blob: 0c9e42838844f8b443cf3450d7b75aa79475dda7 [file] [log] [blame]
/* Copyright (c) 2013-2014, 2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kfifo.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include "esoc.h"
/**
* struct esoc_udev: Userspace char interface
* @dev: interface device.
* @req_fifio: fifo for clink requests.
* @req_wait: signal availability of request from clink
* @req_fifo_lock: serialize access to req fifo
* @evt_fito: fifo for clink events
* @evt_wait: signal availability of clink event
* @evt_fifo_lock: serialize access to event fifo
* @list: entry in esoc dev list.
* @clink: reference to contorl link
*/
struct esoc_udev {
struct device *dev;
struct kfifo req_fifo;
wait_queue_head_t req_wait;
spinlock_t req_fifo_lock;
struct kfifo evt_fifo;
wait_queue_head_t evt_wait;
spinlock_t evt_fifo_lock;
struct list_head list;
struct esoc_clink *clink;
};
/**
* struct esoc_uhandle: Userspace handle of esoc
* @esoc_clink: esoc control link.
* @eng: esoc engine for commands/ requests.
* @esoc_udev: user interface device.
* @req_eng_reg: indicates if engine is registered as request eng
* @cmd_eng_reg: indicates if engine is registered as cmd eng
*/
struct esoc_uhandle {
struct esoc_clink *esoc_clink;
struct esoc_eng eng;
struct esoc_udev *esoc_udev;
bool req_eng_reg;
bool cmd_eng_reg;
};
#define ESOC_MAX_MINOR 256
#define ESOC_MAX_REQ 8
#define ESOC_MAX_EVT 4
static LIST_HEAD(esoc_udev_list);
static DEFINE_SPINLOCK(esoc_udev_list_lock);
struct class *esoc_class;
static int esoc_major;
static struct esoc_udev *get_free_esoc_udev(struct esoc_clink *esoc_clink)
{
struct esoc_udev *esoc_udev;
int err;
if (esoc_clink->id > ESOC_MAX_MINOR) {
pr_err("too many esoc devices\n");
return ERR_PTR(-ENODEV);
}
esoc_udev = kzalloc(sizeof(*esoc_udev), GFP_KERNEL);
if (!esoc_udev)
return ERR_PTR(-ENOMEM);
err = kfifo_alloc(&esoc_udev->req_fifo, (sizeof(u32)) * ESOC_MAX_REQ,
GFP_KERNEL);
if (err) {
pr_err("unable to allocate request fifo for %s\n",
esoc_clink->name);
goto req_fifo_fail;
}
err = kfifo_alloc(&esoc_udev->evt_fifo, (sizeof(u32)) * ESOC_MAX_EVT,
GFP_KERNEL);
if (err) {
pr_err("unable to allocate evt fifo for %s\n",
esoc_clink->name);
goto evt_fifo_fail;
}
init_waitqueue_head(&esoc_udev->req_wait);
init_waitqueue_head(&esoc_udev->evt_wait);
spin_lock_init(&esoc_udev->req_fifo_lock);
spin_lock_init(&esoc_udev->evt_fifo_lock);
esoc_udev->clink = esoc_clink;
spin_lock(&esoc_udev_list_lock);
list_add_tail(&esoc_udev->list, &esoc_udev_list);
spin_unlock(&esoc_udev_list_lock);
return esoc_udev;
evt_fifo_fail:
kfifo_free(&esoc_udev->req_fifo);
req_fifo_fail:
kfree(esoc_udev);
return ERR_PTR(-ENODEV);
}
static void return_esoc_udev(struct esoc_udev *esoc_udev)
{
spin_lock(&esoc_udev_list_lock);
list_del(&esoc_udev->list);
spin_unlock(&esoc_udev_list_lock);
kfifo_free(&esoc_udev->req_fifo);
kfifo_free(&esoc_udev->evt_fifo);
kfree(esoc_udev);
}
static struct esoc_udev *esoc_udev_get_by_minor(unsigned int index)
{
struct esoc_udev *esoc_udev;
spin_lock(&esoc_udev_list_lock);
list_for_each_entry(esoc_udev, &esoc_udev_list, list) {
if (esoc_udev->clink->id == index)
goto found;
}
esoc_udev = NULL;
found:
spin_unlock(&esoc_udev_list_lock);
return esoc_udev;
}
void esoc_udev_handle_clink_req(enum esoc_req req, struct esoc_eng *eng)
{
int err;
u32 clink_req;
struct esoc_clink *esoc_clink = eng->esoc_clink;
struct esoc_udev *esoc_udev = esoc_udev_get_by_minor(esoc_clink->id);
if (!esoc_udev)
return;
clink_req = (u32)req;
err = kfifo_in_spinlocked(&esoc_udev->req_fifo, &clink_req,
sizeof(clink_req),
&esoc_udev->req_fifo_lock);
if (err != sizeof(clink_req)) {
pr_err("unable to queue request for %s\n", esoc_clink->name);
return;
}
wake_up_interruptible(&esoc_udev->req_wait);
}
void esoc_udev_handle_clink_evt(enum esoc_evt evt, struct esoc_eng *eng)
{
int err;
u32 clink_evt;
struct esoc_clink *esoc_clink = eng->esoc_clink;
struct esoc_udev *esoc_udev = esoc_udev_get_by_minor(esoc_clink->id);
if (!esoc_udev)
return;
clink_evt = (u32)evt;
err = kfifo_in_spinlocked(&esoc_udev->evt_fifo, &clink_evt,
sizeof(clink_evt),
&esoc_udev->evt_fifo_lock);
if (err != sizeof(clink_evt)) {
pr_err("unable to queue event for %s\n", esoc_clink->name);
return;
}
wake_up_interruptible(&esoc_udev->evt_wait);
}
static long esoc_dev_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int err;
u32 esoc_cmd, status, req, evt;
struct esoc_uhandle *uhandle = file->private_data;
struct esoc_udev *esoc_udev = uhandle->esoc_udev;
struct esoc_clink *esoc_clink = uhandle->esoc_clink;
const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;
void __user *uarg = (void __user *)arg;
switch (cmd) {
case ESOC_REG_REQ_ENG:
err = esoc_clink_register_req_eng(esoc_clink, &uhandle->eng);
if (err)
return err;
uhandle->req_eng_reg = true;
break;
case ESOC_REG_CMD_ENG:
err = esoc_clink_register_cmd_eng(esoc_clink, &uhandle->eng);
if (err)
return err;
uhandle->cmd_eng_reg = true;
break;
case ESOC_CMD_EXE:
if (esoc_clink->cmd_eng != &uhandle->eng)
return -EACCES;
get_user(esoc_cmd, (u32 __user *)arg);
return clink_ops->cmd_exe(esoc_cmd, esoc_clink);
case ESOC_WAIT_FOR_REQ:
if (esoc_clink->req_eng != &uhandle->eng)
return -EACCES;
err = wait_event_interruptible(esoc_udev->req_wait,
!kfifo_is_empty(&esoc_udev->req_fifo));
if (!err) {
err = kfifo_out_spinlocked(&esoc_udev->req_fifo, &req,
sizeof(req),
&esoc_udev->req_fifo_lock);
if (err != sizeof(req)) {
pr_err("read from clink %s req q failed\n",
esoc_clink->name);
return -EIO;
}
put_user(req, (unsigned int __user *)uarg);
}
return err;
case ESOC_NOTIFY:
get_user(esoc_cmd, (u32 __user *)arg);
clink_ops->notify(esoc_cmd, esoc_clink);
break;
case ESOC_GET_STATUS:
err = clink_ops->get_status(&status, esoc_clink);
if (err)
return err;
put_user(status, (unsigned int __user *)uarg);
break;
case ESOC_WAIT_FOR_CRASH:
err = wait_event_interruptible(esoc_udev->evt_wait,
!kfifo_is_empty(&esoc_udev->evt_fifo));
if (!err) {
err = kfifo_out_spinlocked(&esoc_udev->evt_fifo, &evt,
sizeof(evt),
&esoc_udev->evt_fifo_lock);
if (err != sizeof(evt)) {
pr_err("read from clink %s evt q failed\n",
esoc_clink->name);
return -EIO;
}
put_user(evt, (unsigned int __user *)uarg);
}
return err;
default:
return -EINVAL;
};
return 0;
}
static int esoc_dev_open(struct inode *inode, struct file *file)
{
struct esoc_uhandle *uhandle;
struct esoc_udev *esoc_udev;
struct esoc_clink *esoc_clink;
struct esoc_eng *eng;
unsigned int minor = iminor(inode);
esoc_udev = esoc_udev_get_by_minor(minor);
if (!esoc_udev) {
pr_err("failed to get udev\n");
return -ENOMEM;
}
esoc_clink = get_esoc_clink(esoc_udev->clink->id);
if (!esoc_clink) {
pr_err("failed to get clink\n");
return -ENOMEM;
}
uhandle = kzalloc(sizeof(*uhandle), GFP_KERNEL);
if (!uhandle) {
put_esoc_clink(esoc_clink);
return -ENOMEM;
}
uhandle->esoc_udev = esoc_udev;
uhandle->esoc_clink = esoc_clink;
eng = &uhandle->eng;
eng->handle_clink_req = esoc_udev_handle_clink_req;
eng->handle_clink_evt = esoc_udev_handle_clink_evt;
file->private_data = uhandle;
return 0;
}
static int esoc_dev_release(struct inode *inode, struct file *file)
{
struct esoc_clink *esoc_clink;
struct esoc_uhandle *uhandle = file->private_data;
esoc_clink = uhandle->esoc_clink;
if (uhandle->req_eng_reg)
esoc_clink_unregister_req_eng(esoc_clink, &uhandle->eng);
if (uhandle->cmd_eng_reg)
esoc_clink_unregister_cmd_eng(esoc_clink, &uhandle->eng);
uhandle->req_eng_reg = false;
uhandle->cmd_eng_reg = false;
put_esoc_clink(esoc_clink);
kfree(uhandle);
return 0;
}
static const struct file_operations esoc_dev_fops = {
.owner = THIS_MODULE,
.open = esoc_dev_open,
.unlocked_ioctl = esoc_dev_ioctl,
.release = esoc_dev_release,
};
int esoc_clink_add_device(struct device *dev, void *dummy)
{
struct esoc_udev *esoc_udev;
struct esoc_clink *esoc_clink = to_esoc_clink(dev);
esoc_udev = get_free_esoc_udev(esoc_clink);
if (IS_ERR_OR_NULL(esoc_udev))
return PTR_ERR(esoc_udev);
esoc_udev->dev = device_create(esoc_class, &esoc_clink->dev,
MKDEV(esoc_major, esoc_clink->id),
esoc_clink, "esoc-%d", esoc_clink->id);
if (IS_ERR_OR_NULL(esoc_udev->dev)) {
pr_err("failed to create user device\n");
goto dev_err;
}
return 0;
dev_err:
return_esoc_udev(esoc_udev);
return -ENODEV;
}
int esoc_clink_del_device(struct device *dev, void *dummy)
{
struct esoc_udev *esoc_udev;
struct esoc_clink *esoc_clink = to_esoc_clink(dev);
esoc_udev = esoc_udev_get_by_minor(esoc_clink->id);
if (!esoc_udev)
return 0;
return_esoc_udev(esoc_udev);
device_destroy(esoc_class, MKDEV(esoc_major, esoc_clink->id));
return_esoc_udev(esoc_udev);
return 0;
}
static int esoc_dev_notifier_call(struct notifier_block *nb,
unsigned long action,
void *data)
{
struct device *dev = data;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
return esoc_clink_add_device(dev, NULL);
case BUS_NOTIFY_DEL_DEVICE:
return esoc_clink_del_device(dev, NULL);
};
return 0;
}
static struct notifier_block esoc_dev_notifier = {
.notifier_call = esoc_dev_notifier_call,
};
int __init esoc_dev_init(void)
{
int ret = 0;
esoc_class = class_create(THIS_MODULE, "esoc-dev");
if (IS_ERR_OR_NULL(esoc_class)) {
pr_err("coudn't create class");
return PTR_ERR(esoc_class);
}
esoc_major = register_chrdev(0, "esoc", &esoc_dev_fops);
if (esoc_major < 0) {
pr_err("failed to allocate char dev\n");
ret = esoc_major;
goto class_unreg;
}
ret = bus_register_notifier(&esoc_bus_type, &esoc_dev_notifier);
if (ret)
goto chrdev_unreg;
esoc_for_each_dev(NULL, esoc_clink_add_device);
return ret;
chrdev_unreg:
unregister_chrdev(esoc_major, "esoc");
class_unreg:
class_destroy(esoc_class);
return 0;
}
void __exit esoc_dev_exit(void)
{
bus_unregister_notifier(&esoc_bus_type, &esoc_dev_notifier);
class_destroy(esoc_class);
unregister_chrdev(esoc_major, "esoc-dev");
}
MODULE_LICENSE("GPL v2");
module_init(esoc_dev_init);
module_exit(esoc_dev_exit);