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path: root/drivers/usb/gadget/function/storage_common.c
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Diffstat (limited to 'drivers/usb/gadget/function/storage_common.c')
-rw-r--r--drivers/usb/gadget/function/storage_common.c504
1 files changed, 504 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c
new file mode 100644
index 000000000000..648f9e489b39
--- /dev/null
+++ b/drivers/usb/gadget/function/storage_common.c
@@ -0,0 +1,504 @@
+/*
+ * storage_common.c -- Common definitions for mass storage functionality
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyeight (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz (mina86@mina86.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+/*
+ * This file requires the following identifiers used in USB strings to
+ * be defined (each of type pointer to char):
+ * - fsg_string_interface -- name of the interface
+ */
+
+/*
+ * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
+ * sets the number of pipeline buffers (length of the fsg_buffhd array).
+ * The valid range of num_buffers is: num >= 2 && num <= 4.
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/usb/composite.h>
+
+#include "storage_common.h"
+
+/* There is only one interface. */
+
+struct usb_interface_descriptor fsg_intf_desc = {
+ .bLength = sizeof fsg_intf_desc,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
+ .bInterfaceClass = USB_CLASS_MASS_STORAGE,
+ .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
+ .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
+ .iInterface = FSG_STRING_INTERFACE,
+};
+EXPORT_SYMBOL_GPL(fsg_intf_desc);
+
+/*
+ * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
+ * interrupt-in.
+ */
+
+struct usb_endpoint_descriptor fsg_fs_bulk_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ /* wMaxPacketSize set by autoconfiguration */
+};
+EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc);
+
+struct usb_endpoint_descriptor fsg_fs_bulk_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ /* wMaxPacketSize set by autoconfiguration */
+};
+EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc);
+
+struct usb_descriptor_header *fsg_fs_function[] = {
+ (struct usb_descriptor_header *) &fsg_intf_desc,
+ (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
+ (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
+ NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_fs_function);
+
+
+/*
+ * USB 2.0 devices need to expose both high speed and full speed
+ * descriptors, unless they only run at full speed.
+ *
+ * That means alternate endpoint descriptors (bigger packets)
+ * and a "device qualifier" ... plus more construction options
+ * for the configuration descriptor.
+ */
+struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc);
+
+struct usb_endpoint_descriptor fsg_hs_bulk_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+ .bInterval = 1, /* NAK every 1 uframe */
+};
+EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc);
+
+
+struct usb_descriptor_header *fsg_hs_function[] = {
+ (struct usb_descriptor_header *) &fsg_intf_desc,
+ (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
+ (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
+ NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_hs_function);
+
+struct usb_endpoint_descriptor fsg_ss_bulk_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc);
+
+struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
+ .bLength = sizeof(fsg_ss_bulk_in_comp_desc),
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+
+ /*.bMaxBurst = DYNAMIC, */
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc);
+
+struct usb_endpoint_descriptor fsg_ss_bulk_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc);
+
+struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
+ .bLength = sizeof(fsg_ss_bulk_in_comp_desc),
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+
+ /*.bMaxBurst = DYNAMIC, */
+};
+EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc);
+
+struct usb_descriptor_header *fsg_ss_function[] = {
+ (struct usb_descriptor_header *) &fsg_intf_desc,
+ (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
+ (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
+ (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
+ (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
+ NULL,
+};
+EXPORT_SYMBOL_GPL(fsg_ss_function);
+
+
+ /*-------------------------------------------------------------------------*/
+
+/*
+ * If the next two routines are called while the gadget is registered,
+ * the caller must own fsg->filesem for writing.
+ */
+
+void fsg_lun_close(struct fsg_lun *curlun)
+{
+ if (curlun->filp) {
+ LDBG(curlun, "close backing file\n");
+ fput(curlun->filp);
+ curlun->filp = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(fsg_lun_close);
+
+int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
+{
+ int ro;
+ struct file *filp = NULL;
+ int rc = -EINVAL;
+ struct inode *inode = NULL;
+ loff_t size;
+ loff_t num_sectors;
+ loff_t min_sectors;
+ unsigned int blkbits;
+ unsigned int blksize;
+
+ /* R/W if we can, R/O if we must */
+ ro = curlun->initially_ro;
+ if (!ro) {
+ filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
+ if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
+ ro = 1;
+ }
+ if (ro)
+ filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
+ if (IS_ERR(filp)) {
+ LINFO(curlun, "unable to open backing file: %s\n", filename);
+ return PTR_ERR(filp);
+ }
+
+ if (!(filp->f_mode & FMODE_WRITE))
+ ro = 1;
+
+ inode = file_inode(filp);
+ if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
+ LINFO(curlun, "invalid file type: %s\n", filename);
+ goto out;
+ }
+
+ /*
+ * If we can't read the file, it's no good.
+ * If we can't write the file, use it read-only.
+ */
+ if (!(filp->f_mode & FMODE_CAN_READ)) {
+ LINFO(curlun, "file not readable: %s\n", filename);
+ goto out;
+ }
+ if (!(filp->f_mode & FMODE_CAN_WRITE))
+ ro = 1;
+
+ size = i_size_read(inode->i_mapping->host);
+ if (size < 0) {
+ LINFO(curlun, "unable to find file size: %s\n", filename);
+ rc = (int) size;
+ goto out;
+ }
+
+ if (curlun->cdrom) {
+ blksize = 2048;
+ blkbits = 11;
+ } else if (inode->i_bdev) {
+ blksize = bdev_logical_block_size(inode->i_bdev);
+ blkbits = blksize_bits(blksize);
+ } else {
+ blksize = 512;
+ blkbits = 9;
+ }
+
+ num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
+ min_sectors = 1;
+ if (curlun->cdrom) {
+ min_sectors = 300; /* Smallest track is 300 frames */
+ if (num_sectors >= 256*60*75) {
+ num_sectors = 256*60*75 - 1;
+ 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;
+ }
+
+ if (fsg_lun_is_open(curlun))
+ fsg_lun_close(curlun);
+
+ curlun->blksize = blksize;
+ curlun->blkbits = blkbits;
+ curlun->ro = ro;
+ curlun->filp = filp;
+ curlun->file_length = size;
+ curlun->num_sectors = num_sectors;
+ LDBG(curlun, "open backing file: %s\n", filename);
+ return 0;
+
+out:
+ fput(filp);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_lun_open);
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Sync the file data, don't bother with the metadata.
+ * This code was copied from fs/buffer.c:sys_fdatasync().
+ */
+int fsg_lun_fsync_sub(struct fsg_lun *curlun)
+{
+ struct file *filp = curlun->filp;
+
+ if (curlun->ro || !filp)
+ return 0;
+ return vfs_fsync(filp, 1);
+}
+EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub);
+
+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_unaligned_be32(addr, dest);
+ }
+}
+EXPORT_SYMBOL_GPL(store_cdrom_address);
+
+/*-------------------------------------------------------------------------*/
+
+
+ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf)
+{
+ return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
+ ? curlun->ro
+ : curlun->initially_ro);
+}
+EXPORT_SYMBOL_GPL(fsg_show_ro);
+
+ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf)
+{
+ return sprintf(buf, "%u\n", curlun->nofua);
+}
+EXPORT_SYMBOL_GPL(fsg_show_nofua);
+
+ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ char *buf)
+{
+ char *p;
+ ssize_t rc;
+
+ down_read(filesem);
+ if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
+ p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
+ if (IS_ERR(p))
+ rc = PTR_ERR(p);
+ else {
+ rc = strlen(p);
+ memmove(buf, p, rc);
+ buf[rc] = '\n'; /* Add a newline */
+ buf[++rc] = 0;
+ }
+ } else { /* No file, return 0 bytes */
+ *buf = 0;
+ rc = 0;
+ }
+ up_read(filesem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_show_file);
+
+ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf)
+{
+ return sprintf(buf, "%u\n", curlun->cdrom);
+}
+EXPORT_SYMBOL_GPL(fsg_show_cdrom);
+
+ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf)
+{
+ return sprintf(buf, "%u\n", curlun->removable);
+}
+EXPORT_SYMBOL_GPL(fsg_show_removable);
+
+/*
+ * The caller must hold fsg->filesem for reading when calling this function.
+ */
+static ssize_t _fsg_store_ro(struct fsg_lun *curlun, bool ro)
+{
+ if (fsg_lun_is_open(curlun)) {
+ LDBG(curlun, "read-only status change prevented\n");
+ return -EBUSY;
+ }
+
+ curlun->ro = ro;
+ curlun->initially_ro = ro;
+ LDBG(curlun, "read-only status set to %d\n", curlun->ro);
+
+ return 0;
+}
+
+ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ const char *buf, size_t count)
+{
+ ssize_t rc;
+ bool ro;
+
+ rc = strtobool(buf, &ro);
+ if (rc)
+ return rc;
+
+ /*
+ * Allow the write-enable status to change only while the
+ * backing file is closed.
+ */
+ down_read(filesem);
+ rc = _fsg_store_ro(curlun, ro);
+ if (!rc)
+ rc = count;
+ up_read(filesem);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(fsg_store_ro);
+
+ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count)
+{
+ bool nofua;
+ int ret;
+
+ ret = strtobool(buf, &nofua);
+ if (ret)
+ return ret;
+
+ /* Sync data when switching from async mode to sync */
+ if (!nofua && curlun->nofua)
+ fsg_lun_fsync_sub(curlun);
+
+ curlun->nofua = nofua;
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_nofua);
+
+ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ const char *buf, size_t count)
+{
+ int rc = 0;
+
+ if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
+ LDBG(curlun, "eject attempt prevented\n");
+ return -EBUSY; /* "Door is locked" */
+ }
+
+ /* Remove a trailing newline */
+ if (count > 0 && buf[count-1] == '\n')
+ ((char *) buf)[count-1] = 0; /* Ugh! */
+
+ /* Load new medium */
+ down_write(filesem);
+ if (count > 0 && buf[0]) {
+ /* fsg_lun_open() will close existing file if any. */
+ rc = fsg_lun_open(curlun, buf);
+ if (rc == 0)
+ curlun->unit_attention_data =
+ SS_NOT_READY_TO_READY_TRANSITION;
+ } else if (fsg_lun_is_open(curlun)) {
+ fsg_lun_close(curlun);
+ curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
+ }
+ up_write(filesem);
+ return (rc < 0 ? rc : count);
+}
+EXPORT_SYMBOL_GPL(fsg_store_file);
+
+ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ const char *buf, size_t count)
+{
+ bool cdrom;
+ int ret;
+
+ ret = strtobool(buf, &cdrom);
+ if (ret)
+ return ret;
+
+ down_read(filesem);
+ ret = cdrom ? _fsg_store_ro(curlun, true) : 0;
+
+ if (!ret) {
+ curlun->cdrom = cdrom;
+ ret = count;
+ }
+ up_read(filesem);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fsg_store_cdrom);
+
+ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
+ size_t count)
+{
+ bool removable;
+ int ret;
+
+ ret = strtobool(buf, &removable);
+ if (ret)
+ return ret;
+
+ curlun->removable = removable;
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_removable);
+
+MODULE_LICENSE("GPL");