core.c

omap3 linux 2.6 用nocc去除了冗余代码

	mmc_set_ios(host);
}

/*
 * Allocate a new MMC card
 */
struct mmc_card *mmc_alloc_card(struct mmc_host *host)
{
	struct mmc_card *card;

	card = kmalloc(sizeof(struct mmc_card), GFP_KERNEL);
	if (!card)
		return ERR_PTR(-ENOMEM);

	mmc_init_card(card, host);

	return card;
}

/*
 * Apply power to the MMC stack.  This is a two-stage process.
 * First, we enable power to the card without the clock running.
 * We then wait a bit for the power to stabilise.  Finally,
 * enable the bus drivers and clock to the card.
 *
 * We must _NOT_ enable the clock prior to power stablising.
 *
 * If a host does all the power sequencing itself, ignore the
 * initial MMC_POWER_UP stage.
 */
static void mmc_power_up(struct mmc_host *host)
{
	int bit = fls(host->ocr_avail) - 1;

	host->ios.vdd = bit;
	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
	host->ios.chip_select = MMC_CS_DONTCARE;
	host->ios.power_mode = MMC_POWER_UP;
	host->ios.bus_width = MMC_BUS_WIDTH_1;
	host->ios.timing = MMC_TIMING_LEGACY;
	mmc_set_ios(host);

	mmc_delay(1);

	host->ios.clock = host->f_min;
	host->ios.power_mode = MMC_POWER_ON;
	mmc_set_ios(host);

	mmc_delay(2);
}

static void mmc_power_off(struct mmc_host *host)
{
	host->ios.clock = 0;
	host->ios.vdd = 0;
	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
	host->ios.chip_select = MMC_CS_DONTCARE;
	host->ios.power_mode = MMC_POWER_OFF;
	host->ios.bus_width = MMC_BUS_WIDTH_1;
	host->ios.timing = MMC_TIMING_LEGACY;
	mmc_set_ios(host);
}

/*
 * Assign a mmc bus handler to a host. Only one bus handler may control a
 * host at any given time.
 */
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
{
	unsigned long flags;

	BUG_ON(!host);
	BUG_ON(!ops);

	BUG_ON(!host->claimed);

	spin_lock_irqsave(&host->lock, flags);

	BUG_ON(host->bus_ops);
	BUG_ON(host->bus_refs);

	host->bus_ops = ops;
	host->bus_refs = 1;
	host->bus_dead = 0;

	spin_unlock_irqrestore(&host->lock, flags);
}

/*
 * Remove the current bus handler from a host. Assumes that there are
 * no interesting cards left, so the bus is powered down.
 */
void mmc_detach_bus(struct mmc_host *host)
{
	unsigned long flags;

	BUG_ON(!host);

	BUG_ON(!host->claimed);
	BUG_ON(!host->bus_ops);

	spin_lock_irqsave(&host->lock, flags);

	host->bus_dead = 1;

	spin_unlock_irqrestore(&host->lock, flags);

	mmc_power_off(host);

	mmc_bus_put(host);
}

/*
 * Cleanup when the last reference to the bus operator is dropped.
 */
void __mmc_release_bus(struct mmc_host *host)
{
	BUG_ON(!host);
	BUG_ON(host->bus_refs);
	BUG_ON(!host->bus_dead);

	host->bus_ops = NULL;
}

/**
 *	mmc_detect_change - process change of state on a MMC socket
 *	@host: host which changed state.
 *	@delay: optional delay to wait before detection (jiffies)
 *
 *	All we know is that card(s) have been inserted or removed
 *	from the socket(s).  We don't know which socket or cards.
 */
void mmc_detect_change(struct mmc_host *host, unsigned long delay)
{

	mmc_schedule_delayed_work(&host->detect, delay);
}

EXPORT_SYMBOL(mmc_detect_change);


static void mmc_rescan(struct work_struct *work)
{
	struct mmc_host *host =
		container_of(work, struct mmc_host, detect.work);
	u32 ocr;
	int err;

	mmc_bus_get(host);

	if (host->bus_ops == NULL) {
		/*
		 * Only we can add a new handler, so it's safe to
		 * release the lock here.
		 */
		mmc_bus_put(host);

		mmc_claim_host(host);

		mmc_power_up(host);
		mmc_go_idle(host);

		/* Detect SDIO cards */
		err = io_send_op_cond(host, 0, &ocr);
		if (err == MMC_ERR_NONE) {
			if (mmc_attach_sdio(host, ocr))
				mmc_power_off(host);
		} else {
			/*
		 	 * If we fail to detect any SDIO cards then try
		 	 * searching for SD cards.
		 	 */
			mmc_send_if_cond(host, host->ocr_avail);

			err = mmc_send_app_op_cond(host, 0, &ocr);
			if (err == MMC_ERR_NONE) {
				if (mmc_attach_sd(host, ocr))
					mmc_power_off(host);
			} else {
				/*
			 	 * If we fail to detect any SD cards then try
			 	 * searching for MMC cards.
			 	 */
				err = mmc_send_op_cond(host, 0, &ocr);
				if (err == MMC_ERR_NONE) {
					if (mmc_attach_mmc(host, ocr))
						mmc_power_off(host);
				} else {
					mmc_power_off(host);
					mmc_release_host(host);
				}	
			}
		}
	} else {
		if (host->bus_ops->detect && !host->bus_dead)
			host->bus_ops->detect(host);

		mmc_bus_put(host);
	}
}


/**
 *	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)
{
	struct mmc_host *host;

	host = mmc_alloc_host_sysfs(extra, dev);
	if (host) {
		spin_lock_init(&host->lock);
		init_waitqueue_head(&host->wq);
		INIT_DELAYED_WORK(&host->detect, mmc_rescan);

		/*
		 * 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;
}

EXPORT_SYMBOL(mmc_alloc_host);

/**
 *	mmc_add_host - initialise host hardware
 *	@host: mmc host
 */
int mmc_add_host(struct mmc_host *host)
{
	int ret;

	ret = mmc_add_host_sysfs(host);
	if (ret == 0) {
		mmc_power_off(host);
		mmc_detect_change(host, 0);
	}

	return ret;
}

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.
 */
void mmc_remove_host(struct mmc_host *host)
{

	mmc_flush_scheduled_work();

	mmc_bus_get(host);
	if (host->bus_ops && !host->bus_dead) {
		if (host->bus_ops->remove)
			host->bus_ops->remove(host);

		mmc_claim_host(host);
		mmc_detach_bus(host);
		mmc_release_host(host);
	}
	mmc_bus_put(host);

	BUG_ON(host->card);

	mmc_power_off(host);
	mmc_remove_host_sysfs(host);
}

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)
{
	mmc_free_host_sysfs(host);
}

EXPORT_SYMBOL(mmc_free_host);


/**
 *	mmc_suspend_host - suspend a host
 *	@host: mmc host
 *	@state: suspend mode (PM_SUSPEND_xxx)
 */
int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
{
	mmc_flush_scheduled_work();

	mmc_bus_get(host);
	if (host->bus_ops && !host->bus_dead) {
		if (host->bus_ops->suspend)
			host->bus_ops->suspend(host);
		if (!host->bus_ops->resume) {
			if (host->bus_ops->remove)
				host->bus_ops->remove(host);

			mmc_claim_host(host);
			mmc_detach_bus(host);
			mmc_release_host(host);
		}
	}
	mmc_bus_put(host);

	mmc_power_off(host);

	return 0;
}

EXPORT_SYMBOL(mmc_suspend_host);

/**
 *	mmc_resume_host - resume a previously suspended host
 *	@host: mmc host
 */
int mmc_resume_host(struct mmc_host *host)
{
	mmc_bus_get(host);
	if (host->bus_ops && !host->bus_dead) {
		mmc_power_up(host);
		BUG_ON(!host->bus_ops->resume);
		host->bus_ops->resume(host);
	}
	mmc_bus_put(host);

	/*
	 * We add a slight delay here so that resume can progress
	 * in parallel.
	 */
	mmc_detect_change(host, 1);

	return 0;
}

EXPORT_SYMBOL(mmc_resume_host);


MODULE_LICENSE("GPL");