122 lines
3 KiB
C
122 lines
3 KiB
C
|
/*
|
||
|
|
* intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
|
||
|
|
*
|
||
|
|
* (C) Copyright 2008-2010 Intel Corporation
|
||
|
|
* Author: Sreedhara DS (sreedhara.ds@intel.com)
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU General Public License
|
||
|
|
* as published by the Free Software Foundation; version 2
|
||
|
|
* of the License.
|
||
|
|
*
|
||
|
|
* This driver provides ioctl interfaces to call intel scu ipc driver api
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/errno.h>
|
||
|
|
#include <linux/types.h>
|
||
|
|
#include <linux/fs.h>
|
||
|
|
#include <linux/fcntl.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <asm/intel_scu_ipc.h>
|
||
|
|
|
||
|
|
static int major;
|
||
|
|
|
||
|
|
/* ioctl commnds */
|
||
|
|
#define INTE_SCU_IPC_REGISTER_READ 0
|
||
|
|
#define INTE_SCU_IPC_REGISTER_WRITE 1
|
||
|
|
#define INTE_SCU_IPC_REGISTER_UPDATE 2
|
||
|
|
|
||
|
|
struct scu_ipc_data {
|
||
|
|
u32 count; /* No. of registers */
|
||
|
|
u16 addr[5]; /* Register addresses */
|
||
|
|
u8 data[5]; /* Register data */
|
||
|
|
u8 mask; /* Valid for read-modify-write */
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* scu_reg_access - implement register access ioctls
|
||
|
|
* @cmd: command we are doing (read/write/update)
|
||
|
|
* @data: kernel copy of ioctl data
|
||
|
|
*
|
||
|
|
* Allow the user to perform register accesses on the SCU via the
|
||
|
|
* kernel interface
|
||
|
|
*/
|
||
|
|
|
||
|
|
static int scu_reg_access(u32 cmd, struct scu_ipc_data *data)
|
||
|
|
{
|
||
|
|
unsigned int count = data->count;
|
||
|
|
|
||
|
|
if (count == 0 || count == 3 || count > 4)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
switch (cmd) {
|
||
|
|
case INTE_SCU_IPC_REGISTER_READ:
|
||
|
|
return intel_scu_ipc_readv(data->addr, data->data, count);
|
||
|
|
case INTE_SCU_IPC_REGISTER_WRITE:
|
||
|
|
return intel_scu_ipc_writev(data->addr, data->data, count);
|
||
|
|
case INTE_SCU_IPC_REGISTER_UPDATE:
|
||
|
|
return intel_scu_ipc_update_register(data->addr[0],
|
||
|
|
data->data[0], data->mask);
|
||
|
|
default:
|
||
|
|
return -ENOTTY;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* scu_ipc_ioctl - control ioctls for the SCU
|
||
|
|
* @fp: file handle of the SCU device
|
||
|
|
* @cmd: ioctl coce
|
||
|
|
* @arg: pointer to user passed structure
|
||
|
|
*
|
||
|
|
* Support the I/O and firmware flashing interfaces of the SCU
|
||
|
|
*/
|
||
|
|
static long scu_ipc_ioctl(struct file *fp, unsigned int cmd,
|
||
|
|
unsigned long arg)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
struct scu_ipc_data data;
|
||
|
|
void __user *argp = (void __user *)arg;
|
||
|
|
|
||
|
|
if (!capable(CAP_SYS_RAWIO))
|
||
|
|
return -EPERM;
|
||
|
|
|
||
|
|
if (copy_from_user(&data, argp, sizeof(struct scu_ipc_data)))
|
||
|
|
return -EFAULT;
|
||
|
|
ret = scu_reg_access(cmd, &data);
|
||
|
|
if (ret < 0)
|
||
|
|
return ret;
|
||
|
|
if (copy_to_user(argp, &data, sizeof(struct scu_ipc_data)))
|
||
|
|
return -EFAULT;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct file_operations scu_ipc_fops = {
|
||
|
|
.unlocked_ioctl = scu_ipc_ioctl,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init ipc_module_init(void)
|
||
|
|
{
|
||
|
|
major = register_chrdev(0, "intel_mid_scu", &scu_ipc_fops);
|
||
|
|
if (major < 0)
|
||
|
|
return major;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit ipc_module_exit(void)
|
||
|
|
{
|
||
|
|
unregister_chrdev(major, "intel_mid_scu");
|
||
|
|
}
|
||
|
|
|
||
|
|
module_init(ipc_module_init);
|
||
|
|
module_exit(ipc_module_exit);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL v2");
|
||
|
|
MODULE_DESCRIPTION("Utility driver for intel scu ipc");
|
||
|
|
MODULE_AUTHOR("Sreedhara <sreedhara.ds@intel.com>");
|