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/*
* SPI debugfs interface for spidev register
*
* Copyright (C) 2014, Intel Corporation
* Authors: Huiquan Zhong <huiquan.zhong@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/spi/spi.h>
static struct spi_board_info spidev_info = {
.modalias = "spidev",
.max_speed_hz = 1000000,
.bus_num = 1,
.chip_select = 0,
.mode = SPI_MODE_0,
};
static int spidev_debug_open(struct inode *inode, struct file *filp)
{
filp->private_data = inode->i_private;
return 0;
}
static ssize_t spidev_debug_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[32];
ssize_t buf_size;
char *start = buf;
unsigned int bus_num, cs_num;
if (*ppos < 0 || !cnt)
return -EINVAL;
buf_size = min(cnt, (sizeof(buf)-1));
if (copy_from_user(buf, ubuf, buf_size))
return -EFAULT;
buf[buf_size] = 0;
while (*start == ' ')
start++;
bus_num = simple_strtoul(start, &start, 10);
while (*start == ' ')
start++;
if (kstrtouint(start, 10, &cs_num))
return -EINVAL;
spidev_info.bus_num = bus_num;
spidev_info.chip_select = cs_num;
spi_register_board_info(&spidev_info, 1);
return buf_size;
}
static const struct file_operations spidev_debug_fops = {
.open = spidev_debug_open,
.write = spidev_debug_write,
.llseek = generic_file_llseek,
};
struct dentry *spidev_node;
static __init int spidev_debug_init(void)
{
spidev_node = debugfs_create_file("spidev_node", S_IFREG | S_IWUSR,
NULL, NULL, &spidev_debug_fops);
if (!spidev_node) {
pr_err("Failed to create spidev_node debug file\n");
return -ENOMEM;
}
return 0;
}
static __exit void spidev_debug_exit(void)
{
debugfs_remove(spidev_node);
}
module_init(spidev_debug_init);
module_exit(spidev_debug_exit);
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