diff options
| -rw-r--r-- | drivers/usb/gadget/file_storage.c | 176 |
1 files changed, 154 insertions, 22 deletions
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c index 2e71368f45b..93933155e81 100644 --- a/drivers/usb/gadget/file_storage.c +++ b/drivers/usb/gadget/file_storage.c @@ -1,7 +1,7 @@ /* * file_storage.c -- File-backed USB Storage Gadget, for USB development * - * Copyright (C) 2003-2007 Alan Stern + * Copyright (C) 2003-2008 Alan Stern * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -38,16 +38,17 @@ /* * The File-backed Storage Gadget acts as a USB Mass Storage device, - * appearing to the host as a disk drive. In addition to providing an - * example of a genuinely useful gadget driver for a USB device, it also - * illustrates a technique of double-buffering for increased throughput. - * Last but not least, it gives an easy way to probe the behavior of the - * Mass Storage drivers in a USB host. + * appearing to the host as a disk drive or as a CD-ROM drive. In addition + * to providing an example of a genuinely useful gadget driver for a USB + * device, it also illustrates a technique of double-buffering for increased + * throughput. Last but not least, it gives an easy way to probe the + * behavior of the Mass Storage drivers in a USB host. * * Backing storage is provided by a regular file or a block device, specified * by the "file" module parameter. Access can be limited to read-only by - * setting the optional "ro" module parameter. The gadget will indicate that - * it has removable media if the optional "removable" module parameter is set. + * setting the optional "ro" module parameter. (For CD-ROM emulation, + * access is always read-only.) The gadget will indicate that it has + * removable media if the optional "removable" module parameter is set. * * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI), * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected @@ -64,7 +65,12 @@ * The default number of LUNs is taken from the number of "file" elements; * it is 1 if "file" is not given. If "removable" is not set then a backing * file must be specified for each LUN. If it is set, then an unspecified - * or empty backing filename means the LUN's medium is not loaded. + * or empty backing filename means the LUN's medium is not loaded. Ideally + * each LUN would be settable independently as a disk drive or a CD-ROM + * drive, but currently all LUNs have to be the same type. The CD-ROM + * emulation includes a single data track and no audio tracks; hence there + * need be only one backing file per LUN. Note also that the CD-ROM block + * length is set to 512 rather than the more common value 2048. * * Requirements are modest; only a bulk-in and a bulk-out endpoint are * needed (an interrupt-out endpoint is also needed for CBI). The memory @@ -91,6 +97,8 @@ * USB device controller (usually true), * boolean to permit the driver to halt * bulk endpoints + * cdrom Default false, boolean for whether to emulate + * a CD-ROM drive * transport=XXX Default BBB, transport name (CB, CBI, or BBB) * protocol=YYY Default SCSI, protocol name (RBC, 8020 or * ATAPI, QIC, UFI, 8070, or SCSI; @@ -103,15 +111,16 @@ * PAGE_CACHE_SIZE) * * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro", - * "removable", "luns", and "stall" options are available; default values - * are used for everything else. + * "removable", "luns", "stall", and "cdrom" options are available; default + * values are used for everything else. * * The pathnames of the backing files and the ro settings are available in * the attribute files "file" and "ro" in the lun<n> subdirectory of the * gadget's sysfs directory. If the "removable" option is set, writing to * these files will simulate ejecting/loading the medium (writing an empty * line means eject) and adjusting a write-enable tab. Changes to the ro - * setting are not allowed when the medium is loaded. + * setting are not allowed when the medium is loaded or if CD-ROM emulation + * is being used. * * This gadget driver is heavily based on "Gadget Zero" by David Brownell. * The driver's SCSI command interface was based on the "Information @@ -261,7 +270,7 @@ #define DRIVER_DESC "File-backed Storage Gadget" #define DRIVER_NAME "g_file_storage" -#define DRIVER_VERSION "7 August 2007" +#define DRIVER_VERSION "20 November 2008" static const char longname[] = DRIVER_DESC; static const char shortname[] = DRIVER_NAME; @@ -341,6 +350,7 @@ static struct { int removable; int can_stall; + int cdrom; char *transport_parm; char *protocol_parm; @@ -359,6 +369,7 @@ static struct { .protocol_parm = "SCSI", .removable = 0, .can_stall = 1, + .cdrom = 0, .vendor = DRIVER_VENDOR_ID, .product = DRIVER_PRODUCT_ID, .release = 0xffff, // Use controller chip type @@ -382,6 +393,9 @@ MODULE_PARM_DESC(removable, "true to simulate removable media"); module_param_named(stall, mod_data.can_stall, bool, S_IRUGO); MODULE_PARM_DESC(stall, "false to prevent bulk stalls"); +module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO); +MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk"); + /* In the non-TEST version, only the module parameters listed above * are available. */ @@ -411,6 +425,10 @@ MODULE_PARM_DESC(buflen, "I/O buffer size"); /*-------------------------------------------------------------------------*/ +/* SCSI device types */ +#define TYPE_DISK 0x00 +#define TYPE_CDROM 0x05 + /* USB protocol value = the transport method */ #define USB_PR_CBI 0x00 // Control/Bulk/Interrupt #define USB_PR_CB 0x01 // Control/Bulk w/o interrupt @@ -487,6 +505,8 @@ struct interrupt_data { #define SC_READ_12 0xa8 #define SC_READ_CAPACITY 0x25 #define SC_READ_FORMAT_CAPACITIES 0x23 +#define SC_READ_HEADER 0x44 +#define SC_READ_TOC 0x43 #define SC_RELEASE 0x17 #define SC_REQUEST_SENSE 0x03 #define SC_RESERVE 0x16 @@ -2006,23 +2026,28 @@ static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh) u8 *buf = (u8 *) bh->buf; static char vendor_id[] = "Linux "; - static char product_id[] = "File-Stor Gadget"; + static char product_disk_id[] = "File-Stor Gadget"; + static char product_cdrom_id[] = "File-CD Gadget "; if (!fsg->curlun) { // Unsupported LUNs are okay fsg->bad_lun_okay = 1; memset(buf, 0, 36); buf[0] = 0x7f; // Unsupported, no device-type + buf[4] = 31; // Additional length return 36; } - memset(buf, 0, 8); // Non-removable, direct-access device + memset(buf, 0, 8); + buf[0] = (mod_data.cdrom ? TYPE_CDROM : TYPE_DISK); if (mod_data.removable) buf[1] = 0x80; buf[2] = 2; // ANSI SCSI level 2 buf[3] = 2; // SCSI-2 INQUIRY data format buf[4] = 31; // Additional length // No special options - sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id, + sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, + (mod_data.cdrom ? product_cdrom_id : + product_disk_id), mod_data.release); return 36; } @@ -2101,6 +2126,75 @@ static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh) } +static void store_cdrom_address(u8 *dest, int msf, u32 addr) +{ + if (msf) { + /* Convert to Minutes-Seconds-Frames */ + addr >>= 2; /* Convert to 2048-byte frames */ + addr += 2*75; /* Lead-in occupies 2 seconds */ + dest[3] = addr % 75; /* Frames */ + addr /= 75; + dest[2] = addr % 60; /* Seconds */ + addr /= 60; + dest[1] = addr; /* Minutes */ + dest[0] = 0; /* Reserved */ + } else { + /* Absolute sector */ + put_be32(dest, addr); + } +} + +static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh) +{ + struct lun *curlun = fsg->curlun; + int msf = fsg->cmnd[1] & 0x02; + u32 lba = get_be32(&fsg->cmnd[2]); + u8 *buf = (u8 *) bh->buf; + + if ((fsg->cmnd[1] & ~0x02) != 0) { /* Mask away MSF */ + curlun->sense_data = SS_INVALID_FIELD_IN_CDB; + return -EINVAL; + } + if (lba >= curlun->num_sectors) { + curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE; + return -EINVAL; + } + + memset(buf, 0, 8); + buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */ + store_cdrom_address(&buf[4], msf, lba); + return 8; +} + + +static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh) +{ + struct lun *curlun = fsg->curlun; + int msf = fsg->cmnd[1] & 0x02; + int start_track = fsg->cmnd[6]; + u8 *buf = (u8 *) bh->buf; + + if ((fsg->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */ + start_track > 1) { + curlun->sense_data = SS_INVALID_FIELD_IN_CDB; + return -EINVAL; + } + + memset(buf, 0, 20); + buf[1] = (20-2); /* TOC data length */ + buf[2] = 1; /* First track number */ + buf[3] = 1; /* Last track number */ + buf[5] = 0x16; /* Data track, copying allowed */ + buf[6] = 0x01; /* Only track is number 1 */ + store_cdrom_address(&buf[8], msf, 0); + + buf[13] = 0x16; /* Lead-out track is data */ + buf[14] = 0xAA; /* Lead-out track number */ + store_cdrom_address(&buf[16], msf, curlun->num_sectors); + return 20; +} + + static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh) { struct lun *curlun = fsg->curlun; @@ -2848,6 +2942,26 @@ static int do_scsi_command(struct fsg_dev *fsg) reply = do_read_capacity(fsg, bh); break; + case SC_READ_HEADER: + if (!mod_data.cdrom) + goto unknown_cmnd; + fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]); + if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, + (3<<7) | (0x1f<<1), 1, + "READ HEADER")) == 0) + reply = do_read_header(fsg, bh); + break; + + case SC_READ_TOC: + if (!mod_data.cdrom) + goto unknown_cmnd; + fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]); + if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, + (7<<6) | (1<<1), 1, + "READ TOC")) == 0) + reply = do_read_toc(fsg, bh); + break; + case SC_READ_FORMAT_CAPACITIES: fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, @@ -2933,6 +3047,7 @@ static int do_scsi_command(struct fsg_dev *fsg) // Fall through default: + unknown_cmnd: fsg->data_size_from_cmnd = 0; sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]); if ((reply = check_command(fsg, fsg->cmnd_size, @@ -3498,6 +3613,7 @@ static int open_backing_file(struct lun *curlun, const char *filename) struct inode *inode = NULL; loff_t size; loff_t num_sectors; + loff_t min_sectors; /* R/W if we can, R/O if we must */ ro = curlun->ro; @@ -3541,8 +3657,19 @@ static int open_backing_file(struct lun *curlun, const char *filename) rc = (int) size; goto out; } - num_sectors = size >> 9; // File size in 512-byte sectors - if (num_sectors == 0) { + num_sectors = size >> 9; // File size in 512-byte blocks + min_sectors = 1; + if (mod_data.cdrom) { + num_sectors &= ~3; // Reduce to a multiple of 2048 + min_sectors = 300*4; // Smallest track is 300 frames + if (num_sectors >= 256*60*75*4) { + num_sectors = (256*60*75 - 1) * 4; + LINFO(curlun, "file too big: %s\n", filename); + LINFO(curlun, "using only first %d blocks\n", + (int) num_sectors); + } + } + if (num_sectors < min_sectors) { LINFO(curlun, "file too small: %s\n", filename); rc = -ETOOSMALL; goto out; @@ -3845,9 +3972,12 @@ static int __init fsg_bind(struct usb_gadget *gadget) goto out; if (mod_data.removable) { // Enable the store_xxx attributes - dev_attr_ro.attr.mode = dev_attr_file.attr.mode = 0644; - dev_attr_ro.store = store_ro; + dev_attr_file.attr.mode = 0644; dev_attr_file.store = store_file; + if (!mod_data.cdrom) { + dev_attr_ro.attr.mode = 0644; + dev_attr_ro.store = store_ro; + } } /* Find out how many LUNs there should be */ @@ -3872,6 +4002,8 @@ static int __init fsg_bind(struct usb_gadget *gadget) for (i = 0; i < fsg->nluns; ++i) { curlun = &fsg->luns[i]; curlun->ro = mod_data.ro[i]; + if (mod_data.cdrom) + curlun->ro = 1; curlun->dev.release = lun_release; curlun->dev.parent = &gadget->dev; curlun->dev.driver = &fsg_driver.driver; @@ -4031,9 +4163,9 @@ static int __init fsg_bind(struct usb_gadget *gadget) mod_data.protocol_name, mod_data.protocol_type); DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n", mod_data.vendor, mod_data.product, mod_data.release); - DBG(fsg, "removable=%d, stall=%d, buflen=%u\n", + DBG(fsg, "removable=%d, stall=%d, cdrom=%d, buflen=%u\n", mod_data.removable, mod_data.can_stall, - mod_data.buflen); + mod_data.cdrom, mod_data.buflen); DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task)); set_bit(REGISTERED, &fsg->atomic_bitflags); |