linux/drivers/net/can/sja1000/tscan1.c

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/*
* tscan1.c: driver for Technologic Systems TS-CAN1 PC104 boards
*
* Copyright 2010 Andre B. Oliveira
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/*
* References:
* - Getting started with TS-CAN1, Technologic Systems, Jun 2009
* http://www.embeddedarm.com/documentation/ts-can1-manual.pdf
*/
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/isa.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include "sja1000.h"
MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards");
MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>");
MODULE_LICENSE("GPL");
/* Maximum number of boards (one in each JP1:JP2 setting of IO address) */
#define TSCAN1_MAXDEV 4
/* PLD registers address offsets */
#define TSCAN1_ID1 0
#define TSCAN1_ID2 1
#define TSCAN1_VERSION 2
#define TSCAN1_LED 3
#define TSCAN1_PAGE 4
#define TSCAN1_MODE 5
#define TSCAN1_JUMPERS 6
/* PLD board identifier registers magic values */
#define TSCAN1_ID1_VALUE 0xf6
#define TSCAN1_ID2_VALUE 0xb9
/* PLD mode register SJA1000 IO enable bit */
#define TSCAN1_MODE_ENABLE 0x40
/* PLD jumpers register bits */
#define TSCAN1_JP4 0x10
#define TSCAN1_JP5 0x20
/* PLD IO base addresses start */
#define TSCAN1_PLD_ADDRESS 0x150
/* PLD register space size */
#define TSCAN1_PLD_SIZE 8
/* SJA1000 register space size */
#define TSCAN1_SJA1000_SIZE 32
/* SJA1000 crystal frequency (16MHz) */
#define TSCAN1_SJA1000_XTAL 16000000
/* SJA1000 IO base addresses */
static const unsigned short tscan1_sja1000_addresses[] __devinitconst = {
0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320
};
/* Read SJA1000 register */
static u8 tscan1_read(const struct sja1000_priv *priv, int reg)
{
return inb((unsigned long)priv->reg_base + reg);
}
/* Write SJA1000 register */
static void tscan1_write(const struct sja1000_priv *priv, int reg, u8 val)
{
outb(val, (unsigned long)priv->reg_base + reg);
}
/* Probe for a TS-CAN1 board with JP2:JP1 jumper setting ID */
static int __devinit tscan1_probe(struct device *dev, unsigned id)
{
struct net_device *netdev;
struct sja1000_priv *priv;
unsigned long pld_base, sja1000_base;
int irq, i;
pld_base = TSCAN1_PLD_ADDRESS + id * TSCAN1_PLD_SIZE;
if (!request_region(pld_base, TSCAN1_PLD_SIZE, dev_name(dev)))
return -EBUSY;
if (inb(pld_base + TSCAN1_ID1) != TSCAN1_ID1_VALUE ||
inb(pld_base + TSCAN1_ID2) != TSCAN1_ID2_VALUE) {
release_region(pld_base, TSCAN1_PLD_SIZE);
return -ENODEV;
}
switch (inb(pld_base + TSCAN1_JUMPERS) & (TSCAN1_JP4 | TSCAN1_JP5)) {
case TSCAN1_JP4:
irq = 6;
break;
case TSCAN1_JP5:
irq = 7;
break;
case TSCAN1_JP4 | TSCAN1_JP5:
irq = 5;
break;
default:
dev_err(dev, "invalid JP4:JP5 setting (no IRQ)\n");
release_region(pld_base, TSCAN1_PLD_SIZE);
return -EINVAL;
}
netdev = alloc_sja1000dev(0);
if (!netdev) {
release_region(pld_base, TSCAN1_PLD_SIZE);
return -ENOMEM;
}
dev_set_drvdata(dev, netdev);
SET_NETDEV_DEV(netdev, dev);
netdev->base_addr = pld_base;
netdev->irq = irq;
priv = netdev_priv(netdev);
priv->read_reg = tscan1_read;
priv->write_reg = tscan1_write;
priv->can.clock.freq = TSCAN1_SJA1000_XTAL / 2;
priv->cdr = CDR_CBP | CDR_CLK_OFF;
priv->ocr = OCR_TX0_PUSHPULL;
/* Select the first SJA1000 IO address that is free and that works */
for (i = 0; i < ARRAY_SIZE(tscan1_sja1000_addresses); i++) {
sja1000_base = tscan1_sja1000_addresses[i];
if (!request_region(sja1000_base, TSCAN1_SJA1000_SIZE,
dev_name(dev)))
continue;
/* Set SJA1000 IO base address and enable it */
outb(TSCAN1_MODE_ENABLE | i, pld_base + TSCAN1_MODE);
priv->reg_base = (void __iomem *)sja1000_base;
if (!register_sja1000dev(netdev)) {
/* SJA1000 probe succeeded; turn LED off and return */
outb(0, pld_base + TSCAN1_LED);
netdev_info(netdev, "TS-CAN1 at 0x%lx 0x%lx irq %d\n",
pld_base, sja1000_base, irq);
return 0;
}
/* SJA1000 probe failed; release and try next address */
outb(0, pld_base + TSCAN1_MODE);
release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
}
dev_err(dev, "failed to assign SJA1000 IO address\n");
dev_set_drvdata(dev, NULL);
free_sja1000dev(netdev);
release_region(pld_base, TSCAN1_PLD_SIZE);
return -ENXIO;
}
static int __devexit tscan1_remove(struct device *dev, unsigned id /*unused*/)
{
struct net_device *netdev;
struct sja1000_priv *priv;
unsigned long pld_base, sja1000_base;
netdev = dev_get_drvdata(dev);
unregister_sja1000dev(netdev);
dev_set_drvdata(dev, NULL);
priv = netdev_priv(netdev);
pld_base = netdev->base_addr;
sja1000_base = (unsigned long)priv->reg_base;
outb(0, pld_base + TSCAN1_MODE); /* disable SJA1000 IO space */
release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
release_region(pld_base, TSCAN1_PLD_SIZE);
free_sja1000dev(netdev);
return 0;
}
static struct isa_driver tscan1_isa_driver = {
.probe = tscan1_probe,
.remove = __devexit_p(tscan1_remove),
.driver = {
.name = "tscan1",
},
};
static int __init tscan1_init(void)
{
return isa_register_driver(&tscan1_isa_driver, TSCAN1_MAXDEV);
}
module_init(tscan1_init);
static void __exit tscan1_exit(void)
{
isa_unregister_driver(&tscan1_isa_driver);
}
module_exit(tscan1_exit);