auerswald.c

linux-2.6.15.6

/*****************************************************************************/
/*
 *      auerswald.c  --  Auerswald PBX/System Telephone usb driver.
 *
 *      Copyright (C) 2001  Wolfgang Mües ([e-mail])
 *
 *      Very much code of this driver is borrowed from dabusb.c (Deti Fliegl)
 *      and from the USB Skeleton driver (Greg Kroah-Hartman). Thank you.
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 /*****************************************************************************/

/* Standard Linux module include files */
#include <asm/uaccess.h>
#include <asm/byteorder.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/usb.h>

/*-------------------------------------------------------------------*/
/* Debug support 						     */
#ifdef DEBUG
#define dump( adr, len) \
do {			\
	unsigned int u;	\
	printk (KERN_DEBUG); \
	for (u = 0; u < len; u++) \
		printk (" %02X", adr[u] & 0xFF); \
	printk ("\n"); \
} while (0)
#else
#define dump( adr, len)
#endif

/*-------------------------------------------------------------------*/
/* Version Information */
#define DRIVER_VERSION "0.9.11"
#define DRIVER_AUTHOR  "Wolfgang Mües <[e-mail]>"
#define DRIVER_DESC    "Auerswald PBX/System Telephone usb driver"

/*-------------------------------------------------------------------*/
/* Private declarations for Auerswald USB driver                     */

/* Auerswald Vendor ID */
#define ID_AUERSWALD  	0x09BF

#define AUER_MINOR_BASE	112	/* auerswald driver minor number */

/* we can have up to this number of device plugged in at once */
#define AUER_MAX_DEVICES 16


/* Number of read buffers for each device */
#define AU_RBUFFERS     10

/* Number of chain elements for each control chain */
#define AUCH_ELEMENTS   20

/* Number of retries in communication */
#define AU_RETRIES	10

/*-------------------------------------------------------------------*/
/* vendor specific protocol                                          */
/* Header Byte */
#define AUH_INDIRMASK   0x80    /* mask for direct/indirect bit */
#define AUH_DIRECT      0x00    /* data is for USB device */
#define AUH_INDIRECT    0x80    /* USB device is relay */

#define AUH_SPLITMASK   0x40    /* mask for split bit */
#define AUH_UNSPLIT     0x00    /* data block is full-size */
#define AUH_SPLIT       0x40    /* data block is part of a larger one,
                                   split-byte follows */

#define AUH_TYPEMASK    0x3F    /* mask for type of data transfer */
#define AUH_TYPESIZE    0x40    /* different types */
#define AUH_DCHANNEL    0x00    /* D channel data */
#define AUH_B1CHANNEL   0x01    /* B1 channel transparent */
#define AUH_B2CHANNEL   0x02    /* B2 channel transparent */
/*                0x03..0x0F       reserved for driver internal use */
#define AUH_COMMAND     0x10    /* Command channel */
#define AUH_BPROT       0x11    /* Configuration block protocol */
#define AUH_DPROTANA    0x12    /* D channel protocol analyzer */
#define AUH_TAPI        0x13    /* telephone api data (ATD) */
/*                0x14..0x3F       reserved for other protocols */
#define AUH_UNASSIGNED  0xFF    /* if char device has no assigned service */
#define AUH_FIRSTUSERCH 0x11    /* first channel which is available for driver users */

#define AUH_SIZE	1 	/* Size of Header Byte */

/* Split Byte. Only present if split bit in header byte set.*/
#define AUS_STARTMASK   0x80    /* mask for first block of splitted frame */
#define AUS_FIRST       0x80    /* first block */
#define AUS_FOLLOW      0x00    /* following block */

#define AUS_ENDMASK     0x40    /* mask for last block of splitted frame */
#define AUS_END         0x40    /* last block */
#define AUS_NOEND       0x00    /* not the last block */

#define AUS_LENMASK     0x3F    /* mask for block length information */

/* Request types */
#define AUT_RREQ        (USB_DIR_IN  | USB_TYPE_VENDOR | USB_RECIP_OTHER)   /* Read Request */
#define AUT_WREQ        (USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER)   /* Write Request */

/* Vendor Requests */
#define AUV_GETINFO     0x00    /* GetDeviceInfo */
#define AUV_WBLOCK      0x01    /* Write Block */
#define AUV_RBLOCK      0x02    /* Read Block */
#define AUV_CHANNELCTL  0x03    /* Channel Control */
#define AUV_DUMMY	0x04	/* Dummy Out for retry */

/* Device Info Types */
#define AUDI_NUMBCH     0x0000  /* Number of supported B channels */
#define AUDI_OUTFSIZE   0x0001  /* Size of OUT B channel fifos */
#define AUDI_MBCTRANS   0x0002  /* max. Blocklength of control transfer */

/* Interrupt endpoint definitions */
#define AU_IRQENDP      1       /* Endpoint number */
#define AU_IRQCMDID     16      /* Command-block ID */
#define AU_BLOCKRDY     0       /* Command: Block data ready on ctl endpoint */
#define AU_IRQMINSIZE	5	/* Nr. of bytes decoded in this driver */

/* Device String Descriptors */
#define AUSI_VENDOR   	1	/* "Auerswald GmbH & Co. KG" */
#define AUSI_DEVICE   	2	/* Name of the Device */
#define AUSI_SERIALNR 	3	/* Serial Number */
#define AUSI_MSN      	4	/* "MSN ..." (first) Multiple Subscriber Number */

#define AUSI_DLEN	100	/* Max. Length of Device Description */

#define AUV_RETRY	0x101	/* First Firmware version which can do control retries */

/*-------------------------------------------------------------------*/
/* External data structures / Interface                              */
typedef struct
{
	char __user *buf;	/* return buffer for string contents */
	unsigned int bsize;	/* size of return buffer */
} audevinfo_t,*paudevinfo_t;

/* IO controls */
#define IOCTL_AU_SLEN	  _IOR( 'U', 0xF0, int)         /* return the max. string descriptor length */
#define IOCTL_AU_DEVINFO  _IOWR('U', 0xF1, audevinfo_t) /* get name of a specific device */
#define IOCTL_AU_SERVREQ  _IOW( 'U', 0xF2, int) 	/* request a service channel */
#define IOCTL_AU_BUFLEN	  _IOR( 'U', 0xF3, int)         /* return the max. buffer length for the device */
#define IOCTL_AU_RXAVAIL  _IOR( 'U', 0xF4, int)         /* return != 0 if Receive Data available */
#define IOCTL_AU_CONNECT  _IOR( 'U', 0xF5, int)         /* return != 0 if connected to a service channel */
#define IOCTL_AU_TXREADY  _IOR( 'U', 0xF6, int)         /* return != 0 if Transmitt channel ready to send */
/*                              'U'  0xF7..0xFF reseved */

/*-------------------------------------------------------------------*/
/* Internal data structures                                          */

/* ..................................................................*/
/* urb chain element */
struct  auerchain;                      /* forward for circular reference */
typedef struct
{
        struct auerchain *chain;        /* pointer to the chain to which this element belongs */
        struct urb * urbp;                   /* pointer to attached urb */
        void *context;                  /* saved URB context */
        usb_complete_t complete;        /* saved URB completion function */
        struct list_head list;          /* to include element into a list */
} auerchainelement_t,*pauerchainelement_t;

/* urb chain */
typedef struct auerchain
{
        pauerchainelement_t active;     /* element which is submitted to urb */
	spinlock_t lock;                /* protection agains interrupts */
        struct list_head waiting_list;  /* list of waiting elements */
        struct list_head free_list;     /* list of available elements */
} auerchain_t,*pauerchain_t;

/* urb blocking completion helper struct */
typedef struct
{
	wait_queue_head_t wqh;    	/* wait for completion */
	unsigned int done;		/* completion flag */
} auerchain_chs_t,*pauerchain_chs_t;

/* ...................................................................*/
/* buffer element */
struct  auerbufctl;                     /* forward */
typedef struct
{
        char *bufp;                     /* reference to allocated data buffer */
        unsigned int len;               /* number of characters in data buffer */
	unsigned int retries;		/* for urb retries */
        struct usb_ctrlrequest *dr;	/* for setup data in control messages */
        struct urb * urbp;                   /* USB urb */
        struct auerbufctl *list;        /* pointer to list */
        struct list_head buff_list;     /* reference to next buffer in list */
} auerbuf_t,*pauerbuf_t;

/* buffer list control block */
typedef struct auerbufctl
{
        spinlock_t lock;                /* protection in interrupt */
        struct list_head free_buff_list;/* free buffers */
        struct list_head rec_buff_list; /* buffers with receive data */
} auerbufctl_t,*pauerbufctl_t;

/* ...................................................................*/
/* service context */
struct  auerscon;                       /* forward */
typedef void (*auer_dispatch_t)(struct auerscon*, pauerbuf_t);
typedef void (*auer_disconn_t) (struct auerscon*);
typedef struct auerscon
{
        unsigned int id;                /* protocol service id AUH_xxxx */
        auer_dispatch_t dispatch;       /* dispatch read buffer */
	auer_disconn_t disconnect;	/* disconnect from device, wake up all char readers */
} auerscon_t,*pauerscon_t;

/* ...................................................................*/
/* USB device context */
typedef struct
{
	struct semaphore 	mutex;         	    /* protection in user context */
	char 			name[20];	    /* name of the /dev/usb entry */
	unsigned int		dtindex;	    /* index in the device table */
	struct usb_device *	usbdev;      	    /* USB device handle */
	int			open_count;	    /* count the number of open character channels */
        char 			dev_desc[AUSI_DLEN];/* for storing a textual description */
        unsigned int 		maxControlLength;   /* max. Length of control paket (without header) */
        struct urb * 		inturbp;            /* interrupt urb */
        char *			intbufp;            /* data buffer for interrupt urb */
	unsigned int 		irqsize;	    /* size of interrupt endpoint 1 */
        struct auerchain 	controlchain;  	    /* for chaining of control messages */
	auerbufctl_t 		bufctl;             /* Buffer control for control transfers */
        pauerscon_t 	     	services[AUH_TYPESIZE];/* context pointers for each service */
	unsigned int		version;	    /* Version of the device */
	wait_queue_head_t 	bufferwait;         /* wait for a control buffer */
} auerswald_t,*pauerswald_t;

/* ................................................................... */
/* character device context */
typedef struct
{
	struct semaphore mutex;         /* protection in user context */
	pauerswald_t auerdev;           /* context pointer of assigned device */
        auerbufctl_t bufctl;            /* controls the buffer chain */
        auerscon_t scontext;            /* service context */
	wait_queue_head_t readwait;     /* for synchronous reading */
	struct semaphore readmutex;     /* protection against multiple reads */
	pauerbuf_t readbuf;		/* buffer held for partial reading */
	unsigned int readoffset;	/* current offset in readbuf */
	unsigned int removed;		/* is != 0 if device is removed */
} auerchar_t,*pauerchar_t;


/*-------------------------------------------------------------------*/
/* Forwards */
static void auerswald_ctrlread_complete (struct urb * urb, struct pt_regs *regs);
static void auerswald_removeservice (pauerswald_t cp, pauerscon_t scp);
static struct usb_driver auerswald_driver;


/*-------------------------------------------------------------------*/
/* USB chain helper functions                                        */
/* --------------------------                                        */

/* completion function for chained urbs */
static void auerchain_complete (struct urb * urb, struct pt_regs *regs)
{
	unsigned long flags;
        int result;

        /* get pointer to element and to chain */
        pauerchainelement_t acep = (pauerchainelement_t) urb->context;
        pauerchain_t         acp = acep->chain;

        /* restore original entries in urb */
        urb->context  = acep->context;
        urb->complete = acep->complete;

        dbg ("auerchain_complete called");

        /* call original completion function
           NOTE: this function may lead to more urbs submitted into the chain.
                 (no chain lock at calling complete()!)
                 acp->active != NULL is protecting us against recursion.*/
        urb->complete (urb, regs);

        /* detach element from chain data structure */
	spin_lock_irqsave (&acp->lock, flags);
        if (acp->active != acep) /* paranoia debug check */
	        dbg ("auerchain_complete: completion on non-active element called!");
        else
                acp->active = NULL;

        /* add the used chain element to the list of free elements */
	list_add_tail (&acep->list, &acp->free_list);
        acep = NULL;

        /* is there a new element waiting in the chain? */
        if (!acp->active && !list_empty (&acp->waiting_list)) {
                /* yes: get the entry */
                struct list_head *tmp = acp->waiting_list.next;
                list_del (tmp);
                acep = list_entry (tmp, auerchainelement_t, list);
                acp->active = acep;
        }
        spin_unlock_irqrestore (&acp->lock, flags);

        /* submit the new urb */
        if (acep) {
                urb    = acep->urbp;
                dbg ("auerchain_complete: submitting next urb from chain");
		urb->status = 0;	/* needed! */
		result = usb_submit_urb(urb, GFP_ATOMIC);

                /* check for submit errors */
                if (result) {
                        urb->status = result;
                        dbg("auerchain_complete: usb_submit_urb with error code %d", result);
                        /* and do error handling via *this* completion function (recursive) */
                        auerchain_complete( urb, NULL);
                }
        } else {
                /* simple return without submitting a new urb.
                   The empty chain is detected with acp->active == NULL. */
        };
}


/* submit function for chained urbs
   this function may be called from completion context or from user space!
   early = 1 -> submit in front of chain
*/
static int auerchain_submit_urb_list (pauerchain_t acp, struct urb * urb, int early)
{
        int result;
        unsigned long flags;
        pauerchainelement_t acep = NULL;

        dbg ("auerchain_submit_urb called");

        /* try to get a chain element */
        spin_lock_irqsave (&acp->lock, flags);
        if (!list_empty (&acp->free_list)) {
                /* yes: get the entry */
                struct list_head *tmp = acp->free_list.next;
                list_del (tmp);
                acep = list_entry (tmp, auerchainelement_t, list);
        }
        spin_unlock_irqrestore (&acp->lock, flags);

        /* if no chain element available: return with error */
        if (!acep) {
                return -ENOMEM;
        }

        /* fill in the new chain element values */
        acep->chain    = acp;
        acep->context  = urb->context;
        acep->complete = urb->complete;
        acep->urbp     = urb;
        INIT_LIST_HEAD (&acep->list);

        /* modify urb */
        urb->context   = acep;
        urb->complete  = auerchain_complete;
        urb->status    = -EINPROGRESS;    /* usb_submit_urb does this, too */

        /* add element to chain - or start it immediately */
        spin_lock_irqsave (&acp->lock, flags);
        if (acp->active) {
                /* there is traffic in the chain, simple add element to chain */
		if (early) {
			dbg ("adding new urb to head of chain");
			list_add (&acep->list, &acp->waiting_list);
		} else {
			dbg ("adding new urb to end of chain");
			list_add_tail (&acep->list, &acp->waiting_list);
		}
		acep = NULL;
        } else {
                /* the chain is empty. Prepare restart */
                acp->active = acep;
        }
        /* Spin has to be removed before usb_submit_urb! */
        spin_unlock_irqrestore (&acp->lock, flags);

        /* Submit urb if immediate restart */
        if (acep) {
                dbg("submitting urb immediate");