v4.19.13 snapshot.
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
new file mode 100644
index 0000000..dbf1ab3
--- /dev/null
+++ b/drivers/tty/n_r3964.c
@@ -0,0 +1,1265 @@
+// SPDX-License-Identifier: GPL-1.0+
+/* r3964 linediscipline for linux
+ *
+ * -----------------------------------------------------------
+ * Copyright by
+ * Philips Automation Projects
+ * Kassel (Germany)
+ * -----------------------------------------------------------
+ * 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 <linux/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...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_S
+#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PS(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_E
+#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PE(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_LDISC
+#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_L(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_QUEUE
+#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_Q(fmt, arg...) do {} while (0)
+#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(struct timer_list *t);
+static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
+static int read_telegram(struct r3964_info *pInfo, struct pid *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 ktermios *old);
+static __poll_t 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 struct tty_ldisc_ops 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,
+};
+
+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->tty->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;
+ /* FIXME: put_char should not be called from an IRQ */
+ tty_put_char(tty, ch);
+ pInfo->bcc ^= ch;
+}
+
+static void flush(struct r3964_info *pInfo)
+{
+ struct tty_struct *tty = pInfo->tty;
+
+ if (tty == NULL || tty->ops->flush_chars == NULL)
+ return;
+ tty->ops->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;
+ }
+
+ room = tty_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->tty->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:
+ /* FALLTHROUGH */
+ 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,
+ jiffies + 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, jiffies + 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,
+ jiffies + 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, jiffies + 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(struct timer_list *t)
+{
+ struct r3964_info *pInfo = from_timer(pInfo, t, tmr);
+
+ 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,
+ struct pid *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, struct pid *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_nr(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);
+ }
+ }
+ put_pid(pClient->pid);
+ 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_nr(pid));
+ spin_lock_init(&pClient->lock);
+ pClient->sig_flags = arg;
+ pClient->pid = get_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, struct pid *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),
+ error_code ? GFP_ATOMIC : 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_pid(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", pid_nr(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);
+ mutex_init(&pInfo->read_lock);
+ pInfo->tty = tty;
+ 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;
+ tty->receive_room = 65536;
+
+ timer_setup(&pInfo->tmr, on_timeout, 0);
+
+ return 0;
+}
+
+static void r3964_close(struct tty_struct *tty)
+{
+ struct r3964_info *pInfo = 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);
+ }
+ }
+ put_pid(pClient->pid);
+ 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: */
+ 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 = tty->disc_data;
+ struct r3964_client_info *pClient;
+ struct r3964_message *pMsg;
+ struct r3964_client_message theMsg;
+ int ret;
+
+ TRACE_L("read()");
+
+ /*
+ * Internal serialization of reads.
+ */
+ if (file->f_flags & O_NONBLOCK) {
+ if (!mutex_trylock(&pInfo->read_lock))
+ return -EAGAIN;
+ } else {
+ if (mutex_lock_interruptible(&pInfo->read_lock))
+ return -ERESTARTSYS;
+ }
+
+ pClient = findClient(pInfo, task_pid(current));
+ if (pClient) {
+ pMsg = remove_msg(pInfo, pClient);
+ if (pMsg == NULL) {
+ /* no messages available. */
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+ /* block until there is a message: */
+ wait_event_interruptible(tty->read_wait,
+ (pMsg = remove_msg(pInfo, pClient)));
+ }
+
+ /* If we still haven't got a message, we must have been signalled */
+
+ if (!pMsg) {
+ ret = -EINTR;
+ goto unlock;
+ }
+
+ /* deliver msg to client process: */
+ theMsg.msg_id = pMsg->msg_id;
+ theMsg.arg = pMsg->arg;
+ theMsg.error_code = pMsg->error_code;
+ ret = sizeof(struct r3964_client_message);
+
+ kfree(pMsg);
+ TRACE_M("r3964_read - msg kfree %p", pMsg);
+
+ if (copy_to_user(buf, &theMsg, ret)) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ TRACE_PS("read - return %d", ret);
+ goto unlock;
+ }
+ ret = -EPERM;
+unlock:
+ mutex_unlock(&pInfo->read_lock);
+ return ret;
+}
+
+static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *data, size_t count)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_block_header *pHeader;
+ struct r3964_client_info *pClient;
+ unsigned char *new_data;
+
+ 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;
+
+ pClient = findClient(pInfo, task_pid(current));
+ 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 = tty->disc_data;
+ if (pInfo == NULL)
+ return -EINVAL;
+ switch (cmd) {
+ case R3964_ENABLE_SIGNALS:
+ return enable_signals(pInfo, task_pid(current), 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, task_pid(current),
+ (unsigned char __user *)arg);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+ TRACE_L("set_termios");
+}
+
+/* Called without the kernel lock held - fine */
+static __poll_t r3964_poll(struct tty_struct *tty, struct file *file,
+ struct poll_table_struct *wait)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_client_info *pClient;
+ struct r3964_message *pMsg = NULL;
+ unsigned long flags;
+ __poll_t result = EPOLLOUT;
+
+ TRACE_L("POLL");
+
+ pClient = findClient(pInfo, task_pid(current));
+ if (pClient) {
+ poll_wait(file, &tty->read_wait, wait);
+ spin_lock_irqsave(&pInfo->lock, flags);
+ pMsg = pClient->first_msg;
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+ if (pMsg)
+ result |= EPOLLIN | EPOLLRDNORM;
+ } 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 = tty->disc_data;
+ const unsigned char *p;
+ char *f, flags = TTY_NORMAL;
+ 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);
+ }
+
+ }
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_R3964);