return ret;
 335         case ACPI_THERMAL_GET_TRT:
 336                 return fill_trt(arg);
 337         case ACPI_THERMAL_GET_ART_COUNT:
 338                 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
 339                                 &arts, false);
 340                 kfree(arts);
 341                 if (!ret)
 342                         return put_user(count, (unsigned long __user *)__arg);
 343                 return ret;
 344         case ACPI_THERMAL_GET_ART_LEN:
 345                 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
 346                                 &arts, false);
 347                 kfree(arts);
 348                 length = count * sizeof(union art_object);
 349                 if (!ret)
 350                         return put_user(length, (unsigned long __user *)__arg);
 351                 return ret;
 352
 353         case ACPI_THERMAL_GET_ART:
 354                 return fill_art(arg);
 355
 356         default:
 357                 return -ENOTTY;
 358         }
 359 }
 360
 361 static const struct file_operations acpi_thermal_rel_fops = {
 362         .owner          = THIS_MODULE,
 363         .open           = acpi_thermal_rel_open,
 364         .release        = acpi_thermal_rel_release,
 365         .unlocked_ioctl = acpi_thermal_rel_ioctl,
 366         .llseek         = no_llseek,
 367 };
 368
 369 static struct miscdevice acpi_thermal_rel_misc_device = {
 370         .minor  = MISC_DYNAMIC_MINOR,
 371         "acpi_thermal_rel",
 372         &acpi_thermal_rel_fops
 373 };
 374
 375 int acpi_thermal_rel_misc_device_add(acpi_handle handle)
 376 {
 377         acpi_thermal_rel_handle = handle;
 378
 379         return misc_register(&acpi_thermal_rel_misc_device);
 380 }
 381 EXPORT_SYMBOL(acpi_thermal_rel_misc_device_add);
 382
 383 int acpi_thermal_rel_misc_device_remove(acpi_handle handle)
 384 {
 385         misc_deregister(&acpi_thermal_rel_misc_device);
 386
 387         return 0;
 388 }
 389 EXPORT_SYMBOL(acpi_thermal_rel_misc_device_remove);
 390
 391 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
 392 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com");
 393 MODULE_DESCRIPTION("Intel acpi thermal rel misc dev driver");
 394 MODULE_LICENSE("GPL v2");