serial.c

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/*
 * 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/uts.h>
#include <linux/version.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;								\
})


/* Defines */

#define GS_VERSION_STR			"v1.0"
#define GS_VERSION_NUM			0x0100

#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		2

#define GS_NUM_INTERFACES		1
#define GS_INTERFACE_ID			0
#define GS_ALT_INTERFACE_ID		0

#define GS_NUM_ENDPOINTS		2

#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

/* debug settings */
#if G_SERIAL_DEBUG
static int debug = G_SERIAL_DEBUG;

#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 /* G_SERIAL_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 */


/* 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;
};

/* 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_in_ep;	/* address of in endpoint */
	struct usb_ep		*dev_out_ep;	/* address of out endpoint */
	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, int from_user,
	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 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_desc(u8 *buf, enum usb_device_speed speed,
		u8 type, unsigned int index);

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 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 char gs_tmp_buf[GS_TMP_BUF_SIZE];
static struct semaphore	gs_tmp_buf_sem;

/* 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
	.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_CONFIG_STR_ID	4

/* static strings, in iso 8859/1 */
static char manufacturer[40];
static struct usb_string gs_strings[] = {
	{ GS_MANUFACTURER_STR_ID, manufacturer },
	{ GS_PRODUCT_STR_ID, GS_LONG_NAME },
	{ GS_SERIAL_STR_ID, "0" },
	{ GS_CONFIG_STR_ID, "Bulk" },
	{  } /* 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),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
	.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 const struct usb_config_descriptor gs_config_desc = {
	.bLength =		USB_DT_CONFIG_SIZE,
	.bDescriptorType =	USB_DT_CONFIG,
	/* .wTotalLength set by gs_build_config_desc */
	.bNumInterfaces =	GS_NUM_INTERFACES,
	.bConfigurationValue =	GS_BULK_CONFIG_ID,
	.iConfiguration =	GS_CONFIG_STR_ID,
	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
	.bMaxPower =		1,
};

static const struct usb_interface_descriptor gs_interface_desc = {
	.bLength =		USB_DT_INTERFACE_SIZE,
	.bDescriptorType =	USB_DT_INTERFACE,
	.bNumEndpoints =	GS_NUM_ENDPOINTS,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.iInterface =		GS_CONFIG_STR_ID,
};

static struct usb_endpoint_descriptor gs_fullspeed_in_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor gs_fullspeed_out_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor gs_highspeed_in_desc = {
	.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 gs_highspeed_out_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16(512),
};

#ifdef CONFIG_USB_GADGET_DUALSPEED
static struct usb_qualifier_descriptor gs_qualifier_desc = {
	.bLength =		sizeof(struct usb_qualifier_descriptor),
	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
	.bcdUSB =		__constant_cpu_to_le16 (0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
	/* assumes ep0 uses the same value for both speeds ... */
	.bNumConfigurations =	GS_NUM_CONFIGS,
};
#endif


/* Module */
MODULE_DESCRIPTION(GS_LONG_NAME);
MODULE_AUTHOR("Al Borchers");
MODULE_LICENSE("GPL");

#if G_SERIAL_DEBUG
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable debugging, 0=off, 1=on, larger values for more messages");
#endif

module_param(read_q_size, int, 0);
MODULE_PARM_DESC(read_q_size, "Read request queue size, default=32");

module_param(write_q_size, int, 0);
MODULE_PARM_DESC(write_q_size, "Write request queue size, default=32");

module_param(write_buf_size, int, 0);
MODULE_PARM_DESC(write_buf_size, "Write buffer size, default=8192");

module_init(gs_module_init);
module_exit(gs_module_exit);

/*
*  gs_module_init
*
*  Register as a USB gadget driver and a tty driver.
*/
static int __init gs_module_init(void)
{
	int i;
	int retval;

	retval = usb_gadget_register_driver(&gs_gadget_driver);
	if (retval) {
		printk(KERN_ERR "gs_module_init: cannot register gadget driver, ret=%d\n", retval);
		return retval;
	}

	gs_tty_driver = alloc_tty_driver(GS_NUM_PORTS);
	if (!gs_tty_driver)
		return -ENOMEM;
	gs_tty_driver->owner = THIS_MODULE;
	gs_tty_driver->driver_name = GS_SHORT_NAME;
	gs_tty_driver->name = "ttygs";
	gs_tty_driver->devfs_name = "usb/ttygs/";
	gs_tty_driver->major = GS_MAJOR;
	gs_tty_driver->minor_start = GS_MINOR_START;
	gs_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
	gs_tty_driver->subtype = SERIAL_TYPE_NORMAL;
	gs_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
	gs_tty_driver->init_termios = tty_std_termios;
	gs_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	tty_set_operations(gs_tty_driver, &gs_tty_ops);

	for (i=0; i < GS_NUM_PORTS; i++)
		sema_init(&gs_open_close_sem[i], 1);

	sema_init(&gs_tmp_buf_sem, 1);

	retval = tty_register_driver(gs_tty_driver);
	if (retval) {
		usb_gadget_unregister_driver(&gs_gadget_driver);
		put_tty_driver(gs_tty_driver);
		printk(KERN_ERR "gs_module_init: cannot register tty driver, ret=%d\n", retval);
		return retval;
	}

	printk(KERN_INFO "gs_module_init: %s %s loaded\n", GS_LONG_NAME, GS_VERSION_STR);
	return 0;
}

/*