text: /*
   * (C) Copyright 2003
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * See file CREDITS for list of people who contributed to this
   * project.
   *
   * 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 Free Software Foundation; either version 2 of
   * the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  #include <common.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  #ifdef CONFIG_HARD_I2C
  
  #include <mpc5xxx.h>
  #include <i2c.h>
  
  #if (CFG_I2C_MODULE == 2)
  #define I2C_BASE	MPC5XXX_I2C2
  #elif (CFG_I2C_MODULE == 1)
  #define I2C_BASE	MPC5XXX_I2C1
  #else
  #error CFG_I2C_MODULE is not properly configured
  #endif
  
  #define I2C_TIMEOUT	100
  #define I2C_RETRIES	3
  
  struct mpc5xxx_i2c_tap {
  	int scl2tap;
  	int tap2tap;
  };
  
  static int  mpc_reg_in    (volatile u32 *reg);
  static void mpc_reg_out   (volatile u32 *reg, int val, int mask);
  static int  wait_for_bb   (void);
  static int  wait_for_pin  (int *status);
  static int  do_address    (uchar chip, char rdwr_flag);
  static int  send_bytes    (uchar chip, char *buf, int len);
  static int  receive_bytes (uchar chip, char *buf, int len);
  static int  mpc_get_fdr   (int);
  
  static int mpc_reg_in(volatile u32 *reg)
  {
  	int ret = *reg >> 24;
  	__asm__ __volatile__ ("eieio");
  	return ret;
  }
  
  static void mpc_reg_out(volatile u32 *reg, int val, int mask)
  {
  	int tmp;
  
  	if (!mask) {
  		*reg = val << 24;
  	} else {
  		tmp = mpc_reg_in(reg);
  		*reg = ((tmp & ~mask) | (val & mask)) << 24;
  	}
  	__asm__ __volatile__ ("eieio");
  
  	return;
  }
  
  static int wait_for_bb(void)
  {
  	struct mpc5xxx_i2c *regs    = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 timeout = I2C_TIMEOUT;
  	int                 status;
  
  	status = mpc_reg_in(&regs->msr);
  
  	while (timeout-- && (status & I2C_BB)) {
  #if 1
  		volatile int temp;
  		mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
  		temp = mpc_reg_in(&regs->mdr);
  		mpc_reg_out(&regs->mcr, 0, I2C_STA);
  		mpc_reg_out(&regs->mcr, 0, 0);
  		mpc_reg_out(&regs->mcr, I2C_EN, 0);
  #endif
  		udelay(1000);
  		status = mpc_reg_in(&regs->msr);
  	}
  
  	return (status & I2C_BB);
  }
  
  static int wait_for_pin(int *status)
  {
  	struct mpc5xxx_i2c *regs    = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 timeout = I2C_TIMEOUT;
  
  	*status = mpc_reg_in(&regs->msr);
  
  	while (timeout-- && !(*status & I2C_IF)) {
  		udelay(1000);
  		*status = mpc_reg_in(&regs->msr);
  	}
  
  	if (!(*status & I2C_IF)) {
  		return -1;
  	}
  
  	mpc_reg_out(&regs->msr, 0, I2C_IF);
  
  	return 0;
  }
  
  static int do_address(uchar chip, char rdwr_flag)
  {
  	struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 status;
  
  	chip <<= 1;
  
  	if (rdwr_flag) {
  		chip |= 1;
  	}
  
  	mpc_reg_out(&regs->mcr, I2C_TX, I2C_TX);
  	mpc_reg_out(&regs->mdr, chip, 0);
  
  	if (wait_for_pin(&status)) {
  		return -2;
  	}
  
  	if (status & I2C_RXAK) {
  		return -3;
  	}
  
  	return 0;
  }
  
  static int send_bytes(uchar chip, char *buf, int len)
  {
  	struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 wrcount;
  	int                 status;
  
  	for (wrcount = 0; wrcount < len; ++wrcount) {
  
  		mpc_reg_out(&regs->mdr, buf[wrcount], 0);
  
  		if (wait_for_pin(&status)) {
  			break;
  		}
  
  		if (status & I2C_RXAK) {
  			break;
  		}
  
  	}
  
  	return !(wrcount == len);
  }
  
  static int receive_bytes(uchar chip, char *buf, int len)
  {
  	struct mpc5xxx_i2c *regs    = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 dummy   = 1;
  	int                 rdcount = 0;
  	int                 status;
  	int                 i;
  
  	mpc_reg_out(&regs->mcr, 0, I2C_TX);
  
  	for (i = 0; i < len; ++i) {
  		buf[rdcount] = mpc_reg_in(&regs->mdr);
  
  		if (dummy) {
  			dummy = 0;
  		} else {
  			rdcount++;
  		}
  
  
  		if (wait_for_pin(&status)) {
  			return -4;
  		}
  	}
  
  	mpc_reg_out(&regs->mcr, I2C_TXAK, I2C_TXAK);
  	buf[rdcount++] = mpc_reg_in(&regs->mdr);
  
  	if (wait_for_pin(&status)) {
  		return -5;
  	}
  
  	mpc_reg_out(&regs->mcr, 0, I2C_TXAK);
  
  	return 0;
  }
  
  /**************** I2C API ****************/
  
  void i2c_init(int speed, int saddr)
  {
  	struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
  
  	mpc_reg_out(&regs->mcr, 0, 0);
  	mpc_reg_out(&regs->madr, saddr << 1, 0);
  
  	/* Set clock
  	 */
  	mpc_reg_out(&regs->mfdr, mpc_get_fdr(speed), 0);
  
  	/* Enable module
  	 */
  	mpc_reg_out(&regs->mcr, I2C_EN, I2C_INIT_MASK);
  	mpc_reg_out(&regs->msr, 0, I2C_IF);
  
  	return;
  }
  
  static int mpc_get_fdr(int speed)
  {
  	static int fdr = -1;
  
  	if (fdr == -1) {
  		ulong best_speed = 0;
  		ulong divider;
  		ulong ipb, scl;
  		ulong bestmatch = 0xffffffffUL;
  		int best_i = 0, best_j = 0, i, j;
  		int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8};
  		struct mpc5xxx_i2c_tap scltap[] = {
  			{4, 1},
  			{4, 2},
  			{6, 4},
  			{6, 8},
  			{14, 16},
  			{30, 32},
  			{62, 64},
  			{126, 128}
  		};
  
  		ipb = gd->ipb_clk;
  		for (i = 7; i >= 0; i--) {
  			for (j = 7; j >= 0; j--) {
  				scl = 2 * (scltap[j].scl2tap +
  					(SCL_Tap[i] - 1) * scltap[j].tap2tap + 2);
  				if (ipb <= speed*scl) {
  					if ((speed*scl - ipb) < bestmatch) {
  						bestmatch = speed*scl - ipb;
  						best_i = i;
  						best_j = j;
  						best_speed = ipb/scl;
  					}
  				}
  			}
  		}
  		divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
  		if (gd->flags & GD_FLG_RELOC) {
  			fdr = divider;
  		} else {
  			printf("%ld kHz, ", best_speed / 1000);
  			return divider;
  		}
  	}
  
  	return fdr;
  }
  
  int i2c_probe(uchar chip)
  {
  	struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 i;
  
  	for (i = 0; i < I2C_RETRIES; i++) {
  		mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
  
  		if (! do_address(chip, 0)) {
  			mpc_reg_out(&regs->mcr, 0, I2C_STA);
  			udelay(500);
  			break;
  		}
  
  		mpc_reg_out(&regs->mcr, 0, I2C_STA);
  		udelay(500);
  	}
  
  	return (i == I2C_RETRIES);
  }
  
  int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
  {
  	char                xaddr[4];
  	struct mpc5xxx_i2c * regs        = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                  ret         = -1;
  
  	xaddr[0] = (addr >> 24) & 0xFF;
  	xaddr[1] = (addr >> 16) & 0xFF;
  	xaddr[2] = (addr >>  8) & 0xFF;
  	xaddr[3] =  addr	& 0xFF;
  
  	if (wait_for_bb()) {
  		printf("i2c_read: bus is busy\n");
  		goto Done;
  	}
  
  	mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
  	if (do_address(chip, 0)) {
  		printf("i2c_read: failed to address chip\n");
  		goto Done;
  	}
  
  	if (send_bytes(chip, &xaddr[4-alen], alen)) {
  		printf("i2c_read: send_bytes failed\n");
  		goto Done;
  	}
  
  	mpc_reg_out(&regs->mcr, I2C_RSTA, I2C_RSTA);
  	if (do_address(chip, 1)) {
  		printf("i2c_read: failed to address chip\n");
  		goto Done;
  	}
  
  	if (receive_bytes(chip, (char *)buf, len)) {
  		printf("i2c_read: receive_bytes failed\n");
  		goto Done;
  	}
  
  	ret = 0;
  Done:
  	mpc_reg_out(&regs->mcr, 0, I2C_STA);
  	return ret;
  }
  
  int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
  {
  	char               xaddr[4];
  	struct mpc5xxx_i2c *regs        = (struct mpc5xxx_i2c *)I2C_BASE;
  	int                 ret         = -1;
  
  	xaddr[0] = (addr >> 24) & 0xFF;
  	xaddr[1] = (addr >> 16) & 0xFF;
  	xaddr[2] = (addr >>  8) & 0xFF;
  	xaddr[3] =  addr	& 0xFF;
  
  	if (wait_for_bb()) {
  		printf("i2c_write: bus is busy\n");
  		goto Done;
  	}
  
  	mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
  	if (do_address(chip, 0)) {
  		printf("i2c_write: failed to address chip\n");
  		goto Done;
  	}
  
  	if (send_bytes(chip, &xaddr[4-alen], alen)) {
  		printf("i2c_write: send_bytes failed\n");
  		goto Done;
  	}
  
  	if (send_bytes(chip, (char *)buf, len)) {
  		printf("i2c_write: send_bytes failed\n");
  		goto Done;
  	}
  
  	ret = 0;
  Done:
  	mpc_reg_out(&regs->mcr, 0, I2C_STA);
  	return ret;
  }
  
  uchar i2c_reg_read(uchar chip, uchar reg)
  {
  	uchar buf;
  
  	i2c_read(chip, reg, 1, &buf, 1);
  
  	return buf;
  }
  
  void i2c_reg_write(uchar chip, uchar reg, uchar val)
  {
  	i2c_write(chip, reg, 1, &val, 1);
  
  	return;
  }
  
  #endif	/* CONFIG_HARD_I2C */
  