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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | /* * 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) { 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 (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>"); |