This short program illustrates how to use the DS130x_I2C library. My objective is to share the same RTC with Microchip 18F MCU.
Dependencies: mbed DebugLibrary
NetServices/lwip/netif/slipif.c
- Committer:
- Yann
- Date:
- 2011-02-11
- Revision:
- 1:995212d326ca
- Parent:
- 0:f30e2135b0db
File content as of revision 1:995212d326ca:
/** * @file * SLIP Interface * */ /* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * This file is built upon the file: src/arch/rtxc/netif/sioslip.c * * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com> */ /* * This is an arch independent SLIP netif. The specific serial hooks must be * provided by another file. They are sio_open, sio_read/sio_tryread and sio_send */ #include "netif/slipif.h" #include "lwip/opt.h" #if LWIP_HAVE_SLIPIF #include "lwip/def.h" #include "lwip/pbuf.h" #include "lwip/sys.h" #include "lwip/stats.h" #include "lwip/snmp.h" #include "lwip/sio.h" #define SLIP_BLOCK 1 #define SLIP_DONTBLOCK 0 #define SLIP_END 0300 /* 0xC0 */ #define SLIP_ESC 0333 /* 0xDB */ #define SLIP_ESC_END 0334 /* 0xDC */ #define SLIP_ESC_ESC 0335 /* 0xDD */ #define SLIP_MAX_SIZE 1500 enum slipif_recv_state { SLIP_RECV_NORMAL, SLIP_RECV_ESCAPE, }; struct slipif_priv { sio_fd_t sd; /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */ struct pbuf *p, *q; enum slipif_recv_state state; u16_t i, recved; }; /** * Send a pbuf doing the necessary SLIP encapsulation * * Uses the serial layer's sio_send() * * @param netif the lwip network interface structure for this slipif * @param p the pbuf chaing packet to send * @param ipaddr the ip address to send the packet to (not used for slipif) * @return always returns ERR_OK since the serial layer does not provide return values */ err_t slipif_output(struct netif *netif, struct pbuf *p, ip_addr_t *ipaddr) { struct slipif_priv *priv; struct pbuf *q; u16_t i; u8_t c; LWIP_ASSERT("netif != NULL", (netif != NULL)); LWIP_ASSERT("netif->state != NULL", (netif->state != NULL)); LWIP_ASSERT("p != NULL", (p != NULL)); LWIP_UNUSED_ARG(ipaddr); priv = netif->state; /* Send pbuf out on the serial I/O device. */ sio_send(SLIP_END, priv->sd); for (q = p; q != NULL; q = q->next) { for (i = 0; i < q->len; i++) { c = ((u8_t *)q->payload)[i]; switch (c) { case SLIP_END: sio_send(SLIP_ESC, priv->sd); sio_send(SLIP_ESC_END, priv->sd); break; case SLIP_ESC: sio_send(SLIP_ESC, priv->sd); sio_send(SLIP_ESC_ESC, priv->sd); break; default: sio_send(c, priv->sd); break; } } } sio_send(SLIP_END, priv->sd); return ERR_OK; } /** * Static function for easy use of blockig or non-blocking * sio_read * * @param fd serial device handle * @param data pointer to data buffer for receiving * @param len maximum length (in bytes) of data to receive * @param block if 1, call sio_read; if 0, call sio_tryread * @return return value of sio_read of sio_tryread */ static u32_t slip_sio_read(sio_fd_t fd, u8_t* data, u32_t len, u8_t block) { if (block) { return sio_read(fd, data, len); } else { return sio_tryread(fd, data, len); } } /** * Handle the incoming SLIP stream character by character * * Poll the serial layer by calling sio_read() or sio_tryread(). * * @param netif the lwip network interface structure for this slipif * @param block if 1, block until data is received; if 0, return when all data * from the buffer is received (multiple calls to this function will * return a complete packet, NULL is returned before - used for polling) * @return The IP packet when SLIP_END is received */ static struct pbuf * slipif_input(struct netif *netif, u8_t block) { struct slipif_priv *priv; u8_t c; struct pbuf *t; LWIP_ASSERT("netif != NULL", (netif != NULL)); LWIP_ASSERT("netif->state != NULL", (netif->state != NULL)); priv = netif->state; while (slip_sio_read(priv->sd, &c, 1, block) > 0) { switch (priv->state) { case SLIP_RECV_NORMAL: switch (c) { case SLIP_END: if (priv->recved > 0) { /* Received whole packet. */ /* Trim the pbuf to the size of the received packet. */ pbuf_realloc(priv->q, priv->recved); LINK_STATS_INC(link.recv); LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n")); t = priv->q; priv->p = priv->q = NULL; priv->i = priv->recved = 0; return t; } continue; case SLIP_ESC: priv->state = SLIP_RECV_ESCAPE; continue; } break; case SLIP_RECV_ESCAPE: switch (c) { case SLIP_ESC_END: c = SLIP_END; break; case SLIP_ESC_ESC: c = SLIP_ESC; break; } priv->state = SLIP_RECV_NORMAL; /* FALLTHROUGH */ } /* byte received, packet not yet completely received */ if (priv->p == NULL) { /* allocate a new pbuf */ LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n")); priv->p = pbuf_alloc(PBUF_LINK, (PBUF_POOL_BUFSIZE - PBUF_LINK_HLEN), PBUF_POOL); if (priv->p == NULL) { LINK_STATS_INC(link.drop); LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n")); /* don't process any further since we got no pbuf to receive to */ break; } if (priv->q != NULL) { /* 'chain' the pbuf to the existing chain */ pbuf_cat(priv->q, priv->p); } else { /* p is the first pbuf in the chain */ priv->q = priv->p; } } /* this automatically drops bytes if > SLIP_MAX_SIZE */ if ((priv->p != NULL) && (priv->recved <= SLIP_MAX_SIZE)) { ((u8_t *)priv->p->payload)[priv->i] = c; priv->recved++; priv->i++; if (priv->i >= priv->p->len) { /* on to the next pbuf */ priv->i = 0; if (priv->p->next != NULL && priv->p->next->len > 0) { /* p is a chain, on to the next in the chain */ priv->p = priv->p->next; } else { /* p is a single pbuf, set it to NULL so next time a new * pbuf is allocated */ priv->p = NULL; } } } } return NULL; } #if !NO_SYS /** * The SLIP input thread. * * Feed the IP layer with incoming packets * * @param nf the lwip network interface structure for this slipif */ static void slipif_loop_thread(void *nf) { struct pbuf *p; struct netif *netif = (struct netif *)nf; while (1) { p = slipif_input(netif, SLIP_BLOCK); if (p != NULL) { if (netif->input(p, netif) != ERR_OK) { pbuf_free(p); p = NULL; } } } } #endif /* !NO_SYS */ /** * SLIP netif initialization * * Call the arch specific sio_open and remember * the opened device in the state field of the netif. * * @param netif the lwip network interface structure for this slipif * @return ERR_OK if serial line could be opened, * ERR_MEM if no memory could be allocated, * ERR_IF is serial line couldn't be opened * * @note netif->num must contain the number of the serial port to open * (0 by default) */ err_t slipif_init(struct netif *netif) { struct slipif_priv *priv; LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num)); /* Allocate private data */ priv = mem_malloc(sizeof(struct slipif_priv)); if (!priv) { return ERR_MEM; } netif->name[0] = 's'; netif->name[1] = 'l'; netif->output = slipif_output; netif->mtu = SLIP_MAX_SIZE; netif->flags |= NETIF_FLAG_POINTTOPOINT; /* Try to open the serial port (netif->num contains the port number). */ priv->sd = sio_open(netif->num); if (!priv->sd) { /* Opening the serial port failed. */ mem_free(priv); return ERR_IF; } /* Initialize private data */ priv->p = NULL; priv->q = NULL; priv->state = SLIP_RECV_NORMAL; priv->i = 0; priv->recved = 0; netif->state = priv; /* initialize the snmp variables and counters inside the struct netif * ifSpeed: no assumption can be made without knowing more about the * serial line! */ NETIF_INIT_SNMP(netif, snmp_ifType_slip, 0); /* Create a thread to poll the serial line. */ sys_thread_new(SLIPIF_THREAD_NAME, slipif_loop_thread, netif, SLIPIF_THREAD_STACKSIZE, SLIPIF_THREAD_PRIO); return ERR_OK; } /** * Polls the serial device and feeds the IP layer with incoming packets. * * @param netif The lwip network interface structure for this slipif */ void slipif_poll(struct netif *netif) { struct pbuf *p; struct slipif_priv *priv; LWIP_ASSERT("netif != NULL", (netif != NULL)); LWIP_ASSERT("netif->state != NULL", (netif->state != NULL)); priv = netif->state; while ((p = slipif_input(netif, SLIP_DONTBLOCK)) != NULL) { if (netif->input(p, netif) != ERR_OK) { pbuf_free(p); } } } #endif /* LWIP_HAVE_SLIPIF */