remoteproc_cdev.c 2.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Character device interface driver for Remoteproc framework.
  4. *
  5. * Copyright (c) 2020, The Linux Foundation. All rights reserved.
  6. */
  7. #include <linux/cdev.h>
  8. #include <linux/compat.h>
  9. #include <linux/fs.h>
  10. #include <linux/module.h>
  11. #include <linux/remoteproc.h>
  12. #include <linux/uaccess.h>
  13. #include <uapi/linux/remoteproc_cdev.h>
  14. #include "remoteproc_internal.h"
  15. #define NUM_RPROC_DEVICES 64
  16. static dev_t rproc_major;
  17. static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos)
  18. {
  19. struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
  20. int ret = 0;
  21. char cmd[10];
  22. if (!len || len > sizeof(cmd))
  23. return -EINVAL;
  24. ret = copy_from_user(cmd, buf, len);
  25. if (ret)
  26. return -EFAULT;
  27. if (!strncmp(cmd, "start", len)) {
  28. if (rproc->state == RPROC_RUNNING)
  29. return -EBUSY;
  30. ret = rproc_boot(rproc);
  31. } else if (!strncmp(cmd, "stop", len)) {
  32. if (rproc->state != RPROC_RUNNING)
  33. return -EINVAL;
  34. rproc_shutdown(rproc);
  35. } else {
  36. dev_err(&rproc->dev, "Unrecognized option\n");
  37. ret = -EINVAL;
  38. }
  39. return ret ? ret : len;
  40. }
  41. static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
  42. {
  43. struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
  44. void __user *argp = (void __user *)arg;
  45. s32 param;
  46. switch (ioctl) {
  47. case RPROC_SET_SHUTDOWN_ON_RELEASE:
  48. if (copy_from_user(&param, argp, sizeof(s32)))
  49. return -EFAULT;
  50. rproc->cdev_put_on_release = !!param;
  51. break;
  52. case RPROC_GET_SHUTDOWN_ON_RELEASE:
  53. param = (s32)rproc->cdev_put_on_release;
  54. if (copy_to_user(argp, &param, sizeof(s32)))
  55. return -EFAULT;
  56. break;
  57. default:
  58. dev_err(&rproc->dev, "Unsupported ioctl\n");
  59. return -EINVAL;
  60. }
  61. return 0;
  62. }
  63. static int rproc_cdev_release(struct inode *inode, struct file *filp)
  64. {
  65. struct rproc *rproc = container_of(inode->i_cdev, struct rproc, cdev);
  66. if (rproc->cdev_put_on_release && rproc->state == RPROC_RUNNING)
  67. rproc_shutdown(rproc);
  68. return 0;
  69. }
  70. static const struct file_operations rproc_fops = {
  71. .write = rproc_cdev_write,
  72. .unlocked_ioctl = rproc_device_ioctl,
  73. .compat_ioctl = compat_ptr_ioctl,
  74. .release = rproc_cdev_release,
  75. };
  76. int rproc_char_device_add(struct rproc *rproc)
  77. {
  78. int ret;
  79. cdev_init(&rproc->cdev, &rproc_fops);
  80. rproc->cdev.owner = THIS_MODULE;
  81. rproc->dev.devt = MKDEV(MAJOR(rproc_major), rproc->index);
  82. cdev_set_parent(&rproc->cdev, &rproc->dev.kobj);
  83. ret = cdev_add(&rproc->cdev, rproc->dev.devt, 1);
  84. if (ret < 0)
  85. dev_err(&rproc->dev, "Failed to add char dev for %s\n", rproc->name);
  86. return ret;
  87. }
  88. void rproc_char_device_remove(struct rproc *rproc)
  89. {
  90. cdev_del(&rproc->cdev);
  91. }
  92. void __init rproc_init_cdev(void)
  93. {
  94. int ret;
  95. ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc");
  96. if (ret < 0)
  97. pr_err("Failed to alloc rproc_cdev region, err %d\n", ret);
  98. }