drivers/usb/gadget/f_serial.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/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 =	__constant_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 =	__constant_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;
 }
	/*
	* 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/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 = __constant_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 = __constant_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;
	}