bttv-gpio.c

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/*

    bttv-gpio.c  --  gpio sub drivers

    sysfs-based sub driver interface for bttv
    mainly intended for gpio access


    Copyright (C) 1996,97,98 Ralph  Metzler ([email protected])
               & Marcus Metzler ([email protected])
    (c) 1999-2003 Gerd Knorr <[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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <asm/io.h>

#include "bttvp.h"

/* ----------------------------------------------------------------------- */
/* internal: the bttv "bus"                                                */

static int bttv_sub_bus_match(struct device *dev, struct device_driver *drv)
{
    struct bttv_sub_driver *sub = to_bttv_sub_drv(drv);
    int len = strlen(sub->wanted);

    if (0 == strncmp(dev_name(dev), sub->wanted, len))
        return 1;
    return 0;
}

static int bttv_sub_probe(struct device *dev)
{
    struct bttv_sub_device *sdev = to_bttv_sub_dev(dev);
    struct bttv_sub_driver *sub = to_bttv_sub_drv(dev->driver);

    return sub->probe ? sub->probe(sdev) : -ENODEV;
}

static int bttv_sub_remove(struct device *dev)
{
    struct bttv_sub_device *sdev = to_bttv_sub_dev(dev);
    struct bttv_sub_driver *sub = to_bttv_sub_drv(dev->driver);

    if (sub->remove)
        sub->remove(sdev);
    return 0;
}

struct bus_type bttv_sub_bus_type = {
    .name   = "bttv-sub",
    .match  = &bttv_sub_bus_match,
    .probe  = bttv_sub_probe,
    .remove = bttv_sub_remove,
};

static void release_sub_device(struct device *dev)
{
    struct bttv_sub_device *sub = to_bttv_sub_dev(dev);
    kfree(sub);
}

int bttv_sub_add_device(struct bttv_core *core, char *name)
{
    struct bttv_sub_device *sub;
    int err;

    sub = kzalloc(sizeof(*sub),GFP_KERNEL);
    if (NULL == sub)
        return -ENOMEM;

    sub->core        = core;
    sub->dev.parent  = &core->pci->dev;
    sub->dev.bus     = &bttv_sub_bus_type;
    sub->dev.release = release_sub_device;
    dev_set_name(&sub->dev, "%s%d", name, core->nr);

    err = device_register(&sub->dev);
    if (0 != err) {
        kfree(sub);
        return err;
    }
    pr_info("%d: add subdevice \"%s\"\n", core->nr, dev_name(&sub->dev));
    list_add_tail(&sub->list,&core->subs);
    return 0;
}

int bttv_sub_del_devices(struct bttv_core *core)
{
    struct bttv_sub_device *sub, *save;

    list_for_each_entry_safe(sub, save, &core->subs, list) {
        list_del(&sub->list);
        device_unregister(&sub->dev);
    }
    return 0;
}

/* ----------------------------------------------------------------------- */
/* external: sub-driver register/unregister                                */

int bttv_sub_register(struct bttv_sub_driver *sub, char *wanted)
{
    sub->drv.bus = &bttv_sub_bus_type;
    snprintf(sub->wanted,sizeof(sub->wanted),"%s",wanted);
    return driver_register(&sub->drv);
}
EXPORT_SYMBOL(bttv_sub_register);

int bttv_sub_unregister(struct bttv_sub_driver *sub)
{
    driver_unregister(&sub->drv);
    return 0;
}
EXPORT_SYMBOL(bttv_sub_unregister);

/* ----------------------------------------------------------------------- */
/* external: gpio access functions                                         */

void bttv_gpio_inout(struct bttv_core *core, u32 mask, u32 outbits)
{
    struct bttv *btv = container_of(core, struct bttv, c);
    unsigned long flags;
    u32 data;

    spin_lock_irqsave(&btv->gpio_lock,flags);
    data = btread(BT848_GPIO_OUT_EN);
    data = data & ~mask;
    data = data | (mask & outbits);
    btwrite(data,BT848_GPIO_OUT_EN);
    spin_unlock_irqrestore(&btv->gpio_lock,flags);
}

u32 bttv_gpio_read(struct bttv_core *core)
{
    struct bttv *btv = container_of(core, struct bttv, c);
    u32 value;

    value = btread(BT848_GPIO_DATA);
    return value;
}

void bttv_gpio_write(struct bttv_core *core, u32 value)
{
    struct bttv *btv = container_of(core, struct bttv, c);

    btwrite(value,BT848_GPIO_DATA);
}

void bttv_gpio_bits(struct bttv_core *core, u32 mask, u32 bits)
{
    struct bttv *btv = container_of(core, struct bttv, c);
    unsigned long flags;
    u32 data;

    spin_lock_irqsave(&btv->gpio_lock,flags);
    data = btread(BT848_GPIO_DATA);
    data = data & ~mask;
    data = data | (mask & bits);
    btwrite(data,BT848_GPIO_DATA);
    spin_unlock_irqrestore(&btv->gpio_lock,flags);
}

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */