usb gadget serial: split out CDC ACM function (4d5a73dc) · Commits · 戴 / test

Documentation/DocBook/gadget.tmpl

+2 −0

Original line number	Diff line number	Diff line
		@@ -556,6 +556,8 @@ been converted to this framework.
		Near-term plans include converting all of them, except for "gadgetfs".
		</para>

		!Edrivers/usb/gadget/f_acm.c

		</sect1>

drivers/usb/gadget/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -26,7 +26,7 @@ C_UTILS = composite.o usbstring.o config.o epautoconf.o

		g_zero-objs := zero.o f_sourcesink.o f_loopback.o $(C_UTILS)
		g_ether-objs := ether.o usbstring.o config.o epautoconf.o
		g_serial-objs := serial.o u_serial.o usbstring.o config.o epautoconf.o
		g_serial-objs := serial.o u_serial.o f_acm.o $(C_UTILS)
		g_midi-objs := gmidi.o usbstring.o config.o epautoconf.o
		gadgetfs-objs := inode.o
		g_file_storage-objs := file_storage.o usbstring.o config.o \

drivers/usb/gadget/f_acm.c

0 → 100644

+589 −0

Original line number	Diff line number	Diff line
		/*
		* f_acm.c -- USB CDC serial (ACM) 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.
		*/

		/* #define VERBOSE_DEBUG */

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

		#include "u_serial.h"
		#include "gadget_chips.h"


		/*
		* This CDC ACM function support just wraps control functions and
		* notifications around the generic serial-over-usb code.
		*
		* Because CDC ACM is standardized by the USB-IF, many host operating
		* systems have drivers for it. Accordingly, ACM is the preferred
		* interop solution for serial-port type connections. The control
		* models are often not necessary, and in any case don't do much in
		* this bare-bones implementation.
		*
		* Note that even MS-Windows has some support for ACM. However, that
		* support is somewhat broken because when you use ACM in a composite
		* device, having multiple interfaces confuses the poor OS. It doesn't
		* seem to understand CDC Union descriptors. The new "association"
		* descriptors (roughly equivalent to CDC Unions) may sometimes help.
		*/

		struct acm_ep_descs {
		struct usb_endpoint_descriptor *in;
		struct usb_endpoint_descriptor *out;
		struct usb_endpoint_descriptor *notify;
		};

		struct f_acm {
		struct gserial port;
		u8 ctrl_id, data_id;
		u8 port_num;

		struct usb_descriptor_header **fs_function;
		struct acm_ep_descs fs;
		struct usb_descriptor_header **hs_function;
		struct acm_ep_descs hs;

		struct usb_ep *notify;
		struct usb_endpoint_descriptor *notify_desc;

		struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
		u16 port_handshake_bits;
		#define RS232_RTS (1 << 1) /* unused with full duplex */
		#define RS232_DTR (1 << 0) /* host is ready for data r/w */
		};

		static inline struct f_acm func_to_acm(struct usb_function f)
		{
		return container_of(f, struct f_acm, port.func);
		}

		/-------------------------------------------------------------------------/

		/* notification endpoint uses smallish and infrequent fixed-size messages */

		#define GS_LOG2_NOTIFY_INTERVAL 5 /* 1 << 5 == 32 msec */
		#define GS_NOTIFY_MAXPACKET 8

		/* interface and class descriptors: */

		static struct usb_interface_descriptor acm_control_interface_desc __initdata = {
		.bLength = USB_DT_INTERFACE_SIZE,
		.bDescriptorType = USB_DT_INTERFACE,
		/* .bInterfaceNumber = DYNAMIC */
		.bNumEndpoints = 1,
		.bInterfaceClass = USB_CLASS_COMM,
		.bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
		.bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
		/* .iInterface = DYNAMIC */
		};

		static struct usb_interface_descriptor acm_data_interface_desc __initdata = {
		.bLength = USB_DT_INTERFACE_SIZE,
		.bDescriptorType = USB_DT_INTERFACE,
		/* .bInterfaceNumber = DYNAMIC */
		.bNumEndpoints = 2,
		.bInterfaceClass = USB_CLASS_CDC_DATA,
		.bInterfaceSubClass = 0,
		.bInterfaceProtocol = 0,
		/* .iInterface = DYNAMIC */
		};

		static struct usb_cdc_header_desc acm_header_desc __initdata = {
		.bLength = sizeof(acm_header_desc),
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_HEADER_TYPE,
		.bcdCDC = __constant_cpu_to_le16(0x0110),
		};

		static struct usb_cdc_call_mgmt_descriptor
		acm_call_mgmt_descriptor __initdata = {
		.bLength = sizeof(acm_call_mgmt_descriptor),
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
		.bmCapabilities = 0,
		/* .bDataInterface = DYNAMIC */
		};

		static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
		.bLength = sizeof(acm_descriptor),
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_ACM_TYPE,
		.bmCapabilities = (1 << 1),
		};

		static struct usb_cdc_union_desc acm_union_desc __initdata = {
		.bLength = sizeof(acm_union_desc),
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_UNION_TYPE,
		/* .bMasterInterface0 = DYNAMIC */
		/* .bSlaveInterface0 = DYNAMIC */
		};

		/* full speed support: */

		static struct usb_endpoint_descriptor acm_fs_notify_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,
		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_INT,
		.wMaxPacketSize = __constant_cpu_to_le16(GS_NOTIFY_MAXPACKET),
		.bInterval = 1 << GS_LOG2_NOTIFY_INTERVAL,
		};

		static struct usb_endpoint_descriptor acm_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 acm_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 *acm_fs_function[] __initdata = {
		(struct usb_descriptor_header *) &acm_control_interface_desc,
		(struct usb_descriptor_header *) &acm_header_desc,
		(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
		(struct usb_descriptor_header *) &acm_descriptor,
		(struct usb_descriptor_header *) &acm_union_desc,
		(struct usb_descriptor_header *) &acm_fs_notify_desc,
		(struct usb_descriptor_header *) &acm_data_interface_desc,
		(struct usb_descriptor_header *) &acm_fs_in_desc,
		(struct usb_descriptor_header *) &acm_fs_out_desc,
		NULL,
		};

		/* high speed support: */

		static struct usb_endpoint_descriptor acm_hs_notify_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,
		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_INT,
		.wMaxPacketSize = __constant_cpu_to_le16(GS_NOTIFY_MAXPACKET),
		.bInterval = GS_LOG2_NOTIFY_INTERVAL+4,
		};

		static struct usb_endpoint_descriptor acm_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 acm_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 *acm_hs_function[] __initdata = {
		(struct usb_descriptor_header *) &acm_control_interface_desc,
		(struct usb_descriptor_header *) &acm_header_desc,
		(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
		(struct usb_descriptor_header *) &acm_descriptor,
		(struct usb_descriptor_header *) &acm_union_desc,
		(struct usb_descriptor_header *) &acm_hs_notify_desc,
		(struct usb_descriptor_header *) &acm_data_interface_desc,
		(struct usb_descriptor_header *) &acm_hs_in_desc,
		(struct usb_descriptor_header *) &acm_hs_out_desc,
		NULL,
		};

		/* string descriptors: */

		#define ACM_CTRL_IDX 0
		#define ACM_DATA_IDX 1

		/* static strings, in UTF-8 */
		static struct usb_string acm_string_defs[] = {
		[ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
		[ACM_DATA_IDX].s = "CDC ACM Data",
		{ /* ZEROES END LIST */ },
		};

		static struct usb_gadget_strings acm_string_table = {
		.language = 0x0409, /* en-us */
		.strings = acm_string_defs,
		};

		static struct usb_gadget_strings *acm_strings[] = {
		&acm_string_table,
		NULL,
		};

		/-------------------------------------------------------------------------/

		/* ACM control ... data handling is delegated to tty library code.
		* The main task of this function is to activate and deactivate
		* that code based on device state; track parameters like line
		* speed, handshake state, and so on; and issue notifications.
		*/

		static void acm_complete_set_line_coding(struct usb_ep *ep,
		struct usb_request *req)
		{
		struct f_acm *acm = ep->driver_data;
		struct usb_composite_dev *cdev = acm->port.func.config->cdev;

		if (req->status != 0) {
		DBG(cdev, "acm ttyGS%d completion, err %d\n",
		acm->port_num, req->status);
		return;
		}

		/* normal completion */
		if (req->actual != sizeof(acm->port_line_coding)) {
		DBG(cdev, "acm ttyGS%d short resp, len %d\n",
		acm->port_num, req->actual);
		usb_ep_set_halt(ep);
		} else {
		struct usb_cdc_line_coding *value = req->buf;

		/* REVISIT: we currently just remember this data.
		* If we change that, (a) validate it first, then
		* (b) update whatever hardware needs updating,
		* (c) worry about locking. This is information on
		* the order of 9600-8-N-1 ... most of which means
		* nothing unless we control a real RS232 line.
		*/
		acm->port_line_coding = *value;
		}
		}

		static int acm_setup(struct usb_function f, const struct usb_ctrlrequest ctrl)
		{
		struct f_acm *acm = func_to_acm(f);
		struct usb_composite_dev *cdev = f->config->cdev;
		struct usb_request *req = cdev->req;
		int value = -EOPNOTSUPP;
		u16 w_index = le16_to_cpu(ctrl->wIndex);
		u16 w_value = le16_to_cpu(ctrl->wValue);
		u16 w_length = le16_to_cpu(ctrl->wLength);

		/* composite driver infrastructure handles everything except
		* CDC class messages; interface activation uses set_alt().
		*/
		switch ((ctrl->bRequestType << 8) \| ctrl->bRequest) {

		/* SET_LINE_CODING ... just read and save what the host sends */
		case ((USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE) << 8)
		\| USB_CDC_REQ_SET_LINE_CODING:
		if (w_length != sizeof(struct usb_cdc_line_coding)
		\|\| w_index != acm->ctrl_id)
		goto invalid;

		value = w_length;
		cdev->gadget->ep0->driver_data = acm;
		req->complete = acm_complete_set_line_coding;
		break;

		/* GET_LINE_CODING ... return what host sent, or initial value */
		case ((USB_DIR_IN \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE) << 8)
		\| USB_CDC_REQ_GET_LINE_CODING:
		if (w_index != acm->ctrl_id)
		goto invalid;

		value = min_t(unsigned, w_length,
		sizeof(struct usb_cdc_line_coding));
		memcpy(req->buf, &acm->port_line_coding, value);
		break;

		/* SET_CONTROL_LINE_STATE ... save what the host sent */
		case ((USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE) << 8)
		\| USB_CDC_REQ_SET_CONTROL_LINE_STATE:
		if (w_index != acm->ctrl_id)
		goto invalid;

		value = 0;

		/* FIXME we should not allow data to flow until the
		* host sets the RS232_DTR bit; and when it clears
		* that bit, we should return to that no-flow state.
		*/
		acm->port_handshake_bits = w_value;
		break;

		default:
		invalid:
		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
		ctrl->bRequestType, ctrl->bRequest,
		w_value, w_index, w_length);
		}

		/* respond with data transfer or status phase? */
		if (value >= 0) {
		DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
		acm->port_num, ctrl->bRequestType, ctrl->bRequest,
		w_value, w_index, w_length);
		req->zero = 0;
		req->length = value;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0)
		ERROR(cdev, "acm response on ttyGS%d, err %d\n",
		acm->port_num, value);
		}

		/* device either stalls (value < 0) or reports success */
		return value;
		}

		static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
		{
		struct f_acm *acm = func_to_acm(f);
		struct usb_composite_dev *cdev = f->config->cdev;

		/* we know alt == 0, so this is an activation or a reset */

		if (intf == acm->ctrl_id) {
		/* REVISIT this may need more work when we start to
		* send notifications ...
		*/
		if (acm->notify->driver_data) {
		VDBG(cdev, "reset acm control interface %d\n", intf);
		usb_ep_disable(acm->notify);
		} else {
		VDBG(cdev, "init acm ctrl interface %d\n", intf);
		acm->notify_desc = ep_choose(cdev->gadget,
		acm->hs.notify,
		acm->fs.notify);
		}
		usb_ep_enable(acm->notify, acm->notify_desc);
		acm->notify->driver_data = acm;

		} else if (intf == acm->data_id) {
		if (acm->port.in->driver_data) {
		DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
		gserial_disconnect(&acm->port);
		} else {
		DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
		acm->port.in_desc = ep_choose(cdev->gadget,
		acm->hs.in, acm->fs.in);
		acm->port.out_desc = ep_choose(cdev->gadget,
		acm->hs.out, acm->fs.out);
		}
		gserial_connect(&acm->port, acm->port_num);

		} else
		return -EINVAL;

		return 0;
		}

		static void acm_disable(struct usb_function *f)
		{
		struct f_acm *acm = func_to_acm(f);
		struct usb_composite_dev *cdev = f->config->cdev;

		DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
		gserial_disconnect(&acm->port);
		usb_ep_disable(acm->notify);
		acm->notify->driver_data = NULL;
		}

		/-------------------------------------------------------------------------/

		/* ACM function driver setup/binding */
		static int __init
		acm_bind(struct usb_configuration c, struct usb_function f)
		{
		struct usb_composite_dev *cdev = c->cdev;
		struct f_acm *acm = func_to_acm(f);
		int status;
		struct usb_ep *ep;

		/* allocate instance-specific interface IDs, and patch descriptors */
		status = usb_interface_id(c, f);
		if (status < 0)
		goto fail;
		acm->ctrl_id = status;

		acm_control_interface_desc.bInterfaceNumber = status;
		acm_union_desc .bMasterInterface0 = status;

		status = usb_interface_id(c, f);
		if (status < 0)
		goto fail;
		acm->data_id = status;

		acm_data_interface_desc.bInterfaceNumber = status;
		acm_union_desc.bSlaveInterface0 = status;
		acm_call_mgmt_descriptor.bDataInterface = status;

		status = -ENODEV;

		/* allocate instance-specific endpoints */
		ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
		if (!ep)
		goto fail;
		acm->port.in = ep;
		ep->driver_data = cdev; /* claim */

		ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
		if (!ep)
		goto fail;
		acm->port.out = ep;
		ep->driver_data = cdev; /* claim */

		ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
		if (!ep)
		goto fail;
		acm->notify = ep;
		ep->driver_data = cdev; /* claim */

		/* copy descriptors, and track endpoint copies */
		f->descriptors = usb_copy_descriptors(acm_fs_function);

		acm->fs.in = usb_find_endpoint(acm_fs_function,
		f->descriptors, &acm_fs_in_desc);
		acm->fs.out = usb_find_endpoint(acm_fs_function,
		f->descriptors, &acm_fs_out_desc);
		acm->fs.notify = usb_find_endpoint(acm_fs_function,
		f->descriptors, &acm_fs_notify_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)) {
		acm_hs_in_desc.bEndpointAddress =
		acm_fs_in_desc.bEndpointAddress;
		acm_hs_out_desc.bEndpointAddress =
		acm_fs_out_desc.bEndpointAddress;
		acm_hs_notify_desc.bEndpointAddress =
		acm_fs_notify_desc.bEndpointAddress;

		/* copy descriptors, and track endpoint copies */
		f->hs_descriptors = usb_copy_descriptors(acm_hs_function);

		acm->hs.in = usb_find_endpoint(acm_hs_function,
		f->hs_descriptors, &acm_hs_in_desc);
		acm->hs.out = usb_find_endpoint(acm_hs_function,
		f->hs_descriptors, &acm_hs_out_desc);
		acm->hs.notify = usb_find_endpoint(acm_hs_function,
		f->hs_descriptors, &acm_hs_notify_desc);
		}

		/* FIXME provide a callback for triggering notifications */

		DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
		acm->port_num,
		gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
		acm->port.in->name, acm->port.out->name,
		acm->notify->name);
		return 0;

		fail:
		/* we might as well release our claims on endpoints */
		if (acm->notify)
		acm->notify->driver_data = NULL;
		if (acm->port.out)
		acm->port.out->driver_data = NULL;
		if (acm->port.in)
		acm->port.in->driver_data = NULL;

		ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);

		return status;
		}

		static void
		acm_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_acm(f));
		}

		/* Some controllers can't support CDC ACM ... */
		static inline bool can_support_cdc(struct usb_configuration *c)
		{
		/* SH3 doesn't support multiple interfaces */
		if (gadget_is_sh(c->cdev->gadget))
		return false;

		/* sa1100 doesn't have a third interrupt endpoint */
		if (gadget_is_sa1100(c->cdev->gadget))
		return false;

		/* everything else is probably fine ... */
		return true;
		}

		/**
		* acm_bind_config - add a CDC ACM function to a configuration
		* @c: the configuration to support the CDC ACM 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 acm_bind_config(struct usb_configuration *c, u8 port_num)
		{
		struct f_acm *acm;
		int status;

		if (!can_support_cdc(c))
		return -EINVAL;

		/* REVISIT might want instance-specific strings to help
		* distinguish instances ...
		*/

		/* maybe allocate device-global string IDs, and patch descriptors */
		if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
		status = usb_string_id(c->cdev);
		if (status < 0)
		return status;
		acm_string_defs[ACM_CTRL_IDX].id = status;

		acm_control_interface_desc.iInterface = status;

		status = usb_string_id(c->cdev);
		if (status < 0)
		return status;
		acm_string_defs[ACM_DATA_IDX].id = status;

		acm_data_interface_desc.iInterface = status;
		}

		/* allocate and initialize one new instance */
		acm = kzalloc(sizeof *acm, GFP_KERNEL);
		if (!acm)
		return -ENOMEM;

		acm->port_num = port_num;

		acm->port.func.name = "acm";
		acm->port.func.strings = acm_strings;
		/* descriptors are per-instance copies */
		acm->port.func.bind = acm_bind;
		acm->port.func.unbind = acm_unbind;
		acm->port.func.set_alt = acm_set_alt;
		acm->port.func.setup = acm_setup;
		acm->port.func.disable = acm_disable;

		status = usb_add_function(c, &acm->port.func);
		if (status)
		kfree(acm);
		return status;
		}

drivers/usb/gadget/u_serial.h

+5 −5

Original line number	Diff line number	Diff line
		@@ -12,10 +12,7 @@
		#ifndef __U_SERIAL_H
		#define __U_SERIAL_H

		/* #include <linux/usb/composite.h> */
		#include <linux/usb/ch9.h>
		#include <linux/usb/gadget.h>

		#include <linux/usb/composite.h>
		#include <linux/usb/cdc.h>

		/*
		@@ -32,7 +29,7 @@
		* REVISIT someday, allow multiplexing several TTYs over these endpoints.
		*/
		struct gserial {
		/* struct usb_function func; */
		struct usb_function func;

		/* port is managed by gserial_{connect,disconnect} */
		struct gs_port *ioport;
		@@ -59,4 +56,7 @@ void gserial_cleanup(void);
		int gserial_connect(struct gserial *, u8 port_num);
		void gserial_disconnect(struct gserial *);

		/* functions are bound to configurations by a config or gadget driver */
		int acm_bind_config(struct usb_configuration *c, u8 port_num);

		#endif /* __U_SERIAL_H */

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