* Patches by David Müller, 31 Jan 2003:

  - minimal setup for CardBus bridges
  - add EEPROM read/write support in the CS8900 driver
  - add support for the builtin I2C controller in the Samsung s3c24x0 chips
  - add support for  MPL's VCMA9 (Samsung s3c2410 based) board

* Patch by Steven Scholz, 04 Feb 2003:
  add support for RTC DS1307

* Patch by Reinhard Meyer, 5 Feb 2003:
  fix PLPRCR/SCCR init sequence on 8xx to allow for
  changes of EBDF by software

* Patch by Vladimir Gurevich, 07 Feb 2003:
  "API-compatibility patch" for 4xx I2C driver

1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/s3c24x0_i2c.c b/drivers/s3c24x0_i2c.c
new file mode 100644
index 0000000..bf435c9
--- /dev/null
+++ b/drivers/s3c24x0_i2c.c
@@ -0,0 +1,409 @@
+/*
+ * (C) Copyright 2002
+ * David Mueller, ELSOFT AG, d.mueller@elsoft.ch
+ *
+ * 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
+ */
+
+/* This code should work for both the S3C2400 and the S3C2410
+ * as they seem to have the same I2C controller inside.
+ * The different address mapping is handled by the s3c24xx.h files below.
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_DRIVER_S3C24X0_I2C
+
+#if defined(CONFIG_S3C2400)
+#include <s3c2400.h>
+#elif defined(CONFIG_S3C2410)
+#include <s3c2410.h>
+#endif
+#include <i2c.h>
+
+#ifdef CONFIG_HARD_I2C
+
+#define	IIC_WRITE	0
+#define IIC_READ	1
+
+#define IIC_OK		0
+#define IIC_NOK		1
+#define IIC_NACK	2
+#define IIC_NOK_LA	3		/* Lost arbitration */
+#define IIC_NOK_TOUT	4		/* time out */
+
+#define IICSTAT_BSY	0x20		/* Busy bit */
+#define IICSTAT_NACK	0x01		/* Nack bit */
+#define IICCON_IRPND	0x10		/* Interrupt pending bit */
+#define IIC_MODE_MT	0xC0		/* Master Transmit Mode */
+#define IIC_MODE_MR	0x80		/* Master Receive Mode */
+#define IIC_START_STOP	0x20		/* START / STOP */
+#define IIC_TXRX_ENA	0x10		/* I2C Tx/Rx enable */
+
+#define IIC_TIMEOUT 1			/* 1 seconde */
+
+
+static int GetIICSDA(void)
+{
+	return (rGPEDAT & 0x8000) >> 15;
+}
+
+static void SetIICSDA(int x)
+{
+	rGPEDAT = (rGPEDAT & ~0x8000) | (x&1) << 15;
+}
+
+static void SetIICSCL(int x)
+{
+	rGPEDAT = (rGPEDAT & ~0x4000) | (x&1) << 14;
+}
+
+
+static int WaitForXfer(void)
+{
+    int i, status;
+
+    i = IIC_TIMEOUT * 1000;
+    status = rIICCON;
+    while ((i > 0) && !(status & IICCON_IRPND)) {
+    	udelay(1000);
+	status = rIICCON;
+	i--;
+    }
+
+    return(status & IICCON_IRPND) ? IIC_OK : IIC_NOK_TOUT;
+}
+
+static int IsACK(void)
+{
+    return(!(rIICSTAT & IICSTAT_NACK));
+}
+
+static void ReadWriteByte(void)
+{
+    rIICCON &= ~IICCON_IRPND;
+}
+
+void i2c_init (int speed, int slaveadd)
+{
+    ulong freq, pres = 16, div;
+    int i, status;
+
+    /* wait for some time to give previous transfer a chance to finish */
+
+    i = IIC_TIMEOUT * 1000;
+    status = rIICSTAT;
+    while ((i > 0) && (status & IICSTAT_BSY)) {
+	udelay(1000);
+	status = rIICSTAT;
+	i--;
+    }
+
+    if ((status & IICSTAT_BSY) || GetIICSDA() == 0) {
+	ulong old_gpecon = rGPECON;
+	/* bus still busy probably by (most) previously interrupted transfer */
+
+	/* set IICSDA and IICSCL (GPE15, GPE14) to GPIO */
+	rGPECON = (rGPECON & ~0xF0000000) | 0x10000000;
+
+	/* toggle IICSCL until bus idle */
+	SetIICSCL(0); udelay(1000);
+	i = 10;
+	while ((i > 0) && (GetIICSDA() != 1)) {
+		SetIICSCL(1); udelay(1000);
+		SetIICSCL(0); udelay(1000);
+		i--;
+	}
+	SetIICSCL(1); udelay(1000);
+
+	/* restore pin functions */
+	rGPECON = old_gpecon;
+    }
+
+    /* calculate prescaler and divisor values */
+    freq = get_PCLK();
+    if ((freq / pres / (16+1)) > speed)
+	/* set prescaler to 512 */
+	pres = 512;
+
+    div = 0;
+    while ((freq / pres / (div+1)) > speed)
+	div++;
+
+    /* set prescaler, divisor according to freq, also set
+       ACKGEN, IRQ */
+    rIICCON = (div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0);
+
+    /* init to SLAVE REVEIVE and set slaveaddr */
+    rIICSTAT = 0;
+    rIICADD = slaveadd;
+    /* program Master Transmit (and implicit STOP) */
+    rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA;
+
+}
+
+/*
+  cmd_type is 0 for write 1 for read.
+
+  addr_len can take any value from 0-255, it is only limited
+  by the char, we could make it larger if needed. If it is
+  0 we skip the address write cycle.
+
+*/
+static
+int i2c_transfer(unsigned char cmd_type,
+                 unsigned char chip,
+                 unsigned char addr[],
+                 unsigned char addr_len,
+                 unsigned char data[],
+		 unsigned short data_len)
+{
+    int i, status, result;
+
+    if (data == 0 || data_len == 0) {
+	/*Don't support data transfer of no length or to address 0*/
+	printf( "i2c_transfer: bad call\n" );
+	return IIC_NOK;
+    }
+
+    //CheckDelay();
+
+    /* Check I2C bus idle */
+    i = IIC_TIMEOUT * 1000;
+    status = rIICSTAT;
+    while ((i > 0) && (status & IICSTAT_BSY)) {
+	udelay(1000);
+	status = rIICSTAT;
+	i--;
+    }
+
+
+    if (status & IICSTAT_BSY) {
+	result = IIC_NOK_TOUT;
+        return(result);
+    }
+
+    rIICCON |= 0x80;
+
+    result = IIC_OK;
+
+    switch (cmd_type) {
+	case IIC_WRITE:
+	    if (addr && addr_len) {
+		rIICDS = chip;
+		/* send START */
+		rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA | IIC_START_STOP;
+		i = 0;
+		while ((i < addr_len) && (result == IIC_OK)) {
+		    result = WaitForXfer();
+		    rIICDS = addr[i];
+		    ReadWriteByte();
+		    i++;
+		}
+		i = 0;
+		while ((i < data_len) && (result == IIC_OK)) {
+		    result = WaitForXfer();
+		    rIICDS = data[i];
+		    ReadWriteByte();
+		    i++;
+		}
+	    } else {
+		rIICDS = chip;
+		/* send START */
+		rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA | IIC_START_STOP;
+		i = 0;
+		while ((i < data_len) && (result = IIC_OK)) {
+		    result = WaitForXfer();
+		    rIICDS = data[i];
+		    ReadWriteByte();
+		    i++;
+		}
+	    }
+
+	    if (result == IIC_OK)
+	        result = WaitForXfer();
+
+	    /* send STOP */
+	    rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA;
+	    ReadWriteByte();
+	    break;
+
+	case IIC_READ:
+	    if (addr && addr_len) {
+		rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA;
+		rIICDS = chip;
+		/* send START */
+		rIICSTAT |= IIC_START_STOP;
+		result = WaitForXfer();
+		if (IsACK()) {
+		    i = 0;
+		    while ((i < addr_len) && (result == IIC_OK)) {
+			rIICDS = addr[i];
+			ReadWriteByte();
+			result = WaitForXfer();
+			i++;
+		    }
+
+		    rIICDS = chip;
+		    /* resend START */
+		    rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA | IIC_START_STOP;
+		    ReadWriteByte();
+		    result = WaitForXfer();
+		    i = 0;
+		    while ((i < data_len) && (result == IIC_OK)) {
+			/* disable ACK for final READ */
+			if (i == data_len - 1)
+			    rIICCON &= ~0x80;
+			ReadWriteByte();
+			result = WaitForXfer();
+			data[i] = rIICDS;
+			i++;
+		    }
+		} else {
+		    result = IIC_NACK;
+		}
+
+	    } else {
+		rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA;
+		rIICDS = chip;
+		/* send START */
+		rIICSTAT |= IIC_START_STOP;
+		result = WaitForXfer();
+
+		if (IsACK()) {
+		    i = 0;
+		    while ((i < data_len) && (result == IIC_OK)) {
+			/* disable ACK for final READ */
+			if (i == data_len - 1)
+			    rIICCON &= ~0x80;
+		        ReadWriteByte();
+			result = WaitForXfer();
+			data[i] = rIICDS;
+			i++;
+		    }
+		} else {
+		    result = IIC_NACK;
+		}
+	    }
+
+	    /* send STOP */
+	    rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA;
+	    ReadWriteByte();
+	    break;
+
+	default:
+	    printf( "i2c_transfer: bad call\n" );
+    	    result = IIC_NOK;
+	    break;
+    }
+
+    return (result);
+}
+
+int i2c_probe (uchar chip)
+{
+    uchar buf[1];
+
+    buf[0] = 0;
+
+    /*
+     * What is needed is to send the chip address and verify that the
+     * address was <ACK>ed (i.e. there was a chip at that address which
+     * drove the data line low).
+     */
+    return(i2c_transfer (IIC_READ, chip << 1, 0, 0, buf, 1) != IIC_OK);
+}
+
+int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+    uchar xaddr[4];
+    int ret;
+
+    if ( alen > 4 ) {
+	printf ("I2C read: addr len %d not supported\n", alen);
+	return 1;
+    }
+
+    if ( alen > 0 ) {
+	xaddr[0] = (addr >> 24) & 0xFF;
+        xaddr[1] = (addr >> 16) & 0xFF;
+        xaddr[2] = (addr >> 8) & 0xFF;
+        xaddr[3] = addr & 0xFF;
+    }
+
+
+#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
+    /*
+     * EEPROM chips that implement "address overflow" are ones
+     * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+     * address and the extra bits end up in the "chip address"
+     * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+     * four 256 byte chips.
+     *
+     * Note that we consider the length of the address field to
+     * still be one byte because the extra address bits are
+     * hidden in the chip address.
+     */
+    if( alen > 0 )
+	chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
+#endif
+    if( (ret = i2c_transfer(IIC_READ, chip<<1, &xaddr[4-alen], alen, buffer, len )) != 0) {
+        printf( "I2c read: failed %d\n", ret);
+        return 1;
+    }
+    return 0;
+}
+
+int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+    uchar xaddr[4];
+
+    if ( alen > 4 ) {
+	printf ("I2C write: addr len %d not supported\n", alen);
+	return 1;
+    }
+
+    if ( alen > 0 ) {
+        xaddr[0] = (addr >> 24) & 0xFF;
+        xaddr[1] = (addr >> 16) & 0xFF;
+        xaddr[2] = (addr >> 8) & 0xFF;
+        xaddr[3] = addr & 0xFF;
+    }
+
+#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
+    /*
+     * EEPROM chips that implement "address overflow" are ones
+     * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+     * address and the extra bits end up in the "chip address"
+     * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+     * four 256 byte chips.
+     *
+     * Note that we consider the length of the address field to
+     * still be one byte because the extra address bits are
+     * hidden in the chip address.
+     */
+    if( alen > 0 )
+        chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
+#endif
+    return (i2c_transfer(IIC_WRITE, chip<<1, &xaddr[4-alen], alen, buffer, len ) != 0);
+}
+
+#endif	/* CONFIG_HARD_I2C */
+
+#endif /* CONFIG_DRIVER_S3C24X0_I2C */