1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Character device interface driver for Remoteproc framework.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (c) 2020, The Linux Foundation. All rights reserved.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/cdev.h>
9*4882a593Smuzhiyun #include <linux/compat.h>
10*4882a593Smuzhiyun #include <linux/fs.h>
11*4882a593Smuzhiyun #include <linux/module.h>
12*4882a593Smuzhiyun #include <linux/remoteproc.h>
13*4882a593Smuzhiyun #include <linux/uaccess.h>
14*4882a593Smuzhiyun #include <uapi/linux/remoteproc_cdev.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #include "remoteproc_internal.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun #define NUM_RPROC_DEVICES 64
19*4882a593Smuzhiyun static dev_t rproc_major;
20*4882a593Smuzhiyun
rproc_cdev_write(struct file * filp,const char __user * buf,size_t len,loff_t * pos)21*4882a593Smuzhiyun static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
24*4882a593Smuzhiyun int ret = 0;
25*4882a593Smuzhiyun char cmd[10];
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun if (!len || len > sizeof(cmd))
28*4882a593Smuzhiyun return -EINVAL;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun ret = copy_from_user(cmd, buf, len);
31*4882a593Smuzhiyun if (ret)
32*4882a593Smuzhiyun return -EFAULT;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun if (!strncmp(cmd, "start", len)) {
35*4882a593Smuzhiyun if (rproc->state == RPROC_RUNNING)
36*4882a593Smuzhiyun return -EBUSY;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun ret = rproc_boot(rproc);
39*4882a593Smuzhiyun } else if (!strncmp(cmd, "stop", len)) {
40*4882a593Smuzhiyun if (rproc->state != RPROC_RUNNING)
41*4882a593Smuzhiyun return -EINVAL;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun rproc_shutdown(rproc);
44*4882a593Smuzhiyun } else {
45*4882a593Smuzhiyun dev_err(&rproc->dev, "Unrecognized option\n");
46*4882a593Smuzhiyun ret = -EINVAL;
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun return ret ? ret : len;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
rproc_device_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)52*4882a593Smuzhiyun static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
55*4882a593Smuzhiyun void __user *argp = (void __user *)arg;
56*4882a593Smuzhiyun s32 param;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun switch (ioctl) {
59*4882a593Smuzhiyun case RPROC_SET_SHUTDOWN_ON_RELEASE:
60*4882a593Smuzhiyun if (copy_from_user(¶m, argp, sizeof(s32)))
61*4882a593Smuzhiyun return -EFAULT;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun rproc->cdev_put_on_release = !!param;
64*4882a593Smuzhiyun break;
65*4882a593Smuzhiyun case RPROC_GET_SHUTDOWN_ON_RELEASE:
66*4882a593Smuzhiyun param = (s32)rproc->cdev_put_on_release;
67*4882a593Smuzhiyun if (copy_to_user(argp, ¶m, sizeof(s32)))
68*4882a593Smuzhiyun return -EFAULT;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun break;
71*4882a593Smuzhiyun default:
72*4882a593Smuzhiyun dev_err(&rproc->dev, "Unsupported ioctl\n");
73*4882a593Smuzhiyun return -EINVAL;
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun return 0;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun
rproc_cdev_release(struct inode * inode,struct file * filp)79*4882a593Smuzhiyun static int rproc_cdev_release(struct inode *inode, struct file *filp)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun struct rproc *rproc = container_of(inode->i_cdev, struct rproc, cdev);
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun if (rproc->cdev_put_on_release && rproc->state == RPROC_RUNNING)
84*4882a593Smuzhiyun rproc_shutdown(rproc);
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun return 0;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun static const struct file_operations rproc_fops = {
90*4882a593Smuzhiyun .write = rproc_cdev_write,
91*4882a593Smuzhiyun .unlocked_ioctl = rproc_device_ioctl,
92*4882a593Smuzhiyun .compat_ioctl = compat_ptr_ioctl,
93*4882a593Smuzhiyun .release = rproc_cdev_release,
94*4882a593Smuzhiyun };
95*4882a593Smuzhiyun
rproc_char_device_add(struct rproc * rproc)96*4882a593Smuzhiyun int rproc_char_device_add(struct rproc *rproc)
97*4882a593Smuzhiyun {
98*4882a593Smuzhiyun int ret;
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun cdev_init(&rproc->cdev, &rproc_fops);
101*4882a593Smuzhiyun rproc->cdev.owner = THIS_MODULE;
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun rproc->dev.devt = MKDEV(MAJOR(rproc_major), rproc->index);
104*4882a593Smuzhiyun cdev_set_parent(&rproc->cdev, &rproc->dev.kobj);
105*4882a593Smuzhiyun ret = cdev_add(&rproc->cdev, rproc->dev.devt, 1);
106*4882a593Smuzhiyun if (ret < 0)
107*4882a593Smuzhiyun dev_err(&rproc->dev, "Failed to add char dev for %s\n", rproc->name);
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun return ret;
110*4882a593Smuzhiyun }
111*4882a593Smuzhiyun
rproc_char_device_remove(struct rproc * rproc)112*4882a593Smuzhiyun void rproc_char_device_remove(struct rproc *rproc)
113*4882a593Smuzhiyun {
114*4882a593Smuzhiyun cdev_del(&rproc->cdev);
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun
rproc_init_cdev(void)117*4882a593Smuzhiyun void __init rproc_init_cdev(void)
118*4882a593Smuzhiyun {
119*4882a593Smuzhiyun int ret;
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc");
122*4882a593Smuzhiyun if (ret < 0)
123*4882a593Smuzhiyun pr_err("Failed to alloc rproc_cdev region, err %d\n", ret);
124*4882a593Smuzhiyun }
125