diff options
Diffstat (limited to 'drivers/platform/x86/intel_scu_ipcutil.c')
-rw-r--r-- | drivers/platform/x86/intel_scu_ipcutil.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_scu_ipcutil.c b/drivers/platform/x86/intel_scu_ipcutil.c new file mode 100644 index 000000000..aa4542414 --- /dev/null +++ b/drivers/platform/x86/intel_scu_ipcutil.c @@ -0,0 +1,121 @@ +/* + * 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>"); |