Tsi108 on chip i2c support.

The i2c  Interface provides a master-only, serial interface that can be
used for initializing Tsi108/Tsi109 registers from an EEPROM after a
device reset.

Signed-off-by: Alexandre Bounine <alexandreb@tundra.com>
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>

drivers/tsi108_i2c.c

@@ -0,0 +1,300 @@
+/*
+ * (C) Copyright 2004 Tundra Semiconductor Corp.
+ * Author: Alex Bounine
+ *
+ * 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 <config.h>
+
+#ifdef CONFIG_TSI108_I2C
+
+#include <common.h>
+#include <tsi108.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_I2C)
+
+#define I2C_DELAY           100000
+#undef  DEBUG_I2C
+
+#ifdef DEBUG_I2C
+#define DPRINT(x) printf(x)
+#else
+#define DPRINT(x)
+#endif
+
+/* All functions assume that Tsi108 I2C block is the only master on the bus */
+/* I2C read helper function */
+
+static int i2c_read_byte(
+		uint i2c_chan,	/* I2C channel number: 0 - main, 1 - SDC SPD */
+		uchar chip_addr,/* I2C device address on the bus */
+		uint byte_addr,	/* Byte address within I2C device */
+		uchar * buffer	/* pointer to data buffer */
+		)
+{
+	u32 temp;
+	u32 to_count = I2C_DELAY;
+	u32 op_status = TSI108_I2C_TIMEOUT_ERR;
+	u32 chan_offset = TSI108_I2C_OFFSET;
+
+	DPRINT(("I2C read_byte() %d 0x%02x 0x%02x\n",
+		i2c_chan, chip_addr, byte_addr));
+
+	if (0 != i2c_chan) {
+		chan_offset = TSI108_I2C_SDRAM_OFFSET;
+	}
+
+	/* Check if I2C operation is in progress */
+	temp = *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
+
+	if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
+			  I2C_CNTRL2_START))
+	    ) {
+		/* Set device address and operation (read = 0) */
+		temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
+		    ((chip_addr >> 3) & 0x0F);
+		*(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
+		    temp;
+
+		/* Issue the read command
+		 * (at this moment all other parameters are 0 
+		 * (size = 1 byte, lane = 0)
+		 */
+
+		*(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
+		    (I2C_CNTRL2_START);
+
+		/* Wait until operation completed */
+		do {
+			/* Read I2C operation status */
+			temp =
+			    *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset +
+				      I2C_CNTRL2);
+
+			if (0 ==
+			    (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START)))
+			{
+				if (0 ==
+				    (temp &
+				     (I2C_CNTRL2_I2C_CFGERR |
+				      I2C_CNTRL2_I2C_TO_ERR))
+				    ) {
+					op_status = TSI108_I2C_SUCCESS;
+
+					temp = *(u32 *) (CFG_TSI108_CSR_BASE +
+							 chan_offset +
+							 I2C_RD_DATA);
+
+					*buffer = (u8) (temp & 0xFF);
+				} else {
+					/* report HW error */
+					op_status = TSI108_I2C_IF_ERROR;
+
+					DPRINT(("I2C HW error reported: 0x%02x\n", temp));
+				}
+
+				break;
+			}
+		} while (to_count--);
+	} else {
+		op_status = TSI108_I2C_IF_BUSY;
+
+		DPRINT(("I2C Transaction start failed: 0x%02x\n", temp));
+	}
+
+	DPRINT(("I2C read_byte() status: 0x%02x\n", op_status));
+	return op_status;
+}
+
+/* 
+ * I2C Read interface as defined in "include/i2c.h" :
+ *   chip_addr: I2C chip address, range 0..127
+ *                  (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
+ *              NOTE: The bit 7 in the chip_addr serves as a channel select.
+ *              This hack is for enabling "isdram" command on Tsi108 boards
+ *              without changes to common code. Used for I2C reads only. 
+ *   byte_addr: Memory or register address within the chip
+ *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
+ *              memories, 0 for register type devices with only one
+ *              register)
+ *   buffer:    Pointer to destination buffer for data to be read
+ *   len:       How many bytes to read
+ *
+ *   Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_read(uchar chip_addr, uint byte_addr, int alen, uchar * buffer, int len)
+{
+	u32 op_status = TSI108_I2C_PARAM_ERR;
+	u32 i2c_if = 0;
+
+	/* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
+	if (0xD0 == (chip_addr & ~0x07)) {
+		i2c_if = 1;
+		chip_addr &= 0x7F;
+	}
+	/* Check for valid I2C address */
+	if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
+		while (len--) {
+			op_status =
+			    i2c_read_byte(i2c_if, chip_addr, byte_addr++,
+					  buffer++);
+
+			if (TSI108_I2C_SUCCESS != op_status) {
+				DPRINT(("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
+
+				break;
+			}
+		}
+	}
+
+	DPRINT(("I2C read() status: 0x%02x\n", op_status));
+	return op_status;
+}
+
+/* I2C write helper function */
+
+static int i2c_write_byte(uchar chip_addr,/* I2C device address on the bus */
+			  uint byte_addr, /* Byte address within I2C device */
+			  uchar * buffer  /*  pointer to data buffer */
+			  )
+{
+	u32 temp;
+	u32 to_count = I2C_DELAY;
+	u32 op_status = TSI108_I2C_TIMEOUT_ERR;
+
+	/* Check if I2C operation is in progress */
+	temp = *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
+
+	if (0 ==
+	    (temp &
+	     (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START)))
+	{
+		/* Place data into the I2C Tx Register */
+		*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
+			  I2C_TX_DATA) = (u32) * buffer;
+
+		/* Set device address and operation  */
+		temp =
+		    I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
+		    ((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
+		*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
+			  I2C_CNTRL1) = temp;
+
+		/* Issue the write command (at this moment all other parameters
+		 * are 0 (size = 1 byte, lane = 0)
+		 */
+		
+		*(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
+			  I2C_CNTRL2) = (I2C_CNTRL2_START);
+
+		op_status = TSI108_I2C_TIMEOUT_ERR;
+
+		/* Wait until operation completed */
+		do {
+			// Read I2C operation status
+			temp =
+			    *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
+				      I2C_CNTRL2);
+
+			if (0 ==
+			    (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START)))
+			{
+				if (0 ==
+				    (temp &
+				     (I2C_CNTRL2_I2C_CFGERR |
+				      I2C_CNTRL2_I2C_TO_ERR))) {
+					op_status = TSI108_I2C_SUCCESS;
+				} else {
+					/* report detected HW error */
+					op_status = TSI108_I2C_IF_ERROR;
+
+					DPRINT(("I2C HW error reported: 0x%02x\n", temp));
+				}
+
+				break;
+			}
+
+		} while (to_count--);
+	} else {
+		op_status = TSI108_I2C_IF_BUSY;
+
+		DPRINT(("I2C Transaction start failed: 0x%02x\n", temp));
+	}
+
+	return op_status;
+}
+
+/* 
+ * I2C Write interface as defined in "include/i2c.h" :
+ *   chip_addr: I2C chip address, range 0..127
+ *   byte_addr: Memory or register address within the chip
+ *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
+ *              memories, 0 for register type devices with only one
+ *              register)
+ *   buffer:    Pointer to data to be written
+ *   len:       How many bytes to write
+ *
+ *   Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_write(uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
+	      int len)
+{
+	u32 op_status = TSI108_I2C_PARAM_ERR;
+
+	/* Check for valid I2C address */
+	if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
+		while (len--) {
+			op_status =
+			    i2c_write_byte(chip_addr, byte_addr++, buffer++);
+
+			if (TSI108_I2C_SUCCESS != op_status) {
+				DPRINT(("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
+
+				break;
+			}
+		}
+	}
+
+	return op_status;
+}
+
+/* 
+ * I2C interface function as defined in "include/i2c.h".
+ * Probe the given I2C chip address by reading single byte from offset 0.
+ * Returns 0 if a chip responded, not 0 on failure.
+ */
+
+int i2c_probe(uchar chip)
+{
+	u32 tmp;
+
+	/*
+	 * Try to read the first location of the chip.
+	 * The Tsi108 HW doesn't support sending just the chip address
+	 * and checkong for an <ACK> back.
+	 */
+	return i2c_read(chip, 0, 1, (char *)&tmp, 1);
+}
+
+#endif				/* (CONFIG_COMMANDS & CFG_CMD_I2C) */
+#endif /* CONFIG_TSI108_I2C */