Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6.git] / drivers / platform / x86 / intel_scu_ipcutil.c
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
27 static u32 major;
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 {
120         return register_chrdev(0, "intel_mid_scu", &scu_ipc_fops);
121 }
122
123 static void __exit ipc_module_exit(void)
124 {
125         unregister_chrdev(major, "intel_mid_scu");
126 }
127
128 module_init(ipc_module_init);
129 module_exit(ipc_module_exit);
130
131 MODULE_LICENSE("GPL v2");
132 MODULE_DESCRIPTION("Utility driver for intel scu ipc");
133 MODULE_AUTHOR("Sreedhara <sreedhara.ds@intel.com>");