This is an example of how to create an adapter module for an old-style gadget.
It provides the legacy interface while internally operates on configfs.
Usage is like g_mass_storage.ko, but instead the user needs to do e.g.:
insmod libcomposite.ko
insmod f_mass_storage.ko (not required if request_module works)
insmod g_usb_functions.ko (not required if request_module works)
insmod g_mass_storage_adapter.ko removable=1
Then the user can do something on the lines of:
echo <some file>.img > /sys/devices/platform/s3c-hsotg/gadget/lun0/file
and they can enjoy the mass storage gadget functionality.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/usb/gadget/Kconfig | 9 +
drivers/usb/gadget/Makefile | 4 +
drivers/usb/gadget/ufg_mass_storage.c | 608 +++++++++++++++++++++++++++++++++
3 files changed, 621 insertions(+), 0 deletions(-)
create mode 100644 drivers/usb/gadget/ufg_mass_storage.c
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 61fa2a7..6f6aebd 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -537,6 +537,15 @@ config USB_FG
a USB configuration is composed of and enabling/disabling
the gadget.
+config USB_MASS_STORAGE_TO_UFG
+ tristate "Mass Storage Gadget to USB Functions Gadget adapter"
+ depends on USB_FG
+ help
+ The Mass Storage Gadget used to act as a USB Mass Storage disk drive.
+ Its implementation is now considered obsolete. In order to maintain
+ compatibility an adapter module is used to provide the old interface
+ while using the new gadget infrastructure.
+
config USB_ZERO
tristate "Gadget Zero (DEVELOPMENT)"
select USB_LIBCOMPOSITE
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index db8281a..6be8d8e 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -56,6 +56,7 @@ g_webcam-y := webcam.o
g_ncm-y := ncm.o
g_acm_ms-y := acm_ms.o
g_tcm_usb_gadget-y := tcm_usb_gadget.o
+g_mass_storage_adapter-y := ufg_mass_storage.o
obj-$(CONFIG_USB_FG) += g_usb_functions.o
obj-$(CONFIG_USB_ZERO) += g_zero.o
@@ -79,3 +80,6 @@ obj-$(CONFIG_USB_GADGET_TARGET) += tcm_usb_gadget.o
# USB Functions
obj-$(CONFIG_USB_F_MASS_STORAGE) += f_mass_storage.o
+
+# Gadget adapters
+obj-$(CONFIG_USB_MASS_STORAGE_TO_UFG) += g_mass_storage_adapter.o
diff --git a/drivers/usb/gadget/ufg_mass_storage.c b/drivers/usb/gadget/ufg_mass_storage.c
new file mode 100644
index 0000000..3a66b8a
--- /dev/null
+++ b/drivers/usb/gadget/ufg_mass_storage.c
@@ -0,0 +1,608 @@
+/*
+ * ufg_mass_storage.c -- Mass Storage USB Gadget to UFG adapter
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Author: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+
+#include "usb_functions.h"
+#include "storage_common.h"
+
+#define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
+ module_param_array_named(prefix ## name, params.name, type, \
+ &prefix ## params.name ## _count, \
+ S_IRUGO); \
+ MODULE_PARM_DESC(prefix ## name, desc)
+
+#define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
+ module_param_named(prefix ## name, params.name, type, \
+ S_IRUGO); \
+ MODULE_PARM_DESC(prefix ## name, desc)
+
+#define FSG_MODULE_PARAMETERS(prefix, params) \
+ _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
+ "names of backing files or devices"); \
+ _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
+ "true to force read-only"); \
+ _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
+ "true to simulate removable media"); \
+ _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
+ "true to simulate CD-ROM instead of disk"); \
+ _FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool, \
+ "true to ignore SCSI WRITE(10,12) FUA bit"); \
+ _FSG_MODULE_PARAM(prefix, params, luns, uint, \
+ "number of LUNs"); \
+ _FSG_MODULE_PARAM(prefix, params, stall, bool, \
+ "false to prevent bulk stalls")
+
+#define UFG_MODULE (UFG_SUBSYSTEM->subsys.su_group.cg_item.ci_type->ct_owner)
+#define LUN(i) config->luns[i]
+
+struct fsg_module_parameters {
+ char *file[FSG_MAX_LUNS];
+ bool ro[FSG_MAX_LUNS];
+ bool removable[FSG_MAX_LUNS];
+ bool cdrom[FSG_MAX_LUNS];
+ bool nofua[FSG_MAX_LUNS];
+
+ unsigned int file_count, ro_count, removable_count, cdrom_count;
+ unsigned int nofua_count;
+ unsigned int luns; /* nluns */
+ bool stall; /* can_stall */
+};
+
+struct fsg_config {
+ unsigned nluns;
+ unsigned configfs_nluns;
+ struct fsg_lun_config {
+ const char *filename;
+ char ro;
+ char removable;
+ char cdrom;
+ char nofua;
+ struct device dev;
+ struct dentry *dentry;
+ } luns[FSG_MAX_LUNS];
+
+ char can_stall;
+
+ struct dentry *root;
+ struct dentry *gadget;
+ struct dentry *conf;
+ struct dentry *func;
+ struct dentry *f;
+};
+
+/*
+ * ATTENTION:
+ *
+ * struct configfs_dirent is "borrowed" from fs/configfs/configfs_internal.h.
+ *
+ * The adapters by default will be phased out, so this _should_ be acceptable.
+ */
+struct configfs_dirent {
+ atomic_t s_count;
+ int s_dependent_count;
+ struct list_head s_sibling;
+ struct list_head s_children;
+ struct list_head s_links;
+ void * s_element;
+ int s_type;
+ umode_t s_mode;
+ struct dentry * s_dentry;
+ struct iattr * s_iattr;
+#ifdef CONFIG_LOCKDEP
+ int s_depth;
+#endif
+};
+
+static struct fsg_module_parameters mod_data = {
+ .stall = 1
+};
+
+FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
+
+static struct fsg_config config_struct;
+
+static void
+fsg_config_from_params(struct fsg_config *cfg,
+ const struct fsg_module_parameters *params)
+{
+ struct fsg_lun_config *lun;
+ unsigned i;
+
+ /* Configure LUNs */
+ cfg->nluns =
+ min(params->luns ?: (params->file_count ?: 1u),
+ (unsigned)FSG_MAX_LUNS);
+ for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
+ lun->ro = !!params->ro[i];
+ lun->cdrom = !!params->cdrom[i];
+ lun->removable = !!params->removable[i];
+ lun->filename =
+ params->file_count > i && params->file[i][0]
+ ? params->file[i]
+ : 0;
+ }
+
+ /* Finalise */
+ cfg->can_stall = params->stall;
+}
+
+static inline void init_name(struct qstr *n, const char *s)
+{
+ n->name = s;
+ n->len = strlen(n->name);
+ n->hash = full_name_hash(n->name, n->len);
+}
+
+/*
+ * ATTENTION:
+ *
+ * to_item is "borrowed" from fs/configfs/configfs_internal.h.
+ *
+ * The adapters by default will be phased out, so this _should_ be acceptable.
+ */
+static inline struct config_item *to_item(struct dentry * dentry)
+{
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ return ((struct config_item *) sd->s_element);
+}
+
+static inline struct config_item *mkdir(struct dentry *parent, const char *s,
+ struct dentry **new)
+{
+ struct qstr name;
+ struct config_item *ci;
+ int rc;
+
+ init_name(&name, s);
+ *new = d_alloc(parent, &name);
+ if (IS_ERR_OR_NULL(*new))
+ return ERR_PTR(-ENOMEM);
+
+ d_add(*new, NULL);
+ rc = ufg_mkdir(parent, *new);
+ if (rc) {
+ d_drop(*new);
+ dput(*new);
+
+ return ERR_PTR(rc);
+ }
+ dput(*new);
+
+ ci = to_item(*new);
+ if (!ci) {
+ ufg_rmdir(parent, *new);
+
+ return ERR_PTR(-ENODEV);
+ }
+ return ci;
+}
+
+static int do_store(struct config_item *ci, const char *a, const char *s, int n)
+{
+ struct configfs_attribute *attr;
+ int i;
+ bool found = false;
+
+ if (!ci)
+ return -ENODEV;
+
+ for (i = 0; (attr = ci->ci_type->ct_attrs[i]) != NULL; i++)
+ if (!strcmp(attr->ca_name, a)) {
+ found = true;
+ break;
+ }
+ if (!found)
+ return -ENODEV;
+
+ return ci->ci_type->ct_item_ops->store_attribute(ci, attr, s, n);
+}
+
+static inline int str_store(struct config_item *ci, const char *a, const char *s)
+{
+ return do_store(ci, a, s, strlen(s));
+}
+
+static inline int formatted_store(struct config_item *ci, const char *a, int i, const char *f)
+{
+ char buf[UFG_STR_LEN];
+
+ snprintf(buf, UFG_STR_LEN, f, i);
+ return str_store(ci, a, buf);
+}
+
+static inline int hex_store(struct config_item *ci, const char *a, int i)
+{
+ return formatted_store(ci, a, i, "%x");
+}
+
+static inline int int_store(struct config_item *ci, const char *a, int i)
+{
+ return formatted_store(ci, a, i, "%d");
+}
+
+static int do_show(struct config_item *ci, const char *a, char *s)
+{
+ struct configfs_attribute *attr;
+ int i;
+ bool found = false;
+
+ if (!ci)
+ return -ENODEV;
+
+ for (i = 0; (attr = ci->ci_type->ct_attrs[i]) != NULL; i++)
+ if (!strcmp(attr->ca_name, a)) {
+ found = true;
+ break;
+ }
+ if (!found)
+ return -ENODEV;
+
+ return ci->ci_type->ct_item_ops->show_attribute(ci, attr, s);
+}
+
+static struct device *configfs_prepare(struct fsg_config *config)
+{
+ struct config_item *gadget_ci, *conf_ci, *func_ci, *f_ci;
+ struct ufg_gadget_grp *gadget_grp;
+ struct ufg_dev *ufg_dev;
+ int rc, i;
+
+ if (!UFG_SUBSYSTEM)
+ return ERR_PTR(-ENODEV);
+
+ config->root = UFG_SUBSYSTEM->subsys.su_group.cg_item.ci_dentry;
+
+ /* mkdir the gadget and fill its attributes */
+ gadget_ci = mkdir(config->root, "msg", &config->gadget);
+ if (IS_ERR_OR_NULL(gadget_ci))
+ return ERR_PTR(PTR_ERR(gadget_ci));
+ rc = hex_store(gadget_ci, "idVendor", 0x0525);
+ if (rc < 0)
+ goto remove_gadget;
+ rc = hex_store(gadget_ci, "idProduct", 0xa4a5);
+ if (rc < 0)
+ goto remove_gadget;
+ rc = hex_store(gadget_ci, "bcdDevice", 0xff);
+ if (rc < 0)
+ goto remove_gadget;
+ rc = str_store(gadget_ci, "iManufacturer", "Linux");
+ if (rc < 0)
+ goto remove_gadget;
+ rc = str_store(gadget_ci, "iProduct",
+ LUN(0).cdrom ? "File-Stor Gadget" : "File-CD Gadget");
+ if (rc < 0)
+ goto remove_gadget;
+
+ /* mkdir the config and fill its attributes */
+ conf_ci = mkdir(config->gadget, "conf", &config->conf);
+ if (IS_ERR_OR_NULL(conf_ci)) {
+ rc = PTR_ERR(conf_ci);
+ goto remove_gadget;
+ }
+
+ /* mkdir the function and fill its attributes */
+ func_ci = mkdir(config->conf, "func", &config->func);
+ if (IS_ERR_OR_NULL(func_ci)) {
+ rc = PTR_ERR(func_ci);
+ goto remove_conf;
+ }
+ rc = str_store(func_ci, "name", "MassStorage");
+ if (rc < 0)
+ goto remove_func;
+ /* mkdir the mass storage function and fill its attributes */
+ f_ci = config_group_find_item(to_config_group(to_item(config->func)), "MassStorage");
+ if (IS_ERR_OR_NULL(f_ci)) {
+ rc = PTR_ERR(f_ci);
+ goto remove_func;
+ }
+ config->f = f_ci->ci_dentry;
+ rc = int_store(f_ci, "luns", config->nluns);
+ if (rc < 0)
+ goto remove_f;
+
+ for (i = 0; i < config->nluns; i++) {
+ struct config_item *lun_ci;
+ char buf[UFG_STR_LEN];
+
+ /* mkdir the lun and fill its attributes */
+ snprintf(buf, UFG_STR_LEN, "lun%d", i);
+ lun_ci = config_group_find_item(to_config_group(to_item(config->f)), buf);
+ if (IS_ERR_OR_NULL(lun_ci)) {
+ rc = PTR_ERR(lun_ci);
+ if (i--)
+ goto remove_luns;
+ else
+ goto remove_f;
+ }
+ LUN(i).dentry = lun_ci->ci_dentry;
+ if (LUN(i).filename) {
+ rc = str_store(lun_ci, "file", LUN(i).filename);
+ if (rc < 0)
+ goto remove_luns;
+ }
+ if (LUN(i).ro) {
+ rc = int_store(lun_ci, "ro", 1);
+ if (rc < 0)
+ goto remove_luns;
+ }
+ if (LUN(i).nofua) {
+ rc = int_store(lun_ci, "nofua", 1);
+ if (rc < 0)
+ goto remove_luns;
+ }
+ if (LUN(i).removable) {
+ rc = int_store(lun_ci, "removable", 1);
+ if (rc < 0)
+ goto remove_luns;
+ }
+ }
+ i--;
+
+ rc = -ENODEV;
+ gadget_grp = to_ufg_gadget_grp(gadget_ci);
+ if (!gadget_grp)
+ goto remove_luns;
+
+ rc = int_store(gadget_ci, "ready", 1);
+ if (rc < 0)
+ goto remove_luns;
+ ufg_dev = gadget_grp->gadget_grp_data;
+ if (!ufg_dev)
+ goto remove_luns;
+
+ return &ufg_dev->cdev->gadget->dev;
+
+remove_luns:
+ while (i >= 0)
+ ufg_rmdir(config->f, LUN(i--).dentry);
+
+remove_f:
+ ufg_rmdir(config->func, config->f);
+
+remove_func:
+ ufg_rmdir(config->conf, config->func);
+
+remove_conf:
+ ufg_rmdir(config->gadget, config->conf);
+
+remove_gadget:
+ ufg_rmdir(config->root, config->gadget);
+ return ERR_PTR(rc);
+}
+
+static void lun_release(struct device *dev)
+{
+}
+
+static inline struct fsg_lun_config *dev_to_fsg_lun_config(struct device *dev)
+{
+ return container_of(dev, struct fsg_lun_config, dev);
+}
+
+static ssize_t fsg_show(struct device *dev, struct device_attribute *attr,
+ const char *configfs_name, char *buf)
+{
+ struct fsg_lun_config *lun = dev_to_fsg_lun_config(dev);
+ struct config_item *ci;
+
+ if (!lun)
+ return -ENODEV;
+
+ ci = to_item(lun->dentry);
+ if (!ci)
+ return -ENODEV;
+
+ return do_show(ci, configfs_name, buf);
+}
+
+static inline ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return fsg_show(dev, attr, "ro", buf);
+}
+
+static inline ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return fsg_show(dev, attr, "nofua", buf);
+}
+
+static inline ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return fsg_show(dev, attr, "file", buf);
+}
+
+static ssize_t fsg_store(struct device *dev, struct device_attribute *attr,
+ const char *configfs_name, const char *buf, size_t count)
+{
+ struct fsg_lun_config *lun = dev_to_fsg_lun_config(dev);
+ struct config_item *ci;
+
+ if (!lun)
+ return -ENODEV;
+
+ ci = to_item(lun->dentry);
+ if (!ci)
+ return -ENODEV;
+
+ return do_store(ci, configfs_name, buf, count);
+}
+
+static inline ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return fsg_store(dev, attr, "ro", buf, count);
+}
+
+static inline ssize_t fsg_store_nofua(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return fsg_store(dev, attr, "nofua", buf, count);
+}
+
+static inline ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return fsg_store(dev, attr, "file", buf, count);
+}
+
+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);
+
+static void devices_teardown(struct fsg_config *config)
+{
+ int i = config->nluns;
+
+ while (i--) {
+ device_remove_file(&LUN(i).dev, &dev_attr_nofua);
+ device_remove_file(&LUN(i).dev,
+ LUN(i).cdrom
+ ? &dev_attr_ro_cdrom
+ : &dev_attr_ro);
+ device_remove_file(&LUN(i).dev,
+ LUN(i).removable
+ ? &dev_attr_file
+ : &dev_attr_file_nonremovable);
+ device_unregister(&LUN(i).dev);
+ }
+}
+
+static void configfs_teardown(struct fsg_config *config)
+{
+ struct config_item *ci;
+ int i = config->configfs_nluns;
+
+ ci = to_item(config->gadget);
+ if (ci)
+ int_store(ci, "ready", 0);
+ while (i--)
+ ufg_rmdir(config->f, LUN(i).dentry);
+
+ ufg_rmdir(config->func, config->f);
+ ufg_rmdir(config->conf, config->func);
+ ufg_rmdir(config->gadget, config->conf);
+ ufg_rmdir(config->root, config->gadget);
+}
+
+static int __init msg_init(void)
+{
+ struct device *gadget_dev;
+ struct fsg_config *config = &config_struct;
+ int i = 0, rc;
+
+ rc = request_module("usb_functions");
+ if (rc < 0)
+ return rc;
+ rc = try_module_get(UFG_MODULE);
+ if (rc < 0)
+ return rc;
+
+ fsg_config_from_params(config, &mod_data);
+ gadget_dev = configfs_prepare(config);
+ if (IS_ERR_OR_NULL(gadget_dev)) {
+ rc = PTR_ERR(gadget_dev);
+ goto error_configfs;
+ }
+ config->configfs_nluns = config->nluns;
+ for (i = 0; i < config->nluns; ++i) {
+ dev_set_name(&LUN(i).dev, "lun%d", i);
+ LUN(i).dev.release = lun_release;
+ LUN(i).dev.parent = gadget_dev;
+
+ rc = device_register(&LUN(i).dev);
+ if (rc) {
+ pr_info("failed to register LUN%d: %d\n", i, rc);
+ put_device(&LUN(i).dev);
+ goto error_release;
+ }
+
+ rc = device_create_file(&LUN(i).dev,
+ LUN(i).cdrom
+ ? &dev_attr_ro_cdrom
+ : &dev_attr_ro);
+ if (rc)
+ goto error_ro;
+ rc = device_create_file(&LUN(i).dev,
+ LUN(i).removable
+ ? &dev_attr_file
+ : &dev_attr_file_nonremovable);
+ if (rc)
+ goto error_file;
+ rc = device_create_file(&LUN(i).dev, &dev_attr_nofua);
+ if (rc)
+ goto error_nofua;
+
+ if (!LUN(i).filename && !LUN(i).removable) {
+ pr_err("no file given for LUN%d\n", i);
+ rc = -EINVAL;
+ goto error_filename;
+ }
+ }
+
+ return 0;
+
+error_filename:
+ device_remove_file(&LUN(i).dev, &dev_attr_nofua);
+
+error_nofua:
+ device_remove_file(&LUN(i).dev,
+ LUN(i).removable
+ ? &dev_attr_file
+ : &dev_attr_file_nonremovable);
+
+error_file:
+ device_remove_file(&LUN(i).dev,
+ LUN(i).cdrom
+ ? &dev_attr_ro_cdrom
+ : &dev_attr_ro);
+
+error_ro:
+ device_unregister(&LUN(i).dev);
+
+error_release:
+ config->nluns = i;
+ devices_teardown(config);
+ configfs_teardown(config);
+
+error_configfs:
+ module_put(UFG_MODULE);
+ return rc;
+}
+module_init(msg_init);
+
+static void msg_cleanup(void)
+{
+ struct fsg_config *config = &config_struct;
+
+ devices_teardown(config);
+ configfs_teardown(config);
+ module_put(UFG_MODULE);
+}
+module_exit(msg_cleanup);
+
+MODULE_DESCRIPTION("Mass Storage USB Gadget to UFG adapter");
+MODULE_AUTHOR("Andrzej Pietrasiewicz");
+MODULE_LICENSE("GPL");
+
--
1.7.0.4
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