xref: /kernel/linux/linux-5.10/drivers/usb/gadget/legacy/acm_ms.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * acm_ms.c -- Composite driver, with ACM and mass storage support
 *
 * Copyright (C) 2008 David Brownell
 * Copyright (C) 2008 Nokia Corporation
 * Author: David Brownell
 * Modified: Klaus Schwarzkopf <schwarzkopf@sensortherm.de>
 *
 * Heavily based on multi.c and cdc2.c
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "u_serial.h"

#define DRIVER_DESC		"Composite Gadget (ACM + MS)"
#define DRIVER_VERSION		"2011/10/10"

/*-------------------------------------------------------------------------*/

/*
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#define ACM_MS_VENDOR_NUM	0x1d6b	/* Linux Foundation */
#define ACM_MS_PRODUCT_NUM	0x0106	/* Composite Gadget: ACM + MS*/

#include "f_mass_storage.h"

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

static struct usb_device_descriptor device_desc = {
	.bLength =		sizeof device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	/* .bcdUSB = DYNAMIC */

	.bDeviceClass =		USB_CLASS_MISC /* 0xEF */,
	.bDeviceSubClass =	2,
	.bDeviceProtocol =	1,

	/* .bMaxPacketSize0 = f(hardware) */

	/* Vendor and product id can be overridden by module parameters.  */
	.idVendor =		cpu_to_le16(ACM_MS_VENDOR_NUM),
	.idProduct =		cpu_to_le16(ACM_MS_PRODUCT_NUM),
	/* .bcdDevice = f(hardware) */
	/* .iManufacturer = DYNAMIC */
	/* .iProduct = DYNAMIC */
	/* NO SERIAL NUMBER */
	/*.bNumConfigurations =	DYNAMIC*/
};

static const struct usb_descriptor_header *otg_desc[2];

/* string IDs are assigned dynamically */
static struct usb_string strings_dev[] = {
	[USB_GADGET_MANUFACTURER_IDX].s = "",
	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
	[USB_GADGET_SERIAL_IDX].s = "",
	{  } /* 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,
};

/****************************** Configurations ******************************/

static struct fsg_module_parameters fsg_mod_data = { .stall = 1 };
#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;

#else

/*
 * Number of buffers we will use.
 * 2 is usually enough for good buffering pipeline
 */
#define fsg_num_buffers	CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

FSG_MODULE_PARAMETERS(/* no prefix */, fsg_mod_data);

/*-------------------------------------------------------------------------*/
static struct usb_function *f_acm;
static struct usb_function_instance *f_acm_inst;

static struct usb_function_instance *fi_msg;
static struct usb_function *f_msg;

/*
 * We _always_ have both ACM and mass storage functions.
 */
static int acm_ms_do_config(struct usb_configuration *c)
{
	int	status;

	if (gadget_is_otg(c->cdev->gadget)) {
		c->descriptors = otg_desc;
		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	f_acm = usb_get_function(f_acm_inst);
	if (IS_ERR(f_acm))
		return PTR_ERR(f_acm);

	f_msg = usb_get_function(fi_msg);
	if (IS_ERR(f_msg)) {
		status = PTR_ERR(f_msg);
		goto put_acm;
	}

	status = usb_add_function(c, f_acm);
	if (status < 0)
		goto put_msg;

	status = usb_add_function(c, f_msg);
	if (status)
		goto remove_acm;

	return 0;
remove_acm:
	usb_remove_function(c, f_acm);
put_msg:
	usb_put_function(f_msg);
put_acm:
	usb_put_function(f_acm);
	return status;
}

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

/*-------------------------------------------------------------------------*/

static int acm_ms_bind(struct usb_composite_dev *cdev)
{
	struct usb_gadget	*gadget = cdev->gadget;
	struct fsg_opts		*opts;
	struct fsg_config	config;
	int			status;

	f_acm_inst = usb_get_function_instance("acm");
	if (IS_ERR(f_acm_inst))
		return PTR_ERR(f_acm_inst);

	fi_msg = usb_get_function_instance("mass_storage");
	if (IS_ERR(fi_msg)) {
		status = PTR_ERR(fi_msg);
		goto fail_get_msg;
	}

	/* set up mass storage function */
	fsg_config_from_params(&config, &fsg_mod_data, fsg_num_buffers);
	opts = fsg_opts_from_func_inst(fi_msg);

	opts->no_configfs = true;
	status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers);
	if (status)
		goto fail;

	status = fsg_common_set_cdev(opts->common, cdev, config.can_stall);
	if (status)
		goto fail_set_cdev;

	fsg_common_set_sysfs(opts->common, true);
	status = fsg_common_create_luns(opts->common, &config);
	if (status)
		goto fail_set_cdev;

	fsg_common_set_inquiry_string(opts->common, config.vendor_name,
				      config.product_name);
	/*
	 * Allocate string descriptor numbers ... note that string
	 * contents can be overridden by the composite_dev glue.
	 */
	status = usb_string_ids_tab(cdev, strings_dev);
	if (status < 0)
		goto fail_string_ids;
	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;

	if (gadget_is_otg(gadget) && !otg_desc[0]) {
		struct usb_descriptor_header *usb_desc;

		usb_desc = usb_otg_descriptor_alloc(gadget);
		if (!usb_desc) {
			status = -ENOMEM;
			goto fail_string_ids;
		}
		usb_otg_descriptor_init(gadget, usb_desc);
		otg_desc[0] = usb_desc;
		otg_desc[1] = NULL;
	}

	/* register our configuration */
	status = usb_add_config(cdev, &acm_ms_config_driver, acm_ms_do_config);
	if (status < 0)
		goto fail_otg_desc;

	usb_composite_overwrite_options(cdev, &coverwrite);
	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
			DRIVER_DESC);
	return 0;

	/* error recovery */
fail_otg_desc:
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;
fail_string_ids:
	fsg_common_remove_luns(opts->common);
fail_set_cdev:
	fsg_common_free_buffers(opts->common);
fail:
	usb_put_function_instance(fi_msg);
fail_get_msg:
	usb_put_function_instance(f_acm_inst);
	return status;
}

static int acm_ms_unbind(struct usb_composite_dev *cdev)
{
	usb_put_function(f_msg);
	usb_put_function_instance(fi_msg);
	usb_put_function(f_acm);
	usb_put_function_instance(f_acm_inst);
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;

	return 0;
}

static struct usb_composite_driver acm_ms_driver = {
	.name		= "g_acm_ms",
	.dev		= &device_desc,
	.max_speed	= USB_SPEED_SUPER,
	.strings	= dev_strings,
	.bind		= acm_ms_bind,
	.unbind		= acm_ms_unbind,
};

module_usb_composite_driver(acm_ms_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Klaus Schwarzkopf <schwarzkopf@sensortherm.de>");
MODULE_LICENSE("GPL v2");