/* * (C) Copyright 2003,Motorola Inc. * Xianghua Xiao <x.xiao@motorola.com> * Adapted for Motorola 85xx chip. * * (C) Copyright 2003 * Gleb Natapov <gnatapov@mrv.com> * Some bits are taken from linux driver writen by adrian@humboldt.co.uk * * Hardware I2C driver for MPC107 PCI bridge. * * 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> #include <command.h> #define DEBUG #if defined(DEBUG) #define DEB(x) x #else #define DEB(x) #endif #ifdef CONFIG_HARD_I2C #include <i2c.h> #define TIMEOUT (CFG_HZ/4) #define I2C_Addr ((unsigned *)(CFG_CCSRBAR + 0x3000)) #define I2CADR &I2C_Addr[0] #define I2CFDR &I2C_Addr[1] #define I2CCCR &I2C_Addr[2] #define I2CCSR &I2C_Addr[3] #define I2CCDR &I2C_Addr[4] #define I2CDFSRR &I2C_Addr[5] #define I2C_READ 1 #define I2C_WRITE 0 /* taken from linux include/asm-ppc/io.h */ inline unsigned in_le32(volatile unsigned *addr) { unsigned ret; __asm__ __volatile__("lwbrx %0,0,%1;\n" "twi 0,%0,0;\n" "isync" : "=r" (ret) : "r" (addr), "m" (*addr)); return ret; } inline void out_le32(volatile unsigned *addr, int val) { __asm__ __volatile__("stwbrx %1,0,%2; eieio" : "=m" (*addr) : "r" (val), "r" (addr)); } #define writel(val, addr) out_le32(addr, val) #define readl(addr) in_le32(addr) void i2c_init(int speed, int slaveadd) { /* stop I2C controller */ writel (0x0, I2CCCR); /* set clock */ writel (0x3f, I2CFDR); /* set default filter */ writel (0x10,I2CDFSRR); /* write slave address */ writel (slaveadd, I2CADR); /* clear status register */ writel (0x0, I2CCSR); /* start I2C controller */ writel (MPC85xx_I2CCR_MEN, I2CCCR); } static __inline__ int i2c_wait4bus (void) { ulong timeval = get_timer (0); while (readl (I2CCSR) & MPC85xx_I2CSR_MBB) if (get_timer (timeval) > TIMEOUT) return -1; return 0; } static __inline__ int i2c_wait (int write) { u32 csr; ulong timeval = get_timer (0); do { csr = readl (I2CCSR); if (!(csr & MPC85xx_I2CSR_MIF)) continue; writel (0x0, I2CCSR); if (csr & MPC85xx_I2CSR_MAL) { DEB(printf ("i2c_wait: MAL\n")); return -1; } if (!(csr & MPC85xx_I2CSR_MCF)) { DEB(printf ("i2c_wait: unfinished\n")); return -1; } if (write == I2C_WRITE && (csr & MPC85xx_I2CSR_RXAK)) { DEB(printf ("i2c_wait: No RXACK\n")); return -1; } return 0; } while (get_timer (timeval) < TIMEOUT); DEB(printf ("i2c_wait: timed out\n")); return -1; } static __inline__ int i2c_write_addr (u8 dev, u8 dir, int rsta) { writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX | (rsta?MPC85xx_I2CCR_RSTA:0), I2CCCR); writel ((dev << 1) | dir, I2CCDR); if (i2c_wait (I2C_WRITE) < 0) return 0; return 1; } static __inline__ int __i2c_write (u8 *data, int length) { int i; writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX, I2CCCR); for (i=0; i < length; i++) { writel (data[i], I2CCDR); if (i2c_wait (I2C_WRITE) < 0) break; } return i; } static __inline__ int __i2c_read (u8 *data, int length) { int i; writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | ((length == 1) ? MPC85xx_I2CCR_TXAK : 0), I2CCCR); /* dummy read */ readl (I2CCDR); for (i=0; i < length; i++) { if (i2c_wait (I2C_READ) < 0) break; /* Generate ack on last next to last byte */ if (i == length - 2) writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_TXAK, I2CCCR); /* Generate stop on last byte */ if (i == length - 1) writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_TXAK, I2CCCR); data[i] = readl (I2CCDR); } return i; } int i2c_read (u8 dev, uint addr, int alen, u8 *data, int length) { int i = 0; u8 *a = (u8*)&addr; if (i2c_wait4bus () < 0) goto exit; if (i2c_write_addr (dev, I2C_WRITE, 0) == 0) goto exit; if (__i2c_write (&a[4 - alen], alen) != alen) goto exit; if (i2c_write_addr (dev, I2C_READ, 1) == 0) goto exit; i = __i2c_read (data, length); exit: writel (MPC85xx_I2CCR_MEN, I2CCCR); return !(i == length); } int i2c_write (u8 dev, uint addr, int alen, u8 *data, int length) { int i = 0; u8 *a = (u8*)&addr; if (i2c_wait4bus () < 0) goto exit; if (i2c_write_addr (dev, I2C_WRITE, 0) == 0) goto exit; if (__i2c_write (&a[4 - alen], alen) != alen) goto exit; i = __i2c_write (data, length); exit: writel (MPC85xx_I2CCR_MEN, I2CCCR); return !(i == length); } int i2c_probe (uchar chip) { int tmp; /* * Try to read the first location of the chip. The underlying * driver doesn't appear to support sending just the chip address * and looking for an <ACK> back. */ udelay(10000); return i2c_read (chip, 0, 1, (char *)&tmp, 1); } uchar i2c_reg_read (uchar i2c_addr, uchar reg) { char buf[1]; i2c_read (i2c_addr, reg, 1, buf, 1); return (buf[0]); } void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val) { i2c_write (i2c_addr, reg, 1, &val, 1); } #endif /* CONFIG_HARD_I2C */