375 lines
9.7 KiB
C
375 lines
9.7 KiB
C
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// SPDX-License-Identifier: GPL-2.0+
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/*
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* f_serial.c - generic USB serial function driver
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*
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* Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
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* Copyright (C) 2008 by David Brownell
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* Copyright (C) 2008 by Nokia Corporation
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*/
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include "u_serial.h"
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/*
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* This function packages a simple "generic serial" port with no real
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* control mechanisms, just raw data transfer over two bulk endpoints.
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*
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* Because it's not standardized, this isn't as interoperable as the
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* CDC ACM driver. However, for many purposes it's just as functional
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* if you can arrange appropriate host side drivers.
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*/
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struct f_gser {
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struct gserial port;
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u8 data_id;
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u8 port_num;
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};
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static inline struct f_gser *func_to_gser(struct usb_function *f)
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{
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return container_of(f, struct f_gser, port.func);
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}
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/*-------------------------------------------------------------------------*/
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/* interface descriptor: */
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static struct usb_interface_descriptor gser_interface_desc = {
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.bLength = USB_DT_INTERFACE_SIZE,
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.bDescriptorType = USB_DT_INTERFACE,
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/* .bInterfaceNumber = DYNAMIC */
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.bNumEndpoints = 2,
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.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
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.bInterfaceSubClass = 0,
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.bInterfaceProtocol = 0,
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/* .iInterface = DYNAMIC */
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};
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/* full speed support: */
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static struct usb_endpoint_descriptor gser_fs_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_IN,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_endpoint_descriptor gser_fs_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_OUT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_descriptor_header *gser_fs_function[] = {
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(struct usb_descriptor_header *) &gser_interface_desc,
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(struct usb_descriptor_header *) &gser_fs_in_desc,
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(struct usb_descriptor_header *) &gser_fs_out_desc,
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NULL,
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};
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/* high speed support: */
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static struct usb_endpoint_descriptor gser_hs_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_endpoint_descriptor gser_hs_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_descriptor_header *gser_hs_function[] = {
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(struct usb_descriptor_header *) &gser_interface_desc,
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(struct usb_descriptor_header *) &gser_hs_in_desc,
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(struct usb_descriptor_header *) &gser_hs_out_desc,
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NULL,
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};
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static struct usb_endpoint_descriptor gser_ss_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_endpoint_descriptor gser_ss_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_ss_ep_comp_descriptor gser_ss_bulk_comp_desc = {
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.bLength = sizeof gser_ss_bulk_comp_desc,
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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};
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static struct usb_descriptor_header *gser_ss_function[] = {
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(struct usb_descriptor_header *) &gser_interface_desc,
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(struct usb_descriptor_header *) &gser_ss_in_desc,
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(struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
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(struct usb_descriptor_header *) &gser_ss_out_desc,
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(struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
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NULL,
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};
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/* string descriptors: */
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static struct usb_string gser_string_defs[] = {
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[0].s = "Generic Serial",
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{ } /* end of list */
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};
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static struct usb_gadget_strings gser_string_table = {
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.language = 0x0409, /* en-us */
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.strings = gser_string_defs,
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};
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static struct usb_gadget_strings *gser_strings[] = {
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&gser_string_table,
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NULL,
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};
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/*-------------------------------------------------------------------------*/
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static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
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{
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struct f_gser *gser = func_to_gser(f);
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struct usb_composite_dev *cdev = f->config->cdev;
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/* we know alt == 0, so this is an activation or a reset */
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if (gser->port.in->enabled) {
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dev_dbg(&cdev->gadget->dev,
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"reset generic ttyGS%d\n", gser->port_num);
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gserial_disconnect(&gser->port);
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}
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if (!gser->port.in->desc || !gser->port.out->desc) {
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dev_dbg(&cdev->gadget->dev,
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"activate generic ttyGS%d\n", gser->port_num);
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if (config_ep_by_speed(cdev->gadget, f, gser->port.in) ||
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config_ep_by_speed(cdev->gadget, f, gser->port.out)) {
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gser->port.in->desc = NULL;
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gser->port.out->desc = NULL;
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return -EINVAL;
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}
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}
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gserial_connect(&gser->port, gser->port_num);
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return 0;
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}
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static void gser_disable(struct usb_function *f)
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{
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struct f_gser *gser = func_to_gser(f);
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struct usb_composite_dev *cdev = f->config->cdev;
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dev_dbg(&cdev->gadget->dev,
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"generic ttyGS%d deactivated\n", gser->port_num);
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gserial_disconnect(&gser->port);
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}
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/*-------------------------------------------------------------------------*/
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/* serial function driver setup/binding */
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static int gser_bind(struct usb_configuration *c, struct usb_function *f)
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{
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struct usb_composite_dev *cdev = c->cdev;
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struct f_gser *gser = func_to_gser(f);
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int status;
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struct usb_ep *ep;
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/* REVISIT might want instance-specific strings to help
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* distinguish instances ...
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*/
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/* maybe allocate device-global string ID */
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if (gser_string_defs[0].id == 0) {
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status = usb_string_id(c->cdev);
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if (status < 0)
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return status;
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gser_string_defs[0].id = status;
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}
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/* allocate instance-specific interface IDs */
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status = usb_interface_id(c, f);
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if (status < 0)
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goto fail;
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gser->data_id = status;
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gser_interface_desc.bInterfaceNumber = status;
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status = -ENODEV;
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/* allocate instance-specific endpoints */
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ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
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if (!ep)
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goto fail;
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gser->port.in = ep;
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ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
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if (!ep)
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goto fail;
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gser->port.out = ep;
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/* support all relevant hardware speeds... we expect that when
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* hardware is dual speed, all bulk-capable endpoints work at
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* both speeds
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*/
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gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
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gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
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gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
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gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
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status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function,
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gser_ss_function, NULL);
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if (status)
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goto fail;
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dev_dbg(&cdev->gadget->dev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
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gser->port_num,
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gadget_is_superspeed(c->cdev->gadget) ? "super" :
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gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
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gser->port.in->name, gser->port.out->name);
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return 0;
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fail:
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ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
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return status;
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}
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static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
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{
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return container_of(to_config_group(item), struct f_serial_opts,
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func_inst.group);
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}
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static void serial_attr_release(struct config_item *item)
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{
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struct f_serial_opts *opts = to_f_serial_opts(item);
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usb_put_function_instance(&opts->func_inst);
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}
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static struct configfs_item_operations serial_item_ops = {
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.release = serial_attr_release,
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};
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static ssize_t f_serial_port_num_show(struct config_item *item, char *page)
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{
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return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
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}
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CONFIGFS_ATTR_RO(f_serial_, port_num);
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static struct configfs_attribute *acm_attrs[] = {
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&f_serial_attr_port_num,
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NULL,
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};
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static const struct config_item_type serial_func_type = {
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.ct_item_ops = &serial_item_ops,
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.ct_attrs = acm_attrs,
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.ct_owner = THIS_MODULE,
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};
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static void gser_free_inst(struct usb_function_instance *f)
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{
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struct f_serial_opts *opts;
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opts = container_of(f, struct f_serial_opts, func_inst);
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gserial_free_line(opts->port_num);
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kfree(opts);
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}
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static struct usb_function_instance *gser_alloc_inst(void)
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{
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struct f_serial_opts *opts;
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int ret;
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opts = kzalloc(sizeof(*opts), GFP_KERNEL);
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if (!opts)
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return ERR_PTR(-ENOMEM);
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opts->func_inst.free_func_inst = gser_free_inst;
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ret = gserial_alloc_line(&opts->port_num);
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if (ret) {
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kfree(opts);
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return ERR_PTR(ret);
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}
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config_group_init_type_name(&opts->func_inst.group, "",
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&serial_func_type);
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return &opts->func_inst;
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}
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static void gser_free(struct usb_function *f)
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{
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struct f_gser *serial;
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serial = func_to_gser(f);
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kfree(serial);
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}
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static void gser_unbind(struct usb_configuration *c, struct usb_function *f)
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{
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usb_free_all_descriptors(f);
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}
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static void gser_resume(struct usb_function *f)
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{
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struct f_gser *gser = func_to_gser(f);
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gserial_resume(&gser->port);
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}
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static void gser_suspend(struct usb_function *f)
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{
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struct f_gser *gser = func_to_gser(f);
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gserial_suspend(&gser->port);
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}
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static struct usb_function *gser_alloc(struct usb_function_instance *fi)
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{
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struct f_gser *gser;
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struct f_serial_opts *opts;
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/* allocate and initialize one new instance */
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gser = kzalloc(sizeof(*gser), GFP_KERNEL);
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if (!gser)
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return ERR_PTR(-ENOMEM);
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opts = container_of(fi, struct f_serial_opts, func_inst);
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gser->port_num = opts->port_num;
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gser->port.func.name = "gser";
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gser->port.func.strings = gser_strings;
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gser->port.func.bind = gser_bind;
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gser->port.func.unbind = gser_unbind;
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gser->port.func.set_alt = gser_set_alt;
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gser->port.func.disable = gser_disable;
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gser->port.func.free_func = gser_free;
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gser->port.func.resume = gser_resume;
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gser->port.func.suspend = gser_suspend;
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return &gser->port.func;
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}
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DECLARE_USB_FUNCTION_INIT(gser, gser_alloc_inst, gser_alloc);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Al Borchers");
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MODULE_AUTHOR("David Brownell");
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