diff options
Diffstat (limited to 'drivers/rpmsg/rpmsg_ctrl.c')
| -rw-r--r-- | drivers/rpmsg/rpmsg_ctrl.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c new file mode 100644 index 0000000000..4332538356 --- /dev/null +++ b/drivers/rpmsg/rpmsg_ctrl.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022, STMicroelectronics + * Copyright (c) 2016, Linaro Ltd. + * Copyright (c) 2012, Michal Simek <monstr@monstr.eu> + * Copyright (c) 2012, PetaLogix + * Copyright (c) 2011, Texas Instruments, Inc. + * Copyright (c) 2011, Google, Inc. + * + * Based on rpmsg performance statistics driver by Michal Simek, which in turn + * was based on TI & Google OMX rpmsg driver. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/idr.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rpmsg.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <uapi/linux/rpmsg.h> + +#include "rpmsg_char.h" +#include "rpmsg_internal.h" + +#define RPMSG_DEV_MAX (MINORMASK + 1) + +static dev_t rpmsg_major; + +static DEFINE_IDA(rpmsg_ctrl_ida); +static DEFINE_IDA(rpmsg_minor_ida); + +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) + +/** + * struct rpmsg_ctrldev - control device for instantiating endpoint devices + * @rpdev: underlaying rpmsg device + * @cdev: cdev for the ctrl device + * @dev: device for the ctrl device + * @ctrl_lock: serialize the ioctrls. + */ +struct rpmsg_ctrldev { + struct rpmsg_device *rpdev; + struct cdev cdev; + struct device dev; + struct mutex ctrl_lock; +}; + +static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) +{ + struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); + + get_device(&ctrldev->dev); + filp->private_data = ctrldev; + + return 0; +} + +static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) +{ + struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); + + put_device(&ctrldev->dev); + + return 0; +} + +static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, + unsigned long arg) +{ + struct rpmsg_ctrldev *ctrldev = fp->private_data; + void __user *argp = (void __user *)arg; + struct rpmsg_endpoint_info eptinfo; + struct rpmsg_channel_info chinfo; + struct rpmsg_device *rpdev; + int ret = 0; + + if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) + return -EFAULT; + + memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); + chinfo.name[RPMSG_NAME_SIZE - 1] = '\0'; + chinfo.src = eptinfo.src; + chinfo.dst = eptinfo.dst; + + mutex_lock(&ctrldev->ctrl_lock); + switch (cmd) { + case RPMSG_CREATE_EPT_IOCTL: + ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); + break; + + case RPMSG_CREATE_DEV_IOCTL: + rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo); + if (!rpdev) { + dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name); + ret = -ENXIO; + } + break; + + case RPMSG_RELEASE_DEV_IOCTL: + ret = rpmsg_release_channel(ctrldev->rpdev, &chinfo); + if (ret) + dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n", + chinfo.name, ret); + break; + + default: + ret = -EINVAL; + } + mutex_unlock(&ctrldev->ctrl_lock); + + return ret; +}; + +static const struct file_operations rpmsg_ctrldev_fops = { + .owner = THIS_MODULE, + .open = rpmsg_ctrldev_open, + .release = rpmsg_ctrldev_release, + .unlocked_ioctl = rpmsg_ctrldev_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +static void rpmsg_ctrldev_release_device(struct device *dev) +{ + struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); + + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); + kfree(ctrldev); +} + +static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev) +{ + struct rpmsg_ctrldev *ctrldev; + struct device *dev; + int ret; + + ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); + if (!ctrldev) + return -ENOMEM; + + ctrldev->rpdev = rpdev; + + dev = &ctrldev->dev; + device_initialize(dev); + dev->parent = &rpdev->dev; + dev->class = rpmsg_class; + + mutex_init(&ctrldev->ctrl_lock); + cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); + ctrldev->cdev.owner = THIS_MODULE; + + ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); + if (ret < 0) + goto free_ctrldev; + dev->devt = MKDEV(MAJOR(rpmsg_major), ret); + + ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); + if (ret < 0) + goto free_minor_ida; + dev->id = ret; + dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); + + ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev); + if (ret) + goto free_ctrl_ida; + + /* We can now rely on the release function for cleanup */ + dev->release = rpmsg_ctrldev_release_device; + + dev_set_drvdata(&rpdev->dev, ctrldev); + + return ret; + +free_ctrl_ida: + ida_simple_remove(&rpmsg_ctrl_ida, dev->id); +free_minor_ida: + ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); +free_ctrldev: + put_device(dev); + kfree(ctrldev); + + return ret; +} + +static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev) +{ + struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); + int ret; + + mutex_lock(&ctrldev->ctrl_lock); + /* Destroy all endpoints */ + ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy); + if (ret) + dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); + mutex_unlock(&ctrldev->ctrl_lock); + + cdev_device_del(&ctrldev->cdev, &ctrldev->dev); + put_device(&ctrldev->dev); +} + +static struct rpmsg_driver rpmsg_ctrldev_driver = { + .probe = rpmsg_ctrldev_probe, + .remove = rpmsg_ctrldev_remove, + .drv = { + .name = "rpmsg_ctrl", + }, +}; + +static int rpmsg_ctrldev_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl"); + if (ret < 0) { + pr_err("failed to allocate char dev region\n"); + return ret; + } + + ret = register_rpmsg_driver(&rpmsg_ctrldev_driver); + if (ret < 0) { + pr_err("failed to register rpmsg driver\n"); + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); + } + + return ret; +} +postcore_initcall(rpmsg_ctrldev_init); + +static void rpmsg_ctrldev_exit(void) +{ + unregister_rpmsg_driver(&rpmsg_ctrldev_driver); + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); +} +module_exit(rpmsg_ctrldev_exit); + +MODULE_DESCRIPTION("rpmsg control interface"); +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); +MODULE_LICENSE("GPL v2"); |