WSL2-Linux-Kernel/drivers/mmc/core/host.c

181 строка
3.8 KiB
C

/*
* linux/drivers/mmc/core/host.c
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright (C) 2007-2008 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* MMC host class device management
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/pagemap.h>
#include <linux/leds.h>
#include <linux/mmc/host.h>
#include "core.h"
#include "host.h"
#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
static void mmc_host_classdev_release(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
kfree(host);
}
static struct class mmc_host_class = {
.name = "mmc_host",
.dev_release = mmc_host_classdev_release,
};
int mmc_register_host_class(void)
{
return class_register(&mmc_host_class);
}
void mmc_unregister_host_class(void)
{
class_unregister(&mmc_host_class);
}
static DEFINE_IDR(mmc_host_idr);
static DEFINE_SPINLOCK(mmc_host_lock);
/**
* mmc_alloc_host - initialise the per-host structure.
* @extra: sizeof private data structure
* @dev: pointer to host device model structure
*
* Initialise the per-host structure.
*/
struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
{
int err;
struct mmc_host *host;
if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
return NULL;
host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
if (!host)
return NULL;
spin_lock(&mmc_host_lock);
err = idr_get_new(&mmc_host_idr, host, &host->index);
spin_unlock(&mmc_host_lock);
if (err)
goto free;
dev_set_name(&host->class_dev, "mmc%d", host->index);
host->parent = dev;
host->class_dev.parent = dev;
host->class_dev.class = &mmc_host_class;
device_initialize(&host->class_dev);
spin_lock_init(&host->lock);
init_waitqueue_head(&host->wq);
INIT_DELAYED_WORK(&host->detect, mmc_rescan);
INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
/*
* By default, hosts do not support SGIO or large requests.
* They have to set these according to their abilities.
*/
host->max_hw_segs = 1;
host->max_phys_segs = 1;
host->max_seg_size = PAGE_CACHE_SIZE;
host->max_req_size = PAGE_CACHE_SIZE;
host->max_blk_size = 512;
host->max_blk_count = PAGE_CACHE_SIZE / 512;
return host;
free:
kfree(host);
return NULL;
}
EXPORT_SYMBOL(mmc_alloc_host);
/**
* mmc_add_host - initialise host hardware
* @host: mmc host
*
* Register the host with the driver model. The host must be
* prepared to start servicing requests before this function
* completes.
*/
int mmc_add_host(struct mmc_host *host)
{
int err;
WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
!host->ops->enable_sdio_irq);
led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
err = device_add(&host->class_dev);
if (err)
return err;
#ifdef CONFIG_DEBUG_FS
mmc_add_host_debugfs(host);
#endif
mmc_start_host(host);
return 0;
}
EXPORT_SYMBOL(mmc_add_host);
/**
* mmc_remove_host - remove host hardware
* @host: mmc host
*
* Unregister and remove all cards associated with this host,
* and power down the MMC bus. No new requests will be issued
* after this function has returned.
*/
void mmc_remove_host(struct mmc_host *host)
{
mmc_stop_host(host);
#ifdef CONFIG_DEBUG_FS
mmc_remove_host_debugfs(host);
#endif
device_del(&host->class_dev);
led_trigger_unregister_simple(host->led);
}
EXPORT_SYMBOL(mmc_remove_host);
/**
* mmc_free_host - free the host structure
* @host: mmc host
*
* Free the host once all references to it have been dropped.
*/
void mmc_free_host(struct mmc_host *host)
{
spin_lock(&mmc_host_lock);
idr_remove(&mmc_host_idr, host->index);
spin_unlock(&mmc_host_lock);
put_device(&host->class_dev);
}
EXPORT_SYMBOL(mmc_free_host);