diff options
Diffstat (limited to 'drivers/mtd/maps/vmu-flash.c')
| -rw-r--r-- | drivers/mtd/maps/vmu-flash.c | 832 |
1 files changed, 832 insertions, 0 deletions
diff --git a/drivers/mtd/maps/vmu-flash.c b/drivers/mtd/maps/vmu-flash.c new file mode 100644 index 000000000000..1f73297e7776 --- /dev/null +++ b/drivers/mtd/maps/vmu-flash.c @@ -0,0 +1,832 @@ +/* vmu-flash.c + * Driver for SEGA Dreamcast Visual Memory Unit + * + * Copyright (c) Adrian McMenamin 2002 - 2009 + * Copyright (c) Paul Mundt 2001 + * + * Licensed under version 2 of the + * GNU General Public Licence + */ +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/maple.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/map.h> + +struct vmu_cache { + unsigned char *buffer; /* Cache */ + unsigned int block; /* Which block was cached */ + unsigned long jiffies_atc; /* When was it cached? */ + int valid; +}; + +struct mdev_part { + struct maple_device *mdev; + int partition; +}; + +struct vmupart { + u16 user_blocks; + u16 root_block; + u16 numblocks; + char *name; + struct vmu_cache *pcache; +}; + +struct memcard { + u16 tempA; + u16 tempB; + u32 partitions; + u32 blocklen; + u32 writecnt; + u32 readcnt; + u32 removeable; + int partition; + int read; + unsigned char *blockread; + struct vmupart *parts; + struct mtd_info *mtd; +}; + +struct vmu_block { + unsigned int num; /* block number */ + unsigned int ofs; /* block offset */ +}; + +static struct vmu_block *ofs_to_block(unsigned long src_ofs, + struct mtd_info *mtd, int partition) +{ + struct vmu_block *vblock; + struct maple_device *mdev; + struct memcard *card; + struct mdev_part *mpart; + int num; + + mpart = mtd->priv; + mdev = mpart->mdev; + card = maple_get_drvdata(mdev); + + if (src_ofs >= card->parts[partition].numblocks * card->blocklen) + goto failed; + + num = src_ofs / card->blocklen; + if (num > card->parts[partition].numblocks) + goto failed; + + vblock = kmalloc(sizeof(struct vmu_block), GFP_KERNEL); + if (!vblock) + goto failed; + + vblock->num = num; + vblock->ofs = src_ofs % card->blocklen; + return vblock; + +failed: + return NULL; +} + +/* Maple bus callback function for reads */ +static void vmu_blockread(struct mapleq *mq) +{ + struct maple_device *mdev; + struct memcard *card; + + mdev = mq->dev; + card = maple_get_drvdata(mdev); + /* copy the read in data */ + + if (unlikely(!card->blockread)) + return; + + memcpy(card->blockread, mq->recvbuf->buf + 12, + card->blocklen/card->readcnt); + +} + +/* Interface with maple bus to read blocks + * caching the results so that other parts + * of the driver can access block reads */ +static int maple_vmu_read_block(unsigned int num, unsigned char *buf, + struct mtd_info *mtd) +{ + struct memcard *card; + struct mdev_part *mpart; + struct maple_device *mdev; + int partition, error = 0, x, wait; + unsigned char *blockread = NULL; + struct vmu_cache *pcache; + __be32 sendbuf; + + mpart = mtd->priv; + mdev = mpart->mdev; + partition = mpart->partition; + card = maple_get_drvdata(mdev); + pcache = card->parts[partition].pcache; + pcache->valid = 0; + + /* prepare the cache for this block */ + if (!pcache->buffer) { + pcache->buffer = kmalloc(card->blocklen, GFP_KERNEL); + if (!pcache->buffer) { + dev_err(&mdev->dev, "VMU at (%d, %d) - read fails due" + " to lack of memory\n", mdev->port, + mdev->unit); + error = -ENOMEM; + goto outB; + } + } + + /* + * Reads may be phased - again the hardware spec + * supports this - though may not be any devices in + * the wild that implement it, but we will here + */ + for (x = 0; x < card->readcnt; x++) { + sendbuf = cpu_to_be32(partition << 24 | x << 16 | num); + + if (atomic_read(&mdev->busy) == 1) { + wait_event_interruptible_timeout(mdev->maple_wait, + atomic_read(&mdev->busy) == 0, HZ); + if (atomic_read(&mdev->busy) == 1) { + dev_notice(&mdev->dev, "VMU at (%d, %d)" + " is busy\n", mdev->port, mdev->unit); + error = -EAGAIN; + goto outB; + } + } + + atomic_set(&mdev->busy, 1); + blockread = kmalloc(card->blocklen/card->readcnt, GFP_KERNEL); + if (!blockread) { + error = -ENOMEM; + atomic_set(&mdev->busy, 0); + goto outB; + } + card->blockread = blockread; + + maple_getcond_callback(mdev, vmu_blockread, 0, + MAPLE_FUNC_MEMCARD); + error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD, + MAPLE_COMMAND_BREAD, 2, &sendbuf); + /* Very long timeouts seem to be needed when box is stressed */ + wait = wait_event_interruptible_timeout(mdev->maple_wait, + (atomic_read(&mdev->busy) == 0 || + atomic_read(&mdev->busy) == 2), HZ * 3); + /* + * MTD layer does not handle hotplugging well + * so have to return errors when VMU is unplugged + * in the middle of a read (busy == 2) + */ + if (error || atomic_read(&mdev->busy) == 2) { + if (atomic_read(&mdev->busy) == 2) + error = -ENXIO; + atomic_set(&mdev->busy, 0); + card->blockread = NULL; + goto outA; + } + if (wait == 0 || wait == -ERESTARTSYS) { + card->blockread = NULL; + atomic_set(&mdev->busy, 0); + error = -EIO; + list_del_init(&(mdev->mq->list)); + kfree(mdev->mq->sendbuf); + mdev->mq->sendbuf = NULL; + if (wait == -ERESTARTSYS) { + dev_warn(&mdev->dev, "VMU read on (%d, %d)" + " interrupted on block 0x%X\n", + mdev->port, mdev->unit, num); + } else + dev_notice(&mdev->dev, "VMU read on (%d, %d)" + " timed out on block 0x%X\n", + mdev->port, mdev->unit, num); + goto outA; + } + + memcpy(buf + (card->blocklen/card->readcnt) * x, blockread, + card->blocklen/card->readcnt); + + memcpy(pcache->buffer + (card->blocklen/card->readcnt) * x, + card->blockread, card->blocklen/card->readcnt); + card->blockread = NULL; + pcache->block = num; + pcache->jiffies_atc = jiffies; + pcache->valid = 1; + kfree(blockread); + } + + return error; + +outA: + kfree(blockread); +outB: + return error; +} + +/* communicate with maple bus for phased writing */ +static int maple_vmu_write_block(unsigned int num, const unsigned char *buf, + struct mtd_info *mtd) +{ + struct memcard *card; + struct mdev_part *mpart; + struct maple_device *mdev; + int partition, error, locking, x, phaselen, wait; + __be32 *sendbuf; + + mpart = mtd->priv; + mdev = mpart->mdev; + partition = mpart->partition; + card = maple_get_drvdata(mdev); + + phaselen = card->blocklen/card->writecnt; + + sendbuf = kmalloc(phaselen + 4, GFP_KERNEL); + if (!sendbuf) { + error = -ENOMEM; + goto fail_nosendbuf; + } + for (x = 0; x < card->writecnt; x++) { + sendbuf[0] = cpu_to_be32(partition << 24 | x << 16 | num); + memcpy(&sendbuf[1], buf + phaselen * x, phaselen); + /* wait until the device is not busy doing something else + * or 1 second - which ever is longer */ + if (atomic_read(&mdev->busy) == 1) { + wait_event_interruptible_timeout(mdev->maple_wait, + atomic_read(&mdev->busy) == 0, HZ); + if (atomic_read(&mdev->busy) == 1) { + error = -EBUSY; + dev_notice(&mdev->dev, "VMU write at (%d, %d)" + "failed - device is busy\n", + mdev->port, mdev->unit); + goto fail_nolock; + } + } + atomic_set(&mdev->busy, 1); + + locking = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD, + MAPLE_COMMAND_BWRITE, phaselen / 4 + 2, sendbuf); + wait = wait_event_interruptible_timeout(mdev->maple_wait, + atomic_read(&mdev->busy) == 0, HZ/10); + if (locking) { + error = -EIO; + atomic_set(&mdev->busy, 0); + goto fail_nolock; + } + if (atomic_read(&mdev->busy) == 2) { + atomic_set(&mdev->busy, 0); + } else if (wait == 0 || wait == -ERESTARTSYS) { + error = -EIO; + dev_warn(&mdev->dev, "Write at (%d, %d) of block" + " 0x%X at phase %d failed: could not" + " communicate with VMU", mdev->port, + mdev->unit, num, x); + atomic_set(&mdev->busy, 0); + kfree(mdev->mq->sendbuf); + mdev->mq->sendbuf = NULL; + list_del_init(&(mdev->mq->list)); + goto fail_nolock; + } + } + kfree(sendbuf); + + return card->blocklen; + +fail_nolock: + kfree(sendbuf); +fail_nosendbuf: + dev_err(&mdev->dev, "VMU (%d, %d): write failed\n", mdev->port, + mdev->unit); + return error; +} + +/* mtd function to simulate reading byte by byte */ +static unsigned char vmu_flash_read_char(unsigned long ofs, int *retval, + struct mtd_info *mtd) +{ + struct vmu_block *vblock; + struct memcard *card; + struct mdev_part *mpart; + struct maple_device *mdev; + unsigned char *buf, ret; + int partition, error; + + mpart = mtd->priv; + mdev = mpart->mdev; + partition = mpart->partition; + card = maple_get_drvdata(mdev); + *retval = 0; + + buf = kmalloc(card->blocklen, GFP_KERNEL); + if (!buf) { + *retval = 1; + ret = -ENOMEM; + goto finish; + } + + vblock = ofs_to_block(ofs, mtd, partition); + if (!vblock) { + *retval = 3; + ret = -ENOMEM; + goto out_buf; + } + + error = maple_vmu_read_block(vblock->num, buf, mtd); + if (error) { + ret = error; + *retval = 2; + goto out_vblock; + } + + ret = buf[vblock->ofs]; + +out_vblock: + kfree(vblock); +out_buf: + kfree(buf); +finish: + return ret; +} + +/* mtd higher order function to read flash */ +static int vmu_flash_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + struct maple_device *mdev; + struct memcard *card; + struct mdev_part *mpart; + struct vmu_cache *pcache; + struct vmu_block *vblock; + int index = 0, retval, partition, leftover, numblocks; + unsigned char cx; + + if (len < 1) + return -EIO; + + mpart = mtd->priv; + mdev = mpart->mdev; + partition = mpart->partition; + card = maple_get_drvdata(mdev); + + numblocks = card->parts[partition].numblocks; + if (from + len > numblocks * card->blocklen) + len = numblocks * card->blocklen - from; + if (len == 0) + return -EIO; + /* Have we cached this bit already? */ + pcache = card->parts[partition].pcache; + do { + vblock = ofs_to_block(from + index, mtd, partition); + if (!vblock) + return -ENOMEM; + /* Have we cached this and is the cache valid and timely? */ + if (pcache->valid && + time_before(jiffies, pcache->jiffies_atc + HZ) && + (pcache->block == vblock->num)) { + /* we have cached it, so do necessary copying */ + leftover = card->blocklen - vblock->ofs; + if (vblock->ofs + len - index < card->blocklen) { + /* only a bit of this block to copy */ + memcpy(buf + index, + pcache->buffer + vblock->ofs, + len - index); + index = len; + } else { + /* otherwise copy remainder of whole block */ + memcpy(buf + index, pcache->buffer + + vblock->ofs, leftover); + index += leftover; + } + } else { + /* + * Not cached so read one byte - + * but cache the rest of the block + */ + cx = vmu_flash_read_char(from + index, &retval, mtd); + if (retval) { + *retlen = index; + kfree(vblock); + return cx; + } + memset(buf + index, cx, 1); + index++; + } + kfree(vblock); + } while (len > index); + *retlen = index; + + return 0; +} + +static int vmu_flash_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + struct maple_device *mdev; + struct memcard *card; + struct mdev_part *mpart; + int index = 0, partition, error = 0, numblocks; + struct vmu_cache *pcache; + struct vmu_block *vblock; + unsigned char *buffer; + + mpart = mtd->priv; + mdev = mpart->mdev; + partition = mpart->partition; + card = maple_get_drvdata(mdev); + + /* simple sanity checks */ + if (len < 1) { + error = -EIO; + goto failed; + } + numblocks = card->parts[partition].numblocks; + if (to + len > numblocks * card->blocklen) + len = numblocks * card->blocklen - to; + if (len == 0) { + error = -EIO; + goto failed; + } + + vblock = ofs_to_block(to, mtd, partition); + if (!vblock) { + error = -ENOMEM; + goto failed; + } + + buffer = kmalloc(card->blocklen, GFP_KERNEL); + if (!buffer) { + error = -ENOMEM; + goto fail_buffer; + } + + do { + /* Read in the block we are to write to */ + error = maple_vmu_read_block(vblock->num, buffer, mtd); + if (error) + goto fail_io; + + do { + buffer[vblock->ofs] = buf[index]; + vblock->ofs++; + index++; + if (index >= len) + break; + } while (vblock->ofs < card->blocklen); + + /* write out new buffer */ + error = maple_vmu_write_block(vblock->num, buffer, mtd); + /* invalidate the cache */ + pcache = card->parts[partition].pcache; + pcache->valid = 0; + + if (error != card->blocklen) + goto fail_io; + + vblock->num++; + vblock->ofs = 0; + } while (len > index); + + kfree(buffer); + *retlen = index; + kfree(vblock); + return 0; + +fail_io: + kfree(buffer); +fail_buffer: + kfree(vblock); +failed: + dev_err(&mdev->dev, "VMU write failing with error %d\n", error); + return error; +} + +static void vmu_flash_sync(struct mtd_info *mtd) +{ + /* Do nothing here */ +} + +/* Maple bus callback function to recursively query hardware details */ +static void vmu_queryblocks(struct mapleq *mq) +{ + struct maple_device *mdev; + unsigned short *res; + struct memcard *card; + __be32 partnum; + struct vmu_cache *pcache; + struct mdev_part *mpart; + struct mtd_info *mtd_cur; + struct vmupart *part_cur; + int error; + + mdev = mq->dev; + card = maple_get_drvdata(mdev); + res = (unsigned short *) (mq->recvbuf->buf); + card->tempA = res[12]; + card->tempB = res[6]; + + dev_info(&mdev->dev, "VMU device at partition %d has %d user " + "blocks with a root block at %d\n", card->partition, + card->tempA, card->tempB); + + part_cur = &card->parts[card->partition]; + part_cur->user_blocks = card->tempA; + part_cur->root_block = card->tempB; + part_cur->numblocks = card->tempB + 1; + part_cur->name = kmalloc(12, GFP_KERNEL); + if (!part_cur->name) + goto fail_name; + + sprintf(part_cur->name, "vmu%d.%d.%d", + mdev->port, mdev->unit, card->partition); + mtd_cur = &card->mtd[card->partition]; + mtd_cur->name = part_cur->name; + mtd_cur->type = 8; + mtd_cur->flags = MTD_WRITEABLE|MTD_NO_ERASE; + mtd_cur->size = part_cur->numblocks * card->blocklen; + mtd_cur->erasesize = card->blocklen; + mtd_cur->write = vmu_flash_write; + mtd_cur->read = vmu_flash_read; + mtd_cur->sync = vmu_flash_sync; + mtd_cur->writesize = card->blocklen; + + mpart = kmalloc(sizeof(struct mdev_part), GFP_KERNEL); + if (!mpart) + goto fail_mpart; + + mpart->mdev = mdev; + mpart->partition = card->partition; + mtd_cur->priv = mpart; + mtd_cur->owner = THIS_MODULE; + + pcache = kzalloc(sizeof(struct vmu_cache), GFP_KERNEL); + if (!pcache) + goto fail_cache_create; + part_cur->pcache = pcache; + + error = add_mtd_device(mtd_cur); + if (error) + goto fail_mtd_register; + + maple_getcond_callback(mdev, NULL, 0, + MAPLE_FUNC_MEMCARD); + + /* + * Set up a recursive call to the (probably theoretical) + * second or more partition + */ + if (++card->partition < card->partitions) { + partnum = cpu_to_be32(card->partition << 24); + maple_getcond_callback(mdev, vmu_queryblocks, 0, + MAPLE_FUNC_MEMCARD); + maple_add_packet(mdev, MAPLE_FUNC_MEMCARD, + MAPLE_COMMAND_GETMINFO, 2, &partnum); + } + return; + +fail_mtd_register: + dev_err(&mdev->dev, "Could not register maple device at (%d, %d)" + "error is 0x%X\n", mdev->port, mdev->unit, error); + for (error = 0; error <= card->partition; error++) { + kfree(((card->parts)[error]).pcache); + ((card->parts)[error]).pcache = NULL; + } +fail_cache_create: +fail_mpart: + for (error = 0; error <= card->partition; error++) { + kfree(((card->mtd)[error]).priv); + ((card->mtd)[error]).priv = NULL; + } + maple_getcond_callback(mdev, NULL, 0, + MAPLE_FUNC_MEMCARD); + kfree(part_cur->name); +fail_name: + return; +} + +/* Handles very basic info about the flash, queries for details */ +static int __devinit vmu_connect(struct maple_device *mdev) +{ + unsigned long test_flash_data, basic_flash_data; + int c, error; + struct memcard *card; + u32 partnum = 0; + + test_flash_data = be32_to_cpu(mdev->devinfo.function); + /* Need to count how many bits are set - to find out which + * function_data element has details of the memory card: + * using Brian Kernighan's/Peter Wegner's method */ + for (c = 0; test_flash_data; c++) + test_flash_data &= test_flash_data - 1; + + basic_flash_data = be32_to_cpu(mdev->devinfo.function_data[c - 1]); + + card = kmalloc(sizeof(struct memcard), GFP_KERNEL); + if (!card) { + error = ENOMEM; + goto fail_nomem; + } + + card->partitions = (basic_flash_data >> 24 & 0xFF) + 1; + card->blocklen = ((basic_flash_data >> 16 & 0xFF) + 1) << 5; + card->writecnt = basic_flash_data >> 12 & 0xF; + card->readcnt = basic_flash_data >> 8 & 0xF; + card->removeable = basic_flash_data >> 7 & 1; + + card->partition = 0; + + /* + * Not sure there are actually any multi-partition devices in the + * real world, but the hardware supports them, so, so will we + */ + card->parts = kmalloc(sizeof(struct vmupart) * card->partitions, + GFP_KERNEL); + if (!card->parts) { + error = -ENOMEM; + goto fail_partitions; + } + + card->mtd = kmalloc(sizeof(struct mtd_info) * card->partitions, + GFP_KERNEL); + if (!card->mtd) { + error = -ENOMEM; + goto fail_mtd_info; + } + + maple_set_drvdata(mdev, card); + + /* + * We want to trap meminfo not get cond + * so set interval to zero, but rely on maple bus + * driver to pass back the results of the meminfo + */ + maple_getcond_callback(mdev, vmu_queryblocks, 0, + MAPLE_FUNC_MEMCARD); + + /* Make sure we are clear to go */ + if (atomic_read(&mdev->busy) == 1) { + wait_event_interruptible_timeout(mdev->maple_wait, + atomic_read(&mdev->busy) == 0, HZ); + if (atomic_read(&mdev->busy) == 1) { + dev_notice(&mdev->dev, "VMU at (%d, %d) is busy\n", + mdev->port, mdev->unit); + error = -EAGAIN; + goto fail_device_busy; + } + } + + atomic_set(&mdev->busy, 1); + + /* + * Set up the minfo call: vmu_queryblocks will handle + * the information passed back + */ + error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD, + MAPLE_COMMAND_GETMINFO, 2, &partnum); + if (error) { + dev_err(&mdev->dev, "Could not lock VMU at (%d, %d)" + " error is 0x%X\n", mdev->port, mdev->unit, error); + goto fail_mtd_info; + } + return 0; + +fail_device_busy: + kfree(card->mtd); +fail_mtd_info: + kfree(card->parts); +fail_partitions: + kfree(card); +fail_nomem: + return error; +} + +static void __devexit vmu_disconnect(struct maple_device *mdev) +{ + struct memcard *card; + struct mdev_part *mpart; + int x; + + mdev->callback = NULL; + card = maple_get_drvdata(mdev); + for (x = 0; x < card->partitions; x++) { + mpart = ((card->mtd)[x]).priv; + mpart->mdev = NULL; + del_mtd_device(&((card->mtd)[x])); + kfree(((card->parts)[x]).name); + } + kfree(card->parts); + kfree(card->mtd); + kfree(card); +} + +/* Callback to handle eccentricities of both mtd subsystem + * and general flakyness of Dreamcast VMUs + */ +static int vmu_can_unload(struct maple_device *mdev) +{ + struct memcard *card; + int x; + struct mtd_info *mtd; + + card = maple_get_drvdata(mdev); + for (x = 0; x < card->partitions; x++) { + mtd = &((card->mtd)[x]); + if (mtd->usecount > 0) + return 0; + } + return 1; +} + +#define ERRSTR "VMU at (%d, %d) file error -" + +static void vmu_file_error(struct maple_device *mdev, void *recvbuf) +{ + enum maple_file_errors error = ((int *)recvbuf)[1]; + + switch (error) { + + case MAPLE_FILEERR_INVALID_PARTITION: + dev_notice(&mdev->dev, ERRSTR " invalid partition number\n", + mdev->port, mdev->unit); + break; + + case MAPLE_FILEERR_PHASE_ERROR: + dev_notice(&mdev->dev, ERRSTR " phase error\n", + mdev->port, mdev->unit); + break; + + case MAPLE_FILEERR_INVALID_BLOCK: + dev_notice(&mdev->dev, ERRSTR " invalid block number\n", + mdev->port, mdev->unit); + break; + + case MAPLE_FILEERR_WRITE_ERROR: + dev_notice(&mdev->dev, ERRSTR " write error\n", + mdev->port, mdev->unit); + break; + + case MAPLE_FILEERR_INVALID_WRITE_LENGTH: + dev_notice(&mdev->dev, ERRSTR " invalid write length\n", + mdev->port, mdev->unit); + break; + + case MAPLE_FILEERR_BAD_CRC: + dev_notice(&mdev->dev, ERRSTR " bad CRC\n", + mdev->port, mdev->unit); + break; + + default: + dev_notice(&mdev->dev, ERRSTR " 0x%X\n", + mdev->port, mdev->unit, error); + } +} + + +static int __devinit probe_maple_vmu(struct device *dev) +{ + int error; + struct maple_device *mdev = to_maple_dev(dev); + struct maple_driver *mdrv = to_maple_driver(dev->driver); + + mdev->can_unload = vmu_can_unload; + mdev->fileerr_handler = vmu_file_error; + mdev->driver = mdrv; + + error = vmu_connect(mdev); + if (error) + return error; + + return 0; +} + +static int __devexit remove_maple_vmu(struct device *dev) +{ + struct maple_device *mdev = to_maple_dev(dev); + + vmu_disconnect(mdev); + return 0; +} + +static struct maple_driver vmu_flash_driver = { + .function = MAPLE_FUNC_MEMCARD, + .drv = { + .name = "Dreamcast_visual_memory", + .probe = probe_maple_vmu, + .remove = __devexit_p(remove_maple_vmu), + }, +}; + +static int __init vmu_flash_map_init(void) +{ + return maple_driver_register(&vmu_flash_driver); +} + +static void __exit vmu_flash_map_exit(void) +{ + maple_driver_unregister(&vmu_flash_driver); +} + +module_init(vmu_flash_map_init); +module_exit(vmu_flash_map_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Adrian McMenamin"); +MODULE_DESCRIPTION("Flash mapping for Sega Dreamcast visual memory"); |