// SPDX-License-Identifier: GPL-2.0+
/*
* serial.c -- USB gadget serial driver
*
* Copyright (C) 2003 Al Borchers ([email protected])
* Copyright (C) 2008 by David Brownell
* Copyright (C) 2008 by Nokia Corporation
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include "u_serial.h"
/* Defines */
#define GS_VERSION_STR "v2.4"
#define GS_VERSION_NUM 0x2400
#define GS_LONG_NAME "Gadget Serial"
#define GS_VERSION_NAME GS_LONG_NAME " " GS_VERSION_STR
/*-------------------------------------------------------------------------*/
USB_GADGET_COMPOSITE_OPTIONS();
/* Thanks to NetChip Technologies for donating this product ID.
*
* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
* Instead: allocate your own, using normal USB-IF procedures.
*/
#define GS_VENDOR_ID 0x0525 /* NetChip */
#define GS_PRODUCT_ID 0xa4a6 /* Linux-USB Serial Gadget */
#define GS_CDC_PRODUCT_ID 0xa4a7 /* ... as CDC-ACM */
#define GS_CDC_OBEX_PRODUCT_ID 0xa4a9 /* ... as CDC-OBEX */
/* 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 = NULL /* updated; f(use_acm) */,
{ } /* 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 = DYNAMIC */
/* .bDeviceClass = f(use_acm) */
.bDeviceSubClass = 0,
.bDeviceProtocol = 0,
/* .bMaxPacketSize0 = f(hardware) */
.idVendor = cpu_to_le16(GS_VENDOR_ID),
/* .idProduct = f(use_acm) */
.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
/* .iManufacturer = DYNAMIC */
/* .iProduct = DYNAMIC */
.bNumConfigurations = 1,
};
static const struct usb_descriptor_header *otg_desc[2];
/*-------------------------------------------------------------------------*/
/* Module */
MODULE_DESCRIPTION(GS_VERSION_NAME);
MODULE_AUTHOR("Al Borchers");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
static bool use_acm = true;
module_param(use_acm, bool, 0);
MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
static bool use_obex = false;
module_param(use_obex, bool, 0);
MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
static unsigned n_ports = 1;
module_param(n_ports, uint, 0);
MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
static bool enable = true;
static int switch_gserial_enable(bool do_enable);
static int enable_set(const char *s, const struct kernel_param *kp)
{
bool do_enable;
int ret;
if (!s) /* called for no-arg enable == default */
return 0;
ret = kstrtobool(s, &do_enable);
if (ret || enable == do_enable)
return ret;
ret = switch_gserial_enable(do_enable);
if (!ret)
enable = do_enable;
return ret;
}
static const struct kernel_param_ops enable_ops = {
.set = enable_set,
.get = param_get_bool,
};
module_param_cb(enable, &enable_ops, &enable, 0644);
/*-------------------------------------------------------------------------*/
static struct usb_configuration serial_config_driver = {
/* .label = f(use_acm) */
/* .bConfigurationValue = f(use_acm) */
/* .iConfiguration = DYNAMIC */
.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
};
static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
static int serial_register_ports(struct usb_composite_dev *cdev,
struct usb_configuration *c, const char *f_name)
{
int i;
int ret;
ret = usb_add_config_only(cdev, c);
if (ret)
goto out;
for (i = 0; i < n_ports; i++) {
fi_serial[i] = usb_get_function_instance(f_name);
if (IS_ERR(fi_serial[i])) {
ret = PTR_ERR(fi_serial[i]);
goto fail;
}
f_serial[i] = usb_get_function(fi_serial[i]);
if (IS_ERR(f_serial[i])) {
ret = PTR_ERR(f_serial[i]);
goto err_get_func;
}
ret = usb_add_function(c, f_serial[i]);
if (ret)
goto err_add_func;
}
return 0;
err_add_func:
usb_put_function(f_serial[i]);
err_get_func:
usb_put_function_instance(fi_serial[i]);
fail:
i--;
while (i >= 0) {
usb_remove_function(c, f_serial[i]);
usb_put_function(f_serial[i]);
usb_put_function_instance(fi_serial[i]);
i--;
}
out:
return ret;
}
static int gs_bind(struct usb_composite_dev *cdev)
{
int status;
/* 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;
device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
status = strings_dev[STRING_DESCRIPTION_IDX].id;
serial_config_driver.iConfiguration = status;
if (gadget_is_otg(cdev->gadget)) {
if (!otg_desc[0]) {
struct usb_descriptor_header *usb_desc;
usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
if (!usb_desc) {
status = -ENOMEM;
goto fail;
}
usb_otg_descriptor_init(cdev->gadget, usb_desc);
otg_desc[0] = usb_desc;
otg_desc[1] = NULL;
}
serial_config_driver.descriptors = otg_desc;
serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
}
/* register our configuration */
if (use_acm) {
status = serial_register_ports(cdev, &serial_config_driver,
"acm");
usb_ep_autoconfig_reset(cdev->gadget);
} else if (use_obex)
status = serial_register_ports(cdev, &serial_config_driver,
"obex");
else {
status = serial_register_ports(cdev, &serial_config_driver,
"gser");
}
if (status < 0)
goto fail1;
usb_composite_overwrite_options(cdev, &coverwrite);
INFO(cdev, "%s\n", GS_VERSION_NAME);
return 0;
fail1:
kfree(otg_desc[0]);
otg_desc[0] = NULL;
fail:
return status;
}
static int gs_unbind(struct usb_composite_dev *cdev)
{
int i;
for (i = 0; i < n_ports; i++) {
usb_put_function(f_serial[i]);
usb_put_function_instance(fi_serial[i]);
}
kfree(otg_desc[0]);
otg_desc[0] = NULL;
return 0;
}
static struct usb_composite_driver gserial_driver = {
.name = "g_serial",
.dev = &device_desc,
.strings = dev_strings,
.max_speed = USB_SPEED_SUPER,
.bind = gs_bind,
.unbind = gs_unbind,
};
static int switch_gserial_enable(bool do_enable)
{
if (!serial_config_driver.label)
/* gserial_init() was not called, yet */
return 0;
if (do_enable)
return usb_composite_probe(&gserial_driver);
usb_composite_unregister(&gserial_driver);
return 0;
}
static int __init gserial_init(void)
{
/* We *could* export two configs; that'd be much cleaner...
* but neither of these product IDs was defined that way.
*/
if (use_acm) {
serial_config_driver.label = "CDC ACM config";
serial_config_driver.bConfigurationValue = 2;
device_desc.bDeviceClass = USB_CLASS_COMM;
device_desc.idProduct =
cpu_to_le16(GS_CDC_PRODUCT_ID);
} else if (use_obex) {
serial_config_driver.label = "CDC OBEX config";
serial_config_driver.bConfigurationValue = 3;
device_desc.bDeviceClass = USB_CLASS_COMM;
device_desc.idProduct =
cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
} else {
serial_config_driver.label = "Generic Serial config";
serial_config_driver.bConfigurationValue = 1;
device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
device_desc.idProduct =
cpu_to_le16(GS_PRODUCT_ID);
}
strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
if (!enable)
return 0;
return usb_composite_probe(&gserial_driver);
}
module_init(gserial_init);
static void __exit gserial_cleanup(void)
{
if (enable)
usb_composite_unregister(&gserial_driver);
}
module_exit(gserial_cleanup);
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