+++ /dev/null
-/*
- * (C) Copyright 2000
- * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
- *
- * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
- * Marius Groeger <mgroeger@sysgo.de>
- *
- * (C) Copyright 2003 Pengutronix e.K.
- * Robert Schwebel <r.schwebel@pengutronix.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
- *
- * Back ported to the 8xx platform (from the 8260 platform) by
- * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
- */
-
-/* FIXME: this file is PXA255 specific! What about other XScales? */
-
-#include <common.h>
-
-#ifdef CONFIG_HARD_I2C
-
-/*
- * - CONFIG_SYS_I2C_SPEED
- * - I2C_PXA_SLAVE_ADDR
- */
-
-#include <asm/arch/hardware.h>
-#include <asm/arch/pxa-regs.h>
-#include <i2c.h>
-
-/*#define DEBUG_I2C 1 /###* activate local debugging output */
-#define I2C_PXA_SLAVE_ADDR 0x1 /* slave pxa unit address */
-
-#if (CONFIG_SYS_I2C_SPEED == 400000)
-#define I2C_ICR_INIT (ICR_FM | ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
-#else
-#define I2C_ICR_INIT (ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
-#endif
-
-#define I2C_ISR_INIT 0x7FF
-
-#ifdef DEBUG_I2C
-#define PRINTD(x) printf x
-#else
-#define PRINTD(x)
-#endif
-
-
-/* Shall the current transfer have a start/stop condition? */
-#define I2C_COND_NORMAL 0
-#define I2C_COND_START 1
-#define I2C_COND_STOP 2
-
-/* Shall the current transfer be ack/nacked or being waited for it? */
-#define I2C_ACKNAK_WAITACK 1
-#define I2C_ACKNAK_SENDACK 2
-#define I2C_ACKNAK_SENDNAK 4
-
-/* Specify who shall transfer the data (master or slave) */
-#define I2C_READ 0
-#define I2C_WRITE 1
-
-/* All transfers are described by this data structure */
-struct i2c_msg {
- u8 condition;
- u8 acknack;
- u8 direction;
- u8 data;
-};
-
-
-/**
- * i2c_pxa_reset: - reset the host controller
- *
- */
-
-static void i2c_reset( void )
-{
- ICR &= ~ICR_IUE; /* disable unit */
- ICR |= ICR_UR; /* reset the unit */
- udelay(100);
- ICR &= ~ICR_IUE; /* disable unit */
-#ifdef CONFIG_CPU_MONAHANS
- CKENB |= (CKENB_4_I2C); /* | CKENB_1_PWM1 | CKENB_0_PWM0); */
-#else /* CONFIG_CPU_MONAHANS */
- CKEN |= CKEN14_I2C; /* set the global I2C clock on */
-#endif
- ISAR = I2C_PXA_SLAVE_ADDR; /* set our slave address */
- ICR = I2C_ICR_INIT; /* set control register values */
- ISR = I2C_ISR_INIT; /* set clear interrupt bits */
- ICR |= ICR_IUE; /* enable unit */
- udelay(100);
-}
-
-
-/**
- * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
- * are set and cleared
- *
- * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
- */
-static int i2c_isr_set_cleared( unsigned long set_mask, unsigned long cleared_mask )
-{
- int timeout = 10000;
-
- while( ((ISR & set_mask)!=set_mask) || ((ISR & cleared_mask)!=0) ){
- udelay( 10 );
- if( timeout-- < 0 ) return 0;
- }
-
- return 1;
-}
-
-
-/**
- * i2c_transfer: - Transfer one byte over the i2c bus
- *
- * This function can tranfer a byte over the i2c bus in both directions.
- * It is used by the public API functions.
- *
- * @return: 0: transfer successful
- * -1: message is empty
- * -2: transmit timeout
- * -3: ACK missing
- * -4: receive timeout
- * -5: illegal parameters
- * -6: bus is busy and couldn't be aquired
- */
-int i2c_transfer(struct i2c_msg *msg)
-{
- int ret;
-
- if (!msg)
- goto transfer_error_msg_empty;
-
- switch(msg->direction) {
-
- case I2C_WRITE:
-
- /* check if bus is not busy */
- if (!i2c_isr_set_cleared(0,ISR_IBB))
- goto transfer_error_bus_busy;
-
- /* start transmission */
- ICR &= ~ICR_START;
- ICR &= ~ICR_STOP;
- IDBR = msg->data;
- if (msg->condition == I2C_COND_START) ICR |= ICR_START;
- if (msg->condition == I2C_COND_STOP) ICR |= ICR_STOP;
- if (msg->acknack == I2C_ACKNAK_SENDNAK) ICR |= ICR_ACKNAK;
- if (msg->acknack == I2C_ACKNAK_SENDACK) ICR &= ~ICR_ACKNAK;
- ICR &= ~ICR_ALDIE;
- ICR |= ICR_TB;
-
- /* transmit register empty? */
- if (!i2c_isr_set_cleared(ISR_ITE,0))
- goto transfer_error_transmit_timeout;
-
- /* clear 'transmit empty' state */
- ISR |= ISR_ITE;
-
- /* wait for ACK from slave */
- if (msg->acknack == I2C_ACKNAK_WAITACK)
- if (!i2c_isr_set_cleared(0,ISR_ACKNAK))
- goto transfer_error_ack_missing;
- break;
-
- case I2C_READ:
-
- /* check if bus is not busy */
- if (!i2c_isr_set_cleared(0,ISR_IBB))
- goto transfer_error_bus_busy;
-
- /* start receive */
- ICR &= ~ICR_START;
- ICR &= ~ICR_STOP;
- if (msg->condition == I2C_COND_START) ICR |= ICR_START;
- if (msg->condition == I2C_COND_STOP) ICR |= ICR_STOP;
- if (msg->acknack == I2C_ACKNAK_SENDNAK) ICR |= ICR_ACKNAK;
- if (msg->acknack == I2C_ACKNAK_SENDACK) ICR &= ~ICR_ACKNAK;
- ICR &= ~ICR_ALDIE;
- ICR |= ICR_TB;
-
- /* receive register full? */
- if (!i2c_isr_set_cleared(ISR_IRF,0))
- goto transfer_error_receive_timeout;
-
- msg->data = IDBR;
-
- /* clear 'receive empty' state */
- ISR |= ISR_IRF;
-
- break;
-
- default:
-
- goto transfer_error_illegal_param;
-
- }
-
- return 0;
-
-transfer_error_msg_empty:
- PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
- ret = -1; goto i2c_transfer_finish;
-
-transfer_error_transmit_timeout:
- PRINTD(("i2c_transfer: error: transmit timeout\n"));
- ret = -2; goto i2c_transfer_finish;
-
-transfer_error_ack_missing:
- PRINTD(("i2c_transfer: error: ACK missing\n"));
- ret = -3; goto i2c_transfer_finish;
-
-transfer_error_receive_timeout:
- PRINTD(("i2c_transfer: error: receive timeout\n"));
- ret = -4; goto i2c_transfer_finish;
-
-transfer_error_illegal_param:
- PRINTD(("i2c_transfer: error: illegal parameters\n"));
- ret = -5; goto i2c_transfer_finish;
-
-transfer_error_bus_busy:
- PRINTD(("i2c_transfer: error: bus is busy\n"));
- ret = -6; goto i2c_transfer_finish;
-
-i2c_transfer_finish:
- PRINTD(("i2c_transfer: ISR: 0x%04x\n",ISR));
- i2c_reset();
- return ret;
-
-}
-
-/* ------------------------------------------------------------------------ */
-/* API Functions */
-/* ------------------------------------------------------------------------ */
-
-void i2c_init(int speed, int slaveaddr)
-{
-#ifdef CONFIG_SYS_I2C_INIT_BOARD
- /* call board specific i2c bus reset routine before accessing the */
- /* environment, which might be in a chip on that bus. For details */
- /* about this problem see doc/I2C_Edge_Conditions. */
- i2c_init_board();
-#endif
-}
-
-
-/**
- * i2c_probe: - Test if a chip answers for a given i2c address
- *
- * @chip: address of the chip which is searched for
- * @return: 0 if a chip was found, -1 otherwhise
- */
-
-int i2c_probe(uchar chip)
-{
- struct i2c_msg msg;
-
- i2c_reset();
-
- msg.condition = I2C_COND_START;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = (chip << 1) + 1;
- if (i2c_transfer(&msg)) return -1;
-
- msg.condition = I2C_COND_STOP;
- msg.acknack = I2C_ACKNAK_SENDNAK;
- msg.direction = I2C_READ;
- msg.data = 0x00;
- if (i2c_transfer(&msg)) return -1;
-
- return 0;
-}
-
-
-/**
- * i2c_read: - Read multiple bytes from an i2c device
- *
- * The higher level routines take into account that this function is only
- * called with len < page length of the device (see configuration file)
- *
- * @chip: address of the chip which is to be read
- * @addr: i2c data address within the chip
- * @alen: length of the i2c data address (1..2 bytes)
- * @buffer: where to write the data
- * @len: how much byte do we want to read
- * @return: 0 in case of success
- */
-
-int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
-{
- struct i2c_msg msg;
- u8 addr_bytes[3]; /* lowest...highest byte of data address */
- int ret;
-
- PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, len=0x%02x)\n",chip,addr,alen,len));
-
- i2c_reset();
-
- /* dummy chip address write */
- PRINTD(("i2c_read: dummy chip address write\n"));
- msg.condition = I2C_COND_START;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = (chip << 1);
- msg.data &= 0xFE;
- if ((ret=i2c_transfer(&msg))) return -1;
-
- /*
- * send memory address bytes;
- * alen defines how much bytes we have to send.
- */
- /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
- addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
- addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
- addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
-
- while (--alen >= 0) {
-
- PRINTD(("i2c_read: send memory word address byte %1d\n",alen));
- msg.condition = I2C_COND_NORMAL;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = addr_bytes[alen];
- if ((ret=i2c_transfer(&msg))) return -1;
- }
-
-
- /* start read sequence */
- PRINTD(("i2c_read: start read sequence\n"));
- msg.condition = I2C_COND_START;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = (chip << 1);
- msg.data |= 0x01;
- if ((ret=i2c_transfer(&msg))) return -1;
-
- /* read bytes; send NACK at last byte */
- while (len--) {
-
- if (len==0) {
- msg.condition = I2C_COND_STOP;
- msg.acknack = I2C_ACKNAK_SENDNAK;
- } else {
- msg.condition = I2C_COND_NORMAL;
- msg.acknack = I2C_ACKNAK_SENDACK;
- }
-
- msg.direction = I2C_READ;
- msg.data = 0x00;
- if ((ret=i2c_transfer(&msg))) return -1;
-
- *buffer = msg.data;
- PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",(unsigned int)buffer,*buffer));
- buffer++;
-
- }
-
- i2c_reset();
-
- return 0;
-}
-
-
-/**
- * i2c_write: - Write multiple bytes to an i2c device
- *
- * The higher level routines take into account that this function is only
- * called with len < page length of the device (see configuration file)
- *
- * @chip: address of the chip which is to be written
- * @addr: i2c data address within the chip
- * @alen: length of the i2c data address (1..2 bytes)
- * @buffer: where to find the data to be written
- * @len: how much byte do we want to read
- * @return: 0 in case of success
- */
-
-int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
-{
- struct i2c_msg msg;
- u8 addr_bytes[3]; /* lowest...highest byte of data address */
-
- PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, len=0x%02x)\n",chip,addr,alen,len));
-
- i2c_reset();
-
- /* chip address write */
- PRINTD(("i2c_write: chip address write\n"));
- msg.condition = I2C_COND_START;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = (chip << 1);
- msg.data &= 0xFE;
- if (i2c_transfer(&msg)) return -1;
-
- /*
- * send memory address bytes;
- * alen defines how much bytes we have to send.
- */
- addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
- addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
- addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
-
- while (--alen >= 0) {
-
- PRINTD(("i2c_write: send memory word address\n"));
- msg.condition = I2C_COND_NORMAL;
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = addr_bytes[alen];
- if (i2c_transfer(&msg)) return -1;
- }
-
- /* write bytes; send NACK at last byte */
- while (len--) {
-
- PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",(unsigned int)buffer,*buffer));
-
- if (len==0)
- msg.condition = I2C_COND_STOP;
- else
- msg.condition = I2C_COND_NORMAL;
-
- msg.acknack = I2C_ACKNAK_WAITACK;
- msg.direction = I2C_WRITE;
- msg.data = *(buffer++);
-
- if (i2c_transfer(&msg)) return -1;
-
- }
-
- i2c_reset();
-
- return 0;
-
-}
-
-#endif /* CONFIG_HARD_I2C */
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