/* *****************************************************************
 * (C) Copyright 2007 Benjamin Krill <ben@codiert.org>
 *
 * 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; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 * MA 02110-1301 USA
 * *****************************************************************/
#include <linux/pagemap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/mm.h>
#include "fpgafs.h"

#define VENDOR_ID_ALTERA 0x1172
#define DEVICE_ID_ALTERA 0x0100

static void *vaddr = 0;
static unsigned long memstart = 0, memlen = 0;


static int fpgafs_send_data_rag(struct fpga_context *ctx, const char __user *buf, int len)
{
	int i;
	u8 __user *usr;
	unsigned char dat[2];

	if (len < 2)
		return -EINVAL;

	if (!access_ok(VERIFY_READ, buf, len))
		return -EFAULT;

	for(i=0; i < len; i+=2) {
		usr = (u8*)&buf[i];
		if (__get_user(dat[0], usr))
			return -EFAULT;

		usr = (u8*)&buf[i+1];
		if (__get_user(dat[1], usr))
			return -EFAULT;

		writew((dat[1] << 8)|dat[0], vaddr);
	}

	return i;
}

static int fpgafs_recv_data_rag(struct fpga_context *ctx, unsigned char *buf, int len)
{
	int i; unsigned short d;
	unsigned char b[2];

	if ((len < 2) || ((len % 2) != 0))
		return -EINVAL;

	for(i=0; i < len; i+=2) {
		d=readw((void *)((unsigned long)vaddr | 0x20));
		b[i] = d & 0xff;
		b[i+1] = d >> 8;
		if (copy_to_user(b, ctx->load_buf, 2))
			return -EFAULT;
	}

	return i;
}

int fpgafs_device_probe_rag(struct pci_dev *dev, const struct pci_device_id *id)
{
	int ret;
	ret = pci_enable_device(dev);
	if (ret < 0) {
		printk(KERN_WARNING "FPGAFS_RAG: unable to initialize PCI device\n");
		return ret;
	}

	ret = pci_request_regions(dev, "FPGAFS_RAG");
	if (ret < 0) {
		printk(KERN_WARNING "FPGAFS_RAG: unable to reserve PCI resources\n");
		pci_disable_device(dev);
		return ret;
	}

	memstart = pci_resource_start(dev, 0); /* 0 for BAR0 */
	memlen = pci_resource_len(dev, 0);
	printk(KERN_WARNING "FPGAFS_RAG: memstart=0x%lx memlen=%li\n", memstart, memlen);

	vaddr = ioremap(memstart, memlen);
	printk(KERN_INFO "FPGAFS_RAG: device_probe successful\n");
	return ret;
}

void fpgafs_device_remove_rag(struct pci_dev *dev)
{
	iounmap(vaddr);
	pci_release_regions(dev);
	pci_disable_device(dev);
	printk(KERN_INFO "FPGAFS_RAG: device removed\n");
}

static struct pci_device_id  pci_device_id_fpgafs_rag[] =
{
	{VENDOR_ID_ALTERA, DEVICE_ID_ALTERA, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
	{}  /* EOL */
};

struct pci_driver pci_driver_fpgafs_rag =
{
	name: "FPGAFS_RAG",
	id_table: pci_device_id_fpgafs_rag,
	probe: fpgafs_device_probe_rag,
	remove: fpgafs_device_remove_rag
};

static int fpgafs_init_rag(void)
{
	printk(KERN_INFO "FPGFS_RAG: PCI init\n");
	return pci_register_driver(&pci_driver_fpgafs_rag);
}

static int fpgafs_exit_rag(void)
{
	printk(KERN_INFO "FPGFS_RAG: PCI fini\n");
	pci_unregister_driver(&pci_driver_fpgafs_rag);
	return 0;
}

static struct fpgafs_lldrv fpgafs_lldrv_rag = {
	.name = "rag",
	.init = &fpgafs_init_rag,
	.exit = &fpgafs_exit_rag,
	.send = &fpgafs_send_data_rag,
	.recv = &fpgafs_recv_data_rag,
	.read_load = NULL,
	.write_load = NULL,
};

/* init exit functions ... */
int __init fpgafs_lldrv_rag_init(void)
{
	return fpgafs_register_lldrv(&fpgafs_lldrv_rag);
}

void __exit fpgafs_lldrv_rag_exit(void)
{
	fpgafs_unregister_lldrv(&fpgafs_lldrv_rag);
}

module_init(fpgafs_lldrv_rag_init);
module_exit(fpgafs_lldrv_rag_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Benjamin Krill <ben@codiert.org>");