diff options
Diffstat (limited to 'drivers/remoteproc/remoteproc_cdev.c')
| -rw-r--r-- | drivers/remoteproc/remoteproc_cdev.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c new file mode 100644 index 000000000000..b19ea3057bde --- /dev/null +++ b/drivers/remoteproc/remoteproc_cdev.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Character device interface driver for Remoteproc framework. + * + * Copyright (c) 2020, The Linux Foundation. All rights reserved. + */ + +#include <linux/cdev.h> +#include <linux/compat.h> +#include <linux/fs.h> +#include <linux/module.h> +#include <linux/remoteproc.h> +#include <linux/uaccess.h> +#include <uapi/linux/remoteproc_cdev.h> + +#include "remoteproc_internal.h" + +#define NUM_RPROC_DEVICES 64 +static dev_t rproc_major; + +static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos) +{ + struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev); + int ret = 0; + char cmd[10]; + + if (!len || len > sizeof(cmd)) + return -EINVAL; + + ret = copy_from_user(cmd, buf, len); + if (ret) + return -EFAULT; + + if (!strncmp(cmd, "start", len)) { + if (rproc->state == RPROC_RUNNING) + return -EBUSY; + + ret = rproc_boot(rproc); + } else if (!strncmp(cmd, "stop", len)) { + if (rproc->state != RPROC_RUNNING) + return -EINVAL; + + rproc_shutdown(rproc); + } else { + dev_err(&rproc->dev, "Unrecognized option\n"); + ret = -EINVAL; + } + + return ret ? ret : len; +} + +static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) +{ + struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev); + void __user *argp = (void __user *)arg; + s32 param; + + switch (ioctl) { + case RPROC_SET_SHUTDOWN_ON_RELEASE: + if (copy_from_user(¶m, argp, sizeof(s32))) + return -EFAULT; + + rproc->cdev_put_on_release = !!param; + break; + case RPROC_GET_SHUTDOWN_ON_RELEASE: + param = (s32)rproc->cdev_put_on_release; + if (copy_to_user(argp, ¶m, sizeof(s32))) + return -EFAULT; + + break; + default: + dev_err(&rproc->dev, "Unsupported ioctl\n"); + return -EINVAL; + } + + return 0; +} + +static int rproc_cdev_release(struct inode *inode, struct file *filp) +{ + struct rproc *rproc = container_of(inode->i_cdev, struct rproc, cdev); + + if (rproc->cdev_put_on_release && rproc->state == RPROC_RUNNING) + rproc_shutdown(rproc); + + return 0; +} + +static const struct file_operations rproc_fops = { + .write = rproc_cdev_write, + .unlocked_ioctl = rproc_device_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .release = rproc_cdev_release, +}; + +int rproc_char_device_add(struct rproc *rproc) +{ + int ret; + + cdev_init(&rproc->cdev, &rproc_fops); + rproc->cdev.owner = THIS_MODULE; + + rproc->dev.devt = MKDEV(MAJOR(rproc_major), rproc->index); + cdev_set_parent(&rproc->cdev, &rproc->dev.kobj); + ret = cdev_add(&rproc->cdev, rproc->dev.devt, 1); + if (ret < 0) + dev_err(&rproc->dev, "Failed to add char dev for %s\n", rproc->name); + + return ret; +} + +void rproc_char_device_remove(struct rproc *rproc) +{ + __unregister_chrdev(MAJOR(rproc->dev.devt), rproc->index, 1, "remoteproc"); +} + +void __init rproc_init_cdev(void) +{ + int ret; + + ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc"); + if (ret < 0) + pr_err("Failed to alloc rproc_cdev region, err %d\n", ret); +} |