diff options
Diffstat (limited to 'common/cmd_ace.c')
| -rw-r--r-- | common/cmd_ace.c | 68 |
1 files changed, 47 insertions, 21 deletions
diff --git a/common/cmd_ace.c b/common/cmd_ace.c index 555fbe3..b6f8604 100644 --- a/common/cmd_ace.c +++ b/common/cmd_ace.c @@ -121,6 +121,7 @@ static unsigned long systemace_read(int dev, { unsigned val; int retry; + unsigned blk_countdown; unsigned char*dp = (unsigned char*)buffer; if (get_cf_lock() < 0) { @@ -136,6 +137,10 @@ static unsigned long systemace_read(int dev, return 0; } +#ifdef DEBUG_SYSTEMACE + printf("... systemace read %lu sectors at %lu\n", blkcnt, start); +#endif + retry = 2000; for (;;) { unsigned val = ace_readw(0x04); @@ -161,34 +166,55 @@ static unsigned long systemace_read(int dev, retry -= 1; } - /* Write LBA block address */ - ace_writew(start & 0xffff, 0x10); - start >>= 16; - ace_writew(start & 0xff, 0x12); + /* The SystemACE can only transfer 256 sectors at a time, so + limit the current chunk of sectors. The blk_countdown + variable is the number of sectors left to transfer. */ - /* Write sector count | ReadMemCardData. */ - ace_writew(blkcnt | 0x0300, 0x14); + blk_countdown = blkcnt; + while (blk_countdown > 0) { + unsigned trans = blk_countdown; - /* CONTROLREG = CFGRESET|LOCKREQ */ - ace_writew(0x0082, 0x18); + if (trans > 256) trans = 256; - retry = blkcnt * 16; - while (retry > 0) { - int idx; +#ifdef DEBUG_SYSTEMACE + printf("... transfer %lu sector in a chunk\n", trans); +#endif + /* Write LBA block address */ + ace_writew((start>> 0) & 0xffff, 0x10); + ace_writew((start>>16) & 0x00ff, 0x12); - /* Wait for buffer to become ready. */ - while (! (ace_readw(0x04) & 0x0020)) { - udelay(1000); - } + /* NOTE: in the Write Sector count below, a count of 0 + causes a transfer of 256, so &0xff gives the right + value for whatever transfer count we want. */ + + /* Write sector count | ReadMemCardData. */ + ace_writew((trans&0xff) | 0x0300, 0x14); - /* Read 16 words of 2bytes from the sector buffer. */ - for (idx = 0 ; idx < 16 ; idx += 1) { - unsigned short val = ace_readw(0x40); - *dp++ = val & 0xff; - *dp++ = (val>>8) & 0xff; + /* CONTROLREG = CFGRESET|LOCKREQ */ + ace_writew(0x0082, 0x18); + + retry = trans * 16; + while (retry > 0) { + int idx; + + /* Wait for buffer to become ready. */ + while (! (ace_readw(0x04) & 0x0020)) { + udelay(1000); + } + + /* Read 16 words of 2bytes from the sector buffer. */ + for (idx = 0 ; idx < 16 ; idx += 1) { + unsigned short val = ace_readw(0x40); + *dp++ = val & 0xff; + *dp++ = (val>>8) & 0xff; + } + + retry -= 1; } - retry -= 1; + /* Count the blocks we transfer this time. */ + start += trans; + blk_countdown -= trans; } release_cf_lock(); |