Patch by Kyle Harris, 20 May 2003:

In preparation for an ixp port, rename cpu/xscale and arch-xscale
into cpu/pxa and arch-pxa.

1 files changed, 460 insertions, 0 deletions

diff --git a/cpu/pxa/i2c.c b/cpu/pxa/i2c.c
new file mode 100644
index 0000000..406f825
--- /dev/null
+++ b/cpu/pxa/i2c.c
@@ -0,0 +1,460 @@
+/*
+ * (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
+
+/* 
+ *	- CFG_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           */
+#define I2C_ICR_INIT		(ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
+#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 */
+        CKEN |= CKEN14_I2C;		/* set the global I2C clock on */
+        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: 0 in case of success, 1 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 CFG_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 << CFG_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));
+
+	}
+
+	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;
+
+}
+
+uchar i2c_reg_read (uchar chip, uchar reg)
+{
+	PRINTD(("i2c_reg_read(chip=0x%02x, reg=0x%02x)\n",chip,reg));
+	return 0;
+}
+
+void  i2c_reg_write(uchar chip, uchar reg, uchar val)
+{
+	PRINTD(("i2c_reg_write(chip=0x%02x, reg=0x%02x, val=0x%02x)\n",chip,reg,val));
+}
+
+#endif	/* CONFIG_HARD_I2C */