usb_display.c

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/usb/composite.h>

#include "f_display.h"
#include "f_hid.h"

/* Defines */

#define GS_VERSION_STR			"v0.1"
#define GS_VERSION_NUM			0x0200
#define GS_LONG_NAME			"USB display"
#define GS_VERSION_NAME			GS_LONG_NAME " " GS_VERSION_STR

/*-------------------------------------------------------------------------*/
USB_GADGET_COMPOSITE_OPTIONS();

#define RP_DISP_DRIVER_NAME     "usb_display"
#define RP_DISP_USB_VENDOR_ID   0xFCCF // RP Pseudo vendor id
#define RP_DISP_USB_PRODUCT_ID  0xA001

/* string IDs are assigned dynamically */

#define STRING_DESCRIPTION_IDX		USB_GADGET_FIRST_AVAIL_IDX

static struct usb_string strings_dev[] = {
	[USB_GADGET_MANUFACTURER_IDX].s = "",
	[USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
	[USB_GADGET_SERIAL_IDX].s = "",
	[STRING_DESCRIPTION_IDX].s = GS_LONG_NAME,
	{  } /* end of list */
};

static struct usb_gadget_strings stringtab_dev = {
	.language	= 0x0409,	/* en-us */
	.strings	= strings_dev,
};

static struct usb_gadget_strings *dev_strings[] = {
	&stringtab_dev,
	NULL,
};

static struct usb_device_descriptor device_desc = {
	.bLength =		USB_DT_DEVICE_SIZE,
	.bDescriptorType =	USB_DT_DEVICE,
	.bcdUSB =		cpu_to_le16(0x0200),
	//.bDeviceClass =  USB_CLASS_VENDOR_SPEC,
	.bDeviceClass =  USB_CLASS_PER_INTERFACE,
	.bDeviceSubClass =	0,
	.bDeviceProtocol =	0,
	/* .bMaxPacketSize0 = f(hardware) */
	.idVendor =	cpu_to_le16(RP_DISP_USB_VENDOR_ID),
	.idProduct = cpu_to_le16(RP_DISP_USB_PRODUCT_ID),
	.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
	/* .iManufacturer = DYNAMIC */
	/* .iProduct = DYNAMIC */
	.bNumConfigurations =	1,
};

static struct usb_configuration serial_config_driver = {
	.label = RP_DISP_DRIVER_NAME,
	.bConfigurationValue = 1,
	/* .iConfiguration = DYNAMIC */
	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
};

static int __init gs_bind(struct usb_composite_dev *cdev)
{
	/* Allocate string descriptor numbers ... note that string
	 * contents can be overridden by the composite_dev glue.
	 */
	int	status = usb_string_ids_tab(cdev, strings_dev);
	if (status < 0)
		return status;

	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
	device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;

    // linux的一个BUG，如果不设置usb_composite_dev的desc的bcdDevice的话，默认会设置成内核版本号，参见composite.c的
	// update_unchanged_dev_desc(&cdev->desc, composite->dev);
    // 如果版本小于1.04协议会不同
    cdev->desc.bcdDevice = cpu_to_le16(GS_VERSION_NUM);

    serial_config_driver.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;
	/* support autoresume for remote wakeup testing */
	serial_config_driver.bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
	serial_config_driver.descriptors = NULL;
	//if (autoresume) {
	//	serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	//}

    usb_add_config_only(cdev, &serial_config_driver);
    //return add_hid_function(&serial_config_driver);
    status = add_hid_function(&serial_config_driver);
    if (status)
        return status;

    return add_display_function(&serial_config_driver);
}

static int gs_unbind(struct usb_composite_dev *cdev)
{
	return 0;
}

static __refdata struct usb_composite_driver usb_display_driver = {
	.name		= RP_DISP_DRIVER_NAME,
	.dev		= &device_desc,
	.strings	= dev_strings,
	.max_speed	= USB_SPEED_HIGH,
	.bind		= gs_bind,
	.unbind		= gs_unbind,
};

static int __init init(void)
{
    return usb_composite_probe(&usb_display_driver);
}
module_init(init);

static void __exit cleanup(void)
{
	usb_composite_unregister(&usb_display_driver);
}
module_exit(cleanup);

MODULE_DESCRIPTION(GS_VERSION_NAME);
MODULE_AUTHOR("bobo");
MODULE_LICENSE("GPL");