sja1000_isa.c

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/*
 * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * as published by the Free Software Foundation
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/can/dev.h>
#include <linux/can/platform/sja1000.h>

#include "sja1000.h"

#define DRV_NAME "sja1000_isa"

#define MAXDEV 8

MODULE_AUTHOR("Wolfgang Grandegger <[email protected]>");
MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the ISA bus");
MODULE_LICENSE("GPL v2");

#define CLK_DEFAULT 16000000    /* 16 MHz */
#define CDR_DEFAULT (CDR_CBP | CDR_CLK_OFF)
#define OCR_DEFAULT OCR_TX0_PUSHPULL

static unsigned long port[MAXDEV];
static unsigned long mem[MAXDEV];
static int __devinitdata irq[MAXDEV];
static int __devinitdata clk[MAXDEV];
static unsigned char __devinitdata cdr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
static unsigned char __devinitdata ocr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
static int __devinitdata indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};

module_param_array(port, ulong, NULL, S_IRUGO);
MODULE_PARM_DESC(port, "I/O port number");

module_param_array(mem, ulong, NULL, S_IRUGO);
MODULE_PARM_DESC(mem, "I/O memory address");

module_param_array(indirect, int, NULL, S_IRUGO);
MODULE_PARM_DESC(indirect, "Indirect access via address and data port");

module_param_array(irq, int, NULL, S_IRUGO);
MODULE_PARM_DESC(irq, "IRQ number");

module_param_array(clk, int, NULL, S_IRUGO);
MODULE_PARM_DESC(clk, "External oscillator clock frequency "
         "(default=16000000 [16 MHz])");

module_param_array(cdr, byte, NULL, S_IRUGO);
MODULE_PARM_DESC(cdr, "Clock divider register "
         "(default=0x48 [CDR_CBP | CDR_CLK_OFF])");

module_param_array(ocr, byte, NULL, S_IRUGO);
MODULE_PARM_DESC(ocr, "Output control register "
         "(default=0x18 [OCR_TX0_PUSHPULL])");

#define SJA1000_IOSIZE          0x20
#define SJA1000_IOSIZE_INDIRECT 0x02

static struct platform_device *sja1000_isa_devs[MAXDEV];

static u8 sja1000_isa_mem_read_reg(const struct sja1000_priv *priv, int reg)
{
    return readb(priv->reg_base + reg);
}

static void sja1000_isa_mem_write_reg(const struct sja1000_priv *priv,
                      int reg, u8 val)
{
    writeb(val, priv->reg_base + reg);
}

static u8 sja1000_isa_port_read_reg(const struct sja1000_priv *priv, int reg)
{
    return inb((unsigned long)priv->reg_base + reg);
}

static void sja1000_isa_port_write_reg(const struct sja1000_priv *priv,
                       int reg, u8 val)
{
    outb(val, (unsigned long)priv->reg_base + reg);
}

static u8 sja1000_isa_port_read_reg_indirect(const struct sja1000_priv *priv,
                         int reg)
{
    unsigned long base = (unsigned long)priv->reg_base;

    outb(reg, base);
    return inb(base + 1);
}

static void sja1000_isa_port_write_reg_indirect(const struct sja1000_priv *priv,
                        int reg, u8 val)
{
    unsigned long base = (unsigned long)priv->reg_base;

    outb(reg, base);
    outb(val, base + 1);
}

static int __devinit sja1000_isa_probe(struct platform_device *pdev)
{
    struct net_device *dev;
    struct sja1000_priv *priv;
    void __iomem *base = NULL;
    int iosize = SJA1000_IOSIZE;
    int idx = pdev->id;
    int err;

    dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
        idx, port[idx], mem[idx], irq[idx]);

    if (mem[idx]) {
        if (!request_mem_region(mem[idx], iosize, DRV_NAME)) {
            err = -EBUSY;
            goto exit;
        }
        base = ioremap_nocache(mem[idx], iosize);
        if (!base) {
            err = -ENOMEM;
            goto exit_release;
        }
    } else {
        if (indirect[idx] > 0 ||
            (indirect[idx] == -1 && indirect[0] > 0))
            iosize = SJA1000_IOSIZE_INDIRECT;
        if (!request_region(port[idx], iosize, DRV_NAME)) {
            err = -EBUSY;
            goto exit;
        }
    }

    dev = alloc_sja1000dev(0);
    if (!dev) {
        err = -ENOMEM;
        goto exit_unmap;
    }
    priv = netdev_priv(dev);

    dev->irq = irq[idx];
    priv->irq_flags = IRQF_SHARED;
    if (mem[idx]) {
        priv->reg_base = base;
        dev->base_addr = mem[idx];
        priv->read_reg = sja1000_isa_mem_read_reg;
        priv->write_reg = sja1000_isa_mem_write_reg;
    } else {
        priv->reg_base = (void __iomem *)port[idx];
        dev->base_addr = port[idx];

        if (iosize == SJA1000_IOSIZE_INDIRECT) {
            priv->read_reg = sja1000_isa_port_read_reg_indirect;
            priv->write_reg = sja1000_isa_port_write_reg_indirect;
        } else {
            priv->read_reg = sja1000_isa_port_read_reg;
            priv->write_reg = sja1000_isa_port_write_reg;
        }
    }

    if (clk[idx])
        priv->can.clock.freq = clk[idx] / 2;
    else if (clk[0])
        priv->can.clock.freq = clk[0] / 2;
    else
        priv->can.clock.freq = CLK_DEFAULT / 2;

    if (ocr[idx] != 0xff)
        priv->ocr = ocr[idx];
    else if (ocr[0] != 0xff)
        priv->ocr = ocr[0];
    else
        priv->ocr = OCR_DEFAULT;

    if (cdr[idx] != 0xff)
        priv->cdr = cdr[idx];
    else if (cdr[0] != 0xff)
        priv->cdr = cdr[0];
    else
        priv->cdr = CDR_DEFAULT;

    dev_set_drvdata(&pdev->dev, dev);
    SET_NETDEV_DEV(dev, &pdev->dev);

    err = register_sja1000dev(dev);
    if (err) {
        dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
            DRV_NAME, err);
        goto exit_unmap;
    }

    dev_info(&pdev->dev, "%s device registered (reg_base=0x%p, irq=%d)\n",
         DRV_NAME, priv->reg_base, dev->irq);
    return 0;

 exit_unmap:
    if (mem[idx])
        iounmap(base);
 exit_release:
    if (mem[idx])
        release_mem_region(mem[idx], iosize);
    else
        release_region(port[idx], iosize);
 exit:
    return err;
}

static int __devexit sja1000_isa_remove(struct platform_device *pdev)
{
    struct net_device *dev = dev_get_drvdata(&pdev->dev);
    struct sja1000_priv *priv = netdev_priv(dev);
    int idx = pdev->id;

    unregister_sja1000dev(dev);
    dev_set_drvdata(&pdev->dev, NULL);

    if (mem[idx]) {
        iounmap(priv->reg_base);
        release_mem_region(mem[idx], SJA1000_IOSIZE);
    } else {
        if (priv->read_reg == sja1000_isa_port_read_reg_indirect)
            release_region(port[idx], SJA1000_IOSIZE_INDIRECT);
        else
            release_region(port[idx], SJA1000_IOSIZE);
    }
    free_sja1000dev(dev);

    return 0;
}

static struct platform_driver sja1000_isa_driver = {
    .probe = sja1000_isa_probe,
    .remove = __devexit_p(sja1000_isa_remove),
    .driver = {
        .name = DRV_NAME,
        .owner = THIS_MODULE,
    },
};

static int __init sja1000_isa_init(void)
{
    int idx, err;

    for (idx = 0; idx < MAXDEV; idx++) {
        if ((port[idx] || mem[idx]) && irq[idx]) {
            sja1000_isa_devs[idx] =
                platform_device_alloc(DRV_NAME, idx);
            if (!sja1000_isa_devs[idx]) {
                err = -ENOMEM;
                goto exit_free_devices;
            }
            err = platform_device_add(sja1000_isa_devs[idx]);
            if (err) {
                platform_device_put(sja1000_isa_devs[idx]);
                goto exit_free_devices;
            }
            pr_debug("%s: platform device %d: port=%#lx, mem=%#lx, "
                 "irq=%d\n",
                 DRV_NAME, idx, port[idx], mem[idx], irq[idx]);
        } else if (idx == 0 || port[idx] || mem[idx]) {
                pr_err("%s: insufficient parameters supplied\n",
                       DRV_NAME);
                err = -EINVAL;
                goto exit_free_devices;
        }
    }

    err = platform_driver_register(&sja1000_isa_driver);
    if (err)
        goto exit_free_devices;

    pr_info("Legacy %s driver for max. %d devices registered\n",
        DRV_NAME, MAXDEV);

    return 0;

exit_free_devices:
    while (--idx >= 0) {
        if (sja1000_isa_devs[idx])
            platform_device_unregister(sja1000_isa_devs[idx]);
    }

    return err;
}

static void __exit sja1000_isa_exit(void)
{
    int idx;

    platform_driver_unregister(&sja1000_isa_driver);
    for (idx = 0; idx < MAXDEV; idx++) {
        if (sja1000_isa_devs[idx])
            platform_device_unregister(sja1000_isa_devs[idx]);
    }
}

module_init(sja1000_isa_init);
module_exit(sja1000_isa_exit);