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/**

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    Network Driver for Beckhoff CCAT communication controller

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    Copyright (C) 2015  Beckhoff Automation GmbH & Co. KG

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    Author: Patrick Bruenn <p.bruenn@beckhoff.com>

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    This program is free software; you can redistribute it and/or modify

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    it under the terms of the GNU General Public License as published by

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    the Free Software Foundation; either version 2 of the License, or

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    (at your option) any later version.

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    This program is distributed in the hope that it will be useful,

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    but WITHOUT ANY WARRANTY; without even the implied warranty of

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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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    GNU General Public License for more details.

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    You should have received a copy of the GNU General Public License along

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    with this program; if not, write to the Free Software Foundation, Inc.,

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    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

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*/

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#include "module.h"

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#include <asm/io.h>

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#include <linux/fs.h>

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#include <linux/module.h>

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#include <linux/uaccess.h>

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#define CCAT_SRAM_DEVICES_MAX 4

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static ssize_t __sram_read(struct cdev_buffer *buffer, char __user * buf,

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			   size_t len, loff_t * off)

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{

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	memcpy_fromio(buffer->data, buffer->ccdev->ioaddr + *off, len);

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	if (copy_to_user(buf, buffer->data, len))

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		return -EFAULT;

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	*off += len;

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	return len;

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}

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static ssize_t ccat_sram_read(struct file *const f, char __user * buf,

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			      size_t len, loff_t * off)

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{

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	struct cdev_buffer *buffer = f->private_data;

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	const size_t iosize = buffer->ccdev->iosize;

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	if (*off >= iosize) {

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		return 0;

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	}

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	len = min(len, (size_t) (iosize - *off));

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	return __sram_read(buffer, buf, len, off);

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}

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static ssize_t ccat_sram_write(struct file *const f, const char __user * buf,

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			       size_t len, loff_t * off)

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{

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	struct cdev_buffer *const buffer = f->private_data;

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	if (*off + len > buffer->ccdev->iosize) {

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		return 0;

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	}

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	if (copy_from_user(buffer->data, buf, len)) {

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		return -EFAULT;

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	}

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	memcpy_toio(buffer->ccdev->ioaddr + *off, buffer->data, len);

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	*off += len;

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	return len;

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}

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static struct ccat_cdev dev_table[CCAT_SRAM_DEVICES_MAX];

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static struct ccat_class cdev_class = {

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	.instances = {0},

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	.count = CCAT_SRAM_DEVICES_MAX,

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	.devices = dev_table,

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	.name = "ccat_sram",

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	.fops = {

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		 .owner = THIS_MODULE,

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		 .open = ccat_cdev_open,

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		 .release = ccat_cdev_release,

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		 .read = ccat_sram_read,

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		 .write = ccat_sram_write,

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		 },

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};

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static int ccat_sram_probe(struct ccat_function *func)

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{

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	static const u8 NO_SRAM_CONNECTED = 0;

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	const u8 type = func->info.sram_width & 0x3;

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	const size_t iosize = (1 << func->info.sram_size);

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	pr_info("%s: 0x%04x rev: 0x%04x\n", __FUNCTION__, func->info.type,

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		func->info.rev);

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	if (type == NO_SRAM_CONNECTED) {

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		return -ENODEV;

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	}

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	return ccat_cdev_probe(func, &cdev_class, iosize);

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}

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const struct ccat_driver sram_driver = {

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	.type = CCATINFO_SRAM,

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	.probe = ccat_sram_probe,

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	.remove = ccat_cdev_remove,

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	.cdev_class = &cdev_class,

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};