serial.c

h内核

/*
 * g_serial.c -- USB gadget serial driver
 *
 * Copyright 2003 (C) Al Borchers ([e-mail])
 *
 * This code is based in part on the Gadget Zero driver, which
 * is Copyright (C) 2003 by David Brownell, all rights reserved.
 *
 * This code also borrows from usbserial.c, which is
 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman ([e-mail])
 * Copyright (C) 2000 Peter Berger ([e-mail])
 * Copyright (C) 2000 Al Borchers ([e-mail])
 *
 * 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/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/utsname.h>
#include <linux/wait.h>
#include <linux/proc_fs.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>
#include <asm/uaccess.h>

#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>

#include "gadget_chips.h"


/* Wait Cond */

#define __wait_cond_interruptible(wq, condition, lock, flags, ret)	\
do {									\
	wait_queue_t __wait;						\
	init_waitqueue_entry(&__wait, current);				\
									\
	add_wait_queue(&wq, &__wait);					\
	for (;;) {							\
		set_current_state(TASK_INTERRUPTIBLE);			\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			spin_unlock_irqrestore(lock, flags);		\
			schedule();					\
			spin_lock_irqsave(lock, flags);			\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	current->state = TASK_RUNNING;					\
	remove_wait_queue(&wq, &__wait);				\
} while (0)
	
#define wait_cond_interruptible(wq, condition, lock, flags)		\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_cond_interruptible(wq, condition, lock, flags,	\
						__ret);			\
	__ret;								\
})

#define __wait_cond_interruptible_timeout(wq, condition, lock, flags, 	\
						timeout, ret)		\
do {									\
	signed long __timeout = timeout;				\
	wait_queue_t __wait;						\
	init_waitqueue_entry(&__wait, current);				\
									\
	add_wait_queue(&wq, &__wait);					\
	for (;;) {							\
		set_current_state(TASK_INTERRUPTIBLE);			\
		if (__timeout == 0)					\
			break;						\
		if (condition)						\
			break;						\
		if (!signal_pending(current)) {				\
			spin_unlock_irqrestore(lock, flags);		\
			__timeout = schedule_timeout(__timeout);	\
			spin_lock_irqsave(lock, flags);			\
			continue;					\
		}							\
		ret = -ERESTARTSYS;					\
		break;							\
	}								\
	current->state = TASK_RUNNING;					\
	remove_wait_queue(&wq, &__wait);				\
} while (0)
	
#define wait_cond_interruptible_timeout(wq, condition, lock, flags,	\
						timeout)		\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__wait_cond_interruptible_timeout(wq, condition, lock,	\
						flags, timeout, __ret);	\
	__ret;								\
})


/* CDC-ACM Defines and Structures */

#define USB_CDC_SUBCLASS_ACM			2

#define USB_CDC_CTRL_PROTO_NONE			0
#define USB_CDC_CTRL_PROTO_AT			1
#define USB_CDC_CTRL_PROTO_VENDOR		0xff

#define USB_CDC_SUBTYPE_HEADER			0
#define USB_CDC_SUBTYPE_CALL_MGMT		1
#define USB_CDC_SUBTYPE_ACM			2
#define USB_CDC_SUBTYPE_UNION			6

#define USB_CDC_CALL_MGMT_CAP_CALL_MGMT		0x01
#define USB_CDC_CALL_MGMT_CAP_DATA_INTF		0x02

#define USB_CDC_REQ_SET_LINE_CODING		0x20
#define USB_CDC_REQ_GET_LINE_CODING		0x21
#define USB_CDC_REQ_SET_CONTROL_LINE_STATE	0x22

#define USB_CDC_1_STOP_BITS			0
#define USB_CDC_1_5_STOP_BITS			1
#define USB_CDC_2_STOP_BITS			2

#define USB_CDC_NO_PARITY			0
#define USB_CDC_ODD_PARITY			1
#define USB_CDC_EVEN_PARITY			2
#define USB_CDC_MARK_PARITY			3
#define USB_CDC_SPACE_PARITY			4

/* Header Functional Descriptor from CDC spec 5.2.3.1 */
struct usb_cdc_header_desc {
	u8	bLength;
	u8	bDescriptorType;
	u8	bDescriptorSubType;
	u16	bcdCDC;
} __attribute__ ((packed));

/* Call Management Descriptor from CDC spec 5.2.3.3 */
struct usb_cdc_call_mgmt_desc {
	u8  bLength;
	u8  bDescriptorType;
	u8  bDescriptorSubType;
	u8  bmCapabilities;
	u8  bDataInterface;
} __attribute__ ((packed));

/* Abstract Control Management Descriptor from CDC spec 5.2.3.4 */
struct usb_cdc_acm_desc {
	u8  bLength;
	u8  bDescriptorType;
	u8  bDescriptorSubType;
	u8  bmCapabilities;
} __attribute__ ((packed));

/* Union Functional Descriptor from CDC spec 5.2.3.8 */
struct usb_cdc_union_desc {
	u8	bLength;
	u8	bDescriptorType;
	u8	bDescriptorSubType;
	u8	bMasterInterface0;
	u8	bSlaveInterface0;
	/* ... and there could be other slave interfaces */
} __attribute__ ((packed));

/* Line Coding Structure from CDC spec 6.2.13 */
struct usb_cdc_line_coding {
	u32 dwDTERate;
	u8 bCharFormat;
	u8 bParityType;
	u8 bDataBits;
} __attribute__ ((packed));


/* Defines */

#define GS_VERSION_STR			"v2.0"
#define GS_VERSION_NUM			0x0200

#define GS_LONG_NAME			"Gadget Serial"
#define GS_SHORT_NAME			"g_serial"

#define GS_MAJOR			127
#define GS_MINOR_START			0

#define GS_NUM_PORTS			16

#define GS_NUM_CONFIGS			1
#define GS_NO_CONFIG_ID			0
#define GS_BULK_CONFIG_ID		1
#define GS_ACM_CONFIG_ID		2

#define GS_MAX_NUM_INTERFACES		2
#define GS_BULK_INTERFACE_ID		0
#define GS_CONTROL_INTERFACE_ID		0
#define GS_DATA_INTERFACE_ID		1

#define GS_MAX_DESC_LEN			256

#define GS_DEFAULT_READ_Q_SIZE		32
#define GS_DEFAULT_WRITE_Q_SIZE		32

#define GS_DEFAULT_WRITE_BUF_SIZE	8192
#define GS_TMP_BUF_SIZE			8192

#define GS_CLOSE_TIMEOUT		15

#define GS_DEFAULT_USE_ACM		0

#define GS_DEFAULT_DTE_RATE		9600
#define GS_DEFAULT_DATA_BITS		8
#define GS_DEFAULT_PARITY		USB_CDC_NO_PARITY
#define GS_DEFAULT_CHAR_FORMAT		USB_CDC_1_STOP_BITS

/* select highspeed/fullspeed, hiding highspeed if not configured */
#ifdef CONFIG_USB_GADGET_DUALSPEED
#define GS_SPEED_SELECT(is_hs,hs,fs) ((is_hs) ? (hs) : (fs))
#else
#define GS_SPEED_SELECT(is_hs,hs,fs) (fs)
#endif /* CONFIG_USB_GADGET_DUALSPEED */

/* debug settings */
#ifdef GS_DEBUG
static int debug = 1;

#define gs_debug(format, arg...) \
	do { if (debug) printk(KERN_DEBUG format, ## arg); } while(0)
#define gs_debug_level(level, format, arg...) \
	do { if (debug>=level) printk(KERN_DEBUG format, ## arg); } while(0)

#else

#define gs_debug(format, arg...) \
	do { } while(0)
#define gs_debug_level(level, format, arg...) \
	do { } while(0)

#endif /* GS_DEBUG */

/* 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_LOG2_NOTIFY_INTERVAL		5	/* 1 << 5 == 32 msec */
#define GS_NOTIFY_MAXPACKET		8


/* Structures */

struct gs_dev;

/* circular buffer */
struct gs_buf {
	unsigned int		buf_size;
	char			*buf_buf;
	char			*buf_get;
	char			*buf_put;
};

/* list of requests */
struct gs_req_entry {
	struct list_head	re_entry;
	struct usb_request	*re_req;
};

/* the port structure holds info for each port, one for each minor number */
struct gs_port {
	struct gs_dev 		*port_dev;	/* pointer to device struct */
	struct tty_struct	*port_tty;	/* pointer to tty struct */
	spinlock_t		port_lock;
	int 			port_num;
	int			port_open_count;
	int			port_in_use;	/* open/close in progress */
	wait_queue_head_t	port_write_wait;/* waiting to write */
	struct gs_buf		*port_write_buf;
	struct usb_cdc_line_coding	port_line_coding;
};

/* the device structure holds info for the USB device */
struct gs_dev {
	struct usb_gadget	*dev_gadget;	/* gadget device pointer */
	spinlock_t		dev_lock;	/* lock for set/reset config */
	int			dev_config;	/* configuration number */
	struct usb_ep		*dev_notify_ep;	/* address of notify endpoint */
	struct usb_ep		*dev_in_ep;	/* address of in endpoint */
	struct usb_ep		*dev_out_ep;	/* address of out endpoint */
	struct usb_endpoint_descriptor		/* desciptor of notify ep */
				*dev_notify_ep_desc;
	struct usb_endpoint_descriptor		/* descriptor of in endpoint */
				*dev_in_ep_desc;
	struct usb_endpoint_descriptor		/* descriptor of out endpoint */
				*dev_out_ep_desc;
	struct usb_request	*dev_ctrl_req;	/* control request */
	struct list_head	dev_req_list;	/* list of write requests */
	int			dev_sched_port;	/* round robin port scheduled */
	struct gs_port		*dev_port[GS_NUM_PORTS]; /* the ports */
};


/* Functions */

/* module */
static int __init gs_module_init(void);
static void __exit gs_module_exit(void);

/* tty driver */
static int gs_open(struct tty_struct *tty, struct file *file);
static void gs_close(struct tty_struct *tty, struct file *file);
static int gs_write(struct tty_struct *tty, 
	const unsigned char *buf, int count);
static void gs_put_char(struct tty_struct *tty, unsigned char ch);
static void gs_flush_chars(struct tty_struct *tty);
static int gs_write_room(struct tty_struct *tty);
static int gs_chars_in_buffer(struct tty_struct *tty);
static void gs_throttle(struct tty_struct * tty);
static void gs_unthrottle(struct tty_struct * tty);
static void gs_break(struct tty_struct *tty, int break_state);
static int  gs_ioctl(struct tty_struct *tty, struct file *file,
	unsigned int cmd, unsigned long arg);
static void gs_set_termios(struct tty_struct *tty, struct termios *old);

static int gs_send(struct gs_dev *dev);
static int gs_send_packet(struct gs_dev *dev, char *packet,
	unsigned int size);
static int gs_recv_packet(struct gs_dev *dev, char *packet,
	unsigned int size);
static void gs_read_complete(struct usb_ep *ep, struct usb_request *req);
static void gs_write_complete(struct usb_ep *ep, struct usb_request *req);

/* gadget driver */
static int gs_bind(struct usb_gadget *gadget);
static void gs_unbind(struct usb_gadget *gadget);
static int gs_setup(struct usb_gadget *gadget,
	const struct usb_ctrlrequest *ctrl);
static int gs_setup_standard(struct usb_gadget *gadget,
	const struct usb_ctrlrequest *ctrl);
static int gs_setup_class(struct usb_gadget *gadget,
	const struct usb_ctrlrequest *ctrl);
static void gs_setup_complete(struct usb_ep *ep, struct usb_request *req);
static void gs_disconnect(struct usb_gadget *gadget);
static int gs_set_config(struct gs_dev *dev, unsigned config);
static void gs_reset_config(struct gs_dev *dev);
static int gs_build_config_buf(u8 *buf, enum usb_device_speed speed,
		u8 type, unsigned int index, int is_otg);

static struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned int len,
	int kmalloc_flags);
static void gs_free_req(struct usb_ep *ep, struct usb_request *req);

static struct gs_req_entry *gs_alloc_req_entry(struct usb_ep *ep, unsigned len,
	int kmalloc_flags);
static void gs_free_req_entry(struct usb_ep *ep, struct gs_req_entry *req);

static int gs_alloc_ports(struct gs_dev *dev, int kmalloc_flags);
static void gs_free_ports(struct gs_dev *dev);

/* circular buffer */
static struct gs_buf *gs_buf_alloc(unsigned int size, int kmalloc_flags);
static void gs_buf_free(struct gs_buf *gb);
static void gs_buf_clear(struct gs_buf *gb);
static unsigned int gs_buf_data_avail(struct gs_buf *gb);
static unsigned int gs_buf_space_avail(struct gs_buf *gb);
static unsigned int gs_buf_put(struct gs_buf *gb, const char *buf,
	unsigned int count);
static unsigned int gs_buf_get(struct gs_buf *gb, char *buf,
	unsigned int count);

/* external functions */
extern int net2280_set_fifo_mode(struct usb_gadget *gadget, int mode);


/* Globals */

static struct gs_dev *gs_device;

static const char *EP_IN_NAME;
static const char *EP_OUT_NAME;
static const char *EP_NOTIFY_NAME;

static struct semaphore	gs_open_close_sem[GS_NUM_PORTS];

static unsigned int read_q_size = GS_DEFAULT_READ_Q_SIZE;
static unsigned int write_q_size = GS_DEFAULT_WRITE_Q_SIZE;

static unsigned int write_buf_size = GS_DEFAULT_WRITE_BUF_SIZE;

static unsigned int use_acm = GS_DEFAULT_USE_ACM;


/* tty driver struct */
static struct tty_operations gs_tty_ops = {
	.open =			gs_open,
	.close =		gs_close,
	.write =		gs_write,
	.put_char =		gs_put_char,
	.flush_chars =		gs_flush_chars,
	.write_room =		gs_write_room,
	.ioctl =		gs_ioctl,
	.set_termios =		gs_set_termios,
	.throttle =		gs_throttle,
	.unthrottle =		gs_unthrottle,
	.break_ctl =		gs_break,
	.chars_in_buffer =	gs_chars_in_buffer,
};
static struct tty_driver *gs_tty_driver;

/* gadget driver struct */
static struct usb_gadget_driver gs_gadget_driver = {
#ifdef CONFIG_USB_GADGET_DUALSPEED
	.speed =		USB_SPEED_HIGH,
#else
	.speed =		USB_SPEED_FULL,
#endif /* CONFIG_USB_GADGET_DUALSPEED */
	.function =		GS_LONG_NAME,
	.bind =			gs_bind,
	.unbind =		gs_unbind,
	.setup =		gs_setup,
	.disconnect =		gs_disconnect,
	.driver = {
		.name =		GS_SHORT_NAME,
		/* .shutdown = ... */
		/* .suspend = ...  */
		/* .resume = ...   */
	},
};


/* USB descriptors */

#define GS_MANUFACTURER_STR_ID	1
#define GS_PRODUCT_STR_ID	2
#define GS_SERIAL_STR_ID	3
#define GS_BULK_CONFIG_STR_ID	4
#define GS_ACM_CONFIG_STR_ID	5
#define GS_CONTROL_STR_ID	6
#define GS_DATA_STR_ID		7

/* static strings, in UTF-8 */
static char manufacturer[50];
static struct usb_string gs_strings[] = {
	{ GS_MANUFACTURER_STR_ID, manufacturer },
	{ GS_PRODUCT_STR_ID, GS_LONG_NAME },
	{ GS_SERIAL_STR_ID, "0" },
	{ GS_BULK_CONFIG_STR_ID, "Gadget Serial Bulk" },
	{ GS_ACM_CONFIG_STR_ID, "Gadget Serial CDC ACM" },
	{ GS_CONTROL_STR_ID, "Gadget Serial Control" },
	{ GS_DATA_STR_ID, "Gadget Serial Data" },
	{  } /* end of list */
};

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

static struct usb_device_descriptor gs_device_desc = {
	.bLength =		USB_DT_DEVICE_SIZE,
	.bDescriptorType =	USB_DT_DEVICE,
	.bcdUSB =		__constant_cpu_to_le16(0x0200),
	.bDeviceSubClass =	0,
	.bDeviceProtocol =	0,
	.idVendor =		__constant_cpu_to_le16(GS_VENDOR_ID),
	.idProduct =		__constant_cpu_to_le16(GS_PRODUCT_ID),
	.iManufacturer =	GS_MANUFACTURER_STR_ID,
	.iProduct =		GS_PRODUCT_STR_ID,
	.iSerialNumber =	GS_SERIAL_STR_ID,
	.bNumConfigurations =	GS_NUM_CONFIGS,
};

static struct usb_otg_descriptor gs_otg_descriptor = {