diff options
Diffstat (limited to 'drivers/usb/gadget/f_mass_storage.c')
| -rw-r--r-- | drivers/usb/gadget/f_mass_storage.c | 133 |
1 files changed, 31 insertions, 102 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index f67b453740bd..4f1142efa6d1 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -44,12 +44,12 @@ * function for a USB device, it also illustrates a technique of * double-buffering for increased throughput. * - * Function supports multiple logical units (LUNs). Backing storage - * for each LUN is provided by a regular file or a block device. - * Access for each LUN can be limited to read-only. Moreover, the - * function can indicate that LUN is removable and/or CD-ROM. (The - * later implies read-only access.) - * + * For more information about MSF and in particular its module + * parameters and sysfs interface read the + * <Documentation/usb/mass-storage.txt> file. + */ + +/* * MSF is configured by specifying a fsg_config structure. It has the * following fields: * @@ -75,25 +75,6 @@ * ->nofua Flag specifying that FUA flag in SCSI WRITE(10,12) * commands for this LUN shall be ignored. * - * lun_name_format A printf-like format for names of the LUN - * devices. This determines how the - * directory in sysfs will be named. - * Unless you are using several MSFs in - * a single gadget (as opposed to single - * MSF in many configurations) you may - * leave it as NULL (in which case - * "lun%d" will be used). In the format - * you can use "%d" to index LUNs for - * MSF's with more than one LUN. (Beware - * that there is only one integer given - * as an argument for the format and - * specifying invalid format may cause - * unspecified behaviour.) - * thread_name Name of the kernel thread process used by the - * MSF. You can safely set it to NULL - * (in which case default "file-storage" - * will be used). - * * vendor_name * product_name * release Information used as a reply to INQUIRY @@ -114,62 +95,6 @@ * data track and no audio tracks; hence there need be only one * backing file per LUN. * - * - * MSF includes support for module parameters. If gadget using it - * decides to use it, the following module parameters will be - * available: - * - * file=filename[,filename...] - * Names of the files or block devices used for - * backing storage. - * ro=b[,b...] Default false, boolean for read-only access. - * removable=b[,b...] - * Default true, boolean for removable media. - * cdrom=b[,b...] Default false, boolean for whether to emulate - * a CD-ROM drive. - * nofua=b[,b...] Default false, booleans for ignore FUA flag - * in SCSI WRITE(10,12) commands - * luns=N Default N = number of filenames, number of - * LUNs to support. - * stall Default determined according to the type of - * USB device controller (usually true), - * boolean to permit the driver to halt - * bulk endpoints. - * - * The module parameters may be prefixed with some string. You need - * to consult gadget's documentation or source to verify whether it is - * using those module parameters and if it does what are the prefixes - * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is - * the prefix). - * - * - * Requirements are modest; only a bulk-in and a bulk-out endpoint are - * needed. The memory requirement amounts to two 16K buffers, size - * configurable by a parameter. Support is included for both - * full-speed and high-speed operation. - * - * Note that the driver is slightly non-portable in that it assumes a - * single memory/DMA buffer will be useable for bulk-in, bulk-out, and - * interrupt-in endpoints. With most device controllers this isn't an - * issue, but there may be some with hardware restrictions that prevent - * a buffer from being used by more than one endpoint. - * - * - * The pathnames of the backing files and the ro settings are - * available in the attribute files "file" and "ro" in the lun<n> (or - * to be more precise in a directory which name comes from - * "lun_name_format" option!) 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 or if CD-ROM - * emulation is being used. - * - * When a LUN receive an "eject" SCSI request (Start/Stop Unit), - * if the LUN is removable, the backing file is released to simulate - * ejection. - * - * * This function is heavily based on "File-backed Storage Gadget" by * Alan Stern which in turn is heavily based on "Gadget Zero" by David * Brownell. The driver's SCSI command interface was based on the @@ -211,7 +136,7 @@ * In normal operation the main thread is started during the gadget's * fsg_bind() callback and stopped during fsg_unbind(). But it can * also exit when it receives a signal, and there's no point leaving - * the gadget running when the thread is dead. At of this moment, MSF + * the gadget running when the thread is dead. As of this moment, MSF * provides no way to deregister the gadget when thread dies -- maybe * a callback functions is needed. * @@ -417,9 +342,6 @@ struct fsg_config { char nofua; } luns[FSG_MAX_LUNS]; - const char *lun_name_format; - const char *thread_name; - /* Callback functions. */ const struct fsg_operations *ops; /* Gadget's private data. */ @@ -2687,11 +2609,15 @@ static int fsg_main_thread(void *common_) /*************************** DEVICE ATTRIBUTES ***************************/ -/* Write permission is checked per LUN in store_*() functions. */ static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro); static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua); static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file); +static struct device_attribute dev_attr_ro_cdrom = + __ATTR(ro, 0444, fsg_show_ro, NULL); +static struct device_attribute dev_attr_file_nonremovable = + __ATTR(file, 0444, fsg_show_file, NULL); + /****************************** FSG COMMON ******************************/ @@ -2792,11 +2718,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common, curlun->dev.parent = &gadget->dev; /* curlun->dev.driver = &fsg_driver.driver; XXX */ dev_set_drvdata(&curlun->dev, &common->filesem); - dev_set_name(&curlun->dev, - cfg->lun_name_format - ? cfg->lun_name_format - : "lun%d", - i); + dev_set_name(&curlun->dev, "lun%d", i); rc = device_register(&curlun->dev); if (rc) { @@ -2806,10 +2728,16 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common, goto error_release; } - rc = device_create_file(&curlun->dev, &dev_attr_ro); + rc = device_create_file(&curlun->dev, + curlun->cdrom + ? &dev_attr_ro_cdrom + : &dev_attr_ro); if (rc) goto error_luns; - rc = device_create_file(&curlun->dev, &dev_attr_file); + rc = device_create_file(&curlun->dev, + curlun->removable + ? &dev_attr_file + : &dev_attr_file_nonremovable); if (rc) goto error_luns; rc = device_create_file(&curlun->dev, &dev_attr_nofua); @@ -2878,8 +2806,7 @@ buffhds_first_it: /* Tell the thread to start working */ common->thread_task = - kthread_create(fsg_main_thread, common, - cfg->thread_name ?: "file-storage"); + kthread_create(fsg_main_thread, common, "file-storage"); if (IS_ERR(common->thread_task)) { rc = PTR_ERR(common->thread_task); goto error_release; @@ -2945,8 +2872,14 @@ static void fsg_common_release(struct kref *ref) /* In error recovery common->nluns may be zero. */ for (; i; --i, ++lun) { device_remove_file(&lun->dev, &dev_attr_nofua); - device_remove_file(&lun->dev, &dev_attr_ro); - device_remove_file(&lun->dev, &dev_attr_file); + device_remove_file(&lun->dev, + lun->cdrom + ? &dev_attr_ro_cdrom + : &dev_attr_ro); + device_remove_file(&lun->dev, + lun->removable + ? &dev_attr_file + : &dev_attr_file_nonremovable); fsg_lun_close(lun); device_unregister(&lun->dev); } @@ -3167,8 +3100,7 @@ fsg_config_from_params(struct fsg_config *cfg, for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) { lun->ro = !!params->ro[i]; lun->cdrom = !!params->cdrom[i]; - lun->removable = /* Removable by default */ - params->removable_count <= i || params->removable[i]; + lun->removable = !!params->removable[i]; lun->filename = params->file_count > i && params->file[i][0] ? params->file[i] @@ -3176,8 +3108,6 @@ fsg_config_from_params(struct fsg_config *cfg, } /* Let MSF use defaults */ - cfg->lun_name_format = 0; - cfg->thread_name = 0; cfg->vendor_name = 0; cfg->product_name = 0; cfg->release = 0xffff; @@ -3203,4 +3133,3 @@ fsg_common_from_params(struct fsg_common *common, fsg_config_from_params(&cfg, params); return fsg_common_init(common, cdev, &cfg); } - |