1

/**

     2

    Network Driver for Beckhoff CCAT communication controller

     3

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

     4

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

     5

     6

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

     7

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

     8

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

     9

    (at your option) any later version.

    10

    11

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

    12

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    13

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    14

    GNU General Public License for more details.

    15

    16

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

    17

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

    18

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

    19

*/

    20

    21

#include "module.h"

    22

#include <asm/io.h>

    23

#include <linux/fs.h>

    24

#include <linux/module.h>

    25

#include <linux/uaccess.h>

    26

    27

#define CCAT_SRAM_DEVICES_MAX 4

    28

    29

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

    30

			   size_t len, loff_t * off)

    31

{

    32

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

    33

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

    34

		return -EFAULT;

    35

    36

	*off += len;

    37

	return len;

    38

}

    39

    40

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

    41

			      size_t len, loff_t * off)

    42

{

    43

	struct cdev_buffer *buffer = f->private_data;

    44

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

    45

    46

	if (*off >= iosize) {

    47

		return 0;

    48

	}

    49

    50

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

    51

    52

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

    53

}

    54

    55

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

    56

			       size_t len, loff_t * off)

    57

{

    58

	struct cdev_buffer *const buffer = f->private_data;

    59

    60

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

    61

		return 0;

    62

	}

    63

    64

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

    65

		return -EFAULT;

    66

	}

    67

    68

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

    69

    70

	*off += len;

    71

	return len;

    72

}

    73

    74

static struct ccat_cdev dev_table[CCAT_SRAM_DEVICES_MAX];

    75

static struct ccat_class cdev_class = {

    76

	.instances = {0},

    77

	.count = CCAT_SRAM_DEVICES_MAX,

    78

	.devices = dev_table,

    79

	.name = "ccat_sram",

    80

	.fops = {

    81

		 .owner = THIS_MODULE,

    82

		 .open = ccat_cdev_open,

    83

		 .release = ccat_cdev_release,

    84

		 .read = ccat_sram_read,

    85

		 .write = ccat_sram_write,

    86

		 },

    87

};

    88

    89

static int ccat_sram_probe(struct ccat_function *func)

    90

{

    91

	static const u8 NO_SRAM_CONNECTED = 0;

    92

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

    93

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

    94

    95

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

    96

		func->info.rev);

    97

	if (type == NO_SRAM_CONNECTED) {

    98

		return -ENODEV;

    99

	}

   100

	return ccat_cdev_probe(func, &cdev_class, iosize);

   101

}

   102

   103

struct ccat_driver sram_driver = {

   104

	.type = CCATINFO_SRAM,

   105

	.probe = ccat_sram_probe,

   106

	.remove = ccat_cdev_remove,

   107

	.cdev_class = &cdev_class,

   108

};