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44767708 SG |
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(cmd, buf, len); | |
31 | if (ret) | |
32 | return -EFAULT; | |
33 | ||
34 | if (!strncmp(cmd, "start", len)) { | |
44767708 SG |
35 | ret = rproc_boot(rproc); |
36 | } else if (!strncmp(cmd, "stop", len)) { | |
c13b780c | 37 | ret = rproc_shutdown(rproc); |
5daaeb5f | 38 | } else if (!strncmp(cmd, "detach", len)) { |
5daaeb5f | 39 | ret = rproc_detach(rproc); |
44767708 SG |
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(¶m, argp, 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(argp, ¶m, 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); | |
6e71d2b2 MP |
78 | int ret = 0; |
79 | ||
80 | if (!rproc->cdev_put_on_release) | |
81 | return 0; | |
44767708 | 82 | |
6e71d2b2 | 83 | if (rproc->state == RPROC_RUNNING) |
44767708 | 84 | rproc_shutdown(rproc); |
6e71d2b2 MP |
85 | else if (rproc->state == RPROC_ATTACHED) |
86 | ret = rproc_detach(rproc); | |
44767708 | 87 | |
6e71d2b2 | 88 | return ret; |
44767708 SG |
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(&rproc->cdev, &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 | { | |
930eec0b | 116 | cdev_del(&rproc->cdev); |
44767708 SG |
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 | } |