tb0219.c

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/*
 *  Driver for TANBAC TB0219 base board.
 *
 *  Copyright (C) 2005  Yoichi Yuasa <[email protected]>
 *
 *  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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>

#include <asm/io.h>
#include <asm/reboot.h>
#include <asm/vr41xx/giu.h>
#include <asm/vr41xx/tb0219.h>

MODULE_AUTHOR("Yoichi Yuasa <[email protected]>");
MODULE_DESCRIPTION("TANBAC TB0219 base board driver");
MODULE_LICENSE("GPL");

static int major;   /* default is dynamic major device number */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");

static void (*old_machine_restart)(char *command);
static void __iomem *tb0219_base;
static DEFINE_SPINLOCK(tb0219_lock);

#define tb0219_read(offset)     readw(tb0219_base + (offset))
#define tb0219_write(offset, value) writew((value), tb0219_base + (offset))

#define TB0219_START    0x0a000000UL
#define TB0219_SIZE 0x20UL

#define TB0219_LED          0x00
#define TB0219_GPIO_INPUT       0x02
#define TB0219_GPIO_OUTPUT      0x04
#define TB0219_DIP_SWITCH       0x06
#define TB0219_MISC         0x08
#define TB0219_RESET            0x0e
#define TB0219_PCI_SLOT1_IRQ_STATUS 0x10
#define TB0219_PCI_SLOT2_IRQ_STATUS 0x12
#define TB0219_PCI_SLOT3_IRQ_STATUS 0x14

typedef enum {
    TYPE_LED,
    TYPE_GPIO_OUTPUT,
} tb0219_type_t;

/*
 * Minor device number
 *   0 = 7 segment LED
 *
 *  16 = GPIO IN 0
 *  17 = GPIO IN 1
 *  18 = GPIO IN 2
 *  19 = GPIO IN 3
 *  20 = GPIO IN 4
 *  21 = GPIO IN 5
 *  22 = GPIO IN 6
 *  23 = GPIO IN 7
 *
 *  32 = GPIO OUT 0
 *  33 = GPIO OUT 1
 *  34 = GPIO OUT 2
 *  35 = GPIO OUT 3
 *  36 = GPIO OUT 4
 *  37 = GPIO OUT 5
 *  38 = GPIO OUT 6
 *  39 = GPIO OUT 7
 *
 *  48 = DIP switch 1
 *  49 = DIP switch 2
 *  50 = DIP switch 3
 *  51 = DIP switch 4
 *  52 = DIP switch 5
 *  53 = DIP switch 6
 *  54 = DIP switch 7
 *  55 = DIP switch 8
 */

static inline char get_led(void)
{
    return (char)tb0219_read(TB0219_LED);
}

static inline char get_gpio_input_pin(unsigned int pin)
{
    uint16_t values;

    values = tb0219_read(TB0219_GPIO_INPUT);
    if (values & (1 << pin))
        return '1';

    return '0';
}

static inline char get_gpio_output_pin(unsigned int pin)
{
    uint16_t values;

    values = tb0219_read(TB0219_GPIO_OUTPUT);
    if (values & (1 << pin))
        return '1';

    return '0';
}

static inline char get_dip_switch(unsigned int pin)
{
    uint16_t values;

    values = tb0219_read(TB0219_DIP_SWITCH);
    if (values & (1 << pin))
        return '1';

    return '0';
}

static inline int set_led(char command)
{
    tb0219_write(TB0219_LED, command);

    return 0;
}

static inline int set_gpio_output_pin(unsigned int pin, char command)
{
    unsigned long flags;
    uint16_t value;

    if (command != '0' && command != '1')
        return -EINVAL;

    spin_lock_irqsave(&tb0219_lock, flags);
    value = tb0219_read(TB0219_GPIO_OUTPUT);
    if (command == '0')
        value &= ~(1 << pin);
    else
        value |= 1 << pin;
    tb0219_write(TB0219_GPIO_OUTPUT, value);
    spin_unlock_irqrestore(&tb0219_lock, flags);

    return 0;

}

static ssize_t tanbac_tb0219_read(struct file *file, char __user *buf, size_t len,
                                  loff_t *ppos)
{
    unsigned int minor;
    char value;

    minor = iminor(file->f_path.dentry->d_inode);
    switch (minor) {
    case 0:
        value = get_led();
        break;
    case 16 ... 23:
        value = get_gpio_input_pin(minor - 16);
        break;
    case 32 ... 39:
        value = get_gpio_output_pin(minor - 32);
        break;
    case 48 ... 55:
        value = get_dip_switch(minor - 48);
        break;
    default:
        return -EBADF;
    }

    if (len <= 0)
        return -EFAULT;

    if (put_user(value, buf))
        return -EFAULT;

    return 1;
}

static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
                                   size_t len, loff_t *ppos)
{
    unsigned int minor;
    tb0219_type_t type;
    size_t i;
    int retval = 0;
    char c;

    minor = iminor(file->f_path.dentry->d_inode);
    switch (minor) {
    case 0:
        type = TYPE_LED;
        break;
    case 32 ... 39:
        type = TYPE_GPIO_OUTPUT;
        break;
    default:
        return -EBADF;
    }

    for (i = 0; i < len; i++) {
        if (get_user(c, data + i))
            return -EFAULT;

        switch (type) {
        case TYPE_LED:
            retval = set_led(c);
            break;
        case TYPE_GPIO_OUTPUT:
            retval = set_gpio_output_pin(minor - 32, c);
            break;
        }

        if (retval < 0)
            break;
    }

    return i;
}

static int tanbac_tb0219_open(struct inode *inode, struct file *file)
{
    unsigned int minor;

    minor = iminor(inode);
    switch (minor) {
    case 0:
    case 16 ... 23:
    case 32 ... 39:
    case 48 ... 55:
        return nonseekable_open(inode, file);
    default:
        break;
    }

    return -EBADF;
}

static int tanbac_tb0219_release(struct inode *inode, struct file *file)
{
    return 0;
}

static const struct file_operations tb0219_fops = {
    .owner      = THIS_MODULE,
    .read       = tanbac_tb0219_read,
    .write      = tanbac_tb0219_write,
    .open       = tanbac_tb0219_open,
    .release    = tanbac_tb0219_release,
    .llseek     = no_llseek,
};

static void tb0219_restart(char *command)
{
    tb0219_write(TB0219_RESET, 0);
}

static void tb0219_pci_irq_init(void)
{
    /* PCI Slot 1 */
    vr41xx_set_irq_trigger(TB0219_PCI_SLOT1_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
    vr41xx_set_irq_level(TB0219_PCI_SLOT1_PIN, IRQ_LEVEL_LOW);

    /* PCI Slot 2 */
    vr41xx_set_irq_trigger(TB0219_PCI_SLOT2_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
    vr41xx_set_irq_level(TB0219_PCI_SLOT2_PIN, IRQ_LEVEL_LOW);

    /* PCI Slot 3 */
    vr41xx_set_irq_trigger(TB0219_PCI_SLOT3_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
    vr41xx_set_irq_level(TB0219_PCI_SLOT3_PIN, IRQ_LEVEL_LOW);
}

static int __devinit tb0219_probe(struct platform_device *dev)
{
    int retval;

    if (request_mem_region(TB0219_START, TB0219_SIZE, "TB0219") == NULL)
        return -EBUSY;

    tb0219_base = ioremap(TB0219_START, TB0219_SIZE);
    if (tb0219_base == NULL) {
        release_mem_region(TB0219_START, TB0219_SIZE);
        return -ENOMEM;
    }

    retval = register_chrdev(major, "TB0219", &tb0219_fops);
    if (retval < 0) {
        iounmap(tb0219_base);
        tb0219_base = NULL;
        release_mem_region(TB0219_START, TB0219_SIZE);
        return retval;
    }

    old_machine_restart = _machine_restart;
    _machine_restart = tb0219_restart;

    tb0219_pci_irq_init();

    if (major == 0) {
        major = retval;
        printk(KERN_INFO "TB0219: major number %d\n", major);
    }

    return 0;
}

static int __devexit tb0219_remove(struct platform_device *dev)
{
    _machine_restart = old_machine_restart;

    iounmap(tb0219_base);
    tb0219_base = NULL;

    release_mem_region(TB0219_START, TB0219_SIZE);

    return 0;
}

static struct platform_device *tb0219_platform_device;

static struct platform_driver tb0219_device_driver = {
    .probe      = tb0219_probe,
    .remove     = __devexit_p(tb0219_remove),
    .driver     = {
        .name   = "TB0219",
        .owner  = THIS_MODULE,
    },
};

static int __init tanbac_tb0219_init(void)
{
    int retval;

    tb0219_platform_device = platform_device_alloc("TB0219", -1);
    if (!tb0219_platform_device)
        return -ENOMEM;

    retval = platform_device_add(tb0219_platform_device);
    if (retval < 0) {
        platform_device_put(tb0219_platform_device);
        return retval;
    }

    retval = platform_driver_register(&tb0219_device_driver);
    if (retval < 0)
        platform_device_unregister(tb0219_platform_device);

    return retval;
}

static void __exit tanbac_tb0219_exit(void)
{
    platform_driver_unregister(&tb0219_device_driver);
    platform_device_unregister(tb0219_platform_device);
}

module_init(tanbac_tb0219_init);
module_exit(tanbac_tb0219_exit);