isa.c

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/*
 * ISA bus.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/isa.h>

static struct device isa_bus = {
    .init_name  = "isa"
};

struct isa_dev {
    struct device dev;
    struct device *next;
    unsigned int id;
};

#define to_isa_dev(x) container_of((x), struct isa_dev, dev)

static int isa_bus_match(struct device *dev, struct device_driver *driver)
{
    struct isa_driver *isa_driver = to_isa_driver(driver);

    if (dev->platform_data == isa_driver) {
        if (!isa_driver->match ||
            isa_driver->match(dev, to_isa_dev(dev)->id))
            return 1;
        dev->platform_data = NULL;
    }
    return 0;
}

static int isa_bus_probe(struct device *dev)
{
    struct isa_driver *isa_driver = dev->platform_data;

    if (isa_driver->probe)
        return isa_driver->probe(dev, to_isa_dev(dev)->id);

    return 0;
}

static int isa_bus_remove(struct device *dev)
{
    struct isa_driver *isa_driver = dev->platform_data;

    if (isa_driver->remove)
        return isa_driver->remove(dev, to_isa_dev(dev)->id);

    return 0;
}

static void isa_bus_shutdown(struct device *dev)
{
    struct isa_driver *isa_driver = dev->platform_data;

    if (isa_driver->shutdown)
        isa_driver->shutdown(dev, to_isa_dev(dev)->id);
}

static int isa_bus_suspend(struct device *dev, pm_message_t state)
{
    struct isa_driver *isa_driver = dev->platform_data;

    if (isa_driver->suspend)
        return isa_driver->suspend(dev, to_isa_dev(dev)->id, state);

    return 0;
}

static int isa_bus_resume(struct device *dev)
{
    struct isa_driver *isa_driver = dev->platform_data;

    if (isa_driver->resume)
        return isa_driver->resume(dev, to_isa_dev(dev)->id);

    return 0;
}

static struct bus_type isa_bus_type = {
    .name       = "isa",
    .match      = isa_bus_match,
    .probe      = isa_bus_probe,
    .remove     = isa_bus_remove,
    .shutdown   = isa_bus_shutdown,
    .suspend    = isa_bus_suspend,
    .resume     = isa_bus_resume
};

static void isa_dev_release(struct device *dev)
{
    kfree(to_isa_dev(dev));
}

void isa_unregister_driver(struct isa_driver *isa_driver)
{
    struct device *dev = isa_driver->devices;

    while (dev) {
        struct device *tmp = to_isa_dev(dev)->next;
        device_unregister(dev);
        dev = tmp;
    }
    driver_unregister(&isa_driver->driver);
}
EXPORT_SYMBOL_GPL(isa_unregister_driver);

int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
{
    int error;
    unsigned int id;

    isa_driver->driver.bus  = &isa_bus_type;
    isa_driver->devices = NULL;

    error = driver_register(&isa_driver->driver);
    if (error)
        return error;

    for (id = 0; id < ndev; id++) {
        struct isa_dev *isa_dev;

        isa_dev = kzalloc(sizeof *isa_dev, GFP_KERNEL);
        if (!isa_dev) {
            error = -ENOMEM;
            break;
        }

        isa_dev->dev.parent = &isa_bus;
        isa_dev->dev.bus    = &isa_bus_type;

        dev_set_name(&isa_dev->dev, "%s.%u",
                 isa_driver->driver.name, id);
        isa_dev->dev.platform_data  = isa_driver;
        isa_dev->dev.release        = isa_dev_release;
        isa_dev->id         = id;

        isa_dev->dev.coherent_dma_mask = DMA_BIT_MASK(24);
        isa_dev->dev.dma_mask = &isa_dev->dev.coherent_dma_mask;

        error = device_register(&isa_dev->dev);
        if (error) {
            put_device(&isa_dev->dev);
            break;
        }

        if (isa_dev->dev.platform_data) {
            isa_dev->next = isa_driver->devices;
            isa_driver->devices = &isa_dev->dev;
        } else
            device_unregister(&isa_dev->dev);
    }

    if (!error && !isa_driver->devices)
        error = -ENODEV;

    if (error)
        isa_unregister_driver(isa_driver);

    return error;
}
EXPORT_SYMBOL_GPL(isa_register_driver);

static int __init isa_bus_init(void)
{
    int error;

    error = bus_register(&isa_bus_type);
    if (!error) {
        error = device_register(&isa_bus);
        if (error)
            bus_unregister(&isa_bus_type);
    }
    return error;
}

device_initcall(isa_bus_init);