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Diffstat (limited to 'drivers/tsi108_i2c.c')
-rw-r--r--drivers/tsi108_i2c.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/tsi108_i2c.c b/drivers/tsi108_i2c.c
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+++ b/drivers/tsi108_i2c.c
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+/*
+ * (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>
+#include <common.h>
+
+#ifdef CONFIG_TSI108_I2C
+#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 */
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