usb-char.c
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上传日期:2013-02-24
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- /*
- * (C) Copyright 2000-2001 Extenex Corporation
- *
- * 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.
- *
- * usb-char.c
- *
- * Miscellaneous character device interface for SA1100 USB function
- * driver.
- *
- * Background:
- * The SA1100 function driver ported from the Compaq Itsy project
- * has an interface, usb-eth.c, to feed network packets over the
- * usb wire and into the Linux TCP/IP stack.
- *
- * This file replaces that one with a simple character device
- * interface that allows unstructured "byte pipe" style reads and
- * writes over the USB bulk endpoints by userspace programs.
- *
- * A new define, CONFIG_SA1100_USB_NETLINK, has been created that,
- * when set, (the default) causes the ethernet interface to be used.
- * When not set, this more pedestrian character interface is linked
- * in instead.
- *
- * Please see linux/Documentation/arm/SA1100/SA1100_USB for details.
- *
- * ward.willats@extenex.com
- *
- * To do:
- * - Can't dma into ring buffer directly with pci_map/unmap usb_recv
- * uses and get bytes out at the same time DMA is going on. Investigate:
- * a) changing usb_recv to use alloc_consistent() at client request; or
- * b) non-ring-buffer based data structures. In the meantime, I am using
- * a bounce buffer. Simple, but wasteful.
- */
- #include <linux/module.h>
- #include <linux/config.h>
- #include <linux/miscdevice.h>
- #include <linux/slab.h>
- #include <linux/init.h>
- #include <linux/cache.h>
- #include <linux/poll.h>
- #include <linux/circ_buf.h>
- #include <linux/timer.h>
- #include <asm/io.h>
- #include <asm/semaphore.h>
- #include <asm/proc/page.h>
- #include <asm/mach-types.h>
- #include "usb-char.h"
- #include "pxa_usb.h"
- //////////////////////////////////////////////////////////////////////////////
- // Driver Options
- //////////////////////////////////////////////////////////////////////////////
- #define VERSION "0.4"
- #define VERBOSITY 1
- #if VERBOSITY
- # define PRINTK(x, a...) printk (x, ## a)
- #else
- # define PRINTK(x, a...) /**/
- #endif
- //////////////////////////////////////////////////////////////////////////////
- // Globals - Macros - Enums - Structures
- //////////////////////////////////////////////////////////////////////////////
- #ifndef MIN
- #define MIN( a, b ) ((a)<(b)?(a):(b))
- #endif
- typedef int bool; enum { false = 0, true = 1 };
- static const char pszMe[] = "usbchr: ";
- static wait_queue_head_t wq_read;
- static wait_queue_head_t wq_write;
- static wait_queue_head_t wq_poll;
- /* Serialze multiple writers onto the transmit hardware
- .. since we sleep the writer during transmit to stay in
- .. sync. (Multiple writers don't make much sense, but..) */
- static DECLARE_MUTEX( xmit_sem );
- // size of usb DATA0/1 packets. 64 is standard maximum
- // for bulk transport, though most hosts seem to be able
- // to handle larger.
- #define TX_PACKET_SIZE 64
- #define RX_PACKET_SIZE 64
- #define RBUF_SIZE (4*PAGE_SIZE)
- static struct wcirc_buf {
- char *buf;
- int in;
- int out;
- } rx_ring = { NULL, 0, 0 };
- static struct {
- unsigned long cnt_rx_complete;
- unsigned long cnt_rx_errors;
- unsigned long bytes_rx;
- unsigned long cnt_tx_timeouts;
- unsigned long cnt_tx_errors;
- unsigned long bytes_tx;
- } charstats;
- static char * tx_buf = NULL;
- static char * packet_buffer = NULL;
- static int sending = 0;
- static int usb_ref_count = 0;
- static int last_tx_result = 0;
- static int last_rx_result = 0;
- static int last_tx_size = 0;
- static struct timer_list tx_timer;
- //////////////////////////////////////////////////////////////////////////////
- // Prototypes
- //////////////////////////////////////////////////////////////////////////////
- static char * what_the_f( int e );
- static void free_txrx_buffers( void );
- static void twiddle_descriptors( void );
- static void free_string_descriptors( void ) ;
- static int usbc_open( struct inode *pInode, struct file *pFile );
- static void rx_done_callback_packet_buffer( int flag, int size );
- static void tx_timeout( unsigned long );
- static void tx_done_callback( int flag, int size );
- static ssize_t usbc_read( struct file *, char *, size_t, loff_t * );
- static ssize_t usbc_write( struct file *, const char *, size_t, loff_t * );
- static unsigned int usbc_poll( struct file *pFile, poll_table * pWait );
- static int usbc_ioctl( struct inode *pInode, struct file *pFile,
- unsigned int nCmd, unsigned long argument );
- static int usbc_close( struct inode *pInode, struct file *pFile );
- #ifdef CONFIG_SA1100_EXTENEX1
- static void extenex_configured_notify_proc( void );
- #endif
- //////////////////////////////////////////////////////////////////////////////
- // Private Helpers
- //////////////////////////////////////////////////////////////////////////////
- static char * what_the_f( int e )
- {
- char * p;
- switch( e ) {
- case 0:
- p = "noErr";
- break;
- case -ENODEV:
- p = "ENODEV - usb not in config state";
- break;
- case -EBUSY:
- p = "EBUSY - another request on the hardware";
- break;
- case -EAGAIN:
- p = "EAGAIN";
- break;
- case -EINTR:
- p = "EINTR - interruptedn";
- break;
- case -EPIPE:
- p = "EPIPE - zero length xfern";
- break;
- default:
- p = "????";
- break;
- }
- return p;
- }
- static void free_txrx_buffers( void )
- {
- if ( rx_ring.buf != NULL ) {
- kfree( rx_ring.buf );
- rx_ring.buf = NULL;
- }
- if ( packet_buffer != NULL ) {
- kfree( packet_buffer );
- packet_buffer = NULL;
- }
- if ( tx_buf != NULL ) {
- kfree( tx_buf );
- tx_buf = NULL;
- }
- }
- /* twiddle_descriptors()
- * It is between open() and start(). Setup descriptors.
- */
- static void twiddle_descriptors( void )
- {
- desc_t * pDesc = pxa_usb_get_descriptor_ptr();
- string_desc_t * pString;
- pDesc->b.ep1.wMaxPacketSize = make_word_c( RX_PACKET_SIZE );
- pDesc->b.ep1.bmAttributes = USB_EP_BULK;
- pDesc->b.ep2.wMaxPacketSize = make_word_c( TX_PACKET_SIZE );
- pDesc->b.ep2.bmAttributes = USB_EP_BULK;
- if ( machine_is_extenex1() ) {
- #ifdef CONFIG_SA1100_EXTENEX1
- pDesc->dev.idVendor = make_word_c( 0xC9F );
- pDesc->dev.idProduct = 1;
- pDesc->dev.bcdDevice = make_word_c( 0x0001 );
- pDesc->b.cfg.bmAttributes = USB_CONFIG_SELFPOWERED;
- pDesc->b.cfg.MaxPower = 0;
- pString = pxa_usb_kmalloc_string_descriptor( "Extenex" );
- if ( pString ) {
- pxa_usb_set_string_descriptor( 1, pString );
- pDesc->dev.iManufacturer = 1;
- }
- pString = pxa_usb_kmalloc_string_descriptor( "Handheld Theater" );
- if ( pString ) {
- pxa_usb_set_string_descriptor( 2, pString );
- pDesc->dev.iProduct = 2;
- }
- pString = pxa_usb_kmalloc_string_descriptor( "00000000" );
- if ( pString ) {
- pxa_usb_set_string_descriptor( 3, pString );
- pDesc->dev.iSerialNumber = 3;
- }
- pString = pxa_usb_kmalloc_string_descriptor( "HHT Bulk Transfer" );
- if ( pString ) {
- pxa_usb_set_string_descriptor( 4, pString );
- pDesc->b.intf.iInterface = 4;
- }
- pxa_set_configured_callback( extenex_configured_notify_proc );
- #endif
- }
- }
- static void free_string_descriptors( void )
- {
- if ( machine_is_extenex1() ) {
- string_desc_t * pString;
- int i;
- for( i = 1 ; i <= 4 ; i++ ) {
- pString = pxa_usb_get_string_descriptor( i );
- if ( pString )
- kfree( pString );
- }
- }
- }
- //////////////////////////////////////////////////////////////////////////////
- // ASYNCHRONOUS
- //////////////////////////////////////////////////////////////////////////////
- static void kick_start_rx( void )
- {
- if ( usb_ref_count ) {
- int total_space = CIRC_SPACE( rx_ring.in, rx_ring.out, RBUF_SIZE );
- if ( total_space >= RX_PACKET_SIZE ) {
- pxa_usb_recv( packet_buffer,
- RX_PACKET_SIZE,
- rx_done_callback_packet_buffer
- );
- }
- }
- }
- /*
- * rx_done_callback_packet_buffer()
- * We have completed a DMA xfer into the temp packet buffer.
- * Move to ring.
- *
- * flag values:
- * on init, -EAGAIN
- * on reset, -EINTR
- * on RPE, -EIO
- * on short packet -EPIPE
- */
- static void
- rx_done_callback_packet_buffer( int flag, int size )
- {
- charstats.cnt_rx_complete++;
- if ( flag == 0 || flag == -EPIPE ) {
- size_t n;
- charstats.bytes_rx += size;
- n = CIRC_SPACE_TO_END( rx_ring.in, rx_ring.out, RBUF_SIZE );
- n = MIN( n, size );
- size -= n;
- memcpy( &rx_ring.buf[ rx_ring.in ], packet_buffer, n );
- rx_ring.in = (rx_ring.in + n) & (RBUF_SIZE-1);
- memcpy( &rx_ring.buf[ rx_ring.in ], packet_buffer + n, size );
- rx_ring.in = (rx_ring.in + size) & (RBUF_SIZE-1);
- wake_up_interruptible( &wq_read );
- wake_up_interruptible( &wq_poll );
- last_rx_result = 0;
- kick_start_rx();
- } else if ( flag != -EAGAIN ) {
- charstats.cnt_rx_errors++;
- last_rx_result = flag;
- wake_up_interruptible( &wq_read );
- wake_up_interruptible( &wq_poll );
- }
- else /* init, start a read */
- kick_start_rx();
- }
- static void tx_timeout( unsigned long unused )
- {
- printk( "%stx timeoutn", pszMe );
- pxa_usb_send_reset();
- charstats.cnt_tx_timeouts++;
- }
- // on init, -EAGAIN
- // on reset, -EINTR
- // on TPE, -EIO
- static void tx_done_callback( int flags, int size )
- {
- if ( flags == 0 )
- charstats.bytes_tx += size;
- else
- charstats.cnt_tx_errors++;
- last_tx_size = size;
- last_tx_result = flags;
- sending = 0;
- wake_up_interruptible( &wq_write );
- wake_up_interruptible( &wq_poll );
- }
- //////////////////////////////////////////////////////////////////////////////
- // Workers
- //////////////////////////////////////////////////////////////////////////////
- static int usbc_open( struct inode *pInode, struct file *pFile )
- {
- int retval = 0;
- PRINTK( KERN_DEBUG "%sopen()n", pszMe );
- /* start usb core */
- retval = pxa_usb_open( "usb-char" );
- if ( retval ) return retval;
- /* allocate memory */
- if ( usb_ref_count == 0 ) {
- tx_buf = (char*) kmalloc( TX_PACKET_SIZE, GFP_KERNEL | GFP_DMA );
- if ( tx_buf == NULL ) {
- printk( "%sARGHH! COULD NOT ALLOCATE TX BUFFERn", pszMe );
- goto malloc_fail;
- }
- rx_ring.buf =
- (char*) kmalloc( RBUF_SIZE, GFP_KERNEL );
- if ( rx_ring.buf == NULL ) {
- printk( "%sARGHH! COULD NOT ALLOCATE RX BUFFERn", pszMe );
- goto malloc_fail;
- }
- packet_buffer =
- (char*) kmalloc( RX_PACKET_SIZE, GFP_KERNEL | GFP_DMA );
- if ( packet_buffer == NULL ) {
- printk( "%sARGHH! COULD NOT ALLOCATE RX PACKET BUFFERn", pszMe );
- goto malloc_fail;
- }
- rx_ring.in = rx_ring.out = 0;
- memset( &charstats, 0, sizeof( charstats ) );
- sending = 0;
- last_tx_result = 0;
- last_tx_size = 0;
- }
- /* modify default descriptors */
- twiddle_descriptors();
- retval = pxa_usb_start();
- if ( retval ) {
- printk( "%sAGHH! Could not USB coren", pszMe );
- free_txrx_buffers();
- return retval;
- }
- usb_ref_count++; /* must do _before_ kick_start() */
- MOD_INC_USE_COUNT;
- kick_start_rx();
- return 0;
- malloc_fail:
- free_txrx_buffers();
- return -ENOMEM;
- }
- /*
- * Read endpoint. Note that you can issue a read to an
- * unconfigured endpoint. Eventually, the host may come along
- * and configure underneath this module and data will appear.
- */
- static ssize_t usbc_read( struct file *pFile, char *pUserBuffer,
- size_t stCount, loff_t *pPos )
- {
- ssize_t retval;
- int flags;
- DECLARE_WAITQUEUE( wait, current );
- PRINTK( KERN_DEBUG "%sread()n", pszMe );
- local_irq_save( flags );
- if ( last_rx_result == 0 ) {
- local_irq_restore( flags );
- } else { /* an error happended and receiver is paused */
- local_irq_restore( flags );
- last_rx_result = 0;
- kick_start_rx();
- }
- add_wait_queue( &wq_read, &wait );
- while( 1 ) {
- ssize_t bytes_avail;
- ssize_t bytes_to_end;
- set_current_state( TASK_INTERRUPTIBLE );
- /* snap ring buf state */
- local_irq_save( flags );
- bytes_avail = CIRC_CNT( rx_ring.in, rx_ring.out, RBUF_SIZE );
- bytes_to_end = CIRC_CNT_TO_END( rx_ring.in, rx_ring.out, RBUF_SIZE );
- local_irq_restore( flags );
- if ( bytes_avail != 0 ) {
- ssize_t bytes_to_move = MIN( stCount, bytes_avail );
- retval = 0; // will be bytes transfered
- if ( bytes_to_move != 0 ) {
- size_t n = MIN( bytes_to_end, bytes_to_move );
- if ( copy_to_user( pUserBuffer,
- &rx_ring.buf[ rx_ring.out ],
- n ) ) {
- retval = -EFAULT;
- break;
- }
- bytes_to_move -= n;
- retval += n;
- // might go 1 char off end, so wrap
- rx_ring.out = ( rx_ring.out + n ) & (RBUF_SIZE-1);
- if ( copy_to_user( pUserBuffer + n,
- &rx_ring.buf[ rx_ring.out ],
- bytes_to_move )
- ) {
- retval = -EFAULT;
- break;
- }
- rx_ring.out += bytes_to_move; // cannot wrap
- retval += bytes_to_move;
- kick_start_rx();
- }
- break;
- }
- else if ( last_rx_result ) {
- retval = last_rx_result;
- break;
- }
- else if ( pFile->f_flags & O_NONBLOCK ) { // no data, can't sleep
- retval = -EAGAIN;
- break;
- }
- else if ( signal_pending( current ) ) { // no data, can sleep, but signal
- retval = -ERESTARTSYS;
- break;
- }
- schedule(); // no data, can sleep
- }
- set_current_state( TASK_RUNNING );
- remove_wait_queue( &wq_read, &wait );
- if ( retval < 0 )
- printk( "%sread error %d - %sn", pszMe, retval, what_the_f( retval ) );
- return retval;
- }
- /*
- * Write endpoint. This routine attempts to break the passed in buffer
- * into usb DATA0/1 packet size chunks and send them to the host.
- * (The lower-level driver tries to do this too, but easier for us
- * to manage things here.)
- *
- * We are at the mercy of the host here, in that it must send an IN
- * token to us to pull this data back, so hopefully some higher level
- * protocol is expecting traffic to flow in that direction so the host
- * is actually polling us. To guard against hangs, a 5 second timeout
- * is used.
- *
- * This routine takes some care to only report bytes sent that have
- * actually made it across the wire. Thus we try to stay in lockstep
- * with the completion routine and only have one packet on the xmit
- * hardware at a time. Multiple simultaneous writers will get
- * "undefined" results.
- *
- */
- static ssize_t usbc_write( struct file *pFile, const char * pUserBuffer,
- size_t stCount, loff_t *pPos )
- {
- ssize_t retval = 0;
- ssize_t stSent = 0;
- DECLARE_WAITQUEUE( wait, current );
- PRINTK( KERN_DEBUG "%swrite() %d bytesn", pszMe, stCount );
- down( &xmit_sem ); // only one thread onto the hardware at a time
- while( stCount != 0 && retval == 0 ) {
- int nThisTime = MIN( TX_PACKET_SIZE, stCount );
- copy_from_user( tx_buf, pUserBuffer, nThisTime );
- sending = nThisTime;
- retval = pxa_usb_send( tx_buf, nThisTime, tx_done_callback );
- if ( retval < 0 ) {
- char * p = what_the_f( retval );
- printk( "%sCould not queue xmission. rc=%d - %sn",
- pszMe, retval, p );
- sending = 0;
- break;
- }
- /* now have something on the diving board */
- add_wait_queue( &wq_write, &wait );
- tx_timer.expires = jiffies + ( HZ * 5 );
- add_timer( &tx_timer );
- while( 1 ) {
- set_current_state( TASK_INTERRUPTIBLE );
- if ( sending == 0 ) { /* it jumped into the pool */
- del_timer( &tx_timer );
- retval = last_tx_result;
- if ( retval == 0 ) {
- stSent += last_tx_size;
- pUserBuffer += last_tx_size;
- stCount -= last_tx_size;
- }
- else
- printk( "%sxmission error rc=%d - %sn",
- pszMe, retval, what_the_f(retval) );
- break;
- }
- else if ( signal_pending( current ) ) {
- del_timer( &tx_timer );
- printk( "%ssignaln", pszMe );
- retval = -ERESTARTSYS;
- break;
- }
- schedule();
- }
- set_current_state( TASK_RUNNING );
- remove_wait_queue( &wq_write, &wait );
- }
- up( &xmit_sem );
- if ( 0 == retval )
- retval = stSent;
- return retval;
- }
- static unsigned int usbc_poll( struct file *pFile, poll_table * pWait )
- {
- unsigned int retval = 0;
- PRINTK( KERN_DEBUG "%poll()n", pszMe );
- poll_wait( pFile, &wq_poll, pWait );
- if ( CIRC_CNT( rx_ring.in, rx_ring.out, RBUF_SIZE ) )
- retval |= POLLIN | POLLRDNORM;
- if ( pxa_usb_xmitter_avail() )
- retval |= POLLOUT | POLLWRNORM;
- return retval;
- }
- static int usbc_ioctl( struct inode *pInode, struct file *pFile,
- unsigned int nCmd, unsigned long argument )
- {
- int retval = 0;
- switch( nCmd ) {
- case USBC_IOC_FLUSH_RECEIVER:
- pxa_usb_recv_reset();
- rx_ring.in = rx_ring.out = 0;
- break;
- case USBC_IOC_FLUSH_TRANSMITTER:
- pxa_usb_send_reset();
- break;
- case USBC_IOC_FLUSH_ALL:
- pxa_usb_recv_reset();
- rx_ring.in = rx_ring.out = 0;
- pxa_usb_send_reset();
- break;
- default:
- retval = -ENOIOCTLCMD;
- break;
- }
- return retval;
- }
- static int usbc_close( struct inode *pInode, struct file * pFile )
- {
- PRINTK( KERN_DEBUG "%sclose()n", pszMe );
- if ( --usb_ref_count == 0 ) {
- down( &xmit_sem );
- pxa_usb_stop();
- free_txrx_buffers();
- free_string_descriptors();
- del_timer( &tx_timer );
- pxa_usb_close();
- up( &xmit_sem );
- }
- MOD_DEC_USE_COUNT;
- return 0;
- }
- #ifdef CONFIG_SA1100_EXTENEX1
- #include "../../../drivers/char/ex_gpio.h"
- void extenex_configured_notify_proc( void )
- {
- if ( exgpio_play_string( "440,1:698,1" ) == -EAGAIN )
- printk( "%sWanted to BEEP but ex_gpio not openn", pszMe );
- }
- #endif
- //////////////////////////////////////////////////////////////////////////////
- // Initialization
- //////////////////////////////////////////////////////////////////////////////
- static struct file_operations usbc_fops = {
- owner: THIS_MODULE,
- open: usbc_open,
- read: usbc_read,
- write: usbc_write,
- poll: usbc_poll,
- ioctl: usbc_ioctl,
- release: usbc_close,
- };
- static struct miscdevice usbc_misc_device = {
- USBC_MINOR, "usb_char", &usbc_fops
- };
- /*
- * usbc_init()
- */
- int __init usbc_init( void )
- {
- int rc;
- if ( (rc = misc_register( &usbc_misc_device )) != 0 ) {
- printk( KERN_WARNING "%sCould not register device 10, "
- "%d. (%d)n", pszMe, USBC_MINOR, rc );
- return -EBUSY;
- }
- // initialize wait queues
- init_waitqueue_head( &wq_read );
- init_waitqueue_head( &wq_write );
- init_waitqueue_head( &wq_poll );
- // initialize tx timeout timer
- init_timer( &tx_timer );
- tx_timer.function = tx_timeout;
- printk( KERN_INFO "USB Function Character Driver Interface"
- " - %s, (C) 2001, Extenex Corp.n", VERSION
- );
- return rc;
- }
- void __exit usbc_exit( void )
- {
- }
- EXPORT_NO_SYMBOLS;
- module_init(usbc_init);
- module_exit(usbc_exit);
- // end: usb-char.c