device.c 2.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
  2. /*
  3. * Copyright(c) 2015, 2016 Intel Corporation.
  4. */
  5. #include <linux/cdev.h>
  6. #include <linux/device.h>
  7. #include <linux/fs.h>
  8. #include "hfi.h"
  9. #include "device.h"
  10. static struct class *class;
  11. static struct class *user_class;
  12. static dev_t hfi1_dev;
  13. int hfi1_cdev_init(int minor, const char *name,
  14. const struct file_operations *fops,
  15. struct cdev *cdev, struct device **devp,
  16. bool user_accessible,
  17. struct kobject *parent)
  18. {
  19. const dev_t dev = MKDEV(MAJOR(hfi1_dev), minor);
  20. struct device *device = NULL;
  21. int ret;
  22. cdev_init(cdev, fops);
  23. cdev->owner = THIS_MODULE;
  24. cdev_set_parent(cdev, parent);
  25. kobject_set_name(&cdev->kobj, name);
  26. ret = cdev_add(cdev, dev, 1);
  27. if (ret < 0) {
  28. pr_err("Could not add cdev for minor %d, %s (err %d)\n",
  29. minor, name, -ret);
  30. goto done;
  31. }
  32. if (user_accessible)
  33. device = device_create(user_class, NULL, dev, NULL, "%s", name);
  34. else
  35. device = device_create(class, NULL, dev, NULL, "%s", name);
  36. if (IS_ERR(device)) {
  37. ret = PTR_ERR(device);
  38. device = NULL;
  39. pr_err("Could not create device for minor %d, %s (err %d)\n",
  40. minor, name, -ret);
  41. cdev_del(cdev);
  42. }
  43. done:
  44. *devp = device;
  45. return ret;
  46. }
  47. void hfi1_cdev_cleanup(struct cdev *cdev, struct device **devp)
  48. {
  49. struct device *device = *devp;
  50. if (device) {
  51. device_unregister(device);
  52. *devp = NULL;
  53. cdev_del(cdev);
  54. }
  55. }
  56. static const char *hfi1_class_name = "hfi1";
  57. const char *class_name(void)
  58. {
  59. return hfi1_class_name;
  60. }
  61. static char *hfi1_devnode(struct device *dev, umode_t *mode)
  62. {
  63. if (mode)
  64. *mode = 0600;
  65. return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
  66. }
  67. static const char *hfi1_class_name_user = "hfi1_user";
  68. static const char *class_name_user(void)
  69. {
  70. return hfi1_class_name_user;
  71. }
  72. static char *hfi1_user_devnode(struct device *dev, umode_t *mode)
  73. {
  74. if (mode)
  75. *mode = 0666;
  76. return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
  77. }
  78. int __init dev_init(void)
  79. {
  80. int ret;
  81. ret = alloc_chrdev_region(&hfi1_dev, 0, HFI1_NMINORS, DRIVER_NAME);
  82. if (ret < 0) {
  83. pr_err("Could not allocate chrdev region (err %d)\n", -ret);
  84. goto done;
  85. }
  86. class = class_create(THIS_MODULE, class_name());
  87. if (IS_ERR(class)) {
  88. ret = PTR_ERR(class);
  89. pr_err("Could not create device class (err %d)\n", -ret);
  90. unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
  91. goto done;
  92. }
  93. class->devnode = hfi1_devnode;
  94. user_class = class_create(THIS_MODULE, class_name_user());
  95. if (IS_ERR(user_class)) {
  96. ret = PTR_ERR(user_class);
  97. pr_err("Could not create device class for user accessible files (err %d)\n",
  98. -ret);
  99. class_destroy(class);
  100. class = NULL;
  101. user_class = NULL;
  102. unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
  103. goto done;
  104. }
  105. user_class->devnode = hfi1_user_devnode;
  106. done:
  107. return ret;
  108. }
  109. void dev_cleanup(void)
  110. {
  111. class_destroy(class);
  112. class = NULL;
  113. class_destroy(user_class);
  114. user_class = NULL;
  115. unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
  116. }