[mirror_ubuntu-bionic-kernel.git] / drivers / platform / x86 / intel_scu_ipcutil.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;

#define MAX_FW_SIZE 264192

/* ioctl commnds */
#define	INTE_SCU_IPC_REGISTER_READ	0
#define INTE_SCU_IPC_REGISTER_WRITE	1
#define INTE_SCU_IPC_REGISTER_UPDATE	2
#define INTE_SCU_IPC_FW_UPDATE		0xA2

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)
{
	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 (cmd == INTE_SCU_IPC_FW_UPDATE) {
			u8 *fwbuf = kmalloc(MAX_FW_SIZE, GFP_KERNEL);
			if (fwbuf == NULL)
				return -ENOMEM;
			if (copy_from_user(fwbuf, (u8 *)arg, MAX_FW_SIZE)) {
				kfree(fwbuf);
				return -EFAULT;
			}
			ret = intel_scu_ipc_fw_update(fwbuf, MAX_FW_SIZE);
			kfree(fwbuf);
			return ret;
	} else {
		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>");
Commit	Line	Data
5369c02d SD	1	/*
	2	* intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
	3	*
	4	* (C) Copyright 2008-2010 Intel Corporation
	5	* Author: Sreedhara DS (sreedhara.ds@intel.com)
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; version 2
	10	* of the License.
	11	*
	12	* This driver provides ioctl interfaces to call intel scu ipc driver api
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/kernel.h>
	17	#include <linux/errno.h>
	18	#include <linux/types.h>
	19	#include <linux/fs.h>
	20	#include <linux/fcntl.h>
	21	#include <linux/sched.h>
	22	#include <linux/uaccess.h>
	23	#include <linux/slab.h>
	24	#include <linux/init.h>
	25	#include <asm/intel_scu_ipc.h>
	26
21893ab2	27	static int major;
5369c02d SD	28
	29	#define MAX_FW_SIZE 264192
	30
	31	/* ioctl commnds */
	32	#define INTE_SCU_IPC_REGISTER_READ 0
	33	#define INTE_SCU_IPC_REGISTER_WRITE 1
	34	#define INTE_SCU_IPC_REGISTER_UPDATE 2
	35	#define INTE_SCU_IPC_FW_UPDATE 0xA2
	36
	37	struct scu_ipc_data {
	38	u32 count; /* No. of registers */
	39	u16 addr[5]; /* Register addresses */
	40	u8 data[5]; /* Register data */
	41	u8 mask; /* Valid for read-modify-write */
	42	};
	43
	44	/**
	45	* scu_reg_access - implement register access ioctls
	46	* @cmd: command we are doing (read/write/update)
	47	* @data: kernel copy of ioctl data
	48	*
	49	* Allow the user to perform register accesses on the SCU via the
	50	* kernel interface
	51	*/
	52
	53	static int scu_reg_access(u32 cmd, struct scu_ipc_data *data)
	54	{
	55	int count = data->count;
	56
	57	if (count == 0 \|\| count == 3 \|\| count > 4)
	58	return -EINVAL;
	59
	60	switch (cmd) {
	61	case INTE_SCU_IPC_REGISTER_READ:
	62	return intel_scu_ipc_readv(data->addr, data->data, count);
	63	case INTE_SCU_IPC_REGISTER_WRITE:
	64	return intel_scu_ipc_writev(data->addr, data->data, count);
	65	case INTE_SCU_IPC_REGISTER_UPDATE:
	66	return intel_scu_ipc_update_register(data->addr[0],
	67	data->data[0], data->mask);
	68	default:
	69	return -ENOTTY;
	70	}
	71	}
	72
	73	/**
	74	* scu_ipc_ioctl - control ioctls for the SCU
	75	* @fp: file handle of the SCU device
	76	* @cmd: ioctl coce
	77	* @arg: pointer to user passed structure
	78	*
	79	* Support the I/O and firmware flashing interfaces of the SCU
	80	*/
	81	static long scu_ipc_ioctl(struct file *fp, unsigned int cmd,
	82	unsigned long arg)
	83	{
	84	int ret;
	85	struct scu_ipc_data data;
	86	void __user argp = (void __user )arg;
	87
	88	if (!capable(CAP_SYS_RAWIO))
	89	return -EPERM;
	90
	91	if (cmd == INTE_SCU_IPC_FW_UPDATE) {
92	u8 *fwbuf = kmalloc(MAX_FW_SIZE, GFP_KERNEL);
93	if (fwbuf == NULL)
94	return -ENOMEM;
95	if (copy_from_user(fwbuf, (u8 *)arg, MAX_FW_SIZE)) {
96	kfree(fwbuf);
97	return -EFAULT;
98	}
99	ret = intel_scu_ipc_fw_update(fwbuf, MAX_FW_SIZE);
100	kfree(fwbuf);
101	return ret;
102	} else {
103	if (copy_from_user(&data, argp, sizeof(struct scu_ipc_data)))
104	return -EFAULT;
105	ret = scu_reg_access(cmd, &data);
106	if (ret < 0)
107	return ret;
108	if (copy_to_user(argp, &data, sizeof(struct scu_ipc_data)))
109	return -EFAULT;
110	return 0;
111	}
112	}
113
114	static const struct file_operations scu_ipc_fops = {
115	.unlocked_ioctl = scu_ipc_ioctl,
116	};
117
118	static int __init ipc_module_init(void)
119	{
21893ab2 KS	120	major = register_chrdev(0, "intel_mid_scu", &scu_ipc_fops);
	121	if (major < 0)
	122	return major;
	123
	124	return 0;
5369c02d SD	125	}
	126
	127	static void __exit ipc_module_exit(void)
	128	{
	129	unregister_chrdev(major, "intel_mid_scu");
	130	}
	131
	132	module_init(ipc_module_init);
	133	module_exit(ipc_module_exit);
	134
f5c66d70	135	MODULE_LICENSE("GPL v2");
5369c02d SD	136	MODULE_DESCRIPTION("Utility driver for intel scu ipc");
5369c02d SD	137	MODULE_AUTHOR("Sreedhara <sreedhara.ds@intel.com>");