fpgafs/files.c

/*********************************************
 * Benjamin Krill <ben@codiert.org>
 *********************************************/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include "fpgafs.h"

static unsigned int stat;

static int do_cmd(u32 cmd, u32 data)
{
	switch(cmd) {
		case BLA:
			stat = data;
			break;
		default:
			return -EFAULT;
	}
	return 0;
}

/* generic open function for all pipe-like files */
static int fpgafs_open(struct inode *inode, struct file *file)
{
	//struct fpgafs_inode_info *i = FPGAFS_I(inode);
	//file->private_data = i->i_ctx;

  return 0; // nonseekable_open(inode, file);
}

static ssize_t fpgafs_stat_read(struct file *file, char __user *buf,
                                size_t len, loff_t *pos)
 {
	//struct fpga_context *ctx = file->private_data;
	u32 data;
	data=stat;

	if (copy_to_user(buf, &data, sizeof(data)))
		return -EFAULT;

	return 4;
}

static const struct file_operations fpgafs_stat_fops = {
	.open = fpgafs_open,
	.read = fpgafs_stat_read,
};

static ssize_t fpgafs_cmd_write(struct file *file, const char __user *buf,
                                size_t len, loff_t *pos)
{
	u32 data, __user *udata;

	if (len < 4)
		return -EINVAL;

	udata = (void __user *)buf;
	if (!access_ok(VERIFY_READ, buf, len))
		return -EFAULT;

	if (__get_user(data, udata))
		return -EFAULT;

	do_cmd(BLA,data);
	return 4;
}

static const struct file_operations fpgafs_cmd_fops = {
	.open  = fpgafs_open,
	.write = fpgafs_cmd_write,
};

struct tree_descr fpgafs_dir_contents[] = {
#if 0
	{ "din",  &fpgafs_din_fops, 0222, },
	{ "dout", &fpgafs_dout_fops, 0444, },
	{ "load", &fpgafs_load_fops, 0666, },
#endif
	{ "cmd",  &fpgafs_cmd_fops,  0222, },
	{ "stat", &fpgafs_stat_fops, 0444, },
	{},
};