This adds the gadget side support for the Generic USB Display. It presents a DRM display device as a USB Display configured through configfs.
The display is implemented as a vendor type USB interface with one bulk out endpoint. The protocol is implemented using control requests. lz4 compressed framebuffer data/pixels are sent over the bulk endpoint.
The DRM part of the gadget is placed in the DRM subsystem since it reaches into the DRM internals.
Cc: Felipe Balbi balbi@kernel.org Signed-off-by: Noralf Trønnes noralf@tronnes.org --- .../ABI/testing/configfs-usb-gadget-gud_drm | 10 + MAINTAINERS | 2 + drivers/usb/gadget/Kconfig | 12 + drivers/usb/gadget/function/Makefile | 2 + drivers/usb/gadget/function/f_gud_drm.c | 678 ++++++++++++++++++ 5 files changed, 704 insertions(+) create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-gud_drm create mode 100644 drivers/usb/gadget/function/f_gud_drm.c
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-gud_drm b/Documentation/ABI/testing/configfs-usb-gadget-gud_drm new file mode 100644 index 000000000000..4f865e7fea58 --- /dev/null +++ b/Documentation/ABI/testing/configfs-usb-gadget-gud_drm @@ -0,0 +1,10 @@ +What: /config/usb-gadget/gadget/functions/gud_drm.name +Date: May 2020 +KernelVersion: 5.9 +Description: + The attributes: + + drm_dev - DRM device number + backlight_dev - Backlight device name (optional) + The backlight brightness scale should be + perceptual not linear. diff --git a/MAINTAINERS b/MAINTAINERS index 7494a21ea41e..4bc5dc7296b8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5296,7 +5296,9 @@ M: Noralf Trønnes noralf@tronnes.org S: Maintained W: https://github.com/notro/gud/wiki T: git git://anongit.freedesktop.org/drm/drm-misc +F: Documentation/ABI/testing/configfs-usb-gadget-gud_drm F: drivers/gpu/drm/gud/ +F: drivers/usb/gadget/function/f_gud_drm.c F: include/drm/gud_drm.h
DRM DRIVER FOR GRAIN MEDIA GM12U320 PROJECTORS diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index c6db0a0a340c..8d90add495b6 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -216,6 +216,9 @@ config USB_F_PRINTER config USB_F_TCM tristate
+config USB_F_GUD_DRM + tristate + # this first set of drivers all depend on bulk-capable hardware.
config USB_CONFIGFS @@ -483,6 +486,15 @@ config USB_CONFIGFS_F_TCM Both protocols can work on USB2.0 and USB3.0. UAS utilizes the USB 3.0 feature called streams support.
+config USB_CONFIGFS_F_GUD_DRM + bool "Generic USB Display Gadget function" + depends on USB_CONFIGFS + depends on DRM + select DRM_GUD_GADGET + select USB_F_GUD_DRM + help + This presents a DRM display device as a Generic USB Display. + source "drivers/usb/gadget/legacy/Kconfig"
endif # USB_GADGET diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile index 5d3a6cf02218..cd71caa2a34c 100644 --- a/drivers/usb/gadget/function/Makefile +++ b/drivers/usb/gadget/function/Makefile @@ -50,3 +50,5 @@ usb_f_printer-y := f_printer.o obj-$(CONFIG_USB_F_PRINTER) += usb_f_printer.o usb_f_tcm-y := f_tcm.o obj-$(CONFIG_USB_F_TCM) += usb_f_tcm.o +usb_f_gud_drm-y := f_gud_drm.o +obj-$(CONFIG_USB_F_GUD_DRM) += usb_f_gud_drm.o diff --git a/drivers/usb/gadget/function/f_gud_drm.c b/drivers/usb/gadget/function/f_gud_drm.c new file mode 100644 index 000000000000..9a2d6bb9739f --- /dev/null +++ b/drivers/usb/gadget/function/f_gud_drm.c @@ -0,0 +1,678 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Noralf Trønnes + */ + +#include <linux/configfs.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/usb/composite.h> +#include <linux/usb/gadget.h> +#include <linux/workqueue.h> + +#include <drm/gud_drm.h> + +struct f_gud_drm { + struct usb_function func; + struct work_struct worker; + size_t max_buffer_size; + void *ctrl_req_buf; + + u8 interface_id; + struct usb_request *ctrl_req; + + struct usb_ep *bulk_ep; + struct usb_request *bulk_req; + + struct gud_drm_gadget *gdg; + + spinlock_t lock; /* Protects the following members: */ + bool ctrl_pending; + bool status_pending; + bool bulk_pending; + bool disable_pending; + u8 errno; + u16 request; + u16 value; +}; + +static inline struct f_gud_drm *func_to_f_gud_drm(struct usb_function *f) +{ + return container_of(f, struct f_gud_drm, func); +} + +struct f_gud_drm_opts { + struct usb_function_instance func_inst; + struct mutex lock; + int refcnt; + + unsigned int drm_dev; + const char *backlight_dev; +}; + +static inline struct f_gud_drm_opts *fi_to_f_gud_drm_opts(const struct usb_function_instance *fi) +{ + return container_of(fi, struct f_gud_drm_opts, func_inst); +} + +static inline struct f_gud_drm_opts *ci_to_f_gud_drm_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_gud_drm_opts, + func_inst.group); +} + +#define F_MUD_DEFINE_BULK_ENDPOINT_DESCRIPTOR(name, addr, size) \ + static struct usb_endpoint_descriptor name = { \ + .bLength = USB_DT_ENDPOINT_SIZE, \ + .bDescriptorType = USB_DT_ENDPOINT, \ + .bEndpointAddress = addr, \ + .bmAttributes = USB_ENDPOINT_XFER_BULK, \ + .wMaxPacketSize = cpu_to_le16(size), \ + } + +static struct usb_interface_descriptor f_gud_drm_intf = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + .bNumEndpoints = 1, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, +}; + +F_MUD_DEFINE_BULK_ENDPOINT_DESCRIPTOR(f_gud_drm_fs_out_desc, USB_DIR_OUT, 0); + +static struct usb_descriptor_header *f_gud_drm_fs_function[] = { + (struct usb_descriptor_header *)&f_gud_drm_intf, + (struct usb_descriptor_header *)&f_gud_drm_fs_out_desc, + NULL, +}; + +F_MUD_DEFINE_BULK_ENDPOINT_DESCRIPTOR(f_gud_drm_hs_out_desc, USB_DIR_OUT, 512); + +static struct usb_descriptor_header *f_gud_drm_hs_function[] = { + (struct usb_descriptor_header *)&f_gud_drm_intf, + (struct usb_descriptor_header *)&f_gud_drm_hs_out_desc, + NULL, +}; + +F_MUD_DEFINE_BULK_ENDPOINT_DESCRIPTOR(f_gud_drm_ss_out_desc, USB_DIR_OUT, 1024); + +static struct usb_ss_ep_comp_descriptor f_gud_drm_ss_bulk_comp_desc = { + .bLength = USB_DT_SS_EP_COMP_SIZE, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, +}; + +static struct usb_descriptor_header *f_gud_drm_ss_function[] = { + (struct usb_descriptor_header *)&f_gud_drm_intf, + (struct usb_descriptor_header *)&f_gud_drm_ss_out_desc, + (struct usb_descriptor_header *)&f_gud_drm_ss_bulk_comp_desc, + NULL, +}; + +static struct usb_string f_gud_drm_string_defs[] = { + [0].s = "Generic USB Display", + { } /* end of list */ +}; + +static struct usb_gadget_strings f_gud_drm_string_table = { + .language = 0x0409, /* en-us */ + .strings = f_gud_drm_string_defs, +}; + +static struct usb_gadget_strings *f_gud_drm_strings[] = { + &f_gud_drm_string_table, + NULL, +}; + +static void f_gud_drm_bulk_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_gud_drm *fgd = req->context; + unsigned long flags; + + if (req->status || req->actual != req->length) + return; + + spin_lock_irqsave(&fgd->lock, flags); + fgd->bulk_pending = true; + spin_unlock_irqrestore(&fgd->lock, flags); + + queue_work(system_long_wq, &fgd->worker); +} + +static int f_gud_drm_ctrl_req_set_buffer(struct f_gud_drm *fgd, void *buf, size_t len) +{ + int ret; + + if (len != sizeof(struct gud_drm_req_set_buffer)) + return -EINVAL; + + ret = gud_drm_gadget_set_buffer(fgd->gdg, buf); + if (ret < 0) + return ret; + + if (ret > fgd->max_buffer_size) + return -EOVERFLOW; + + fgd->bulk_req->length = ret; + + return usb_ep_queue(fgd->bulk_ep, fgd->bulk_req, GFP_KERNEL); +} + +static void f_gud_drm_worker(struct work_struct *work) +{ + struct f_gud_drm *fgd = container_of(work, struct f_gud_drm, worker); + bool ctrl_pending, bulk_pending, disable_pending; + struct gud_drm_gadget *gdg = fgd->gdg; + unsigned long flags; + u16 request, value; + int ret; + + spin_lock_irqsave(&fgd->lock, flags); + request = fgd->request; + value = fgd->value; + ctrl_pending = fgd->ctrl_pending; + bulk_pending = fgd->bulk_pending; + disable_pending = fgd->disable_pending; + spin_unlock_irqrestore(&fgd->lock, flags); + + pr_debug("%s: bulk_pending=%u ctrl_pending=%u disable_pending=%u\n", + __func__, bulk_pending, ctrl_pending, disable_pending); + + if (disable_pending) { + gud_drm_gadget_disable_pipe(gdg); + + spin_lock_irqsave(&fgd->lock, flags); + fgd->disable_pending = false; + spin_unlock_irqrestore(&fgd->lock, flags); + return; + } + + if (bulk_pending) { + struct usb_request *req = fgd->bulk_req; + + ret = gud_drm_gadget_write_buffer(gdg, req->buf, req->actual); + if (ret) + pr_err("%s: Failed to write buffer, error=%d\n", __func__, ret); + + spin_lock_irqsave(&fgd->lock, flags); + fgd->bulk_pending = false; + spin_unlock_irqrestore(&fgd->lock, flags); + } + + if (ctrl_pending) { + unsigned int length = fgd->ctrl_req->length; + void *buf = fgd->ctrl_req->buf; + + if (request == GUD_DRM_USB_REQ_SET_BUFFER) + ret = f_gud_drm_ctrl_req_set_buffer(fgd, buf, length); + else + ret = gud_drm_gadget_ctrl_set(gdg, request, value, buf, length); + + spin_lock_irqsave(&fgd->lock, flags); + if (!fgd->errno) /* Don't scribble over an EBUSY or ESHUTDOWN */ + fgd->errno = -ret; + fgd->ctrl_pending = false; + fgd->status_pending = false; + spin_unlock_irqrestore(&fgd->lock, flags); + } +} + +static void f_gud_drm_ctrl_req_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_gud_drm *fgd = req->context; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&fgd->lock, flags); + + if (req->status) + ret = req->status; + else if (req->actual != req->length) + ret = -EREMOTEIO; + if (ret) { + fgd->errno = -ret; + fgd->status_pending = false; + } else { + fgd->ctrl_pending = true; + } + + spin_unlock_irqrestore(&fgd->lock, flags); + + if (!ret) + queue_work(system_long_wq, &fgd->worker); +} + +static int f_gud_drm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) +{ + struct usb_composite_dev *cdev = f->config->cdev; + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + bool in = ctrl->bRequestType & USB_DIR_IN; + u16 length = le16_to_cpu(ctrl->wLength); + u16 value = le16_to_cpu(ctrl->wValue); + unsigned long flags; + int ret; + + if (ctrl->bRequest == USB_REQ_GET_STATUS) { + struct gud_drm_req_get_status *status = cdev->req->buf; + + if (!in || length != sizeof(*status)) + return -EINVAL; + + spin_lock_irqsave(&fgd->lock, flags); + status->flags = 0; + if (fgd->status_pending) + status->flags |= GUD_DRM_STATUS_PENDING; + status->errno = fgd->errno; + spin_unlock_irqrestore(&fgd->lock, flags); + } else if (in) { + if (length > USB_COMP_EP0_BUFSIZ) /* 4k */ + return -EOVERFLOW; + + ret = gud_drm_gadget_ctrl_get(fgd->gdg, ctrl->bRequest, value, + cdev->req->buf, length); + spin_lock_irqsave(&fgd->lock, flags); + fgd->status_pending = false; + fgd->errno = ret < 0 ? -ret : 0; + spin_unlock_irqrestore(&fgd->lock, flags); + if (ret < 0) + return ret; + + length = ret; + } else { + if (length > GUD_DRM_MAX_TRANSFER_SIZE) + return -EOVERFLOW; + + spin_lock_irqsave(&fgd->lock, flags); + if (fgd->ctrl_pending) { + /* If we get here the host has timed out on the previous request */ + ret = -EBUSY; + fgd->status_pending = false; + fgd->errno = -ret; + } else { + ret = 0; + fgd->errno = 0; + fgd->request = ctrl->bRequest; + fgd->value = value; + fgd->status_pending = true; + } + spin_unlock_irqrestore(&fgd->lock, flags); + + if (ret) + return ret; + + fgd->ctrl_req->length = length; + + return usb_ep_queue(cdev->gadget->ep0, fgd->ctrl_req, GFP_ATOMIC); + } + + cdev->req->length = length; + + return usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC); +} + +static bool f_gud_drm_req_match(struct usb_function *f, const struct usb_ctrlrequest *ctrl, + bool config0) +{ + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + + if (config0) + return false; + + if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_VENDOR) + return false; + + if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE) + return false; + + return fgd->interface_id == le16_to_cpu(ctrl->wIndex); +} + +static int f_gud_drm_set_alt(struct usb_function *f, unsigned int intf, unsigned int alt) +{ + struct usb_composite_dev *cdev = f->config->cdev; + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + unsigned long flags; + + if (alt || intf != fgd->interface_id) + return -EINVAL; + + if (!fgd->bulk_ep->desc) { + pr_debug("%s: init\n", __func__); + if (config_ep_by_speed(cdev->gadget, f, fgd->bulk_ep)) { + fgd->bulk_ep->desc = NULL; + return -EINVAL; + } + } + + pr_debug("%s: reset\n", __func__); + + usb_ep_disable(fgd->bulk_ep); + usb_ep_enable(fgd->bulk_ep); + + spin_lock_irqsave(&fgd->lock, flags); + fgd->ctrl_pending = false; + fgd->bulk_pending = false; + fgd->disable_pending = false; + spin_unlock_irqrestore(&fgd->lock, flags); + + return 0; +} + +static void f_gud_drm_disable(struct usb_function *f) +{ + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + unsigned long flags; + + pr_debug("%s\n", __func__); + + usb_ep_disable(fgd->bulk_ep); + + spin_lock_irqsave(&fgd->lock, flags); + fgd->ctrl_pending = false; + fgd->bulk_pending = false; + fgd->status_pending = false; + fgd->disable_pending = true; + fgd->errno = ESHUTDOWN; + spin_unlock_irqrestore(&fgd->lock, flags); + + queue_work(system_long_wq, &fgd->worker); +} + +static void f_gud_drm_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + struct usb_composite_dev *cdev = fgd->func.config->cdev; + + flush_work(&fgd->worker); + + gud_drm_gadget_fini(fgd->gdg); + fgd->gdg = NULL; + + kfree(fgd->bulk_req->buf); + usb_ep_free_request(fgd->bulk_ep, fgd->bulk_req); + usb_ep_free_request(cdev->gadget->ep0, fgd->ctrl_req); + fgd->ctrl_req = NULL; + fgd->bulk_req = NULL; + fgd->bulk_ep = NULL; + + usb_free_all_descriptors(f); +} + +static int f_gud_drm_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct f_gud_drm_opts *opts = fi_to_f_gud_drm_opts(f->fi); + struct usb_composite_dev *cdev = c->cdev; + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + struct usb_request *ctrl_req, *bulk_req; + struct gud_drm_gadget *gdg; + struct usb_string *us; + void *buf; + int ret; + + us = usb_gstrings_attach(cdev, f_gud_drm_strings, + ARRAY_SIZE(f_gud_drm_string_defs)); + if (IS_ERR(us)) + return PTR_ERR(us); + + f_gud_drm_intf.iInterface = us[0].id; + + ret = usb_interface_id(c, f); + if (ret < 0) + return ret; + + fgd->interface_id = ret; + f_gud_drm_intf.bInterfaceNumber = fgd->interface_id; + + fgd->bulk_ep = usb_ep_autoconfig(cdev->gadget, &f_gud_drm_fs_out_desc); + if (!fgd->bulk_ep) + return -ENODEV; + + f_gud_drm_hs_out_desc.bEndpointAddress = f_gud_drm_fs_out_desc.bEndpointAddress; + + f_gud_drm_ss_out_desc.bEndpointAddress = f_gud_drm_fs_out_desc.bEndpointAddress; + + ret = usb_assign_descriptors(f, f_gud_drm_fs_function, f_gud_drm_hs_function, + f_gud_drm_ss_function, NULL); + if (ret) + return ret; + + ctrl_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); + if (!ctrl_req) { + ret = -ENOMEM; + goto fail_free_descs; + } + + ctrl_req->buf = fgd->ctrl_req_buf; + ctrl_req->complete = f_gud_drm_ctrl_req_complete; + ctrl_req->context = fgd; + + gdg = gud_drm_gadget_init(opts->drm_dev, opts->backlight_dev, &fgd->max_buffer_size); + if (IS_ERR(gdg)) { + ret = PTR_ERR(gdg); + goto fail_free_ctrl_req; + } + + bulk_req = usb_ep_alloc_request(fgd->bulk_ep, GFP_KERNEL); + if (!bulk_req) { + ret = -ENOMEM; + goto fail_free_ctrl_req; + } + + buf = kmalloc(fgd->max_buffer_size, GFP_KERNEL); + if (!buf) { + ret = -ENOMEM; + goto fail_free_bulk_req; + } + + bulk_req->complete = f_gud_drm_bulk_complete; + bulk_req->context = fgd; + bulk_req->buf = buf; + + fgd->ctrl_req = ctrl_req; + fgd->bulk_req = bulk_req; + fgd->gdg = gdg; + + return 0; + +fail_free_bulk_req: + usb_ep_free_request(fgd->bulk_ep, bulk_req); +fail_free_ctrl_req: + usb_ep_free_request(cdev->gadget->ep0, ctrl_req); +fail_free_descs: + usb_free_all_descriptors(f); + + return ret; +} + +static void f_gud_drm_free_func(struct usb_function *f) +{ + struct f_gud_drm_opts *opts = container_of(f->fi, struct f_gud_drm_opts, func_inst); + struct f_gud_drm *fgd = func_to_f_gud_drm(f); + + mutex_lock(&opts->lock); + opts->refcnt--; + mutex_unlock(&opts->lock); + + kfree(fgd->ctrl_req_buf); + kfree(fgd); +} + +static struct usb_function *f_gud_drm_alloc_func(struct usb_function_instance *fi) +{ + struct f_gud_drm_opts *opts = fi_to_f_gud_drm_opts(fi); + struct usb_function *func; + struct f_gud_drm *fgd; + + fgd = kzalloc(sizeof(*fgd), GFP_KERNEL); + if (!fgd) + return ERR_PTR(-ENOMEM); + + fgd->ctrl_req_buf = kmalloc(GUD_DRM_MAX_TRANSFER_SIZE, GFP_KERNEL); + if (!fgd->ctrl_req_buf) + goto error; + + spin_lock_init(&fgd->lock); + INIT_WORK(&fgd->worker, f_gud_drm_worker); + + mutex_lock(&opts->lock); + opts->refcnt++; + mutex_unlock(&opts->lock); + + func = &fgd->func; + func->name = "gud_drm"; + func->bind = f_gud_drm_bind; + func->unbind = f_gud_drm_unbind; + func->set_alt = f_gud_drm_set_alt; + func->req_match = f_gud_drm_req_match; + func->setup = f_gud_drm_setup; + func->disable = f_gud_drm_disable; + func->free_func = f_gud_drm_free_func; + + return func; + +error: + kfree(fgd); + + return ERR_PTR(-ENOMEM); +} + +static ssize_t f_gud_drm_opts_drm_dev_show(struct config_item *item, char *page) +{ + struct f_gud_drm_opts *opts = ci_to_f_gud_drm_opts(item); + int result; + + mutex_lock(&opts->lock); + result = sprintf(page, "%u\n", opts->drm_dev); + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_gud_drm_opts_drm_dev_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_gud_drm_opts *opts = ci_to_f_gud_drm_opts(item); + unsigned int num; + int ret; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto unlock; + } + + ret = kstrtouint(page, 0, &num); + if (ret) + goto unlock; + + opts->drm_dev = num; + ret = len; +unlock: + mutex_unlock(&opts->lock); + + return ret; +} + +CONFIGFS_ATTR(f_gud_drm_opts_, drm_dev); + +static ssize_t f_gud_drm_opts_backlight_dev_show(struct config_item *item, char *page) +{ + struct f_gud_drm_opts *opts = ci_to_f_gud_drm_opts(item); + ssize_t ret = 0; + + mutex_lock(&opts->lock); + if (opts->backlight_dev) + ret = strscpy(page, opts->backlight_dev, PAGE_SIZE); + else + page[0] = '\0'; + mutex_unlock(&opts->lock); + + return ret; +} + +static ssize_t f_gud_drm_opts_backlight_dev_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_gud_drm_opts *opts = ci_to_f_gud_drm_opts(item); + ssize_t ret; + char *name; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto unlock; + } + + name = kstrndup(page, len, GFP_KERNEL); + if (!name) { + ret = -ENOMEM; + goto unlock; + } + + kfree(opts->backlight_dev); + opts->backlight_dev = name; + ret = len; +unlock: + mutex_unlock(&opts->lock); + + return ret; +} + +CONFIGFS_ATTR(f_gud_drm_opts_, backlight_dev); + +static struct configfs_attribute *f_gud_drm_attrs[] = { + &f_gud_drm_opts_attr_drm_dev, + &f_gud_drm_opts_attr_backlight_dev, + NULL, +}; + +static void f_gud_drm_attr_release(struct config_item *item) +{ + struct f_gud_drm_opts *opts = ci_to_f_gud_drm_opts(item); + + usb_put_function_instance(&opts->func_inst); +} + +static struct configfs_item_operations f_gud_drm_item_ops = { + .release = f_gud_drm_attr_release, +}; + +static const struct config_item_type f_gud_drm_func_type = { + .ct_item_ops = &f_gud_drm_item_ops, + .ct_attrs = f_gud_drm_attrs, + .ct_owner = THIS_MODULE, +}; + +static void f_gud_drm_free_func_inst(struct usb_function_instance *fi) +{ + struct f_gud_drm_opts *opts = fi_to_f_gud_drm_opts(fi); + + mutex_destroy(&opts->lock); + kfree(opts->backlight_dev); + kfree(opts); +} + +static struct usb_function_instance *f_gud_drm_alloc_func_inst(void) +{ + struct f_gud_drm_opts *opts; + + opts = kzalloc(sizeof(*opts), GFP_KERNEL); + if (!opts) + return ERR_PTR(-ENOMEM); + + mutex_init(&opts->lock); + opts->func_inst.free_func_inst = f_gud_drm_free_func_inst; + + config_group_init_type_name(&opts->func_inst.group, "", &f_gud_drm_func_type); + + return &opts->func_inst; +} + +DECLARE_USB_FUNCTION_INIT(gud_drm, f_gud_drm_alloc_func_inst, f_gud_drm_alloc_func); + +MODULE_DESCRIPTION("Generic USB Display Gadget"); +MODULE_AUTHOR("Noralf Trønnes"); +MODULE_LICENSE("GPL");