Extend sdio_readsb(), sdio_writesb(), sdio_memcpy_fromio(), and
sdio_memcpy_toio() to handle any length of buffer by splitting the transfer
into several IO_RW_EXTENDED commands. Typically, a transfer would be split
into a single block mode transfer followed by a byte mode transfer for the
remainder.

For this to work the block size must be limited to the maximum size of a
byte mode transfer (512 bytes).  This limitation could be revisited if
there are any cards out there that require a block size > 512.

Signed-off-by: David Vrabel <[EMAIL PROTECTED]>

---
commit 1c701a6566f373ede250b51c99216227fd881535
tree 2bbc5005de65bbdc497c8603e8a68486465065dc
parent 6d367fd822cbb2b8089ab7ef83f706f1984ab25b
author David Vrabel <[EMAIL PROTECTED]> Tue, 31 Jul 2007 11:08:49 +0100
committer David Vrabel <[EMAIL PROTECTED]> Tue, 31 Jul 2007 11:44:44 +0100

 drivers/mmc/core/sdio_io.c  |   63 ++++++++++++++++++++++++++++++++++---------
 drivers/mmc/core/sdio_ops.c |   17 +++++++-----
 drivers/mmc/core/sdio_ops.h |    2 +
 3 files changed, 61 insertions(+), 21 deletions(-)

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index e74e605..8fb1880 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -156,6 +156,13 @@ int sdio_set_block_size(struct sdio_func *func, unsigned 
short blksz)
 {
        int ret;
 
+       /* The standard permits block sizes up to 2048 bytes, but
+        * sdio_readsb() etc. can only work with block size <= 512. */
+       if (blksz > 512) {
+               blksz = 512;
+               dev_warn(&func->dev, "block size limited to 512 bytes\n");
+       }
+
        ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_FBR_BLKSIZE(func->num),
                               blksz & 0xff, NULL);
        if (ret)
@@ -228,6 +235,39 @@ void sdio_writeb(struct sdio_func *func, unsigned char b, 
unsigned int addr,
 
 EXPORT_SYMBOL_GPL(sdio_writeb);
 
+/* 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 fn, unsigned addr, int incr_addr, u8 *buf, unsigned size)
+{
+       unsigned remainder = size;
+       int ret;
+
+       while (remainder > func->block_size) {
+               unsigned blocks;
+
+               blocks = remainder % func->block_size;
+               if (blocks > 511)
+                       blocks = 511;
+               size = blocks * func->block_size;
+
+               ret = mmc_io_rw_extended(func->card, write, fn, addr,
+                        incr_addr, buf, blocks, func->block_size);
+               if (ret)
+                       return ret;
+
+               remainder -= size;
+               buf += size;
+               if (incr_addr)
+                       addr += size;
+       }
+
+       if (remainder)
+               ret = mmc_io_rw_extended(func->card, write, fn, addr,
+                        incr_addr, buf, 1, remainder);
+       return ret;
+}
+
 /**
  *     sdio_memcpy_fromio - read a chunk of memory from a SDIO function
  *     @func: SDIO function to access
@@ -235,14 +275,13 @@ EXPORT_SYMBOL_GPL(sdio_writeb);
  *     @addr: address to begin reading from
  *     @count: number of bytes to read
  *
- *     Reads up to 512 bytes from the address space of a given SDIO
- *     function. Return value indicates if the transfer succeeded or
- *     not.
+ *     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 mmc_io_rw_extended(func->card, 0, func->num, addr, 0, dst,
+       return sdio_io_rw_ext_helper(func, 0, func->num, addr, 1, dst,
                count);
 }
 
@@ -255,14 +294,13 @@ EXPORT_SYMBOL_GPL(sdio_memcpy_fromio);
  *     @src: buffer that contains the data to write
  *     @count: number of bytes to write
  *
- *     Writes up to 512 bytes to the address space of a given SDIO
- *     function. Return value indicates if the transfer succeeded or
- *     not.
+ *     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 mmc_io_rw_extended(func->card, 1, func->num, addr, 0, src,
+       return sdio_io_rw_ext_helper(func, 1, func->num, addr, 1, src,
                count);
 }
 
@@ -273,14 +311,13 @@ int sdio_memcpy_toio(struct sdio_func *func, unsigned int 
addr,
  *     @addr: address of (single byte) FIFO
  *     @count: number of bytes to read
  *
- *     Reads up to 512 bytes from the specified FIFO of a given SDIO
- *     function. Return value indicates if the transfer succeeded or
- *     not.
+ *     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 mmc_io_rw_extended(func->card, 0, func->num, addr, 1, dst,
+       return sdio_io_rw_ext_helper(func, 0, func->num, addr, 0, dst,
                count);
 }
 
@@ -300,7 +337,7 @@ EXPORT_SYMBOL_GPL(sdio_readsb);
 int sdio_writesb(struct sdio_func *func, unsigned int addr, void *src,
        int count)
 {
-       return mmc_io_rw_extended(func->card, 1, func->num, addr, 1, src,
+       return sdio_io_rw_ext_helper(func, 1, func->num, addr, 0, src,
                count);
 }
 
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index a91fe41..72590c4 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -92,7 +92,7 @@ int mmc_io_rw_direct(struct mmc_card *card, int write, 
unsigned fn,
 }
 
 int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
-       unsigned addr, int bang, u8 *buf, unsigned size)
+       unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)
 {
        struct mmc_request mrq;
        struct mmc_command cmd;
@@ -101,7 +101,6 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, 
unsigned fn,
 
        BUG_ON(!card);
        BUG_ON(fn > 7);
-       BUG_ON(size > 512);
 
        memset(&mrq, 0, sizeof(struct mmc_request));
        memset(&cmd, 0, sizeof(struct mmc_command));
@@ -113,18 +112,22 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, 
unsigned fn,
        cmd.opcode = SD_IO_RW_EXTENDED;
        cmd.arg = write ? 0x80000000 : 0x00000000;
        cmd.arg |= fn << 28;
-       cmd.arg |= bang ? 0x00000000 : 0x04000000;
+       cmd.arg |= incr_addr ? 0x04000000 : 0x00000000;
        cmd.arg |= addr << 9;
-       cmd.arg |= (size == 512) ? 0 : size;
+       if (blocks > 1) {
+               cmd.arg |= 0x08000000;
+               cmd.arg |= blocks;
+       } else
+               cmd.arg |= (blksz == 512) ? 0 : blksz;
        cmd.flags = MMC_RSP_R5 | MMC_CMD_ADTC;
 
-       data.blksz = size;
-       data.blocks = 1;
+       data.blksz = blksz;
+       data.blocks = blocks;
        data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
        data.sg = &sg;
        data.sg_len = 1;
 
-       sg_init_one(&sg, buf, size);
+       sg_init_one(&sg, buf, blksz * blocks);
 
        mmc_set_data_timeout(&data, card, 0);
 
diff --git a/drivers/mmc/core/sdio_ops.h b/drivers/mmc/core/sdio_ops.h
index 1d42e4f..e2e74b0 100644
--- a/drivers/mmc/core/sdio_ops.h
+++ b/drivers/mmc/core/sdio_ops.h
@@ -16,7 +16,7 @@ int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 
*rocr);
 int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
        unsigned addr, u8 in, u8* out);
 int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
-       unsigned addr, int bang, u8 *data, unsigned size);
+       unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz);
 
 #endif
 
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