-/*
+/*
* sllin.c - serial line LIN interface driver (using tty line discipline)
*
- * This file is derived from linux/drivers/net/slip.c
- *
- * slip.c Authors : Laurence Culhane <loz@holmes.demon.co.uk>
- * Fred N. van Kempen <waltje@uwalt.nl.mugnet.org>
- * sllin.c Author : Oliver Hartkopp <socketcan@hartkopp.net>
+ * This file is derived from drivers/net/can/slcan.c
+ * slcan.c Author: Oliver Hartkopp <socketcan@hartkopp.net>
*
* 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
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
- * Send feedback to <socketcan-users@lists.berlios.de>
- *
+ * Idea: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
+ * Copyright: (c) 2011 Czech Technical University in Prague
+ * (c) 2011 Volkswagen Group Research
+ * Authors: Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ * Rostislav Lisovy <lisovy@kormus.cz>
+ * Michal Sojka <sojkam1@fel.cvut.cz>
+ * Funded by: Volkswagen Group Research
*/
+#define DEBUG 1 /* Enables pr_debug() printouts */
+
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/can.h>
#include <linux/kthread.h>
#include <linux/hrtimer.h>
+#include "linux/lin_bus.h"
/* Should be in include/linux/tty.h */
-#define N_SLLIN 25
+#define N_SLLIN 25
+/* -------------------------------- */
static __initdata const char banner[] =
KERN_INFO "sllin: serial line LIN interface driver\n";
MODULE_ALIAS_LDISC(N_SLLIN);
MODULE_DESCRIPTION("serial line LIN interface");
MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
+MODULE_AUTHOR("Pavel Pisa <pisa@cmp.felk.cvut.cz>");
+
+#define SLLIN_MAGIC 0x53CA
+/* #define BREAK_BY_BAUD */
+
+static int master = true;
+static int baudrate = 0; /* Use LIN_DEFAULT_BAUDRATE when not set */
-#define SLLIN_MAGIC 0x53CA
-// #define BREAK_BY_BAUD
+module_param(master, bool, 0);
+MODULE_PARM_DESC(master, "LIN interface is Master device");
+module_param(baudrate, int, 0);
+MODULE_PARM_DESC(baudrate, "Baudrate of LIN interface");
static int maxdev = 10; /* MAX number of SLLIN channels;
This can be overridden with
MODULE_PARM_DESC(maxdev, "Maximum number of sllin interfaces");
/* maximum buffer len to store whole LIN message*/
-#define SLLIN_DATA_MAX 8
-#define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \
- SLLIN_DATA_MAX + 1 /*checksum*/)
-#define SLLIN_BUFF_BREAK 0
-#define SLLIN_BUFF_SYNC 1
-#define SLLIN_BUFF_ID 2
-#define SLLIN_BUFF_DATA 3
+#define SLLIN_DATA_MAX 8
+#define SLLIN_BUFF_LEN (1 /*break*/ + 1 /*sync*/ + 1 /*ID*/ + \
+ SLLIN_DATA_MAX + 1 /*checksum*/)
+#define SLLIN_BUFF_BREAK 0
+#define SLLIN_BUFF_SYNC 1
+#define SLLIN_BUFF_ID 2
+#define SLLIN_BUFF_DATA 3
-#define SLLIN_ID_MASK 0x3f
+#define SLLIN_SAMPLES_PER_CHAR 10
+#define SLLIN_CHARS_TO_TIMEOUT 24
enum slstate {
SLSTATE_IDLE = 0,
SLSTATE_BREAK_SENT,
SLSTATE_ID_SENT,
- SLSTATE_RESPONSE_WAIT,
+ SLSTATE_RESPONSE_WAIT, /* Wait for response */
+ SLSTATE_RESPONSE_WAIT_BUS, /* Wait for response from LIN bus
+ only (CAN frames from network stack
+ are not processed in this moment) */
SLSTATE_RESPONSE_SENT,
};
+struct sllin_conf_entry {
+ int dlc; /* Length of data in LIN frame */
+ canid_t frame_fl; /* LIN frame flags. Passed from userspace as
+ canid_t data type */
+ u8 data[8]; /* LIN frame data payload */
+};
+
struct sllin {
int magic;
int lin_state; /* state */
char id_to_send; /* there is ID to be sent */
char data_to_send; /* there are data to be sent */
+ char resp_len_known; /* Length of the response is known */
+ char header_received;/* In Slave mode, set when header was already
+ received */
+ char rx_len_unknown; /* We are not sure how much data will be sent to us --
+ we just guess the length */
unsigned long flags; /* Flag values/ mode etc */
#define SLF_INUSE 0 /* Channel in use */
dev_t line;
struct task_struct *kwthread;
- wait_queue_head_t kwt_wq;
+ wait_queue_head_t kwt_wq; /* Wait queue used by kwthread */
struct hrtimer rx_timer; /* RX timeout timer */
ktime_t rx_timer_timeout; /* RX timeout timer value */
- struct sk_buff *rec_skb; /* Socket buffer with received CAN frame */
+ struct sk_buff *tx_req_skb; /* Socket buffer with CAN frame
+ received from network stack*/
+
+ /* List with configurations for each of 0 to LIN_ID_MAX LIN IDs */
+ struct sllin_conf_entry linfr_cache[LIN_ID_MAX + 1];
};
static struct net_device **sllin_devs;
+static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf);
+
+/* Values of two parity bits in LIN Protected
+ Identifier for each particular LIN ID */
const unsigned char sllin_id_parity_table[] = {
- 0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
- 0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
- 0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80,
- 0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
- 0x00,0x40,0xc0,0x80,0x40,0x00,0x80,0xc0,
- 0x80,0xc0,0x40,0x00,0xc0,0x80,0x00,0x40,
- 0xc0,0x80,0x00,0x40,0x80,0xc0,0x40,0x00,
- 0x40,0x00,0x80,0xc0,0x00,0x40,0xc0,0x80
+ 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
+ 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
+ 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80,
+ 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
+ 0x00, 0x40, 0xc0, 0x80, 0x40, 0x00, 0x80, 0xc0,
+ 0x80, 0xc0, 0x40, 0x00, 0xc0, 0x80, 0x00, 0x40,
+ 0xc0, 0x80, 0x00, 0x40, 0x80, 0xc0, 0x40, 0x00,
+ 0x40, 0x00, 0x80, 0xc0, 0x00, 0x40, 0xc0, 0x80
};
+/**
+ * sltty_change_speed() -- Change baudrate of Serial device belonging
+ * to particular @tty
+ *
+ * @tty: Pointer to TTY to change speed for.
+ * @speed: Integer value of new speed. It is possible to
+ * assign non-standard values, i.e. those which
+ * are not defined in termbits.h.
+ */
static int sltty_change_speed(struct tty_struct *tty, unsigned speed)
{
struct ktermios old_termios;
mutex_lock(&tty->termios_mutex);
old_termios = *(tty->termios);
- cflag = tty->termios->c_cflag;
+
+ cflag = CS8 | CREAD | CLOCAL | HUPCL;
cflag &= ~(CBAUD | CIBAUD);
cflag |= BOTHER;
tty->termios->c_cflag = cflag;
+ tty->termios->c_oflag = 0;
+ tty->termios->c_lflag = 0;
+
+ /* Enable interrupt when UART-Break or Framing error received */
+ tty->termios->c_iflag = BRKINT | INPCK;
tty_encode_baud_rate(tty, speed, speed);
return 0;
}
-
-/* Send one completely decapsulated can_frame to the network layer */
-static void sll_bump(struct sllin *sl)
+/* Send one can_frame to the network layer */
+static void sllin_send_canfr(struct sllin *sl, canid_t id, char *data, int len)
{
struct sk_buff *skb;
struct can_frame cf;
- cf.can_id = sl->rx_buff[SLLIN_BUFF_ID] & SLLIN_ID_MASK;
- cf.can_dlc = sl->rx_cnt - SLLIN_BUFF_DATA;
- memcpy(&cf.data, sl->rx_buff + SLLIN_BUFF_DATA, cf.can_dlc);
+ cf.can_id = id;
+ cf.can_dlc = len;
+ if (cf.can_dlc > 0) {
+ memcpy(&cf.data, data, cf.can_dlc);
+ }
skb = dev_alloc_skb(sizeof(struct can_frame));
if (!skb)
sl->dev->stats.rx_bytes += cf.can_dlc;
}
+/**
+ * sll_bump() -- Send data of received LIN frame (existing in sl->rx_buff)
+ * as CAN frame
+ *
+ * @sl:
+ */
+static void sll_bump(struct sllin *sl)
+{
+ int len = sl->rx_cnt - SLLIN_BUFF_DATA - 1; /* without checksum */
+ len = (len < 0) ? 0 : len;
- /************************************************************************
- * STANDARD SLLIN ENCAPSULATION *
- ************************************************************************/
+ sllin_send_canfr(sl, sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK,
+ sl->rx_buff + SLLIN_BUFF_DATA, len);
+}
-/* Convert particular CAN frame into LIN frame and send it to TTY queue. */
-static void sll_encaps(struct sllin *sl, struct can_frame *cf)
+static void sll_send_rtr(struct sllin *sl)
{
-// int actual, idx, i;
-// char lframe[16] = {0x00, 0x55}; /* Fake break, Sync byte */
-// struct tty_struct *tty = sl->tty;
-//
-// pr_debug("sllin: %s() invoked\n", __FUNCTION__);
-//
-// /* We do care only about SFF frames */
-// if (cf->can_id & CAN_EFF_FLAG)
-// return;
-//
-// /* Send only header */
-// if (cf->can_id & CAN_RTR_FLAG) {
-// pr_debug("sllin: %s() RTR CAN frame\n", __FUNCTION__);
-// lframe[2] = (u8)cf->can_id; /* Get one byte LIN ID */
-//
-// sltty_change_speed(tty, sl->lin_baud * 2 / 3);
-// tty->ops->write(tty, &lframe[0], 1);
-// sltty_change_speed(tty, sl->lin_baud);
-// tty->ops->write(tty, &lframe[1], 1);
-// tty->ops->write(tty, &lframe[2], 1);
-// } else {
-// pr_debug("sllin: %s() non-RTR CAN frame\n", __FUNCTION__);
-// /* idx = strlen(sl->xbuff);
-//
-// for (i = 0; i < cf->can_dlc; i++)
-// sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]);
-//
-// * Order of next two lines is *very* important.
-// * When we are sending a little amount of data,
-// * the transfer may be completed inside the ops->write()
-// * routine, because it's running with interrupts enabled.
-// * In this case we *never* got WRITE_WAKEUP event,
-// * if we did not request it before write operation.
-// * 14 Oct 1994 Dmitry Gorodchanin.
-//
-// set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
-// actual = sl->tty->ops->write(sl->tty, sl->xbuff, strlen(sl->xbuff));
-// sl->xleft = strlen(sl->xbuff) - actual;
-// sl->xhead = sl->xbuff + actual;
-// sl->dev->stats.tx_bytes += cf->can_dlc;
-// */
-// }
-//
+ sllin_send_canfr(sl, (sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK) |
+ CAN_RTR_FLAG, NULL, 0);
}
/*
remains = SLLIN_BUFF_BREAK + 1 - sl->tx_cnt;
if (remains > 0) {
- actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt, sl->tx_cnt - sl->tx_lim);
+ actual = tty->ops->write(tty, sl->tx_buff + sl->tx_cnt,
+ sl->tx_cnt - sl->tx_lim);
sl->tx_cnt += actual;
if (sl->tx_cnt < sl->tx_lim) {
- printk(KERN_INFO "sllin_write_wakeup sent %d, remains %d, waiting\n",
+ pr_debug("sllin: sllin_write_wakeup sent %d, "
+ "remains %d, waiting\n",
sl->tx_cnt, sl->tx_lim - sl->tx_cnt);
return;
}
set_bit(SLF_TXEVENT, &sl->flags);
wake_up(&sl->kwt_wq);
- printk(KERN_INFO "sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt);
+ pr_debug("sllin: sllin_write_wakeup sent %d, wakeup\n", sl->tx_cnt);
}
-/* Send a can_frame to a TTY queue. */
+/**
+ * sll_xmit() -- Send a can_frame to a TTY queue.
+ *
+ * @skb: Pointer to Socket buffer to be sent.
+ * @dev: Network device where @skb will be sent.
+ */
static netdev_tx_t sll_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct sllin *sl = netdev_priv(dev);
+ struct can_frame *cf;
if (skb->len != sizeof(struct can_frame))
goto err_out;
spin_lock(&sl->lock);
if (!netif_running(dev)) {
- spin_unlock(&sl->lock);
printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
- goto err_out;
+ goto err_out_unlock;
}
if (sl->tty == NULL) {
- spin_unlock(&sl->lock);
- goto err_out;
+ goto err_out_unlock;
+ }
+
+ cf = (struct can_frame *) skb->data;
+ if (cf->can_id & LIN_CTRL_FRAME) {
+ sllin_configure_frame_cache(sl, cf);
+ goto free_out_unlock;
}
netif_stop_queue(sl->dev);
- sl->rec_skb = skb;
+ sl->tx_req_skb = skb;
set_bit(SLF_MSGEVENT, &sl->flags);
wake_up(&sl->kwt_wq);
spin_unlock(&sl->lock);
return NETDEV_TX_OK;
+free_out_unlock:
+err_out_unlock:
+ spin_unlock(&sl->lock);
err_out:
kfree_skb(skb);
return NETDEV_TX_OK;
/******************************************
Routines looking at TTY side.
******************************************/
+#define SLL_RESPONSE_RECEIVED ((sl->header_received == true) && \
+ ((sl->rx_cnt >= sl->rx_expect) || \
+ ((sl->rx_len_unknown == true) && (count == 0))))
-/*
- * Handle the 'receiver data ready' interrupt.
- * This function is called by the 'tty_io' module in the kernel when
- * a block of SLLIN data has been received, which can now be decapsulated
- * and sent on to some IP layer for further processing. This will not
- * be re-entered while running but other ldisc functions may be called
- * in parallel
- */
+#define SLL_HEADER_RECEIVED ((sl->header_received == false) && \
+ (sl->rx_cnt >= (SLLIN_BUFF_ID + 1)))
static void sllin_receive_buf(struct tty_struct *tty,
const unsigned char *cp, char *fp, int count)
{
struct sllin *sl = (struct sllin *) tty->disc_data;
-
- printk(KERN_INFO "sllin_receive_buf invoked\n");
+ pr_debug("sllin: sllin_receive_buf invoked, count = %u\n", count);
if (!sl || sl->magic != SLLIN_MAGIC || !netif_running(sl->dev))
return;
/* Read the characters out of the buffer */
while (count--) {
if (fp && *fp++) {
- if (!test_and_set_bit(SLF_ERROR, &sl->flags))
- sl->dev->stats.rx_errors++;
- printk(KERN_INFO "sllin_receive_buf char 0x%02x ignored "
+ pr_debug("sllin: sllin_receive_buf char 0x%02x ignored "
"due marker 0x%02x, flags 0x%lx\n",
*cp, *(fp-1), sl->flags);
- cp++;
- continue;
+
+ if (sl->lin_master == true) { /* Report error */
+ set_bit(SLF_ERROR, &sl->flags);
+ wake_up(&sl->kwt_wq);
+ return;
+ } else { /* Received Break */
+ sl->rx_cnt = 0;
+ sl->rx_expect = SLLIN_BUFF_ID + 1;
+ sl->rx_len_unknown = false; /* We do know exact length of the header */
+ sl->header_received = false;
+ }
}
- if (sl->rx_cnt < SLLIN_BUFF_LEN) {
#ifndef BREAK_BY_BAUD
- /* We didn't receive Break character */
- if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
- sl->rx_buff[sl->rx_cnt++] = 0x00;
- }
+ /* We didn't receive Break character -- fake it! */
+ if ((sl->rx_cnt == SLLIN_BUFF_BREAK) && (*cp == 0x55)) {
+ pr_debug("sllin: LIN_RX[%d]: 0x00\n", sl->rx_cnt);
+ sl->rx_buff[sl->rx_cnt++] = 0x00;
+ }
#endif
- printk(KERN_INFO "LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
+ if (sl->rx_cnt < SLLIN_BUFF_LEN) {
+ pr_debug("sllin: LIN_RX[%d]: 0x%02x\n", sl->rx_cnt, *cp);
sl->rx_buff[sl->rx_cnt++] = *cp++;
}
- }
- if (sl->rx_cnt >= sl->rx_expect) {
- set_bit(SLF_RXEVENT, &sl->flags);
- wake_up(&sl->kwt_wq);
- printk(KERN_INFO "sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
- } else {
- printk(KERN_INFO "sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
+ if (sl->lin_master == true) {
+ if (SLL_RESPONSE_RECEIVED) {
+ set_bit(SLF_RXEVENT, &sl->flags);
+ wake_up(&sl->kwt_wq);
+ pr_debug("sllin: sllin_receive_buf count %d, wakeup\n", sl->rx_cnt);
+ } else {
+ pr_debug("sllin: sllin_receive_buf count %d, waiting\n", sl->rx_cnt);
+ }
+ } else { /* LIN slave */
+ int lin_id;
+ struct sllin_conf_entry *sce;
+
+ pr_debug("sllin: rx_cnt = %u; header_received = %u\n",
+ sl->rx_cnt, sl->header_received);
+
+ if (SLL_HEADER_RECEIVED) {
+ lin_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+ sce = &sl->linfr_cache[lin_id];
+
+ /* Is the length of data set in frame cache? */
+ if (sce->frame_fl & LIN_LOC_SLAVE_CACHE) {
+ sl->rx_expect += sce->dlc;
+ sl->rx_len_unknown = false;
+ } else {
+ sl->rx_expect += SLLIN_DATA_MAX + 1; /* + checksum */
+ sl->rx_len_unknown = true;
+ }
+
+ sl->header_received = true;
+ sll_send_rtr(sl);
+ continue;
+ }
+
+ if (SLL_RESPONSE_RECEIVED) {
+ sll_bump(sl);
+ pr_debug("sllin: Received LIN header & LIN response. "
+ "rx_cnt = %u, rx_expect = %u\n", sl->rx_cnt,
+ sl->rx_expect);
+
+ /* Prepare for reception of new header */
+ sl->rx_cnt = 0;
+ sl->rx_expect = SLLIN_BUFF_ID + 1;
+ sl->rx_len_unknown = false; /* We do know exact length of the header */
+ sl->header_received = false;
+ }
+ }
}
}
/*****************************************
* sllin message helper routines
*****************************************/
+/**
+ * sllin_report_error() -- Report an error by sending CAN frame
+ * with particular error flag set in can_id
+ *
+ * @sl:
+ * @err: Error flag to be sent.
+ */
+void sllin_report_error(struct sllin *sl, int err)
+{
+ switch (err) {
+ case LIN_ERR_CHECKSUM:
+ sl->dev->stats.rx_crc_errors++;
+ break;
+
+ case LIN_ERR_RX_TIMEOUT:
+ sl->dev->stats.rx_errors++;
+ break;
+
+ case LIN_ERR_FRAMING:
+ sl->dev->stats.rx_frame_errors++;
+ break;
+ }
+
+ sllin_send_canfr(sl, 0 | CAN_EFF_FLAG |
+ (err & ~LIN_ID_MASK), NULL, 0);
+}
+
+/**
+ * sllin_configure_frame_cache() -- Configure particular entry in linfr_cache
+ *
+ * @sl:
+ * @cf: Pointer to CAN frame sent to this driver
+ * holding configuration information
+ */
+static int sllin_configure_frame_cache(struct sllin *sl, struct can_frame *cf)
+{
+ struct sllin_conf_entry *sce;
+ if (!(cf->can_id & LIN_ID_CONF))
+ return -1;
+
+ sce = &sl->linfr_cache[cf->can_id & LIN_ID_MASK];
+ pr_debug("sllin: Setting frame cache with EFF CAN frame. "
+ "LIN ID = %d\n", cf->can_id & LIN_ID_MASK);
+
+ sce->dlc = cf->can_dlc;
+ if (sce->dlc > SLLIN_DATA_MAX)
+ sce->dlc = SLLIN_DATA_MAX;
+
+ sce->frame_fl = (cf->can_id & ~LIN_ID_MASK) & CAN_EFF_MASK;
+ memcpy(sce->data, cf->data, cf->can_dlc);
+
+ return 0;
+}
+
+/**
+ * sllin_checksum() -- Count checksum for particular data
+ *
+ * @data: Pointer to the buffer containing whole LIN
+ * frame (i.e. including break and sync bytes).
+ * @length: Length of the buffer.
+ * @enhanced_fl: Flag determining whether Enhanced or Classic
+ * checksum should be counted.
+ */
+static inline unsigned sllin_checksum(unsigned char *data, int length, int enhanced_fl)
+{
+ unsigned csum = 0;
+ int i;
+
+ if (enhanced_fl) {
+ i = SLLIN_BUFF_ID;
+ } else {
+ i = SLLIN_BUFF_DATA;
+ }
+
+ for (; i < length; i++) {
+ csum += data[i];
+ if (csum > 255)
+ csum -= 255;
+ }
+
+ return ~csum & 0xff;
+}
+
+#define SLLIN_STPMSG_RESPONLY (1) /* Message will be LIN Response only */
+#define SLLIN_STPMSG_CHCKSUM_CLS (1 << 1)
+#define SLLIN_STPMSG_CHCKSUM_ENH (1 << 2)
int sllin_setup_msg(struct sllin *sl, int mode, int id,
unsigned char *data, int len)
{
- if (id > SLLIN_ID_MASK)
+ if (id > LIN_ID_MASK)
return -1;
- sl->rx_cnt = 0;
- sl->tx_cnt = 0;
- sl->rx_expect = 0;
- sl->rx_lim = SLLIN_BUFF_LEN;
+ if (!(mode & SLLIN_STPMSG_RESPONLY)) {
+ sl->rx_cnt = 0;
+ sl->tx_cnt = 0;
+ sl->rx_expect = 0;
+ sl->rx_lim = SLLIN_BUFF_LEN;
+ }
sl->tx_buff[SLLIN_BUFF_BREAK] = 0;
sl->tx_buff[SLLIN_BUFF_SYNC] = 0x55;
sl->tx_lim = SLLIN_BUFF_DATA;
if ((data != NULL) && len) {
- int i;
- unsigned csum = 0;
-
sl->tx_lim += len;
memcpy(sl->tx_buff + SLLIN_BUFF_DATA, data, len);
- /* compute data parity there */
- for (i = SLLIN_BUFF_DATA; i < sl->tx_lim; i++) {
- csum += sl->tx_buff[i];
- if (csum > 255)
- csum -= 255;
- }
-
- sl->tx_buff[sl->tx_lim++] = csum;
+ sl->tx_buff[sl->tx_lim++] = sllin_checksum(sl->tx_buff,
+ sl->tx_lim, mode & SLLIN_STPMSG_CHCKSUM_ENH);
}
if (len != 0)
sl->rx_lim = SLLIN_BUFF_DATA + len + 1;
return 0;
}
+static void sllin_reset_buffs(struct sllin *sl)
+{
+ sl->rx_cnt = 0;
+ sl->rx_expect = 0;
+ sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
+ sl->tx_cnt = 0;
+ sl->tx_lim = 0;
+ sl->id_to_send = false;
+ sl->data_to_send = false;
+}
int sllin_send_tx_buff(struct sllin *sl)
{
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
return -1;
}
-
+
remains -= res;
sl->tx_cnt += res;
}
- printk(KERN_INFO "sllin_send_tx_buff sent %d, remains %d\n",
+ pr_debug("sllin: sllin_send_tx_buff sent %d, remains %d\n",
sl->tx_cnt, remains);
return 0;
int sllin_send_break(struct sllin *sl)
{
struct tty_struct *tty = sl->tty;
- unsigned long break_baud;
- unsigned long flags;
int retval;
+ unsigned long break_baud;
+ unsigned long usleep_range_min;
+ unsigned long usleep_range_max;
+ break_baud = ((sl->lin_baud * 2) / 3);
sl->rx_cnt = SLLIN_BUFF_BREAK;
sl->rx_expect = SLLIN_BUFF_BREAK + 1;
sl->lin_state = SLSTATE_BREAK_SENT;
- /* Do the break ourselves; Inspired by
+ /* Do the break ourselves; Inspired by
http://lxr.linux.no/#linux+v3.1.2/drivers/tty/tty_io.c#L2452 */
retval = tty->ops->break_ctl(tty, -1);
if (retval)
return retval;
- //udelay(712);
- usleep_range(650, 750);
+ /* udelay(712); */
+ usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR) / break_baud;
+ usleep_range_max = usleep_range_min + 50;
+ usleep_range(usleep_range_min, usleep_range_max);
retval = tty->ops->break_ctl(tty, 0);
- usleep_range(50, 100);
-
+ usleep_range_min = (1000000l * 1 /* 1 bit */) / break_baud;
+ usleep_range_max = usleep_range_min + 30;
+ usleep_range(usleep_range_min, usleep_range_max);
+
tty->ops->flush_buffer(tty);
sl->tx_cnt = SLLIN_BUFF_SYNC;
- printk(KERN_INFO "sllin: Break sent.\n");
+ pr_debug("sllin: Break sent.\n");
set_bit(SLF_RXEVENT, &sl->flags);
wake_up(&sl->kwt_wq);
{
struct sllin *sl = container_of(hrtimer, struct sllin, rx_timer);
+ sllin_report_error(sl, LIN_ERR_RX_TIMEOUT);
set_bit(SLF_TMOUTEVENT, &sl->flags);
wake_up(&sl->kwt_wq);
return HRTIMER_NORESTART;
}
+/**
+ * sllin_rx_validate() -- Validate received frame, i,e. check checksum
+ *
+ * @sl:
+ */
+static int sllin_rx_validate(struct sllin *sl)
+{
+ int actual_id;
+ int ext_chcks_fl;
+ int lin_dlc;
+ unsigned char rec_chcksm = sl->rx_buff[sl->rx_cnt - 1];
+ struct sllin_conf_entry *scf;
+
+ actual_id = sl->rx_buff[SLLIN_BUFF_ID] & LIN_ID_MASK;
+ scf = &sl->linfr_cache[actual_id];
+ lin_dlc = scf->dlc;
+ ext_chcks_fl = scf->frame_fl & LIN_CHECKSUM_EXTENDED;
+
+ if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1, ext_chcks_fl) !=
+ rec_chcksm) {
+
+ /* Type of checksum is configured for particular frame */
+ if (lin_dlc > 0) {
+ return -1;
+ } else {
+ if (sllin_checksum(sl->rx_buff, sl->rx_cnt - 1,
+ !ext_chcks_fl) != rec_chcksm) {
+ return -1;
+ }
+ }
+ }
+
+ return 0;
+}
/*****************************************
* sllin_kwthread - kernel worker thread
struct sllin *sl = (struct sllin *)ptr;
struct tty_struct *tty = sl->tty;
struct sched_param schparam = { .sched_priority = 40 };
- int res;
- struct can_frame *cf;
+ int tx_bytes = 0; /* Used for Network statistics */
+
- printk(KERN_INFO "sllin: sllin_kwthread started.\n");
+ pr_debug("sllin: sllin_kwthread started.\n");
sched_setscheduler(current, SCHED_FIFO, &schparam);
clear_bit(SLF_ERROR, &sl->flags);
sltty_change_speed(tty, sl->lin_baud);
while (!kthread_should_stop()) {
+ struct can_frame *cf;
+ u8 *lin_data;
+ int lin_dlc;
+ u8 lin_data_buff[SLLIN_DATA_MAX];
+
+
if ((sl->lin_state == SLSTATE_IDLE) && sl->lin_master &&
sl->id_to_send) {
if(sllin_send_break(sl) < 0) {
test_bit(SLF_RXEVENT, &sl->flags) ||
test_bit(SLF_TXEVENT, &sl->flags) ||
test_bit(SLF_TMOUTEVENT, &sl->flags) ||
- ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)));
+ test_bit(SLF_ERROR, &sl->flags) ||
+ (((sl->lin_state == SLSTATE_IDLE) ||
+ (sl->lin_state == SLSTATE_RESPONSE_WAIT))
+ && test_bit(SLF_MSGEVENT, &sl->flags)));
if (test_and_clear_bit(SLF_RXEVENT, &sl->flags)) {
- printk(KERN_INFO "sllin_kthread RXEVENT \n");
+ pr_debug("sllin: sllin_kthread RXEVENT\n");
+ }
+
+ if (test_and_clear_bit(SLF_ERROR, &sl->flags)) {
+ unsigned long usleep_range_min;
+ unsigned long usleep_range_max;
+ hrtimer_cancel(&sl->rx_timer);
+ pr_debug("sllin: sllin_kthread ERROR\n");
+
+ if (sl->lin_state != SLSTATE_IDLE)
+ sllin_report_error(sl, LIN_ERR_FRAMING);
+
+ usleep_range_min = (1000000l * SLLIN_SAMPLES_PER_CHAR * 10) /
+ sl->lin_baud;
+ usleep_range_max = usleep_range_min + 50;
+ usleep_range(usleep_range_min, usleep_range_max);
+ sllin_reset_buffs(sl);
+ sl->lin_state = SLSTATE_IDLE;
}
if (test_and_clear_bit(SLF_TXEVENT, &sl->flags)) {
- printk(KERN_INFO "sllin_kthread TXEVENT \n");
+ pr_debug("sllin: sllin_kthread TXEVENT\n");
}
if (test_and_clear_bit(SLF_TMOUTEVENT, &sl->flags)) {
- printk(KERN_INFO "sllin_kthread TMOUTEVENT \n");
- sl->rx_cnt = 0;
- sl->rx_expect = 0;
- sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
- sl->tx_cnt = 0;
- sl->tx_lim = 0;
- sl->id_to_send = false;
- sl->data_to_send = false;
-
+ pr_debug("sllin: sllin_kthread TMOUTEVENT\n");
+ sllin_reset_buffs(sl);
+
sl->lin_state = SLSTATE_IDLE;
}
- if ((sl->lin_state == SLSTATE_IDLE) && test_bit(SLF_MSGEVENT, &sl->flags)) {
- cf = (struct can_frame *)sl->rec_skb->data;
-
- /* We do care only about SFF frames */
- if (cf->can_id & CAN_EFF_FLAG)
- goto release_skb;
-
- if (cf->can_id & CAN_RTR_FLAG) {
- printk(KERN_INFO "%s: RTR CAN frame, ID = %x\n",
- __FUNCTION__, cf->can_id & CAN_SFF_MASK);
- if (sllin_setup_msg(sl, 0,
- cf->can_id & CAN_SFF_MASK, NULL, 0) != -1) {
- sl->id_to_send = true;
- sl->data_to_send = false;
+ switch (sl->lin_state) {
+ case SLSTATE_IDLE:
+ if (!test_bit(SLF_MSGEVENT, &sl->flags))
+ break;
+
+ cf = (struct can_frame *)sl->tx_req_skb->data;
+
+ /* SFF RTR CAN frame -> LIN header */
+ if (cf->can_id & CAN_RTR_FLAG) {
+ spin_lock(&sl->lock);
+ pr_debug("sllin: %s: RTR SFF CAN frame, ID = %x\n",
+ __FUNCTION__, cf->can_id & LIN_ID_MASK);
+
+ /* Is there Slave response in linfr_cache to be sent? */
+ if ((sl->linfr_cache[cf->can_id & LIN_ID_MASK].frame_fl &
+ LIN_LOC_SLAVE_CACHE)
+ && (sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc > 0)) {
+
+ pr_debug("sllin: Sending LIN response from linfr_cache\n");
+ lin_data = sl->linfr_cache[cf->can_id & LIN_ID_MASK].data;
+ lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc;
+ if (lin_dlc > SLLIN_DATA_MAX)
+ lin_dlc = SLLIN_DATA_MAX;
+ memcpy(lin_data_buff, lin_data, lin_dlc);
+ lin_data = lin_data_buff;
+ } else {
+ lin_data = NULL;
+ lin_dlc = sl->linfr_cache[cf->can_id & LIN_ID_MASK].dlc;
+ }
+ spin_unlock(&sl->lock);
+ } else { /* SFF NON-RTR CAN frame -> LIN header + LIN response */
+ pr_debug("sllin: %s: NON-RTR SFF CAN frame, ID = %x\n",
+ __FUNCTION__, (int)cf->can_id & LIN_ID_MASK);
+
+ lin_data = cf->data;
+ lin_dlc = cf->can_dlc;
+ if (lin_dlc > SLLIN_DATA_MAX)
+ lin_dlc = SLLIN_DATA_MAX;
+ tx_bytes = lin_dlc;
}
- } else {
- printk(KERN_INFO "%s: NON-RTR CAN frame, ID = %x\n",
- __FUNCTION__, (int)cf->can_id & CAN_SFF_MASK);
- if (sllin_setup_msg(sl, 0, cf->can_id & CAN_SFF_MASK,
- cf->data, cf->can_dlc) != -1) {
+ if (sllin_setup_msg(sl, 0, cf->can_id & LIN_ID_MASK,
+ lin_data, lin_dlc) != -1) {
+
sl->id_to_send = true;
- sl->data_to_send = true;
+ sl->data_to_send = (lin_data != NULL) ? true : false;
+ sl->resp_len_known = (lin_dlc > 0) ? true : false;
+ sl->dev->stats.tx_packets++;
+ sl->dev->stats.tx_bytes += tx_bytes;
}
- }
- release_skb:
- clear_bit(SLF_MSGEVENT, &sl->flags);
- kfree_skb(sl->rec_skb);
- netif_wake_queue(sl->dev);
- }
+ clear_bit(SLF_MSGEVENT, &sl->flags);
+ kfree_skb(sl->tx_req_skb);
+ netif_wake_queue(sl->dev);
+ hrtimer_start(&sl->rx_timer,
+ ktime_add(ktime_get(), sl->rx_timer_timeout),
+ HRTIMER_MODE_ABS);
+ break;
- switch (sl->lin_state) {
case SLSTATE_BREAK_SENT:
#ifdef BREAK_BY_BAUD
if (sl->rx_cnt <= SLLIN_BUFF_BREAK)
break;
case SLSTATE_ID_SENT:
+ hrtimer_cancel(&sl->rx_timer);
sl->id_to_send = false;
if (sl->data_to_send) {
sllin_send_tx_buff(sl);
sl->rx_expect = sl->tx_lim;
goto slstate_response_sent;
} else {
- sl->rx_expect = SLLIN_BUFF_DATA + 2;
+ if (sl->resp_len_known) {
+ sl->rx_expect = sl->rx_lim;
+ } else {
+ sl->rx_expect = SLLIN_BUFF_DATA + 2;
+ }
sl->lin_state = SLSTATE_RESPONSE_WAIT;
/* If we don't receive anything, timer will "unblock" us */
- hrtimer_start(&sl->rx_timer,
+ hrtimer_start(&sl->rx_timer,
ktime_add(ktime_get(), sl->rx_timer_timeout),
HRTIMER_MODE_ABS);
goto slstate_response_wait;
case SLSTATE_RESPONSE_WAIT:
slstate_response_wait:
+ if (test_bit(SLF_MSGEVENT, &sl->flags)) {
+ unsigned char *lin_buff;
+ cf = (struct can_frame *)sl->tx_req_skb->data;
+
+ lin_buff = (sl->lin_master) ? sl->tx_buff : sl->rx_buff;
+ if (cf->can_id == (lin_buff[SLLIN_BUFF_ID] & LIN_ID_MASK)) {
+ hrtimer_cancel(&sl->rx_timer);
+ pr_debug("sllin: received LIN response in a CAN frame.\n");
+ if (sllin_setup_msg(sl, SLLIN_STPMSG_RESPONLY,
+ cf->can_id & LIN_ID_MASK,
+ cf->data, cf->can_dlc) != -1) {
+
+ sl->rx_expect = sl->tx_lim;
+ sl->data_to_send = true;
+ sl->dev->stats.tx_packets++;
+ sl->dev->stats.tx_bytes += tx_bytes;
+
+ if (!sl->lin_master) {
+ sl->tx_cnt = SLLIN_BUFF_DATA;
+ }
+
+ sllin_send_tx_buff(sl);
+ clear_bit(SLF_MSGEVENT, &sl->flags);
+ kfree_skb(sl->tx_req_skb);
+ netif_wake_queue(sl->dev);
+
+ sl->lin_state = SLSTATE_RESPONSE_SENT;
+ goto slstate_response_sent;
+ }
+ } else {
+ sl->lin_state = SLSTATE_RESPONSE_WAIT_BUS;
+ }
+ }
+
+ /* Be aware, no BREAK here */
+ case SLSTATE_RESPONSE_WAIT_BUS:
if (sl->rx_cnt < sl->rx_expect)
continue;
-
+
hrtimer_cancel(&sl->rx_timer);
- printk(KERN_INFO "sllin: response received ID %d len %d\n",
+ pr_debug("sllin: response received ID %d len %d\n",
sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
- // check checksum in sl->rx_buff
- // send CAN non-RTR frame with data
- printk(KERN_INFO "sllin: sending NON-RTR CAN frame with LIN payload.");
- sll_bump(sl); //send packet to the network layer
+
+ if (sllin_rx_validate(sl) == -1) {
+ pr_debug("sllin: RX validation failed.\n");
+ sllin_report_error(sl, LIN_ERR_CHECKSUM);
+ } else {
+ /* Send CAN non-RTR frame with data */
+ pr_debug("sllin: sending NON-RTR CAN"
+ "frame with LIN payload.");
+ sll_bump(sl); /* send packet to the network layer */
+ }
+
sl->id_to_send = false;
sl->lin_state = SLSTATE_IDLE;
break;
slstate_response_sent:
if (sl->rx_cnt < sl->tx_lim)
continue;
-
- printk(KERN_INFO "sllin: response sent ID %d len %d\n",
+
+ hrtimer_cancel(&sl->rx_timer);
+ sll_bump(sl); /* send packet to the network layer */
+ pr_debug("sllin: response sent ID %d len %d\n",
sl->rx_buff[SLLIN_BUFF_ID], sl->rx_cnt - SLLIN_BUFF_DATA - 1);
sl->id_to_send = false;
sl->lin_state = SLSTATE_IDLE;
break;
}
-
-
-
-
- /* sl->dev->stats.tx_packets++; send frames statistic */
- /* netif_wake_queue(sl->dev); allow next Tx packet arrival */
}
hrtimer_cancel(&sl->rx_timer);
- printk(KERN_INFO "sllin: sllin_kwthread stopped.\n");
+ pr_debug("sllin: sllin_kwthread stopped.\n");
return 0;
}
}
sl = netdev_priv(dev);
-
/* Initialize channel control data */
sl->magic = SLLIN_MAGIC;
sl->dev = dev;
if (!test_bit(SLF_INUSE, &sl->flags)) {
/* Perform the low-level SLLIN initialization. */
- sl->lin_master = true;
+ sl->lin_master = master;
+#ifdef DEBUG
+ if (master)
+ pr_debug("sllin: Configured as MASTER\n");
+ else
+ pr_debug("sllin: Configured as SLAVE\n");
+#endif
- sl->rx_cnt = 0;
- sl->rx_expect = 0;
- sl->rx_lim = sl->lin_master ? 0 : SLLIN_BUFF_LEN;
- sl->tx_cnt = 0;
- sl->tx_lim = 0;
- sl->id_to_send = false;
- sl->data_to_send = false;
+ sllin_reset_buffs(sl);
- sl->lin_baud = 19200;
+ sl->lin_baud = (baudrate == 0) ? LIN_DEFAULT_BAUDRATE : baudrate;
+ pr_debug("sllin: Baudrate set to %u\n", sl->lin_baud);
sl->lin_state = SLSTATE_IDLE;
-#define SAMPLES_PER_CHAR 10
-#define CHARS_TO_TIMEOUT 12
hrtimer_init(&sl->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sl->rx_timer.function = sllin_rx_timeout_handler;
/* timeval_to_ktime(msg_head->ival1); */
sl->rx_timer_timeout = ns_to_ktime(
- (1000000000 / sl->lin_baud) *
- SAMPLES_PER_CHAR * CHARS_TO_TIMEOUT);
-
+ (1000000000l / sl->lin_baud) *
+ SLLIN_SAMPLES_PER_CHAR * SLLIN_CHARS_TO_TIMEOUT);
+
set_bit(SLF_INUSE, &sl->flags);
init_waitqueue_head(&sl->kwt_wq);
/* Done. We have linked the TTY line to a channel. */
rtnl_unlock();
- tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */
+ tty->receive_room = SLLIN_BUFF_LEN * 40; /* We don't flow control */
/* TTY layer expects 0 on success */
return 0;
maxdev = 4; /* Sanity */
printk(banner);
- printk(KERN_INFO "sllin: %d dynamic interface channels.\n", maxdev);
+ pr_debug("sllin: %d dynamic interface channels.\n", maxdev);
sllin_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL);
if (!sllin_devs) {
printk(KERN_ERR "sllin: can't register line discipline\n");
kfree(sllin_devs);
}
+
+#ifdef BREAK_BY_BAUD
+ pr_debug("sllin: Break is generated by baud-rate change.");
+#else
+ pr_debug("sllin: Break is generated manually with tiny sleep.");
+#endif
+
return status;
}