127 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*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 6419static dev_t rproc_major;20 21static 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)) {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 48static 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 75static 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 91static 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 98int 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 114void rproc_char_device_remove(struct rproc *rproc)115{116 cdev_del(&rproc->cdev);117}118 119void __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