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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
27static int major;
28
29/* ioctl commnds */
30#define INTE_SCU_IPC_REGISTER_READ 0
31#define INTE_SCU_IPC_REGISTER_WRITE 1
32#define INTE_SCU_IPC_REGISTER_UPDATE 2
33
34struct scu_ipc_data {
35 u32 count; /* No. of registers */
36 u16 addr[5]; /* Register addresses */
37 u8 data[5]; /* Register data */
38 u8 mask; /* Valid for read-modify-write */
39};
40
41/**
42 * scu_reg_access - implement register access ioctls
43 * @cmd: command we are doing (read/write/update)
44 * @data: kernel copy of ioctl data
45 *
46 * Allow the user to perform register accesses on the SCU via the
47 * kernel interface
48 */
49
50static int scu_reg_access(u32 cmd, struct scu_ipc_data *data)
51{
52 unsigned int count = data->count;
53
54 if (count == 0 || count == 3 || count > 4)
55 return -EINVAL;
56
57 switch (cmd) {
58 case INTE_SCU_IPC_REGISTER_READ:
59 return intel_scu_ipc_readv(data->addr, data->data, count);
60 case INTE_SCU_IPC_REGISTER_WRITE:
61 return intel_scu_ipc_writev(data->addr, data->data, count);
62 case INTE_SCU_IPC_REGISTER_UPDATE:
63 return intel_scu_ipc_update_register(data->addr[0],
64 data->data[0], data->mask);
65 default:
66 return -ENOTTY;
67 }
68}
69
70/**
71 * scu_ipc_ioctl - control ioctls for the SCU
72 * @fp: file handle of the SCU device
73 * @cmd: ioctl coce
74 * @arg: pointer to user passed structure
75 *
76 * Support the I/O and firmware flashing interfaces of the SCU
77 */
78static long scu_ipc_ioctl(struct file *fp, unsigned int cmd,
79 unsigned long arg)
80{
81 int ret;
82 struct scu_ipc_data data;
83 void __user *argp = (void __user *)arg;
84
85 if (!capable(CAP_SYS_RAWIO))
86 return -EPERM;
87
88 if (copy_from_user(&data, argp, sizeof(struct scu_ipc_data)))
89 return -EFAULT;
90 ret = scu_reg_access(cmd, &data);
91 if (ret < 0)
92 return ret;
93 if (copy_to_user(argp, &data, sizeof(struct scu_ipc_data)))
94 return -EFAULT;
95 return 0;
96}
97
98static const struct file_operations scu_ipc_fops = {
99 .unlocked_ioctl = scu_ipc_ioctl,
100};
101
102static int __init ipc_module_init(void)
103{
104 major = register_chrdev(0, "intel_mid_scu", &scu_ipc_fops);
105 if (major < 0)
106 return major;
107
108 return 0;
109}
110
111static void __exit ipc_module_exit(void)
112{
113 unregister_chrdev(major, "intel_mid_scu");
114}
115
116module_init(ipc_module_init);
117module_exit(ipc_module_exit);
118
119MODULE_LICENSE("GPL v2");
120MODULE_DESCRIPTION("Utility driver for intel scu ipc");
121MODULE_AUTHOR("Sreedhara <sreedhara.ds@intel.com>");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for the Intel SCU IPC mechanism
4 *
5 * (C) Copyright 2008-2010 Intel Corporation
6 * Author: Sreedhara DS (sreedhara.ds@intel.com)
7 *
8 * This driver provides IOCTL interfaces to call Intel SCU IPC driver API.
9 */
10
11#include <linux/errno.h>
12#include <linux/fcntl.h>
13#include <linux/fs.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/types.h>
19#include <linux/uaccess.h>
20
21#include <asm/intel_scu_ipc.h>
22
23static int major;
24
25struct intel_scu_ipc_dev *scu;
26static DEFINE_MUTEX(scu_lock);
27
28/* IOCTL commands */
29#define INTE_SCU_IPC_REGISTER_READ 0
30#define INTE_SCU_IPC_REGISTER_WRITE 1
31#define INTE_SCU_IPC_REGISTER_UPDATE 2
32
33struct scu_ipc_data {
34 u32 count; /* No. of registers */
35 u16 addr[5]; /* Register addresses */
36 u8 data[5]; /* Register data */
37 u8 mask; /* Valid for read-modify-write */
38};
39
40/**
41 * scu_reg_access - implement register access ioctls
42 * @cmd: command we are doing (read/write/update)
43 * @data: kernel copy of ioctl data
44 *
45 * Allow the user to perform register accesses on the SCU via the
46 * kernel interface
47 */
48
49static int scu_reg_access(u32 cmd, struct scu_ipc_data *data)
50{
51 unsigned int count = data->count;
52
53 if (count == 0 || count == 3 || count > 4)
54 return -EINVAL;
55
56 switch (cmd) {
57 case INTE_SCU_IPC_REGISTER_READ:
58 return intel_scu_ipc_dev_readv(scu, data->addr, data->data, count);
59 case INTE_SCU_IPC_REGISTER_WRITE:
60 return intel_scu_ipc_dev_writev(scu, data->addr, data->data, count);
61 case INTE_SCU_IPC_REGISTER_UPDATE:
62 return intel_scu_ipc_dev_update(scu, data->addr[0], data->data[0],
63 data->mask);
64 default:
65 return -ENOTTY;
66 }
67}
68
69/**
70 * scu_ipc_ioctl - control ioctls for the SCU
71 * @fp: file handle of the SCU device
72 * @cmd: ioctl coce
73 * @arg: pointer to user passed structure
74 *
75 * Support the I/O and firmware flashing interfaces of the SCU
76 */
77static long scu_ipc_ioctl(struct file *fp, unsigned int cmd,
78 unsigned long arg)
79{
80 int ret;
81 struct scu_ipc_data data;
82 void __user *argp = (void __user *)arg;
83
84 if (!capable(CAP_SYS_RAWIO))
85 return -EPERM;
86
87 if (copy_from_user(&data, argp, sizeof(struct scu_ipc_data)))
88 return -EFAULT;
89 ret = scu_reg_access(cmd, &data);
90 if (ret < 0)
91 return ret;
92 if (copy_to_user(argp, &data, sizeof(struct scu_ipc_data)))
93 return -EFAULT;
94 return 0;
95}
96
97static int scu_ipc_open(struct inode *inode, struct file *file)
98{
99 int ret = 0;
100
101 /* Only single open at the time */
102 mutex_lock(&scu_lock);
103 if (scu) {
104 ret = -EBUSY;
105 goto unlock;
106 }
107
108 scu = intel_scu_ipc_dev_get();
109 if (!scu)
110 ret = -ENODEV;
111
112unlock:
113 mutex_unlock(&scu_lock);
114 return ret;
115}
116
117static int scu_ipc_release(struct inode *inode, struct file *file)
118{
119 mutex_lock(&scu_lock);
120 intel_scu_ipc_dev_put(scu);
121 scu = NULL;
122 mutex_unlock(&scu_lock);
123
124 return 0;
125}
126
127static const struct file_operations scu_ipc_fops = {
128 .unlocked_ioctl = scu_ipc_ioctl,
129 .open = scu_ipc_open,
130 .release = scu_ipc_release,
131};
132
133static int __init ipc_module_init(void)
134{
135 major = register_chrdev(0, "intel_mid_scu", &scu_ipc_fops);
136 if (major < 0)
137 return major;
138
139 return 0;
140}
141
142static void __exit ipc_module_exit(void)
143{
144 unregister_chrdev(major, "intel_mid_scu");
145}
146
147module_init(ipc_module_init);
148module_exit(ipc_module_exit);
149
150MODULE_LICENSE("GPL v2");
151MODULE_DESCRIPTION("Utility driver for intel scu ipc");
152MODULE_AUTHOR("Sreedhara <sreedhara.ds@intel.com>");