/*
 *  linux/drivers/mmc/core/sdio_io.c
 *
 *  Copyright 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 as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>

#include "sdio_ops.h"

/**
 *      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);

        mmc_claim_host(func->card->host);
}
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);

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

        reg |= 1 << func->num;

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

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

        ret = mmc_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 = mmc_io_rw_direct(func->card, 1, 0,
                SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE,
                blksz & 0xff, NULL);
        if (ret)
                return ret;
        ret = mmc_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);
        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 = mmc_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 (func->card->cccr.multi_block) {
                /*
                 * 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 = mmc_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 = mmc_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 = mmc_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 = mmc_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;

        /* Do the bulk of the transfer using block mode (if supported). */
        if (func->card->cccr.multi_block && (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 = mmc_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 = mmc_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 = mmc_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 = mmc_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 = mmc_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 = mmc_io_rw_direct(func->card, 1, 0, addr, b, NULL);
        if (err_ret)
                *err_ret = ret;
}
EXPORT_SYMBOL_GPL(sdio_f0_writeb);