/** @file * Copyright (c) 2001 Leon Woestenberg <leon.woestenberg@axon.nl>
 * Copyright (c) 2001 Axon Digital Design B.V., The Netherlands.
 * All rights reserved. *
 * This is a device driver for the Crystal Semiconductor CS8900 * chip in combination with the lwIP stack.
 *
 * This is work under development. Please coordinate changes
 * and requests with Leon Woestenberg <leon.woestenberg@axon.nl>
 *
 * The Swedish Institute of Computer Science and Adam Dunkels
 * are specifically granted permission to redistribute this
 * source code under any conditions they seem fit.
 *
 * A quick function roadmap:
 *
 * cs8900_*() are low level, cs8900 hardware specific functions.
 * These are static functions of the device driver source and
 * SHOULD NOT need to be called from outside this source.
 *
 * cs8900if_*() are the lwIP network interface functions.
 * 
 * cs8900_interrupt() is an early interrupt service routine (ISR).
 * It merely sets a flag to indicate the cs8900 needs servicing.
 * (This function MAY be tied to an interrupt vector, IF present).
 *
 * cs8900_service() is the actual interrupt event service routine.
 * It must be called whenever the cs8900 needs servicing. It MAY
 * be polled safely (so, you do NOT NEED interrupt support.)
 *
 * cs8900_init() sets up the cs8900, using its register set. When
 * using the driver on your particular hardware platform, make sure
 * the register setups match.
 * Function is called from cs8900if_init().
 *
 * cs8900_input() transfers a received packet from the chip.
 * Function is called from cs8900if_input().
 *
 * cs8900_output() transfers a packet to the chip for transmission.
 * Function is called from cs8900if_output().
 *
 * cs8900if_init() initializes the lwIP network interface, and
 * calls cs8900_init() to intialize the hardware.
 * Function is called from lwIP.
 * 
 * cs8900if_service() is the service routine, which must be called
 * upon the need for service, or on a regular basis, in order to
 * service the Ethernet chip.
 *
 * cs8900if_input() calls cs8900_input() to get a received packet
 * and then forwards the packet to protocol(s) handler(s).
 * Function is called from cs8900_service().
 *
 * cs8900if_output() resolves the hardware address, then
 * calls cs8900_output() to transfer the packet.
 * Function is called from lwIP.
 *
 * Future development:
 * 
 * Split the generic Ethernet functionality (a lot of the
 * cs8900if_*() functions) and the actual cs8900a dependencies.
 *
 * Enhance the interrupt handler to service the Ethernet
 * chip (to decrease latency); support early packet
 * inspection (during reception) to early drop unwanted
 * packets, minimize chip buffer use and maximize throughput.
 *
 * Statistics gathering.
 *
 */#include "lwip/debug.h"#include "lwip/opt.h"#include "lwip/def.h"#include "lwip/mem.h"#include "lwip/pbuf.h"#include "lwip/stats.h"#include "lwip/sys.h"#include "netif/etharp.h"

#if 1
#  define DBG_LEVEL 1
#  include "leds.h"
#  include "display.h"
//#  include "page.h"
#else
#  define leds_on()
#  define leds_off()
#endif

#include "cs8900if.h"
#ifdef SNMP
#  include "snmp.h"
#  include "mib2if.h"
#endif
/* Define those to better describe your network interface. */#define IFNAME0 'e'#define IFNAME1 'n'

extern far unsigned char sector16[30]; // A piece of ROM/RAM where the MAC resides
far unsigned char *eth_oui = &sector16[0]; // Ethernet MAC address
static const struct eth_addr ethbroadcast = {{0xffU,0xffU,0xffU,0xffU,0xffU,0xffU}};
/* Forward declarations. */static void  cs8900if_input(struct netif *netif);static err_t cs8900if_output(struct netif *netif, struct pbuf *p,			       struct ip_addr *ipaddr);
static err_t cs8900_output(struct netif *netif, struct pbuf *p);static struct pbuf *cs8900_input(struct netif *netif);static void cs8900_service(struct netif *netif);
/* Define these to match your hardware setup */
#define MEM_BASE 0x00E000#define IO_BASE 0x800#define INT_NR 0x00
#define RXTXREG  *((volatile u16_t *)(MEM_BASE + IO_BASE))#define TXCMD    *((volatile u16_t *)(MEM_BASE + IO_BASE + 0x04))#define TXLENGTH *((volatile u16_t *)(MEM_BASE + IO_BASE + 0x06))#define ISQ      *((volatile u16_t *)(MEM_BASE + IO_BASE + 0x08))#define PACKETPP *((volatile u16_t *)(MEM_BASE + IO_BASE + 0x0A))#define PPDATA   *((volatile u16_t *)(MEM_BASE + IO_BASE + 0x0C))
// CS8900 PacketPage register offsets 

#define  CS_PP_EISA        0x0000          // EISA Registration number of CS8900
#define  CS_PP_PRODID      0x0002          // Product ID Number
#define  CS_PP_IOBASE      0x0020          // I/O Base Address
#define  CS_PP_INTNUM      0x0022          // Interrupt number (0,1,2, or 3)
#define  CS_PP_RXCFG       0x0102          // Receiver Configuration
#define  CS_PP_RXCTL       0x0104          // Receiver Control
#define  CS_PP_TXCFG       0x0106          // Transmit Configuration
#define  CS_PP_BUFCFG      0x010A          // Buffer Configuration
#define  CS_PP_LINECTL     0x0112          // Line Control Register offset
#define  CS_PP_SELFCTL     0x0114          // Self Control
#define  CS_PP_BUSCTL      0x0116          // Bus Control
#define  CS_PP_TESTCTL     0x0118          // Test Control
#define  CS_PP_ISQ         0x0120          // Interrupt status queue
#define  CS_PP_RXEVENT     0x0124          // Receiver Event
#define  CS_PP_TX_EVENT    0x0128          // Transmitter Event
#define  CS_PP_BUF_EVENT   0x012C          // Buffer Event
#define  CS_PP_RXMISS      0x0130          // Receiver Miss Counter
#define  CS_PP_TXCOL       0x0132          // Transmit Collision Counter
#define  CS_PP_LINESTATUS  0x0134          // Line Status
#define  CS_PP_SELFTEST    0x0136          // Self Status
#define  CS_PP_BUSSTATUS   0x0138          // Bus Status
#define  CS_PP_TXCMD       0x0144          // Transmit Command Request
#define  CS_PP_TXLEN       0x0146          // Transmit Length
#define  CS_PP_IA1         0x0158          // Individual Address (IA)
#define  CS_PP_IA2         0x015A          // Individual Address (IA)
#define  CS_PP_IA3         0x015C          // Individual Address (IA)

#define  CS_PP_RXSTATUS    0x0400          // Receive Status
#define  CS_PP_RXLEN       0x0402          // Receive Length
#define  CS_PP_RXFRAME     0x0404          // Receive Frame Location
#define  CS_PP_TXFRAME     0x0A00          // Transmit Frame Location

// network interface state
static struct netif *cs8900if_netif;
// hardware interrupt vector handler 
interrupt (0x18) void cs8900_interrupt(void)
{
  struct cs8900if *cs8900if = cs8900if_netif->state;
  // network interface is configured?
  if (cs8900if != NULL)
  {
    // chip needs service
    cs8900if->needs_service = 1;
#if (CS8900_STATS > 0)
    cs8900if->interrupts++;
#endif
  }
  leds_on(LED_FP1);
}

// cs8900_init()
//
// initializes the CS8900A
static void cs8900_init(struct netif *netif){  u16_t dummy;  leds_off(LED_FP1);
  /* MAC address */  ((struct cs8900if *)netif->state)->ethaddr->addr[0] = eth_oui[0];  ((struct cs8900if *)netif->state)->ethaddr->addr[1] = eth_oui[1];  ((struct cs8900if *)netif->state)->ethaddr->addr[2] = eth_oui[2];  ((struct cs8900if *)netif->state)->ethaddr->addr[3] = eth_oui[3];  ((struct cs8900if *)netif->state)->ethaddr->addr[4] = eth_oui[4];  ((struct cs8900if *)netif->state)->ethaddr->addr[5] = eth_oui[5];
  // set RESET bit  PACKETPP = CS_PP_SELFCTL;
  PPDATA = 0x0055U;

  // { the RESET bit will be cleared by the cs8900a
  //   as a result of the reset }
#if (DBG_LEVEL > 0)
  page_printf("\f\vwaiting for RESET zero\n");
#endif
  // RESET bit cleared?
  while((PPDATA & 0x0040U) != 0); // TODO: add timeout

  // { after full initialization of the cs8900a
  //   the INITD bit will be set }

  PACKETPP = CS_PP_SELFTEST;
#if (DBG_LEVEL > 0)
  page_printf("\f\vwaiting for INITD set\n");
#endif
  // INITD bit still clear?
  while ((PPDATA & 0x0080U) == 0); // TODO: add timeout
  // { INITD bit is set }

#if 0
#if (DBG_LEVEL > 0)
  page_printf("\f\vwaiting for SIBUSY zero\n");
#endif

  // SIBUSY bit still set?
  while ((PPDATA & 0x0100U) == 0x0100); // TODO: add timeout
  // { SIBUSY bit clear }
#endif

#if 0
  // datasheet section 3.3.3   dummy = *(u16_t *)(MEM_BASE + IO_BASE + 0x0D);  /* Dummy read, put chip in 16bit-mode */  dummy = *(u16_t *)(MEM_BASE + IO_BASE + 0x0D);#endif

  // Set MAC address  PACKETPP = CS_PP_IA1;  PPDATA = (u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[0] | ((u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[1] << 8U);  PACKETPP = CS_PP_IA2;  PPDATA = (u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[2] | ((u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[3] << 8U);  PACKETPP = CS_PP_IA3;  PPDATA = (u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[4] | ((u16_t)((struct cs8900if *)netif->state)->ethaddr->addr[5] << 8U);

  // accept valid unicast or broadcast frames
  PACKETPP = CS_PP_RXCTL;
  PPDATA = (0x0005U | 0x0800U/*broadcast*/ | 0x0400U/*individual*/ | 0x0100U/*RxOK*/);
 
  // enable receive interrupt
  PACKETPP = CS_PP_RXCFG;
  PPDATA = (0x0003U | 0x0100U/*RXIRQ*/);
  // disable transmit interrupt (is default)
  PACKETPP = CS_PP_TXCFG;
  PPDATA = (0x0007U | 0);

  // use interrupt number 0
  PACKETPP = CS_PP_INTNUM;
  PPDATA = (0x0000U);

  // generate interrupt event on:
  // - the RxMISS counter reaches 0x200, or
  // - a received frame is lost
  PACKETPP = CS_PP_BUFCFG;
  PPDATA = (0x000bU |
#if (CS8900_STATS > 0) // interrupt before counter overflow 
  (0x2000U/*MissOvfloiE*/ | 0x1000U/*TxColOvfloiE*/) |
#endif
#if (CS8900_STATS > 1) // interrupt on counter increment
  (0x0400U/*RxMissiE*/) |
#endif
  0x0000);

  // enable interrupt generation
  PACKETPP = CS_PP_BUSCTL;
  PPDATA = (0x0017U | 0x8000U/*EnableIRQ*/);

  // enable:
  // - receiver
  // - transmitter
  PACKETPP = CS_PP_LINECTL;
  PPDATA = (0x0013U | 0x0080U/*SerTxOn*/ | 0x0040U/*SerRxOn*/);
  page_printf("\f\vCS8900A configured\n");
}
static err_t cs8900_output(struct netif *netif, struct pbuf *p){	int tries = 0;
  // exit if link has failed
  PACKETPP = CS_PP_LINESTATUS;
  if ((PPDATA & 0x0080U/*LinkOK*/) == 0) return ERR_CONN; // no Ethernet link

  // transmit command  TXCMD = 0x00C9U;  TXLENGTH = p->tot_len;  PACKETPP = CS_PP_BUSSTATUS;
  // not ready for transmission and still within 100 retries?  while(((PPDATA & 0x0100U/*Rdy4TxNOW*/) == 0) && (tries++ < 100))
  {
    // throw away the last committed received frame
    PACKETPP = CS_PP_RXCFG;
    PPDATA = (0x0003U | 0x0040U/*Skip_1*/ | 0x0100U/*RxOKiE*/);    PACKETPP = CS_PP_BUSSTATUS;    /* cs8900if->dropped++; // CHECK: we do not know if we actually will drop a frame here */ 
  }
  // ready to transmit?
  if((PPDATA & 0x0100U/*Rdy4TxNOW*/) != 0)
  {
    // q traverses through linked list of pbuf's
    struct pbuf *q;    for(q = p; q != NULL; q = q->next)
    {      u16_t i;      u16_t *ptr = (u16_t *)q->payload;      // Send the data from the pbuf to the interface, one pbuf at a      // time. The size of the data in each pbuf is kept in the ->len      // variable.      for(i = 0; i < q->len; i += 2)
      {        RXTXREG = *ptr++;      }
#if (CS8900_STATS > 0)
      ((struct cs8900if *)netif->state)->sentbytes += q->len;
#endif
#ifdef SNMP
    if_add_ifOutOctets(p->tot_len);
#endif
    }
#if (CS8900_STATS > 0)
    ((struct cs8900if *)netif->state)->sentpackets++;
#endif
  }
  else
  {
    // { not ready to transmit!? }
  }  return ERR_OK;}
/* * cs8900_input(): * * Allocates a pbuf and transfers the bytes of the incoming * packet from the interface into the pbuf. * */
// To be called just after reading an ISQ event
// containing the "Receiver Event" register.
//
// This function copies a frame from the CS8900A.
// It is designed fail-safe:
// - It does not assume a frame is actually present.
// - It checks for non-zero length
// - It does not overflow the frame buffer
static struct pbuf *cs8900_input(struct netif *netif){  struct pbuf *p = 0, *q;  u16_t len = 0;  u16_t event_type;  u16_t i;  u16_t *ptr;
  // read RxStatus
  event_type = RXTXREG;

  // correctly received frame, either broadcast or individual address?
  // TODO: think where these checks should appear: here or in cs8900_input()
  if ((event_type & 0x0100U/*RxOK*/) && (event_type & 0x0c00U/*Broadcast | Individual*/))
  {
#ifdef SNMP
//    if (event_type & 0x0400U/*Individual*/) if_inc_ifInUcastPkts() else if_inc_ifInNUcastPkts();
#endif
    event_type = 0; 
    // read RxLength
    len = RXTXREG;
    DEBUGF(ETH_DEBUG, ("cs8900_input: packet len %u\n", len));
#ifdef SNMP    
    if_add_ifInOctets(len);
#endif
    // positive length?
    if (len > 0)
    {
      // allocate a pbuf chain with total length 'len' 
      p = pbuf_alloc(PBUF_LINK, len, PBUF_POOL);
      if (p != 0)
      {
        for (q = p; q != 0; q = q->next)
	      {
          DEBUGF(ETH_DEBUG, ("cs8900_input: pbuf @%p len %u\n", q, q->len));
	        ptr = q->payload;
          // TODO: CHECK: what if q->len is odd? we don't use the last byte?
	        for (i = 0; i < (q->len + 1) / 2; i++)
      	  {
	          *ptr = RXTXREG;
	          ptr++;
      	  }
      	}
      }