/* stnic.c : A SH7750 specific part of driver for NS DP83902A ST-NIC.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Copyright (C) 1999 kaz Kojima
   */

  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/interrupt.h>
  #include <linux/ioport.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  
  #include <asm/system.h>
  #include <asm/io.h>

  #include <mach-se/mach/se.h>

  #include <asm/machvec.h>

  #ifdef CONFIG_SH_STANDARD_BIOS

  #include <asm/sh_bios.h>
  #endif
  
  #include "8390.h"
  
  #define DRV_NAME "stnic"
  
  #define byte	unsigned char
  #define half	unsigned short
  #define word	unsigned int
  #define vbyte	volatile unsigned char
  #define vhalf	volatile unsigned short
  #define vword	volatile unsigned int
  
  #define STNIC_RUN	0x01	/* 1 == Run, 0 == reset. */
  
  #define START_PG	0	/* First page of TX buffer */
  #define STOP_PG		128	/* Last page +1 of RX ring */
  
  /* Alias */
  #define STNIC_CR	E8390_CMD
  #define PG0_RSAR0	EN0_RSARLO
  #define PG0_RSAR1	EN0_RSARHI
  #define PG0_RBCR0	EN0_RCNTLO
  #define PG0_RBCR1	EN0_RCNTHI
  
  #define CR_RRD		E8390_RREAD
  #define CR_RWR		E8390_RWRITE
  #define CR_PG0		E8390_PAGE0
  #define CR_STA		E8390_START
  #define CR_RDMA		E8390_NODMA
  
  /* FIXME! YOU MUST SET YOUR OWN ETHER ADDRESS.  */
  static byte stnic_eadr[6] =
  {0x00, 0xc0, 0x6e, 0x00, 0x00, 0x07};
  
  static struct net_device *stnic_dev;

  static void stnic_reset (struct net_device *dev);
  static void stnic_get_hdr (struct net_device *dev, struct e8390_pkt_hdr *hdr,
  			   int ring_page);
  static void stnic_block_input (struct net_device *dev, int count,
  			       struct sk_buff *skb , int ring_offset);
  static void stnic_block_output (struct net_device *dev, int count,
  				const unsigned char *buf, int start_page);
  
  static void stnic_init (struct net_device *dev);
  
  /* SH7750 specific read/write io. */
  static inline void
  STNIC_DELAY (void)
  {
    vword trash;
    trash = *(vword *) 0xa0000000;
    trash = *(vword *) 0xa0000000;
    trash = *(vword *) 0xa0000000;
  }
  
  static inline byte
  STNIC_READ (int reg)
  {
    byte val;
  
    val = (*(vhalf *) (PA_83902 + ((reg) << 1)) >> 8) & 0xff;
    STNIC_DELAY ();
    return val;
  }
  
  static inline void
  STNIC_WRITE (int reg, byte val)
  {
    *(vhalf *) (PA_83902 + ((reg) << 1)) = ((half) (val) << 8);
    STNIC_DELAY ();
  }

  static int __init stnic_probe(void)
  {
    struct net_device *dev;
    int i, err;
  
    /* If we are not running on a SolutionEngine, give up now */
    if (! MACH_SE)
      return -ENODEV;
  
    /* New style probing API */
    dev = alloc_ei_netdev();
    if (!dev)
    	return -ENOMEM;

  #ifdef CONFIG_SH_STANDARD_BIOS

    sh_bios_get_node_addr (stnic_eadr);
  #endif
    for (i = 0; i < ETHER_ADDR_LEN; i++)
      dev->dev_addr[i] = stnic_eadr[i];
  
    /* Set the base address to point to the NIC, not the "real" base! */
    dev->base_addr = 0x1000;
    dev->irq = IRQ_STNIC;

    dev->netdev_ops = &ei_netdev_ops;

  
    /* Snarf the interrupt now.  There's no point in waiting since we cannot
       share and the board will usually be enabled. */
    err = request_irq (dev->irq, ei_interrupt, 0, DRV_NAME, dev);
    if (err)  {
        printk (KERN_EMERG " unable to get IRQ %d.
  ", dev->irq);
        free_netdev(dev);
        return err;
      }
  
    ei_status.name = dev->name;
    ei_status.word16 = 1;

  #ifdef __LITTLE_ENDIAN__

    ei_status.bigendian = 0;
  #else
    ei_status.bigendian = 1;
  #endif
    ei_status.tx_start_page = START_PG;
    ei_status.rx_start_page = START_PG + TX_PAGES;
    ei_status.stop_page = STOP_PG;
  
    ei_status.reset_8390 = &stnic_reset;
    ei_status.get_8390_hdr = &stnic_get_hdr;
    ei_status.block_input = &stnic_block_input;
    ei_status.block_output = &stnic_block_output;
  
    stnic_init (dev);
  
    err = register_netdev(dev);
    if (err) {
      free_irq(dev->irq, dev);
      free_netdev(dev);
      return err;
    }
    stnic_dev = dev;
  
    printk (KERN_INFO "NS ST-NIC 83902A
  ");
  
    return 0;
  }

  static void
  stnic_reset (struct net_device *dev)
  {
    *(vhalf *) PA_83902_RST = 0;
    udelay (5);
    if (ei_debug > 1)
      printk (KERN_WARNING "8390 reset done (%ld).
  ", jiffies);
    *(vhalf *) PA_83902_RST = ~0;
    udelay (5);
  }
  
  static void
  stnic_get_hdr (struct net_device *dev, struct e8390_pkt_hdr *hdr,
  	       int ring_page)
  {
    half buf[2];
  
    STNIC_WRITE (PG0_RSAR0, 0);
    STNIC_WRITE (PG0_RSAR1, ring_page);
    STNIC_WRITE (PG0_RBCR0, 4);
    STNIC_WRITE (PG0_RBCR1, 0);
    STNIC_WRITE (STNIC_CR, CR_RRD | CR_PG0 | CR_STA);
  
    buf[0] = *(vhalf *) PA_83902_IF;
    STNIC_DELAY ();
    buf[1] = *(vhalf *) PA_83902_IF;
    STNIC_DELAY ();
    hdr->next = buf[0] >> 8;
    hdr->status = buf[0] & 0xff;
  #ifdef __LITTLE_ENDIAN__
    hdr->count = buf[1];
  #else
    hdr->count = ((buf[1] >> 8) & 0xff) | (buf[1] << 8);
  #endif
  
    if (ei_debug > 1)
      printk (KERN_DEBUG "ring %x status %02x next %02x count %04x.
  ",
  	    ring_page, hdr->status, hdr->next, hdr->count);
  
    STNIC_WRITE (STNIC_CR, CR_RDMA | CR_PG0 | CR_STA);
  }
  
  /* Block input and output, similar to the Crynwr packet driver. If you are
     porting to a new ethercard look at the packet driver source for hints.
     The HP LAN doesn't use shared memory -- we put the packet
     out through the "remote DMA" dataport. */
  
  static void
  stnic_block_input (struct net_device *dev, int length, struct sk_buff *skb,
  		   int offset)
  {
    char *buf = skb->data;
    half val;
  
    STNIC_WRITE (PG0_RSAR0, offset & 0xff);
    STNIC_WRITE (PG0_RSAR1, offset >> 8);
    STNIC_WRITE (PG0_RBCR0, length & 0xff);
    STNIC_WRITE (PG0_RBCR1, length >> 8);
    STNIC_WRITE (STNIC_CR, CR_RRD | CR_PG0 | CR_STA);
  
    if (length & 1)
      length++;
  
    while (length > 0)
      {
        val = *(vhalf *) PA_83902_IF;
  #ifdef __LITTLE_ENDIAN__
        *buf++ = val & 0xff;
        *buf++ = val >> 8;
  #else
        *buf++ = val >> 8;
        *buf++ = val & 0xff;
  #endif
        STNIC_DELAY ();
        length -= sizeof (half);
      }
  
    STNIC_WRITE (STNIC_CR, CR_RDMA | CR_PG0 | CR_STA);
  }
  
  static void
  stnic_block_output (struct net_device *dev, int length,
  		    const unsigned char *buf, int output_page)
  {
    STNIC_WRITE (PG0_RBCR0, 1);	/* Write non-zero value */
    STNIC_WRITE (STNIC_CR, CR_RRD | CR_PG0 | CR_STA);
    STNIC_DELAY ();
  
    STNIC_WRITE (PG0_RBCR0, length & 0xff);
    STNIC_WRITE (PG0_RBCR1, length >> 8);
    STNIC_WRITE (PG0_RSAR0, 0);
    STNIC_WRITE (PG0_RSAR1, output_page);
    STNIC_WRITE (STNIC_CR, CR_RWR | CR_PG0 | CR_STA);
  
    if (length & 1)
      length++;
  
    while (length > 0)
      {
  #ifdef __LITTLE_ENDIAN__
        *(vhalf *) PA_83902_IF = ((half) buf[1] << 8) | buf[0];
  #else
        *(vhalf *) PA_83902_IF = ((half) buf[0] << 8) | buf[1];
  #endif
        STNIC_DELAY ();
        buf += sizeof (half);
        length -= sizeof (half);
      }
  
    STNIC_WRITE (STNIC_CR, CR_RDMA | CR_PG0 | CR_STA);
  }
  
  /* This function resets the STNIC if something screws up.  */
  static void
  stnic_init (struct net_device *dev)
  {
    stnic_reset (dev);
    NS8390_init (dev, 0);
    return;
  }
  
  static void __exit stnic_cleanup(void)
  {
  	unregister_netdev(stnic_dev);
  	free_irq(stnic_dev->irq, stnic_dev);
  	free_netdev(stnic_dev);
  }
  
  module_init(stnic_probe);
  module_exit(stnic_cleanup);
  MODULE_LICENSE("GPL");