/*
* f_serial.c - generic USB serial function driver
*
* Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
* Copyright (C) 2008 by David Brownell
* Copyright (C) 2008 by Nokia Corporation
*
* This software is distributed under the terms of the GNU General
* Public License ("GPL") as published by the Free Software Foundation,
* either version 2 of that License or (at your option) any later version.
*/
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include "u_serial.h"
#include "gadget_chips.h"
/*
* This function packages a simple "generic serial" port with no real
* control mechanisms, just raw data transfer over two bulk endpoints.
*
* Because it's not standardized, this isn't as interoperable as the
* CDC ACM driver. However, for many purposes it's just as functional
* if you can arrange appropriate host side drivers.
*/
struct gser_descs {
struct usb_endpoint_descriptor *in;
struct usb_endpoint_descriptor *out;
};
struct f_gser {
struct gserial port;
u8 data_id;
u8 port_num;
struct gser_descs fs;
struct gser_descs hs;
};
static inline struct f_gser *func_to_gser(struct usb_function *f)
{
return container_of(f, struct f_gser, port.func);
}
/*-------------------------------------------------------------------------*/
/* interface descriptor: */
static struct usb_interface_descriptor gser_interface_desc __initdata = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
.bInterfaceSubClass = 0,
.bInterfaceProtocol = 0,
/* .iInterface = DYNAMIC */
};
/* full speed support: */
static struct usb_endpoint_descriptor gser_fs_in_desc __initdata = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_endpoint_descriptor gser_fs_out_desc __initdata = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_descriptor_header *gser_fs_function[] __initdata = {
(struct usb_descriptor_header *) &gser_interface_desc,
(struct usb_descriptor_header *) &gser_fs_in_desc,
(struct usb_descriptor_header *) &gser_fs_out_desc,
NULL,
};
/* high speed support: */
static struct usb_endpoint_descriptor gser_hs_in_desc __initdata = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
static struct usb_endpoint_descriptor gser_hs_out_desc __initdata = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
static struct usb_descriptor_header *gser_hs_function[] __initdata = {
(struct usb_descriptor_header *) &gser_interface_desc,
(struct usb_descriptor_header *) &gser_hs_in_desc,
(struct usb_descriptor_header *) &gser_hs_out_desc,
NULL,
};
/* string descriptors: */
static struct usb_string gser_string_defs[] = {
[0].s = "Generic Serial",
{ } /* end of list */
};
static struct usb_gadget_strings gser_string_table = {
.language = 0x0409, /* en-us */
.strings = gser_string_defs,
};
static struct usb_gadget_strings *gser_strings[] = {
&gser_string_table,
NULL,
};
/*-------------------------------------------------------------------------*/
static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
struct f_gser *gser = func_to_gser(f);
struct usb_composite_dev *cdev = f->config->cdev;
/* we know alt == 0, so this is an activation or a reset */
if (gser->port.in->driver_data) {
DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
gserial_disconnect(&gser->port);
} else {
DBG(cdev, "activate generic ttyGS%d\n", gser->port_num);
gser->port.in_desc = ep_choose(cdev->gadget,
gser->hs.in, gser->fs.in);
gser->port.out_desc = ep_choose(cdev->gadget,
gser->hs.out, gser->fs.out);
}
gserial_connect(&gser->port, gser->port_num);
return 0;
}
static void gser_disable(struct usb_function *f)
{
struct f_gser *gser = func_to_gser(f);
struct usb_composite_dev *cdev = f->config->cdev;
DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num);
gserial_disconnect(&gser->port);
}
/*-------------------------------------------------------------------------*/
/* serial function driver setup/binding */
static int __init
gser_bind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_composite_dev *cdev = c->cdev;
struct f_gser *gser = func_to_gser(f);
int status;
struct usb_ep *ep;
/* allocate instance-specific interface IDs */
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
gser->data_id = status;
gser_interface_desc.bInterfaceNumber = status;
status = -ENODEV;
/* allocate instance-specific endpoints */
ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
if (!ep)
goto fail;
gser->port.in = ep;
ep->driver_data = cdev; /* claim */
ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
if (!ep)
goto fail;
gser->port.out = ep;
ep->driver_data = cdev; /* claim */
/* copy descriptors, and track endpoint copies */
f->descriptors = usb_copy_descriptors(gser_fs_function);
gser->fs.in = usb_find_endpoint(gser_fs_function,
f->descriptors, &gser_fs_in_desc);
gser->fs.out = usb_find_endpoint(gser_fs_function,
f->descriptors, &gser_fs_out_desc);
/* support all relevant hardware speeds... we expect that when
* hardware is dual speed, all bulk-capable endpoints work at
* both speeds
*/
if (gadget_is_dualspeed(c->cdev->gadget)) {
gser_hs_in_desc.bEndpointAddress =
gser_fs_in_desc.bEndpointAddress;
gser_hs_out_desc.bEndpointAddress =
gser_fs_out_desc.bEndpointAddress;
/* copy descriptors, and track endpoint copies */
f->hs_descriptors = usb_copy_descriptors(gser_hs_function);
gser->hs.in = usb_find_endpoint(gser_hs_function,
f->hs_descriptors, &gser_hs_in_desc);
gser->hs.out = usb_find_endpoint(gser_hs_function,
f->hs_descriptors, &gser_hs_out_desc);
}
DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
gser->port_num,
gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
gser->port.in->name, gser->port.out->name);
return 0;
fail:
/* we might as well release our claims on endpoints */
if (gser->port.out)
gser->port.out->driver_data = NULL;
if (gser->port.in)
gser->port.in->driver_data = NULL;
ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
return status;
}
static void
gser_unbind(struct usb_configuration *c, struct usb_function *f)
{
if (gadget_is_dualspeed(c->cdev->gadget))
usb_free_descriptors(f->hs_descriptors);
usb_free_descriptors(f->descriptors);
kfree(func_to_gser(f));
}
/**
* gser_bind_config - add a generic serial function to a configuration
* @c: the configuration to support the serial instance
* @port_num: /dev/ttyGS* port this interface will use
* Context: single threaded during gadget setup
*
* Returns zero on success, else negative errno.
*
* Caller must have called @gserial_setup() with enough ports to
* handle all the ones it binds. Caller is also responsible
* for calling @gserial_cleanup() before module unload.
*/
int __init gser_bind_config(struct usb_configuration *c, u8 port_num)
{
struct f_gser *gser;
int status;
/* REVISIT might want instance-specific strings to help
* distinguish instances ...
*/
/* maybe allocate device-global string ID */
if (gser_string_defs[0].id == 0) {
status = usb_string_id(c->cdev);
if (status < 0)
return status;
gser_string_defs[0].id = status;
}
/* allocate and initialize one new instance */
gser = kzalloc(sizeof *gser, GFP_KERNEL);
if (!gser)
return -ENOMEM;
gser->port_num = port_num;
gser->port.func.name = "gser";
gser->port.func.strings = gser_strings;
gser->port.func.bind = gser_bind;
gser->port.func.unbind = gser_unbind;
gser->port.func.set_alt = gser_set_alt;
gser->port.func.disable = gser_disable;
status = usb_add_function(c, &gser->port.func);
if (status)
kfree(gser);
return status;
}
