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 | |
8 | #include <linux/cdev.h> |
9 | #include <linux/compat.h> |
10 | #include <linux/fs.h> |
11 | #include <linux/module.h> |
12 | #include <linux/remoteproc.h> |
13 | #include <linux/uaccess.h> |
14 | #include <uapi/linux/remoteproc_cdev.h> |
15 | |
16 | #include "remoteproc_internal.h" |
17 | |
18 | #define NUM_RPROC_DEVICES 64 |
19 | static dev_t rproc_major; |
20 | |
21 | static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos) |
22 | { |
23 | struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev); |
24 | int ret = 0; |
25 | char cmd[10]; |
26 | |
27 | if (!len || len > sizeof(cmd)) |
28 | return -EINVAL; |
29 | |
30 | ret = copy_from_user(to: cmd, from: buf, n: len); |
31 | if (ret) |
32 | return -EFAULT; |
33 | |
34 | if (!strncmp(cmd, "start" , len)) { |
35 | ret = rproc_boot(rproc); |
36 | } else if (!strncmp(cmd, "stop" , len)) { |
37 | ret = rproc_shutdown(rproc); |
38 | } else if (!strncmp(cmd, "detach" , len)) { |
39 | ret = rproc_detach(rproc); |
40 | } else { |
41 | dev_err(&rproc->dev, "Unrecognized option\n" ); |
42 | ret = -EINVAL; |
43 | } |
44 | |
45 | return ret ? ret : len; |
46 | } |
47 | |
48 | static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) |
49 | { |
50 | struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev); |
51 | void __user *argp = (void __user *)arg; |
52 | s32 param; |
53 | |
54 | switch (ioctl) { |
55 | case RPROC_SET_SHUTDOWN_ON_RELEASE: |
56 | if (copy_from_user(to: ¶m, from: argp, n: sizeof(s32))) |
57 | return -EFAULT; |
58 | |
59 | rproc->cdev_put_on_release = !!param; |
60 | break; |
61 | case RPROC_GET_SHUTDOWN_ON_RELEASE: |
62 | param = (s32)rproc->cdev_put_on_release; |
63 | if (copy_to_user(to: argp, from: ¶m, n: sizeof(s32))) |
64 | return -EFAULT; |
65 | |
66 | break; |
67 | default: |
68 | dev_err(&rproc->dev, "Unsupported ioctl\n" ); |
69 | return -EINVAL; |
70 | } |
71 | |
72 | return 0; |
73 | } |
74 | |
75 | static int rproc_cdev_release(struct inode *inode, struct file *filp) |
76 | { |
77 | struct rproc *rproc = container_of(inode->i_cdev, struct rproc, cdev); |
78 | int ret = 0; |
79 | |
80 | if (!rproc->cdev_put_on_release) |
81 | return 0; |
82 | |
83 | if (rproc->state == RPROC_RUNNING) |
84 | rproc_shutdown(rproc); |
85 | else if (rproc->state == RPROC_ATTACHED) |
86 | ret = rproc_detach(rproc); |
87 | |
88 | return ret; |
89 | } |
90 | |
91 | static const struct file_operations rproc_fops = { |
92 | .write = rproc_cdev_write, |
93 | .unlocked_ioctl = rproc_device_ioctl, |
94 | .compat_ioctl = compat_ptr_ioctl, |
95 | .release = rproc_cdev_release, |
96 | }; |
97 | |
98 | int rproc_char_device_add(struct rproc *rproc) |
99 | { |
100 | int ret; |
101 | |
102 | cdev_init(&rproc->cdev, &rproc_fops); |
103 | rproc->cdev.owner = THIS_MODULE; |
104 | |
105 | rproc->dev.devt = MKDEV(MAJOR(rproc_major), rproc->index); |
106 | cdev_set_parent(p: &rproc->cdev, kobj: &rproc->dev.kobj); |
107 | ret = cdev_add(&rproc->cdev, rproc->dev.devt, 1); |
108 | if (ret < 0) |
109 | dev_err(&rproc->dev, "Failed to add char dev for %s\n" , rproc->name); |
110 | |
111 | return ret; |
112 | } |
113 | |
114 | void rproc_char_device_remove(struct rproc *rproc) |
115 | { |
116 | cdev_del(&rproc->cdev); |
117 | } |
118 | |
119 | void __init rproc_init_cdev(void) |
120 | { |
121 | int ret; |
122 | |
123 | ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc" ); |
124 | if (ret < 0) |
125 | pr_err("Failed to alloc rproc_cdev region, err %d\n" , ret); |
126 | } |
127 | |