amlogic-aml8726-mx-kernel/drivers/amlogic/cardreader/sdio_io.c

/*
 *  linux/drivers/amlogic/cardreader/sdio_io.c
 *
 *  Copyright 20108 Amlogic
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/delay.h>

#include <linux/cardreader/sdio.h>
#include <linux/cardreader/card_block.h>
#include "sdio_ops.h"

static int process_sdio_pending_irqs(struct memory_card *card)
{
	int i, ret, count;
	unsigned char pending;

	ret = sdio_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
	if (ret) {
		printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n",
		       card_card_id(card), ret);
		return ret;
	}


	count = 0;
	for (i = 1; i <= 7; i++) {
		if (pending & (1 << i)) {
			struct sdio_func *func = card->sdio_func[i - 1];
			if (!func) {
				printk(KERN_WARNING "%s: pending IRQ for "
					"non-existant function,pending = %x\n",
					card_card_id(card), pending);
				ret = -EINVAL;
			} else if (func->irq_handler) {
				//printk("sdio irq received and handled at func %d\n", i);
				func->irq_handler(func);
				count++;
			} else {
				printk(KERN_WARNING "%s: pending IRQ with no handler fun_num: %d\n", sdio_func_id(func), i);
				ret = -EINVAL;
			}
		}
	}

	sdio_irq_handled = 1;
	if (count)
		return count;

	return ret;
}

static int sdio_irq_thread(void *_host)
{
	struct card_host *host = _host;
	struct sched_param param = { .sched_priority = 1 };
	unsigned long period, idle_period;
	int ret;

	//set_cpus_allowed_ptr(current, cpumask_of(0));
	sched_setscheduler(current, SCHED_FIFO, &param);

	/*
	 * We want to allow for SDIO cards to work even on non SDIO
	 * aware hosts.  One thing that non SDIO host cannot do is
	 * asynchronous notification of pending SDIO card interrupts
	 * hence we poll for them in that case.
	 */
	idle_period = msecs_to_jiffies(10);
	period = (host->caps & CARD_CAP_SDIO_IRQ) ?
		MAX_SCHEDULE_TIMEOUT : idle_period;

	pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
		 card_hostname(host), period);

	do {
		/*
		 * We claim the host here on drivers behalf for a couple
		 * reasons:
		 *
		 * 1) it is already needed to retrieve the CCCR_INTx;
		 * 2) we want the driver(s) to clear the IRQ condition ASAP;
		 * 3) we need to control the abort condition locally.
		 *
		 * Just like traditional hard IRQ handlers, we expect SDIO
		 * IRQ handlers to be quick and to the point, so that the
		 * holding of the host lock does not cover too much work
		 * that doesn't require that lock to be held.
		 */
		//ret = __card_claim_host(host, &host->sdio_irq_thread_abort);
		card_claim_host(host);
		//if (ret)
			//break;
		ret = process_sdio_pending_irqs(host->card);
		card_release_host(host);

		/*
		 * Give other threads a chance to run in the presence of
		 * errors.
		 */
		if (ret < 0) {
			set_current_state(TASK_INTERRUPTIBLE);
			if (!kthread_should_stop())
				schedule_timeout(HZ);
			set_current_state(TASK_RUNNING);
		}

		/*
		 * Adaptive polling frequency based on the assumption
		 * that an interrupt will be closely followed by more.
		 * This has a substantial benefit for network devices.
		 */
		if (!(host->caps & CARD_CAP_SDIO_IRQ)) {
			if (ret > 0)
				period /= 2;
			else {
				period++;
				if (period > idle_period)
					period = idle_period;
			}
		}

		set_current_state(TASK_INTERRUPTIBLE);
		if (host->caps & CARD_CAP_SDIO_IRQ) {
			host->ops->enable_sdio_irq(host, 1);
			schedule();
		}
		else if (!kthread_should_stop())
		    msleep(10);
			//schedule_timeout(period);
                set_current_state(TASK_INTERRUPTIBLE);
		if(host->sdio_task_state)
		{
			schedule();
		}
		set_current_state(TASK_RUNNING);
	} while (!kthread_should_stop());

	if (host->caps & CARD_CAP_SDIO_IRQ)
		host->ops->enable_sdio_irq(host, 0);

	pr_debug("%s: IRQ thread exiting with code %d\n",
		 card_hostname(host), ret);

	return ret;
}

static int sdio_card_irq_get(struct memory_card *card)
{
	struct card_host *host = card->host;

	WARN_ON(!host->claimed);

	if (!host->sdio_irqs++) {
		atomic_set(&host->sdio_irq_thread_abort, 0);
		host->sdio_irq_thread =
			kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
				card_hostname(host));
		if (IS_ERR(host->sdio_irq_thread)) {
			int err = PTR_ERR(host->sdio_irq_thread);
			host->sdio_irqs--;
			return err;
		}
	}

	return 0;
}

static int sdio_card_irq_put(struct memory_card *card)
{
	struct card_host *host = card->host;

	WARN_ON(!host->claimed);
	BUG_ON(host->sdio_irqs < 1);

	if (!--host->sdio_irqs) {
		atomic_set(&host->sdio_irq_thread_abort, 1);
		kthread_stop(host->sdio_irq_thread);
	}

	return 0;
}

/**
 *	sdio_claim_irq - claim the IRQ for a SDIO function
 *	@func: SDIO function
 *	@handler: IRQ handler callback
 *
 *	Claim and activate the IRQ for the given SDIO function. The provided
 *	handler will be called when that IRQ is asserted.  The host is always
 *	claimed already when the handler is called so the handler must not
 *	call sdio_claim_host() nor sdio_release_host().
 */
int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
{
	int ret;
	unsigned char reg;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));

	if (func->irq_handler) {
		pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
		return -EBUSY;
	}

	ret = sdio_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	if (ret)
		return ret;

	reg |= 1 << func->num;

	reg |= 1; /* Master interrupt enable */

	ret = sdio_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	if (ret)
		return ret;

	func->irq_handler = handler;
	ret = sdio_card_irq_get(func->card);
	if (ret)
		func->irq_handler = NULL;

	return ret;
}
EXPORT_SYMBOL_GPL(sdio_claim_irq);

/**
 *	sdio_release_irq - release the IRQ for a SDIO function
 *	@func: SDIO function
 *
 *	Disable and release the IRQ for the given SDIO function.
 */
int sdio_release_irq(struct sdio_func *func)
{
	int ret;
	unsigned char reg;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));

	if (func->irq_handler) {
		func->irq_handler = NULL;
		sdio_card_irq_put(func->card);
	}

	ret = sdio_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
	if (ret)
		return ret;

	reg &= ~(1 << func->num);

	/* Disable master interrupt with the last function interrupt */
	if (!(reg & 0xFE))
		reg = 0;

	ret = sdio_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
	if (ret)
		return ret;

	return 0;
}
EXPORT_SYMBOL_GPL(sdio_release_irq);

/**
 *	sdio_claim_host - exclusively claim a bus for a certain SDIO function
 *	@func: SDIO function that will be accessed
 *
 *	Claim a bus for a set of operations. The SDIO function given
 *	is used to figure out which bus is relevant.
 */
void sdio_claim_host(struct sdio_func *func)
{
	BUG_ON(!func);
	BUG_ON(!func->card);

	__card_claim_host(func->card->host, func->card);
}
EXPORT_SYMBOL_GPL(sdio_claim_host);

/**
 *	sdio_release_host - release a bus for a certain SDIO function
 *	@func: SDIO function that was accessed
 *
 *	Release a bus, allowing others to claim the bus for their
 *	operations.
 */
void sdio_release_host(struct sdio_func *func)
{
	BUG_ON(!func);
	BUG_ON(!func->card);

	card_release_host(func->card->host);
}
EXPORT_SYMBOL_GPL(sdio_release_host);

/**
 *	sdio_enable_func - enables a SDIO function for usage
 *	@func: SDIO function to enable
 *
 *	Powers up and activates a SDIO function so that register
 *	access is possible.
 */
int sdio_enable_func(struct sdio_func *func)
{
	int ret;
	unsigned char reg;
	unsigned long timeout;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Enabling device %s...\n", sdio_func_id(func));

	ret = sdio_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
	if (ret)
		goto err;

	reg |= 1 << func->num;

	ret = sdio_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
	if (ret)
		goto err;

	timeout = jiffies + msecs_to_jiffies(func->enable_timeout);

	while (1) {
		ret = sdio_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IORx, 0, &reg);
		if (ret)
			goto err;
		if (reg & (1 << func->num))
			break;
		ret = -ETIME;
		if (time_after(jiffies, timeout))
			goto err;
	}

	pr_debug("SDIO: Enabled device %s\n", sdio_func_id(func));

	return 0;

err:
	pr_debug("SDIO: Failed to enable device %s\n", sdio_func_id(func));
	return ret;
}
EXPORT_SYMBOL_GPL(sdio_enable_func);

/**
 *	sdio_disable_func - disable a SDIO function
 *	@func: SDIO function to disable
 *
 *	Powers down and deactivates a SDIO function. Register access
 *	to this function will fail until the function is reenabled.
 */
int sdio_disable_func(struct sdio_func *func)
{
	int ret;
	unsigned char reg;

	BUG_ON(!func);
	BUG_ON(!func->card);

	pr_debug("SDIO: Disabling device %s...\n", sdio_func_id(func));

	ret = sdio_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
	if (ret)
		goto err;

	reg &= ~(1 << func->num);

	ret = sdio_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
	if (ret)
		goto err;

	pr_debug("SDIO: Disabled device %s\n", sdio_func_id(func));

	return 0;

err:
	pr_debug("SDIO: Failed to disable device %s\n", sdio_func_id(func));
	return -EIO;
}
EXPORT_SYMBOL_GPL(sdio_disable_func);

/**
 *	sdio_set_block_size - set the block size of an SDIO function
 *	@func: SDIO function to change
 *	@blksz: new block size or 0 to use the default.
 *
 *	The default block size is the largest supported by both the function
 *	and the host, with a maximum of 512 to ensure that arbitrarily sized
 *	data transfer use the optimal (least) number of commands.
 *
 *	A driver may call this to override the default block size set by the
 *	core. This can be used to set a block size greater than the maximum
 *	that reported by the card; it is the driver's responsibility to ensure
 *	it uses a value that the card supports.
 *
 *	Returns 0 on success, -EINVAL if the host does not support the
 *	requested block size, or -EIO (etc.) if one of the resultant FBR block
 *	size register writes failed.
 *
 */
int sdio_set_block_size(struct sdio_func *func, unsigned blksz)
{
	int ret;

	if (blksz > func->card->host->max_blk_size)
		return -EINVAL;

	if (blksz == 0) {
		blksz = min(func->max_blksize, func->card->host->max_blk_size);
		blksz = min(blksz, 512u);
	}

	ret = sdio_io_rw_direct(func->card, 1, 0,
		SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE,
		blksz & 0xff, NULL);
	if (ret)
		return ret;
	ret = sdio_io_rw_direct(func->card, 1, 0,
		SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE + 1,
		(blksz >> 8) & 0xff, NULL);
	if (ret)
		return ret;
	func->cur_blksize = blksz;

	return 0;
}
EXPORT_SYMBOL_GPL(sdio_set_block_size);

/*
 * Calculate the maximum byte mode transfer size
 */
static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
{
	unsigned mval =	min(func->card->host->max_seg_size,
			    func->card->host->max_blk_size);

	/*if (mmc_blksz_for_byte_mode(func->card))
		mval = min(mval, func->cur_blksize);
	else
		mval = min(mval, func->max_blksize);*/

	return min(mval, 512u); /* maximum size for byte mode */
}

/**
 *	sdio_align_size - pads a transfer size to a more optimal value
 *	@func: SDIO function
 *	@sz: original transfer size
 *
 *	Pads the original data size with a number of extra bytes in
 *	order to avoid controller bugs and/or performance hits
 *	(e.g. some controllers revert to PIO for certain sizes).
 *
 *	If possible, it will also adjust the size so that it can be
 *	handled in just a single request.
 *
 *	Returns the improved size, which might be unmodified.
 */
unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
{
	unsigned int orig_sz;
	unsigned int blk_sz, byte_sz;
	unsigned chunk_sz;

	orig_sz = sz;

	/*
	 * Do a first check with the controller, in case it
	 * wants to increase the size up to a point where it
	 * might need more than one block.
	 */
	sz = card_align_data_size(func->card, sz);

	/*
	 * If we can still do this with just a byte transfer, then
	 * we're done.
	 */
	if (sz <= sdio_max_byte_size(func))
		return sz;

	if (1) {
		/*
		 * Check if the transfer is already block aligned
		 */
		if ((sz % func->cur_blksize) == 0)
			return sz;

		/*
		 * Realign it so that it can be done with one request,
		 * and recheck if the controller still likes it.
		 */
		blk_sz = ((sz + func->cur_blksize - 1) /
			func->cur_blksize) * func->cur_blksize;
		blk_sz = card_align_data_size(func->card, blk_sz);

		/*
		 * This value is only good if it is still just
		 * one request.
		 */
		if ((blk_sz % func->cur_blksize) == 0)
			return blk_sz;

		/*
		 * We failed to do one request, but at least try to
		 * pad the remainder properly.
		 */
		byte_sz = card_align_data_size(func->card,
				sz % func->cur_blksize);
		if (byte_sz <= sdio_max_byte_size(func)) {
			blk_sz = sz / func->cur_blksize;
			return blk_sz * func->cur_blksize + byte_sz;
		}
	} else {
		/*
		 * We need multiple requests, so first check that the
		 * controller can handle the chunk size;
		 */
		chunk_sz = card_align_data_size(func->card,
				sdio_max_byte_size(func));
		if (chunk_sz == sdio_max_byte_size(func)) {
			/*
			 * Fix up the size of the remainder (if any)
			 */
			byte_sz = orig_sz % chunk_sz;
			if (byte_sz) {
				byte_sz = card_align_data_size(func->card,
						byte_sz);
			}

			return (orig_sz / chunk_sz) * chunk_sz + byte_sz;
		}
	}

	/*
	 * The controller is simply incapable of transferring the size
	 * we want in decent manner, so just return the original size.
	 */
	return orig_sz;
}
EXPORT_SYMBOL_GPL(sdio_align_size);

/* Split an arbitrarily sized data transfer into several
 * IO_RW_EXTENDED commands. */
static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
	unsigned addr, int incr_addr, u8 *buf, unsigned size)
{
	unsigned remainder = size;
	unsigned max_blocks;
	int ret;
	//printk("sdio rw ext addr %x at fun %d cnt: %d read_or_write %d\n", 
			//addr, func->num, size, write);

	/* Do the bulk of the transfer using block mode (if supported). */
	if ((size > sdio_max_byte_size(func))) {
		/* Blocks per command is limited by host count, host transfer
		 * size (we only use a single sg entry) and the maximum for
		 * IO_RW_EXTENDED of 511 blocks. */
		max_blocks = min(func->card->host->max_blk_count,
			func->card->host->max_seg_size / func->cur_blksize);
		max_blocks = min(max_blocks, 511u);

		while (remainder > func->cur_blksize) {
			unsigned blocks;

			blocks = remainder / func->cur_blksize;
			if (blocks > max_blocks)
				blocks = max_blocks;
			size = blocks * func->cur_blksize;

			ret = sdio_io_rw_extended(func->card, write,
				func->num, addr, incr_addr, buf,
				blocks, func->cur_blksize);
			if (ret)
				return ret;

			remainder -= size;
			buf += size;
			if (incr_addr)
				addr += size;
		}
	}

	/* Write the remainder using byte mode. */
	while (remainder > 0) {
		size = min(remainder, sdio_max_byte_size(func));

		ret = sdio_io_rw_extended(func->card, write, func->num, addr,
			 incr_addr, buf, 1, size);
		if (ret)
			return ret;

		remainder -= size;
		buf += size;
		if (incr_addr)
			addr += size;
	}
	return 0;
}

/**
 *	sdio_readb - read a single byte from a SDIO function
 *	@func: SDIO function to access
 *	@addr: address to read
 *	@err_ret: optional status value from transfer
 *
 *	Reads a single byte from the address space of a given SDIO
 *	function. If there is a problem reading the address, 0xff
 *	is returned and @err_ret will contain the error code.
 */
u8 sdio_readb(struct sdio_func *func, unsigned int addr, int *err_ret)
{
	int ret;
	u8 val;

	BUG_ON(!func);

	if (err_ret)
		*err_ret = 0;

	ret = sdio_io_rw_direct(func->card, 0, func->num, addr, 0, &val);
	if (ret) {
		if (err_ret)
			*err_ret = ret;
		return 0xFF;
	}

	return val;
}
EXPORT_SYMBOL_GPL(sdio_readb);

/**
 *	sdio_writeb - write a single byte to a SDIO function
 *	@func: SDIO function to access
 *	@b: byte to write
 *	@addr: address to write to
 *	@err_ret: optional status value from transfer
 *
 *	Writes a single byte to the address space of a given SDIO
 *	function. @err_ret will contain the status of the actual
 *	transfer.
 */
void sdio_writeb(struct sdio_func *func, u8 b, unsigned int addr, int *err_ret)
{
	int ret;

	BUG_ON(!func);

	ret = sdio_io_rw_direct(func->card, 1, func->num, addr, b, NULL);
	if (err_ret)
		*err_ret = ret;
}
EXPORT_SYMBOL_GPL(sdio_writeb);

/**
 *	sdio_memcpy_fromio - read a chunk of memory from a SDIO function
 *	@func: SDIO function to access
 *	@dst: buffer to store the data
 *	@addr: address to begin reading from
 *	@count: number of bytes to read
 *
 *	Reads from the address space of a given SDIO function. Return
 *	value indicates if the transfer succeeded or not.
 */
int sdio_memcpy_fromio(struct sdio_func *func, void *dst,
	unsigned int addr, int count)
{
	return sdio_io_rw_ext_helper(func, 0, addr, 1, dst, count);
}
EXPORT_SYMBOL_GPL(sdio_memcpy_fromio);

/**
 *	sdio_memcpy_toio - write a chunk of memory to a SDIO function
 *	@func: SDIO function to access
 *	@addr: address to start writing to
 *	@src: buffer that contains the data to write
 *	@count: number of bytes to write
 *
 *	Writes to the address space of a given SDIO function. Return
 *	value indicates if the transfer succeeded or not.
 */
int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,
	void *src, int count)
{
	return sdio_io_rw_ext_helper(func, 1, addr, 1, src, count);
}
EXPORT_SYMBOL_GPL(sdio_memcpy_toio);

/**
 *	sdio_readsb - read from a FIFO on a SDIO function
 *	@func: SDIO function to access
 *	@dst: buffer to store the data
 *	@addr: address of (single byte) FIFO
 *	@count: number of bytes to read
 *
 *	Reads from the specified FIFO of a given SDIO function. Return
 *	value indicates if the transfer succeeded or not.
 */
int sdio_readsb(struct sdio_func *func, void *dst, unsigned int addr,
	int count)
{
	return sdio_io_rw_ext_helper(func, 0, addr, 0, dst, count);
}
EXPORT_SYMBOL_GPL(sdio_readsb);

/**
 *	sdio_writesb - write to a FIFO of a SDIO function
 *	@func: SDIO function to access
 *	@addr: address of (single byte) FIFO
 *	@src: buffer that contains the data to write
 *	@count: number of bytes to write
 *
 *	Writes to the specified FIFO of a given SDIO function. Return
 *	value indicates if the transfer succeeded or not.
 */
int sdio_writesb(struct sdio_func *func, unsigned int addr, void *src,
	int count)
{
	return sdio_io_rw_ext_helper(func, 1, addr, 0, src, count);
}
EXPORT_SYMBOL_GPL(sdio_writesb);

/**
 *	sdio_readw - read a 16 bit integer from a SDIO function
 *	@func: SDIO function to access
 *	@addr: address to read
 *	@err_ret: optional status value from transfer
 *
 *	Reads a 16 bit integer from the address space of a given SDIO
 *	function. If there is a problem reading the address, 0xffff
 *	is returned and @err_ret will contain the error code.
 */
u16 sdio_readw(struct sdio_func *func, unsigned int addr, int *err_ret)
{
	int ret;

	if (err_ret)
		*err_ret = 0;

	ret = sdio_memcpy_fromio(func, func->tmpbuf, addr, 2);
	if (ret) {
		if (err_ret)
			*err_ret = ret;
		return 0xFFFF;
	}

	return le16_to_cpup((__le16 *)func->tmpbuf);
}
EXPORT_SYMBOL_GPL(sdio_readw);

/**
 *	sdio_writew - write a 16 bit integer to a SDIO function
 *	@func: SDIO function to access
 *	@b: integer to write
 *	@addr: address to write to
 *	@err_ret: optional status value from transfer
 *
 *	Writes a 16 bit integer to the address space of a given SDIO
 *	function. @err_ret will contain the status of the actual
 *	transfer.
 */
void sdio_writew(struct sdio_func *func, u16 b, unsigned int addr, int *err_ret)
{
	int ret;

	*(__le16 *)func->tmpbuf = cpu_to_le16(b);

	ret = sdio_memcpy_toio(func, addr, func->tmpbuf, 2);
	if (err_ret)
		*err_ret = ret;
}
EXPORT_SYMBOL_GPL(sdio_writew);

/**
 *	sdio_readl - read a 32 bit integer from a SDIO function
 *	@func: SDIO function to access
 *	@addr: address to read
 *	@err_ret: optional status value from transfer
 *
 *	Reads a 32 bit integer from the address space of a given SDIO
 *	function. If there is a problem reading the address,
 *	0xffffffff is returned and @err_ret will contain the error
 *	code.
 */
u32 sdio_readl(struct sdio_func *func, unsigned int addr, int *err_ret)
{
	int ret;

	if (err_ret)
		*err_ret = 0;

	ret = sdio_memcpy_fromio(func, func->tmpbuf, addr, 4);
	if (ret) {
		if (err_ret)
			*err_ret = ret;
		return 0xFFFFFFFF;
	}

	return le32_to_cpup((__le32 *)func->tmpbuf);
}
EXPORT_SYMBOL_GPL(sdio_readl);

/**
 *	sdio_writel - write a 32 bit integer to a SDIO function
 *	@func: SDIO function to access
 *	@b: integer to write
 *	@addr: address to write to
 *	@err_ret: optional status value from transfer
 *
 *	Writes a 32 bit integer to the address space of a given SDIO
 *	function. @err_ret will contain the status of the actual
 *	transfer.
 */
void sdio_writel(struct sdio_func *func, u32 b, unsigned int addr, int *err_ret)
{
	int ret;

	*(__le32 *)func->tmpbuf = cpu_to_le32(b);

	ret = sdio_memcpy_toio(func, addr, func->tmpbuf, 4);
	if (err_ret)
		*err_ret = ret;
}
EXPORT_SYMBOL_GPL(sdio_writel);

/**
 *	sdio_f0_readb - read a single byte from SDIO function 0
 *	@func: an SDIO function of the card
 *	@addr: address to read
 *	@err_ret: optional status value from transfer
 *
 *	Reads a single byte from the address space of SDIO function 0.
 *	If there is a problem reading the address, 0xff is returned
 *	and @err_ret will contain the error code.
 */
unsigned char sdio_f0_readb(struct sdio_func *func, unsigned int addr,
	int *err_ret)
{
	int ret;
	unsigned char val;

	BUG_ON(!func);

	if (err_ret)
		*err_ret = 0;

	ret = sdio_io_rw_direct(func->card, 0, 0, addr, 0, &val);
	if (ret) {
		if (err_ret)
			*err_ret = ret;
		return 0xFF;
	}

	return val;
}
EXPORT_SYMBOL_GPL(sdio_f0_readb);

/**
 *	sdio_f0_writeb - write a single byte to SDIO function 0
 *	@func: an SDIO function of the card
 *	@b: byte to write
 *	@addr: address to write to
 *	@err_ret: optional status value from transfer
 *
 *	Writes a single byte to the address space of SDIO function 0.
 *	@err_ret will contain the status of the actual transfer.
 *
 *	Only writes to the vendor specific CCCR registers (0xF0 -
 *	0xFF) are permiited; @err_ret will be set to -EINVAL for *
 *	writes outside this range.
 */
void sdio_f0_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,
	int *err_ret)
{
	int ret;

	BUG_ON(!func);

	if ((addr < 0xF0 || addr > 0xFF)) {
		if (err_ret)
			*err_ret = -EINVAL;
		return;
	}

	ret = sdio_io_rw_direct(func->card, 1, 0, addr, b, NULL);
	if (err_ret)
		*err_ret = ret;
}
EXPORT_SYMBOL_GPL(sdio_f0_writeb);

/**
 *	sdio_get_host_pm_caps - get host power management capabilities
 *	@func: SDIO function attached to host
 *
 *	Returns a capability bitmask corresponding to power management
 *	features supported by the host controller that the card function
 *	might rely upon during a system suspend.  The host doesn't need
 *	to be claimed, nor the function active, for this information to be
 *	obtained.
 */
card_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func)
{
	BUG_ON(!func);
	BUG_ON(!func->card);

	return func->card->host->pm_caps;
}
EXPORT_SYMBOL_GPL(sdio_get_host_pm_caps);

/**
 *	sdio_set_host_pm_flags - set wanted host power management capabilities
 *	@func: SDIO function attached to host
 *
 *	Set a capability bitmask corresponding to wanted host controller
 *	power management features for the upcoming suspend state.
 *	This must be called, if needed, each time the suspend method of
 *	the function driver is called, and must contain only bits that
 *	were returned by sdio_get_host_pm_caps().
 *	The host doesn't need to be claimed, nor the function active,
 *	for this information to be set.
 */
int sdio_set_host_pm_flags(struct sdio_func *func, card_pm_flag_t flags)
{
	struct card_host *host;

	BUG_ON(!func);
	BUG_ON(!func->card);

	host = func->card->host;

	if (flags & ~host->pm_caps)
		return -EINVAL;

	/* function suspend methods are serialized, hence no lock needed */
	host->pm_flags |= flags;
	return 0;
}
EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);