/*
* Silicon Labs C2 port Linux support for Eurotech Duramar 2150
*
* Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it>
* Copyright (c) 2008 Eurotech S.p.A. <info@eurotech.it>
*
* 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/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/c2port.h>
#define DATA_PORT 0x325
#define DIR_PORT 0x326
#define C2D (1 << 0)
#define C2CK (1 << 1)
static DEFINE_MUTEX(update_lock);
/*
* C2 port operations
*/
static void duramar2150_c2port_access(struct c2port_device *dev, int status)
{
u8 v;
mutex_lock(&update_lock);
v = inb(DIR_PORT);
/* 0 = input, 1 = output */
if (status)
outb(v | (C2D | C2CK), DIR_PORT);
else
/* When access is "off" is important that both lines are set
* as inputs or hi-impedance */
outb(v & ~(C2D | C2CK), DIR_PORT);
mutex_unlock(&update_lock);
}
static void duramar2150_c2port_c2d_dir(struct c2port_device *dev, int dir)
{
u8 v;
mutex_lock(&update_lock);
v = inb(DIR_PORT);
if (dir)
outb(v & ~C2D, DIR_PORT);
else
outb(v | C2D, DIR_PORT);
mutex_unlock(&update_lock);
}
static int duramar2150_c2port_c2d_get(struct c2port_device *dev)
{
return inb(DATA_PORT) & C2D;
}
static void duramar2150_c2port_c2d_set(struct c2port_device *dev, int status)
{
u8 v;
mutex_lock(&update_lock);
v = inb(DATA_PORT);
if (status)
outb(v | C2D, DATA_PORT);
else
outb(v & ~C2D, DATA_PORT);
mutex_unlock(&update_lock);
}
static void duramar2150_c2port_c2ck_set(struct c2port_device *dev, int status)
{
u8 v;
mutex_lock(&update_lock);
v = inb(DATA_PORT);
if (status)
outb(v | C2CK, DATA_PORT);
else
outb(v & ~C2CK, DATA_PORT);
mutex_unlock(&update_lock);
}
static struct c2port_ops duramar2150_c2port_ops = {
.block_size = 512, /* bytes */
.blocks_num = 30, /* total flash size: 15360 bytes */
.access = duramar2150_c2port_access,
.c2d_dir = duramar2150_c2port_c2d_dir,
.c2d_get = duramar2150_c2port_c2d_get,
.c2d_set = duramar2150_c2port_c2d_set,
.c2ck_set = duramar2150_c2port_c2ck_set,
};
static struct c2port_device *duramar2150_c2port_dev;
/*
* Module stuff
*/
static int __init duramar2150_c2port_init(void)
{
struct resource *res;
int ret = 0;
res = request_region(0x325, 2, "c2port");
if (!res)
return -EBUSY;
duramar2150_c2port_dev = c2port_device_register("uc",
&duramar2150_c2port_ops, NULL);
if (!duramar2150_c2port_dev) {
ret = -ENODEV;
goto free_region;
}
return 0;
free_region:
release_region(0x325, 2);
return ret;
}
static void __exit duramar2150_c2port_exit(void)
{
/* Setup the GPIOs as input by default (access = 0) */
duramar2150_c2port_access(duramar2150_c2port_dev, 0);
c2port_device_unregister(duramar2150_c2port_dev);
release_region(0x325, 2);
}
module_init(duramar2150_c2port_init);
module_exit(duramar2150_c2port_exit);
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150");
MODULE_LICENSE("GPL");
