| /* r3964 linediscipline for linux |
| * |
| * ----------------------------------------------------------- |
| * Copyright by |
| * Philips Automation Projects |
| * Kassel (Germany) |
| * http://www.pap-philips.de |
| * ----------------------------------------------------------- |
| * This software may be used and distributed according to the terms of |
| * the GNU General Public License, incorporated herein by reference. |
| * |
| * Author: |
| * L. Haag |
| * |
| * $Log: n_r3964.c,v $ |
| * Revision 1.10 2001/03/18 13:02:24 dwmw2 |
| * Fix timer usage, use spinlocks properly. |
| * |
| * Revision 1.9 2001/03/18 12:52:14 dwmw2 |
| * Merge changes in 2.4.2 |
| * |
| * Revision 1.8 2000/03/23 14:14:54 dwmw2 |
| * Fix race in sleeping in r3964_read() |
| * |
| * Revision 1.7 1999/28/08 11:41:50 dwmw2 |
| * Port to 2.3 kernel |
| * |
| * Revision 1.6 1998/09/30 00:40:40 dwmw2 |
| * Fixed compilation on 2.0.x kernels |
| * Updated to newly registered tty-ldisc number 9 |
| * |
| * Revision 1.5 1998/09/04 21:57:36 dwmw2 |
| * Signal handling bug fixes, port to 2.1.x. |
| * |
| * Revision 1.4 1998/04/02 20:26:59 lhaag |
| * select, blocking, ... |
| * |
| * Revision 1.3 1998/02/12 18:58:43 root |
| * fixed some memory leaks |
| * calculation of checksum characters |
| * |
| * Revision 1.2 1998/02/07 13:03:34 root |
| * ioctl read_telegram |
| * |
| * Revision 1.1 1998/02/06 19:21:03 root |
| * Initial revision |
| * |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/interrupt.h> |
| #include <linux/ptrace.h> |
| #include <linux/ioport.h> |
| #include <linux/in.h> |
| #include <linux/slab.h> |
| #include <linux/tty.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> /* used in new tty drivers */ |
| #include <linux/signal.h> /* used in new tty drivers */ |
| #include <linux/ioctl.h> |
| #include <linux/n_r3964.h> |
| #include <linux/poll.h> |
| #include <linux/init.h> |
| #include <asm/uaccess.h> |
| |
| |
| //#define DEBUG_QUEUE |
| |
| /* Log successful handshake and protocol operations */ |
| //#define DEBUG_PROTO_S |
| |
| /* Log handshake and protocol errors: */ |
| //#define DEBUG_PROTO_E |
| |
| /* Log Linediscipline operations (open, close, read, write...): */ |
| //#define DEBUG_LDISC |
| |
| /* Log module and memory operations (init, cleanup; kmalloc, kfree): */ |
| //#define DEBUG_MODUL |
| |
| /* Macro helpers for debug output: */ |
| #define TRACE(format, args...) printk("r3964: " format "\n" , ## args); |
| |
| #ifdef DEBUG_MODUL |
| #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args); |
| #else |
| #define TRACE_M(fmt, arg...) /**/ |
| #endif |
| |
| #ifdef DEBUG_PROTO_S |
| #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args); |
| #else |
| #define TRACE_PS(fmt, arg...) /**/ |
| #endif |
| |
| #ifdef DEBUG_PROTO_E |
| #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args); |
| #else |
| #define TRACE_PE(fmt, arg...) /**/ |
| #endif |
| |
| #ifdef DEBUG_LDISC |
| #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args); |
| #else |
| #define TRACE_L(fmt, arg...) /**/ |
| #endif |
| |
| #ifdef DEBUG_QUEUE |
| #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args); |
| #else |
| #define TRACE_Q(fmt, arg...) /**/ |
| #endif |
| |
| static void add_tx_queue(struct r3964_info *, struct r3964_block_header *); |
| static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code); |
| static void put_char(struct r3964_info *pInfo, unsigned char ch); |
| static void trigger_transmit(struct r3964_info *pInfo); |
| static void retry_transmit(struct r3964_info *pInfo); |
| static void transmit_block(struct r3964_info *pInfo); |
| static void receive_char(struct r3964_info *pInfo, const unsigned char c); |
| static void receive_error(struct r3964_info *pInfo, const char flag); |
| static void on_timeout(unsigned long priv); |
| static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg); |
| static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf); |
| static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg, |
| int error_code, struct r3964_block_header *pBlock); |
| static struct r3964_message* remove_msg(struct r3964_info *pInfo, |
| struct r3964_client_info *pClient); |
| static void remove_client_block(struct r3964_info *pInfo, |
| struct r3964_client_info *pClient); |
| |
| static int r3964_open(struct tty_struct *tty); |
| static void r3964_close(struct tty_struct *tty); |
| static ssize_t r3964_read(struct tty_struct *tty, struct file *file, |
| unsigned char __user *buf, size_t nr); |
| static ssize_t r3964_write(struct tty_struct * tty, struct file * file, |
| const unsigned char * buf, size_t nr); |
| static int r3964_ioctl(struct tty_struct * tty, struct file * file, |
| unsigned int cmd, unsigned long arg); |
| static void r3964_set_termios(struct tty_struct *tty, struct termios * old); |
| static unsigned int r3964_poll(struct tty_struct * tty, struct file * file, |
| struct poll_table_struct *wait); |
| static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| char *fp, int count); |
| static int r3964_receive_room(struct tty_struct *tty); |
| |
| static struct tty_ldisc tty_ldisc_N_R3964 = { |
| .owner = THIS_MODULE, |
| .magic = TTY_LDISC_MAGIC, |
| .name = "R3964", |
| .open = r3964_open, |
| .close = r3964_close, |
| .read = r3964_read, |
| .write = r3964_write, |
| .ioctl = r3964_ioctl, |
| .set_termios = r3964_set_termios, |
| .poll = r3964_poll, |
| .receive_buf = r3964_receive_buf, |
| .receive_room = r3964_receive_room, |
| }; |
| |
| |
| |
| static void dump_block(const unsigned char *block, unsigned int length) |
| { |
| unsigned int i,j; |
| char linebuf[16*3+1]; |
| |
| for(i=0;i<length;i+=16) |
| { |
| for(j=0;(j<16) && (j+i<length);j++) |
| { |
| sprintf(linebuf+3*j,"%02x ",block[i+j]); |
| } |
| linebuf[3*j]='\0'; |
| TRACE_PS("%s",linebuf); |
| } |
| } |
| |
| |
| |
| |
| /************************************************************* |
| * Driver initialisation |
| *************************************************************/ |
| |
| |
| /************************************************************* |
| * Module support routines |
| *************************************************************/ |
| |
| static void __exit r3964_exit(void) |
| { |
| int status; |
| |
| TRACE_M ("cleanup_module()"); |
| |
| status=tty_unregister_ldisc(N_R3964); |
| |
| if(status!=0) |
| { |
| printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status); |
| } |
| else |
| { |
| TRACE_L("linediscipline successfully unregistered"); |
| } |
| |
| } |
| |
| static int __init r3964_init(void) |
| { |
| int status; |
| |
| printk ("r3964: Philips r3964 Driver $Revision: 1.10 $\n"); |
| |
| /* |
| * Register the tty line discipline |
| */ |
| |
| status = tty_register_ldisc (N_R3964, &tty_ldisc_N_R3964); |
| if (status == 0) |
| { |
| TRACE_L("line discipline %d registered", N_R3964); |
| TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags, |
| tty_ldisc_N_R3964.num); |
| TRACE_L("open=%p", tty_ldisc_N_R3964.open); |
| TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964); |
| } |
| else |
| { |
| printk (KERN_ERR "r3964: error registering line discipline: %d\n", status); |
| } |
| return status; |
| } |
| |
| module_init(r3964_init); |
| module_exit(r3964_exit); |
| |
| |
| /************************************************************* |
| * Protocol implementation routines |
| *************************************************************/ |
| |
| static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&pInfo->lock, flags); |
| |
| pHeader->next = NULL; |
| |
| if(pInfo->tx_last == NULL) |
| { |
| pInfo->tx_first = pInfo->tx_last = pHeader; |
| } |
| else |
| { |
| pInfo->tx_last->next = pHeader; |
| pInfo->tx_last = pHeader; |
| } |
| |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| TRACE_Q("add_tx_queue %p, length %d, tx_first = %p", |
| pHeader, pHeader->length, pInfo->tx_first ); |
| } |
| |
| static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code) |
| { |
| struct r3964_block_header *pHeader; |
| unsigned long flags; |
| #ifdef DEBUG_QUEUE |
| struct r3964_block_header *pDump; |
| #endif |
| |
| pHeader = pInfo->tx_first; |
| |
| if(pHeader==NULL) |
| return; |
| |
| #ifdef DEBUG_QUEUE |
| printk("r3964: remove_from_tx_queue: %p, length %u - ", |
| pHeader, pHeader->length ); |
| for(pDump=pHeader;pDump;pDump=pDump->next) |
| printk("%p ", pDump); |
| printk("\n"); |
| #endif |
| |
| |
| if(pHeader->owner) |
| { |
| if(error_code) |
| { |
| add_msg(pHeader->owner, R3964_MSG_ACK, 0, |
| error_code, NULL); |
| } |
| else |
| { |
| add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length, |
| error_code, NULL); |
| } |
| wake_up_interruptible (&pInfo->read_wait); |
| } |
| |
| spin_lock_irqsave(&pInfo->lock, flags); |
| |
| pInfo->tx_first = pHeader->next; |
| if(pInfo->tx_first==NULL) |
| { |
| pInfo->tx_last = NULL; |
| } |
| |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| kfree(pHeader); |
| TRACE_M("remove_from_tx_queue - kfree %p",pHeader); |
| |
| TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p", |
| pInfo->tx_first, pInfo->tx_last ); |
| } |
| |
| static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&pInfo->lock, flags); |
| |
| pHeader->next = NULL; |
| |
| if(pInfo->rx_last == NULL) |
| { |
| pInfo->rx_first = pInfo->rx_last = pHeader; |
| } |
| else |
| { |
| pInfo->rx_last->next = pHeader; |
| pInfo->rx_last = pHeader; |
| } |
| pInfo->blocks_in_rx_queue++; |
| |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d", |
| pHeader, pHeader->length, |
| pInfo->rx_first, pInfo->blocks_in_rx_queue); |
| } |
| |
| static void remove_from_rx_queue(struct r3964_info *pInfo, |
| struct r3964_block_header *pHeader) |
| { |
| unsigned long flags; |
| struct r3964_block_header *pFind; |
| |
| if(pHeader==NULL) |
| return; |
| |
| TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d", |
| pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue ); |
| TRACE_Q("remove_from_rx_queue: %p, length %u", |
| pHeader, pHeader->length ); |
| |
| spin_lock_irqsave(&pInfo->lock, flags); |
| |
| if(pInfo->rx_first == pHeader) |
| { |
| /* Remove the first block in the linked list: */ |
| pInfo->rx_first = pHeader->next; |
| |
| if(pInfo->rx_first==NULL) |
| { |
| pInfo->rx_last = NULL; |
| } |
| pInfo->blocks_in_rx_queue--; |
| } |
| else |
| { |
| /* Find block to remove: */ |
| for(pFind=pInfo->rx_first; pFind; pFind=pFind->next) |
| { |
| if(pFind->next == pHeader) |
| { |
| /* Got it. */ |
| pFind->next = pHeader->next; |
| pInfo->blocks_in_rx_queue--; |
| if(pFind->next==NULL) |
| { |
| /* Oh, removed the last one! */ |
| pInfo->rx_last = pFind; |
| } |
| break; |
| } |
| } |
| } |
| |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| kfree(pHeader); |
| TRACE_M("remove_from_rx_queue - kfree %p",pHeader); |
| |
| TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d", |
| pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue ); |
| } |
| |
| static void put_char(struct r3964_info *pInfo, unsigned char ch) |
| { |
| struct tty_struct *tty = pInfo->tty; |
| |
| if(tty==NULL) |
| return; |
| |
| if(tty->driver->put_char) |
| { |
| tty->driver->put_char(tty, ch); |
| } |
| pInfo->bcc ^= ch; |
| } |
| |
| static void flush(struct r3964_info *pInfo) |
| { |
| struct tty_struct *tty = pInfo->tty; |
| |
| if(tty==NULL) |
| return; |
| |
| if(tty->driver->flush_chars) |
| { |
| tty->driver->flush_chars(tty); |
| } |
| } |
| |
| static void trigger_transmit(struct r3964_info *pInfo) |
| { |
| unsigned long flags; |
| |
| |
| spin_lock_irqsave(&pInfo->lock, flags); |
| |
| if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL)) |
| { |
| pInfo->state = R3964_TX_REQUEST; |
| pInfo->nRetry=0; |
| pInfo->flags &= ~R3964_ERROR; |
| mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ); |
| |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| TRACE_PS("trigger_transmit - sent STX"); |
| |
| put_char(pInfo, STX); |
| flush(pInfo); |
| |
| pInfo->bcc = 0; |
| } |
| else |
| { |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| } |
| } |
| |
| static void retry_transmit(struct r3964_info *pInfo) |
| { |
| if(pInfo->nRetry<R3964_MAX_RETRIES) |
| { |
| TRACE_PE("transmission failed. Retry #%d", |
| pInfo->nRetry); |
| pInfo->bcc = 0; |
| put_char(pInfo, STX); |
| flush(pInfo); |
| pInfo->state = R3964_TX_REQUEST; |
| pInfo->nRetry++; |
| mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ); |
| } |
| else |
| { |
| TRACE_PE("transmission failed after %d retries", |
| R3964_MAX_RETRIES); |
| |
| remove_from_tx_queue(pInfo, R3964_TX_FAIL); |
| |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| pInfo->state = R3964_IDLE; |
| |
| trigger_transmit(pInfo); |
| } |
| } |
| |
| |
| static void transmit_block(struct r3964_info *pInfo) |
| { |
| struct tty_struct *tty = pInfo->tty; |
| struct r3964_block_header *pBlock = pInfo->tx_first; |
| int room=0; |
| |
| if((tty==NULL) || (pBlock==NULL)) |
| { |
| return; |
| } |
| |
| if(tty->driver->write_room) |
| room=tty->driver->write_room(tty); |
| |
| TRACE_PS("transmit_block %p, room %d, length %d", |
| pBlock, room, pBlock->length); |
| |
| while(pInfo->tx_position < pBlock->length) |
| { |
| if(room<2) |
| break; |
| |
| if(pBlock->data[pInfo->tx_position]==DLE) |
| { |
| /* send additional DLE char: */ |
| put_char(pInfo, DLE); |
| } |
| put_char(pInfo, pBlock->data[pInfo->tx_position++]); |
| |
| room--; |
| } |
| |
| if((pInfo->tx_position == pBlock->length) && (room>=3)) |
| { |
| put_char(pInfo, DLE); |
| put_char(pInfo, ETX); |
| if(pInfo->flags & R3964_BCC) |
| { |
| put_char(pInfo, pInfo->bcc); |
| } |
| pInfo->state = R3964_WAIT_FOR_TX_ACK; |
| mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ); |
| } |
| flush(pInfo); |
| } |
| |
| static void on_receive_block(struct r3964_info *pInfo) |
| { |
| unsigned int length; |
| struct r3964_client_info *pClient; |
| struct r3964_block_header *pBlock; |
| |
| length=pInfo->rx_position; |
| |
| /* compare byte checksum characters: */ |
| if(pInfo->flags & R3964_BCC) |
| { |
| if(pInfo->bcc!=pInfo->last_rx) |
| { |
| TRACE_PE("checksum error - got %x but expected %x", |
| pInfo->last_rx, pInfo->bcc); |
| pInfo->flags |= R3964_CHECKSUM; |
| } |
| } |
| |
| /* check for errors (parity, overrun,...): */ |
| if(pInfo->flags & R3964_ERROR) |
| { |
| TRACE_PE("on_receive_block - transmission failed error %x", |
| pInfo->flags & R3964_ERROR); |
| |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| if(pInfo->nRetry<R3964_MAX_RETRIES) |
| { |
| pInfo->state=R3964_WAIT_FOR_RX_REPEAT; |
| pInfo->nRetry++; |
| mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC); |
| } |
| else |
| { |
| TRACE_PE("on_receive_block - failed after max retries"); |
| pInfo->state=R3964_IDLE; |
| } |
| return; |
| } |
| |
| |
| /* received block; submit DLE: */ |
| put_char(pInfo, DLE); |
| flush(pInfo); |
| del_timer_sync(&pInfo->tmr); |
| TRACE_PS(" rx success: got %d chars", length); |
| |
| /* prepare struct r3964_block_header: */ |
| pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL); |
| TRACE_M("on_receive_block - kmalloc %p",pBlock); |
| |
| if(pBlock==NULL) |
| return; |
| |
| pBlock->length = length; |
| pBlock->data = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header); |
| pBlock->locks = 0; |
| pBlock->next = NULL; |
| pBlock->owner = NULL; |
| |
| memcpy(pBlock->data, pInfo->rx_buf, length); |
| |
| /* queue block into rx_queue: */ |
| add_rx_queue(pInfo, pBlock); |
| |
| /* notify attached client processes: */ |
| for(pClient=pInfo->firstClient; pClient; pClient=pClient->next) |
| { |
| if(pClient->sig_flags & R3964_SIG_DATA) |
| { |
| add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock); |
| } |
| } |
| wake_up_interruptible (&pInfo->read_wait); |
| |
| pInfo->state = R3964_IDLE; |
| |
| trigger_transmit(pInfo); |
| } |
| |
| |
| static void receive_char(struct r3964_info *pInfo, const unsigned char c) |
| { |
| switch(pInfo->state) |
| { |
| case R3964_TX_REQUEST: |
| if(c==DLE) |
| { |
| TRACE_PS("TX_REQUEST - got DLE"); |
| |
| pInfo->state = R3964_TRANSMITTING; |
| pInfo->tx_position = 0; |
| |
| transmit_block(pInfo); |
| } |
| else if(c==STX) |
| { |
| if(pInfo->nRetry==0) |
| { |
| TRACE_PE("TX_REQUEST - init conflict"); |
| if(pInfo->priority == R3964_SLAVE) |
| { |
| goto start_receiving; |
| } |
| } |
| else |
| { |
| TRACE_PE("TX_REQUEST - secondary init conflict!?" |
| " Switching to SLAVE mode for next rx."); |
| goto start_receiving; |
| } |
| } |
| else |
| { |
| TRACE_PE("TX_REQUEST - char != DLE: %x", c); |
| retry_transmit(pInfo); |
| } |
| break; |
| case R3964_TRANSMITTING: |
| if(c==NAK) |
| { |
| TRACE_PE("TRANSMITTING - got NAK"); |
| retry_transmit(pInfo); |
| } |
| else |
| { |
| TRACE_PE("TRANSMITTING - got invalid char"); |
| |
| pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY; |
| mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ); |
| } |
| break; |
| case R3964_WAIT_FOR_TX_ACK: |
| if(c==DLE) |
| { |
| TRACE_PS("WAIT_FOR_TX_ACK - got DLE"); |
| remove_from_tx_queue(pInfo, R3964_OK); |
| |
| pInfo->state = R3964_IDLE; |
| trigger_transmit(pInfo); |
| } |
| else |
| { |
| retry_transmit(pInfo); |
| } |
| break; |
| case R3964_WAIT_FOR_RX_REPEAT: |
| /* FALLTROUGH */ |
| case R3964_IDLE: |
| if(c==STX) |
| { |
| /* Prevent rx_queue from overflow: */ |
| if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE) |
| { |
| TRACE_PE("IDLE - got STX but no space in rx_queue!"); |
| pInfo->state=R3964_WAIT_FOR_RX_BUF; |
| mod_timer(&pInfo->tmr, R3964_TO_NO_BUF); |
| break; |
| } |
| start_receiving: |
| /* Ok, start receiving: */ |
| TRACE_PS("IDLE - got STX"); |
| pInfo->rx_position = 0; |
| pInfo->last_rx = 0; |
| pInfo->flags &= ~R3964_ERROR; |
| pInfo->state=R3964_RECEIVING; |
| mod_timer(&pInfo->tmr, R3964_TO_ZVZ); |
| pInfo->nRetry = 0; |
| put_char(pInfo, DLE); |
| flush(pInfo); |
| pInfo->bcc = 0; |
| } |
| break; |
| case R3964_RECEIVING: |
| if(pInfo->rx_position < RX_BUF_SIZE) |
| { |
| pInfo->bcc ^= c; |
| |
| if(c==DLE) |
| { |
| if(pInfo->last_rx==DLE) |
| { |
| pInfo->last_rx = 0; |
| goto char_to_buf; |
| } |
| pInfo->last_rx = DLE; |
| break; |
| } |
| else if((c==ETX) && (pInfo->last_rx==DLE)) |
| { |
| if(pInfo->flags & R3964_BCC) |
| { |
| pInfo->state = R3964_WAIT_FOR_BCC; |
| mod_timer(&pInfo->tmr, R3964_TO_ZVZ); |
| } |
| else |
| { |
| on_receive_block(pInfo); |
| } |
| } |
| else |
| { |
| pInfo->last_rx = c; |
| char_to_buf: |
| pInfo->rx_buf[pInfo->rx_position++] = c; |
| mod_timer(&pInfo->tmr, R3964_TO_ZVZ); |
| } |
| } |
| /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */ |
| break; |
| case R3964_WAIT_FOR_BCC: |
| pInfo->last_rx = c; |
| on_receive_block(pInfo); |
| break; |
| } |
| } |
| |
| static void receive_error(struct r3964_info *pInfo, const char flag) |
| { |
| switch (flag) |
| { |
| case TTY_NORMAL: |
| break; |
| case TTY_BREAK: |
| TRACE_PE("received break") |
| pInfo->flags |= R3964_BREAK; |
| break; |
| case TTY_PARITY: |
| TRACE_PE("parity error") |
| pInfo->flags |= R3964_PARITY; |
| break; |
| case TTY_FRAME: |
| TRACE_PE("frame error") |
| pInfo->flags |= R3964_FRAME; |
| break; |
| case TTY_OVERRUN: |
| TRACE_PE("frame overrun") |
| pInfo->flags |= R3964_OVERRUN; |
| break; |
| default: |
| TRACE_PE("receive_error - unknown flag %d", flag); |
| pInfo->flags |= R3964_UNKNOWN; |
| break; |
| } |
| } |
| |
| static void on_timeout(unsigned long priv) |
| { |
| struct r3964_info *pInfo = (void *)priv; |
| |
| switch(pInfo->state) |
| { |
| case R3964_TX_REQUEST: |
| TRACE_PE("TX_REQUEST - timeout"); |
| retry_transmit(pInfo); |
| break; |
| case R3964_WAIT_ZVZ_BEFORE_TX_RETRY: |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| retry_transmit(pInfo); |
| break; |
| case R3964_WAIT_FOR_TX_ACK: |
| TRACE_PE("WAIT_FOR_TX_ACK - timeout"); |
| retry_transmit(pInfo); |
| break; |
| case R3964_WAIT_FOR_RX_BUF: |
| TRACE_PE("WAIT_FOR_RX_BUF - timeout"); |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| pInfo->state=R3964_IDLE; |
| break; |
| case R3964_RECEIVING: |
| TRACE_PE("RECEIVING - timeout after %d chars", |
| pInfo->rx_position); |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| pInfo->state=R3964_IDLE; |
| break; |
| case R3964_WAIT_FOR_RX_REPEAT: |
| TRACE_PE("WAIT_FOR_RX_REPEAT - timeout"); |
| pInfo->state=R3964_IDLE; |
| break; |
| case R3964_WAIT_FOR_BCC: |
| TRACE_PE("WAIT_FOR_BCC - timeout"); |
| put_char(pInfo, NAK); |
| flush(pInfo); |
| pInfo->state=R3964_IDLE; |
| break; |
| } |
| } |
| |
| static struct r3964_client_info *findClient( |
| struct r3964_info *pInfo, pid_t pid) |
| { |
| struct r3964_client_info *pClient; |
| |
| for(pClient=pInfo->firstClient; pClient; pClient=pClient->next) |
| { |
| if(pClient->pid == pid) |
| { |
| return pClient; |
| } |
| } |
| return NULL; |
| } |
| |
| static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg) |
| { |
| struct r3964_client_info *pClient; |
| struct r3964_client_info **ppClient; |
| struct r3964_message *pMsg; |
| |
| if((arg & R3964_SIG_ALL)==0) |
| { |
| /* Remove client from client list */ |
| for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next) |
| { |
| pClient = *ppClient; |
| |
| if(pClient->pid == pid) |
| { |
| TRACE_PS("removing client %d from client list", pid); |
| *ppClient = pClient->next; |
| while(pClient->msg_count) |
| { |
| pMsg=remove_msg(pInfo, pClient); |
| if(pMsg) |
| { |
| kfree(pMsg); |
| TRACE_M("enable_signals - msg kfree %p",pMsg); |
| } |
| } |
| kfree(pClient); |
| TRACE_M("enable_signals - kfree %p",pClient); |
| return 0; |
| } |
| } |
| return -EINVAL; |
| } |
| else |
| { |
| pClient=findClient(pInfo, pid); |
| if(pClient) |
| { |
| /* update signal options */ |
| pClient->sig_flags=arg; |
| } |
| else |
| { |
| /* add client to client list */ |
| pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL); |
| TRACE_M("enable_signals - kmalloc %p",pClient); |
| if(pClient==NULL) |
| return -ENOMEM; |
| |
| TRACE_PS("add client %d to client list", pid); |
| spin_lock_init(&pClient->lock); |
| pClient->sig_flags=arg; |
| pClient->pid = pid; |
| pClient->next=pInfo->firstClient; |
| pClient->first_msg = NULL; |
| pClient->last_msg = NULL; |
| pClient->next_block_to_read = NULL; |
| pClient->msg_count = 0; |
| pInfo->firstClient=pClient; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf) |
| { |
| struct r3964_client_info *pClient; |
| struct r3964_block_header *block; |
| |
| if(!buf) |
| { |
| return -EINVAL; |
| } |
| |
| pClient=findClient(pInfo,pid); |
| if(pClient==NULL) |
| { |
| return -EINVAL; |
| } |
| |
| block=pClient->next_block_to_read; |
| if(!block) |
| { |
| return 0; |
| } |
| else |
| { |
| if (copy_to_user (buf, block->data, block->length)) |
| return -EFAULT; |
| |
| remove_client_block(pInfo, pClient); |
| return block->length; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg, |
| int error_code, struct r3964_block_header *pBlock) |
| { |
| struct r3964_message *pMsg; |
| unsigned long flags; |
| |
| if(pClient->msg_count<R3964_MAX_MSG_COUNT-1) |
| { |
| queue_the_message: |
| |
| pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL); |
| TRACE_M("add_msg - kmalloc %p",pMsg); |
| if(pMsg==NULL) { |
| return; |
| } |
| |
| spin_lock_irqsave(&pClient->lock, flags); |
| |
| pMsg->msg_id = msg_id; |
| pMsg->arg = arg; |
| pMsg->error_code = error_code; |
| pMsg->block = pBlock; |
| pMsg->next = NULL; |
| |
| if(pClient->last_msg==NULL) |
| { |
| pClient->first_msg=pClient->last_msg=pMsg; |
| } |
| else |
| { |
| pClient->last_msg->next = pMsg; |
| pClient->last_msg=pMsg; |
| } |
| |
| pClient->msg_count++; |
| |
| if(pBlock!=NULL) |
| { |
| pBlock->locks++; |
| } |
| spin_unlock_irqrestore(&pClient->lock, flags); |
| } |
| else |
| { |
| if((pClient->last_msg->msg_id == R3964_MSG_ACK) |
| && (pClient->last_msg->error_code==R3964_OVERFLOW)) |
| { |
| pClient->last_msg->arg++; |
| TRACE_PE("add_msg - inc prev OVERFLOW-msg"); |
| } |
| else |
| { |
| msg_id = R3964_MSG_ACK; |
| arg = 0; |
| error_code = R3964_OVERFLOW; |
| pBlock = NULL; |
| TRACE_PE("add_msg - queue OVERFLOW-msg"); |
| goto queue_the_message; |
| } |
| } |
| /* Send SIGIO signal to client process: */ |
| if(pClient->sig_flags & R3964_USE_SIGIO) |
| { |
| kill_proc(pClient->pid, SIGIO, 1); |
| } |
| } |
| |
| static struct r3964_message *remove_msg(struct r3964_info *pInfo, |
| struct r3964_client_info *pClient) |
| { |
| struct r3964_message *pMsg=NULL; |
| unsigned long flags; |
| |
| if(pClient->first_msg) |
| { |
| spin_lock_irqsave(&pClient->lock, flags); |
| |
| pMsg = pClient->first_msg; |
| pClient->first_msg = pMsg->next; |
| if(pClient->first_msg==NULL) |
| { |
| pClient->last_msg = NULL; |
| } |
| |
| pClient->msg_count--; |
| if(pMsg->block) |
| { |
| remove_client_block(pInfo, pClient); |
| pClient->next_block_to_read = pMsg->block; |
| } |
| spin_unlock_irqrestore(&pClient->lock, flags); |
| } |
| return pMsg; |
| } |
| |
| static void remove_client_block(struct r3964_info *pInfo, |
| struct r3964_client_info *pClient) |
| { |
| struct r3964_block_header *block; |
| |
| TRACE_PS("remove_client_block PID %d", pClient->pid); |
| |
| block=pClient->next_block_to_read; |
| if(block) |
| { |
| block->locks--; |
| if(block->locks==0) |
| { |
| remove_from_rx_queue(pInfo, block); |
| } |
| } |
| pClient->next_block_to_read = NULL; |
| } |
| |
| |
| /************************************************************* |
| * Line discipline routines |
| *************************************************************/ |
| |
| static int r3964_open(struct tty_struct *tty) |
| { |
| struct r3964_info *pInfo; |
| |
| TRACE_L("open"); |
| TRACE_L("tty=%p, PID=%d, disc_data=%p", |
| tty, current->pid, tty->disc_data); |
| |
| pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL); |
| TRACE_M("r3964_open - info kmalloc %p",pInfo); |
| |
| if(!pInfo) |
| { |
| printk(KERN_ERR "r3964: failed to alloc info structure\n"); |
| return -ENOMEM; |
| } |
| |
| pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL); |
| TRACE_M("r3964_open - rx_buf kmalloc %p",pInfo->rx_buf); |
| |
| if(!pInfo->rx_buf) |
| { |
| printk(KERN_ERR "r3964: failed to alloc receive buffer\n"); |
| kfree(pInfo); |
| TRACE_M("r3964_open - info kfree %p",pInfo); |
| return -ENOMEM; |
| } |
| |
| pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL); |
| TRACE_M("r3964_open - tx_buf kmalloc %p",pInfo->tx_buf); |
| |
| if(!pInfo->tx_buf) |
| { |
| printk(KERN_ERR "r3964: failed to alloc transmit buffer\n"); |
| kfree(pInfo->rx_buf); |
| TRACE_M("r3964_open - rx_buf kfree %p",pInfo->rx_buf); |
| kfree(pInfo); |
| TRACE_M("r3964_open - info kfree %p",pInfo); |
| return -ENOMEM; |
| } |
| |
| spin_lock_init(&pInfo->lock); |
| pInfo->tty = tty; |
| init_waitqueue_head (&pInfo->read_wait); |
| pInfo->priority = R3964_MASTER; |
| pInfo->rx_first = pInfo->rx_last = NULL; |
| pInfo->tx_first = pInfo->tx_last = NULL; |
| pInfo->rx_position = 0; |
| pInfo->tx_position = 0; |
| pInfo->last_rx = 0; |
| pInfo->blocks_in_rx_queue = 0; |
| pInfo->firstClient=NULL; |
| pInfo->state=R3964_IDLE; |
| pInfo->flags = R3964_DEBUG; |
| pInfo->nRetry = 0; |
| |
| tty->disc_data = pInfo; |
| |
| init_timer(&pInfo->tmr); |
| pInfo->tmr.data = (unsigned long)pInfo; |
| pInfo->tmr.function = on_timeout; |
| |
| return 0; |
| } |
| |
| static void r3964_close(struct tty_struct *tty) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| struct r3964_client_info *pClient, *pNext; |
| struct r3964_message *pMsg; |
| struct r3964_block_header *pHeader, *pNextHeader; |
| unsigned long flags; |
| |
| TRACE_L("close"); |
| |
| /* |
| * Make sure that our task queue isn't activated. If it |
| * is, take it out of the linked list. |
| */ |
| del_timer_sync(&pInfo->tmr); |
| |
| /* Remove client-structs and message queues: */ |
| pClient=pInfo->firstClient; |
| while(pClient) |
| { |
| pNext=pClient->next; |
| while(pClient->msg_count) |
| { |
| pMsg=remove_msg(pInfo, pClient); |
| if(pMsg) |
| { |
| kfree(pMsg); |
| TRACE_M("r3964_close - msg kfree %p",pMsg); |
| } |
| } |
| kfree(pClient); |
| TRACE_M("r3964_close - client kfree %p",pClient); |
| pClient=pNext; |
| } |
| /* Remove jobs from tx_queue: */ |
| spin_lock_irqsave(&pInfo->lock, flags); |
| pHeader=pInfo->tx_first; |
| pInfo->tx_first=pInfo->tx_last=NULL; |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| |
| while(pHeader) |
| { |
| pNextHeader=pHeader->next; |
| kfree(pHeader); |
| pHeader=pNextHeader; |
| } |
| |
| /* Free buffers: */ |
| wake_up_interruptible(&pInfo->read_wait); |
| kfree(pInfo->rx_buf); |
| TRACE_M("r3964_close - rx_buf kfree %p",pInfo->rx_buf); |
| kfree(pInfo->tx_buf); |
| TRACE_M("r3964_close - tx_buf kfree %p",pInfo->tx_buf); |
| kfree(pInfo); |
| TRACE_M("r3964_close - info kfree %p",pInfo); |
| } |
| |
| static ssize_t r3964_read(struct tty_struct *tty, struct file *file, |
| unsigned char __user *buf, size_t nr) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| struct r3964_client_info *pClient; |
| struct r3964_message *pMsg; |
| struct r3964_client_message theMsg; |
| DECLARE_WAITQUEUE (wait, current); |
| |
| int pid = current->pid; |
| int count; |
| |
| TRACE_L("read()"); |
| |
| pClient=findClient(pInfo, pid); |
| if(pClient) |
| { |
| pMsg = remove_msg(pInfo, pClient); |
| if(pMsg==NULL) |
| { |
| /* no messages available. */ |
| if (file->f_flags & O_NONBLOCK) |
| { |
| return -EAGAIN; |
| } |
| /* block until there is a message: */ |
| add_wait_queue(&pInfo->read_wait, &wait); |
| repeat: |
| current->state = TASK_INTERRUPTIBLE; |
| pMsg = remove_msg(pInfo, pClient); |
| if (!pMsg && !signal_pending(current)) |
| { |
| schedule(); |
| goto repeat; |
| } |
| current->state = TASK_RUNNING; |
| remove_wait_queue(&pInfo->read_wait, &wait); |
| } |
| |
| /* If we still haven't got a message, we must have been signalled */ |
| |
| if (!pMsg) return -EINTR; |
| |
| /* deliver msg to client process: */ |
| theMsg.msg_id = pMsg->msg_id; |
| theMsg.arg = pMsg->arg; |
| theMsg.error_code = pMsg->error_code; |
| count = sizeof(struct r3964_client_message); |
| |
| kfree(pMsg); |
| TRACE_M("r3964_read - msg kfree %p",pMsg); |
| |
| if (copy_to_user(buf,&theMsg, count)) |
| return -EFAULT; |
| |
| TRACE_PS("read - return %d", count); |
| return count; |
| } |
| return -EPERM; |
| } |
| |
| static ssize_t r3964_write(struct tty_struct * tty, struct file * file, |
| const unsigned char *data, size_t count) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| struct r3964_block_header *pHeader; |
| struct r3964_client_info *pClient; |
| unsigned char *new_data; |
| int pid; |
| |
| TRACE_L("write request, %d characters", count); |
| /* |
| * Verify the pointers |
| */ |
| |
| if(!pInfo) |
| return -EIO; |
| |
| /* |
| * Ensure that the caller does not wish to send too much. |
| */ |
| if (count > R3964_MTU) |
| { |
| if (pInfo->flags & R3964_DEBUG) |
| { |
| TRACE_L (KERN_WARNING |
| "r3964_write: truncating user packet " |
| "from %u to mtu %d", count, R3964_MTU); |
| } |
| count = R3964_MTU; |
| } |
| /* |
| * Allocate a buffer for the data and copy it from the buffer with header prepended |
| */ |
| new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL); |
| TRACE_M("r3964_write - kmalloc %p",new_data); |
| if (new_data == NULL) { |
| if (pInfo->flags & R3964_DEBUG) |
| { |
| printk (KERN_ERR |
| "r3964_write: no memory\n"); |
| } |
| return -ENOSPC; |
| } |
| |
| pHeader = (struct r3964_block_header *)new_data; |
| pHeader->data = new_data + sizeof(struct r3964_block_header); |
| pHeader->length = count; |
| pHeader->locks = 0; |
| pHeader->owner = NULL; |
| |
| pid=current->pid; |
| |
| pClient=findClient(pInfo, pid); |
| if(pClient) |
| { |
| pHeader->owner = pClient; |
| } |
| |
| memcpy(pHeader->data, data, count); /* We already verified this */ |
| |
| if(pInfo->flags & R3964_DEBUG) |
| { |
| dump_block(pHeader->data, count); |
| } |
| |
| /* |
| * Add buffer to transmit-queue: |
| */ |
| add_tx_queue(pInfo, pHeader); |
| trigger_transmit(pInfo); |
| |
| return 0; |
| } |
| |
| static int r3964_ioctl(struct tty_struct * tty, struct file * file, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| if(pInfo==NULL) |
| return -EINVAL; |
| switch(cmd) |
| { |
| case R3964_ENABLE_SIGNALS: |
| return enable_signals(pInfo, current->pid, arg); |
| case R3964_SETPRIORITY: |
| if(arg<R3964_MASTER || arg>R3964_SLAVE) |
| return -EINVAL; |
| pInfo->priority = arg & 0xff; |
| return 0; |
| case R3964_USE_BCC: |
| if(arg) |
| pInfo->flags |= R3964_BCC; |
| else |
| pInfo->flags &= ~R3964_BCC; |
| return 0; |
| case R3964_READ_TELEGRAM: |
| return read_telegram(pInfo, current->pid, (unsigned char __user *)arg); |
| default: |
| return -ENOIOCTLCMD; |
| } |
| } |
| |
| static void r3964_set_termios(struct tty_struct *tty, struct termios * old) |
| { |
| TRACE_L("set_termios"); |
| } |
| |
| /* Called without the kernel lock held - fine */ |
| static unsigned int r3964_poll(struct tty_struct * tty, struct file * file, |
| struct poll_table_struct *wait) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| int pid=current->pid; |
| struct r3964_client_info *pClient; |
| struct r3964_message *pMsg=NULL; |
| unsigned long flags; |
| int result = POLLOUT; |
| |
| TRACE_L("POLL"); |
| |
| pClient=findClient(pInfo,pid); |
| if(pClient) |
| { |
| poll_wait(file, &pInfo->read_wait, wait); |
| spin_lock_irqsave(&pInfo->lock, flags); |
| pMsg=pClient->first_msg; |
| spin_unlock_irqrestore(&pInfo->lock, flags); |
| if(pMsg) |
| result |= POLLIN | POLLRDNORM; |
| } |
| else |
| { |
| result = -EINVAL; |
| } |
| return result; |
| } |
| |
| static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| char *fp, int count) |
| { |
| struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; |
| const unsigned char *p; |
| char *f, flags = 0; |
| int i; |
| |
| for (i=count, p = cp, f = fp; i; i--, p++) { |
| if (f) |
| flags = *f++; |
| if(flags==TTY_NORMAL) |
| { |
| receive_char(pInfo, *p); |
| } |
| else |
| { |
| receive_error(pInfo, flags); |
| } |
| |
| } |
| } |
| |
| static int r3964_receive_room(struct tty_struct *tty) |
| { |
| TRACE_L("receive_room"); |
| return -1; |
| } |
| |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_LDISC(N_R3964); |
