/*
   * Cirrus Logic CS8900A Ethernet
   *
   * (C) 2009 Ben Warren , biggerbadderben@gmail.com
   *     Converted to use CONFIG_NET_MULTI API
   *
   * (C) 2003 Wolfgang Denk, wd@denx.de
   *     Extension to synchronize ethaddr environment variable
   *     against value in EEPROM
   *
   * (C) Copyright 2002
   * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   * Marius Groeger <mgroeger@sysgo.de>
   *
   * Copyright (C) 1999 Ben Williamson <benw@pobox.com>
   *
   * This program is loaded into SRAM in bootstrap mode, where it waits
   * for commands on UART1 to read and write memory, jump to code etc.
   * A design goal for this program is to be entirely independent of the
   * target board.  Anything with a CL-PS7111 or EP7211 should be able to run
   * this code in bootstrap mode.  All the board specifics can be handled on
   * the host.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <command.h>
  #include <asm/io.h>
  #include <net.h>
  #include <malloc.h>
  #include "cs8900.h"
  
  #undef DEBUG
  
  /* packet page register access functions */
  
  #ifdef CONFIG_CS8900_BUS32
  
  #define REG_WRITE(v, a) writel((v),(a))
  #define REG_READ(a) readl((a))
  
  /* we don't need 16 bit initialisation on 32 bit bus */
  #define get_reg_init_bus(r,d) get_reg((r),(d))
  
  #else
  
  #define REG_WRITE(v, a) writew((v),(a))
  #define REG_READ(a) readw((a))
  
  static u16 get_reg_init_bus(struct eth_device *dev, int regno)
  {
  	/* force 16 bit busmode */
  	struct cs8900_priv *priv = (struct cs8900_priv *)(dev->priv);
  	uint8_t volatile * const iob = (uint8_t volatile * const)dev->iobase;
  
  	readb(iob);
  	readb(iob + 1);
  	readb(iob);
  	readb(iob + 1);
  	readb(iob);
  
  	REG_WRITE(regno, &priv->regs->pptr);
  	return REG_READ(&priv->regs->pdata);
  }
  #endif
  
  static u16 get_reg(struct eth_device *dev, int regno)
  {
  	struct cs8900_priv *priv = (struct cs8900_priv *)(dev->priv);
  	REG_WRITE(regno, &priv->regs->pptr);
  	return REG_READ(&priv->regs->pdata);
  }
  
  
  static void put_reg(struct eth_device *dev, int regno, u16 val)
  {
  	struct cs8900_priv *priv = (struct cs8900_priv *)(dev->priv);
  	REG_WRITE(regno, &priv->regs->pptr);
  	REG_WRITE(val, &priv->regs->pdata);
  }
  
  static void cs8900_reset(struct eth_device *dev)
  {
  	int tmo;
  	u16 us;
  
  	/* reset NIC */
  	put_reg(dev, PP_SelfCTL, get_reg(dev, PP_SelfCTL) | PP_SelfCTL_Reset);
  
  	/* wait for 200ms */
  	udelay(200000);
  	/* Wait until the chip is reset */
  
  	tmo = get_timer(0) + 1 * CONFIG_SYS_HZ;
  	while ((((us = get_reg_init_bus(dev, PP_SelfSTAT)) &
  		PP_SelfSTAT_InitD) == 0) && tmo < get_timer(0))
  		/*NOP*/;
  }
  
  static void cs8900_reginit(struct eth_device *dev)
  {
  	/* receive only error free packets addressed to this card */
  	put_reg(dev, PP_RxCTL,
  		PP_RxCTL_IA | PP_RxCTL_Broadcast | PP_RxCTL_RxOK);
  	/* do not generate any interrupts on receive operations */
  	put_reg(dev, PP_RxCFG, 0);
  	/* do not generate any interrupts on transmit operations */
  	put_reg(dev, PP_TxCFG, 0);
  	/* do not generate any interrupts on buffer operations */
  	put_reg(dev, PP_BufCFG, 0);
  	/* enable transmitter/receiver mode */
  	put_reg(dev, PP_LineCTL, PP_LineCTL_Rx | PP_LineCTL_Tx);
  }
  
  void cs8900_get_enetaddr(struct eth_device *dev)
  {
  	int i;
  
  	/* verify chip id */
  	if (get_reg_init_bus(dev, PP_ChipID) != 0x630e)
  		return;
  	cs8900_reset(dev);
  	if ((get_reg(dev, PP_SelfSTAT) &
  		(PP_SelfSTAT_EEPROM | PP_SelfSTAT_EEPROM_OK)) ==
  		(PP_SelfSTAT_EEPROM | PP_SelfSTAT_EEPROM_OK)) {
  
  		/* Load the MAC from EEPROM */
  		for (i = 0; i < 3; i++) {
  			u32 Addr;
  
  			Addr = get_reg(dev, PP_IA + i * 2);
  			dev->enetaddr[i * 2] = Addr & 0xFF;
  			dev->enetaddr[i * 2 + 1] = Addr >> 8;
  		}
  	}
  }
  
  void cs8900_halt(struct eth_device *dev)
  {
  	/* disable transmitter/receiver mode */
  	put_reg(dev, PP_LineCTL, 0);
  
  	/* "shutdown" to show ChipID or kernel wouldn't find he cs8900 ... */
  	get_reg_init_bus(dev, PP_ChipID);
  }
  
  static int cs8900_init(struct eth_device *dev, bd_t * bd)
  {
  	uchar *enetaddr = dev->enetaddr;
  	u16 id;
  
  	/* verify chip id */
  	id = get_reg_init_bus(dev, PP_ChipID);
  	if (id != 0x630e) {
  		printf ("CS8900 Ethernet chip not found: "
  			"ID=0x%04x instead 0x%04x
  ", id, 0x630e);
  		return 1;
  	}
  
  	cs8900_reset (dev);
  	/* set the ethernet address */
  	put_reg(dev, PP_IA + 0, enetaddr[0] | (enetaddr[1] << 8));
  	put_reg(dev, PP_IA + 2, enetaddr[2] | (enetaddr[3] << 8));
  	put_reg(dev, PP_IA + 4, enetaddr[4] | (enetaddr[5] << 8));
  
  	cs8900_reginit(dev);
  	return 0;
  }
  
  /* Get a data block via Ethernet */
  static int cs8900_recv(struct eth_device *dev)
  {
  	int i;
  	u16 rxlen;
  	u16 *addr;
  	u16 status;
  
  	struct cs8900_priv *priv = (struct cs8900_priv *)(dev->priv);
  
  	status = get_reg(dev, PP_RER);
  
  	if ((status & PP_RER_RxOK) == 0)
  		return 0;
  
  	status = REG_READ(&priv->regs->rtdata);
  	rxlen = REG_READ(&priv->regs->rtdata);
  
  	if (rxlen > PKTSIZE_ALIGN + PKTALIGN)
  		debug("packet too big!
  ");
  	for (addr = (u16 *) NetRxPackets[0], i = rxlen >> 1; i > 0;
  		 i--)
  		*addr++ = REG_READ(&priv->regs->rtdata);
  	if (rxlen & 1)
  		*addr++ = REG_READ(&priv->regs->rtdata);
  
  	/* Pass the packet up to the protocol layers. */
  	NetReceive (NetRxPackets[0], rxlen);
  	return rxlen;
  }
  
  /* Send a data block via Ethernet. */
  static int cs8900_send(struct eth_device *dev, void *packet, int length)
  {
  	volatile u16 *addr;
  	int tmo;
  	u16 s;
  	struct cs8900_priv *priv = (struct cs8900_priv *)(dev->priv);
  
  retry:
  	/* initiate a transmit sequence */
  	REG_WRITE(PP_TxCmd_TxStart_Full, &priv->regs->txcmd);
  	REG_WRITE(length, &priv->regs->txlen);
  
  	/* Test to see if the chip has allocated memory for the packet */
  	if ((get_reg(dev, PP_BusSTAT) & PP_BusSTAT_TxRDY) == 0) {
  		/* Oops... this should not happen! */
  		debug("cs: unable to send packet; retrying...
  ");
  		for (tmo = get_timer(0) + 5 * CONFIG_SYS_HZ;
  			get_timer(0) < tmo;)
  			/*NOP*/;
  		cs8900_reset(dev);
  		cs8900_reginit(dev);
  		goto retry;
  	}
  
  	/* Write the contents of the packet */
  	/* assume even number of bytes */
  	for (addr = packet; length > 0; length -= 2)
  		REG_WRITE(*addr++, &priv->regs->rtdata);
  
  	/* wait for transfer to succeed */
  	tmo = get_timer(0) + 5 * CONFIG_SYS_HZ;
  	while ((s = get_reg(dev, PP_TER) & ~0x1F) == 0) {
  		if (get_timer(0) >= tmo)
  			break;
  	}
  
  	/* nothing */ ;
  	if((s & (PP_TER_CRS | PP_TER_TxOK)) != PP_TER_TxOK) {
  		debug("
  transmission error %#x
  ", s);
  	}
  
  	return 0;
  }
  
  static void cs8900_e2prom_ready(struct eth_device *dev)
  {
  	while (get_reg(dev, PP_SelfSTAT) & SI_BUSY)
  		;
  }
  
  /***********************************************************/
  /* read a 16-bit word out of the EEPROM                    */
  /***********************************************************/
  
  int cs8900_e2prom_read(struct eth_device *dev,
  			u8 addr, u16 *value)
  {
  	cs8900_e2prom_ready(dev);
  	put_reg(dev, PP_EECMD, EEPROM_READ_CMD | addr);
  	cs8900_e2prom_ready(dev);
  	*value = get_reg(dev, PP_EEData);
  
  	return 0;
  }
  
  
  /***********************************************************/
  /* write a 16-bit word into the EEPROM                     */
  /***********************************************************/
  
  int cs8900_e2prom_write(struct eth_device *dev, u8 addr, u16 value)
  {
  	cs8900_e2prom_ready(dev);
  	put_reg(dev, PP_EECMD, EEPROM_WRITE_EN);
  	cs8900_e2prom_ready(dev);
  	put_reg(dev, PP_EEData, value);
  	put_reg(dev, PP_EECMD, EEPROM_WRITE_CMD | addr);
  	cs8900_e2prom_ready(dev);
  	put_reg(dev, PP_EECMD, EEPROM_WRITE_DIS);
  	cs8900_e2prom_ready(dev);
  
  	return 0;
  }
  
  int cs8900_initialize(u8 dev_num, int base_addr)
  {
  	struct eth_device *dev;
  	struct cs8900_priv *priv;
  
  	dev = malloc(sizeof(*dev));
  	if (!dev) {
  		return 0;
  	}
  	memset(dev, 0, sizeof(*dev));
  
  	priv = malloc(sizeof(*priv));
  	if (!priv) {
  		free(dev);
  		return 0;
  	}
  	memset(priv, 0, sizeof(*priv));
  	priv->regs = (struct cs8900_regs *)base_addr;
  
  	dev->iobase = base_addr;
  	dev->priv = priv;
  	dev->init = cs8900_init;
  	dev->halt = cs8900_halt;
  	dev->send = cs8900_send;
  	dev->recv = cs8900_recv;
  
  	/* Load MAC address from EEPROM */
  	cs8900_get_enetaddr(dev);
  
  	sprintf(dev->name, "%s-%hu", CS8900_DRIVERNAME, dev_num);
  
  	eth_register(dev);
  	return 0;
  }