+++ /dev/null
-/*
- * Copyright (C) 2003 PMC-Sierra Inc.
- * Author: Manish Lachwani (lachwani@pmc-sierra.com)
- *
- * 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 SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
- * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * 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.,
- * 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-/*
- * Detailed Description:
- *
- * This block implements the I2C interface to the slave devices like the
- * Atmel 24C32 EEPROM and the MAX 1619 Sensors device. The I2C Master interface
- * can be controlled by the SCMB block. And the SCMB block kicks in only when
- * using the Ethernet Mode of operation and __not__ the SysAD mode
- *
- * The SCMB controls the two modes: MDIO and the I2C. The MDIO mode is used to
- * communicate with the Quad-PHY from Marvel. The I2C is used to communicate
- * with the I2C slave devices. It seems that the driver does not explicitly
- * deal with the control of SDA and SCL serial lines. So, the driver will set
- * the slave address, drive the command and then the data. The SCMB will then
- * control the two serial lines as required.
- *
- * It seems the documents are very unclear abt this. Hence, I took some time
- * out to write the desciption to have an idea of how the I2C can actually
- * work. Currently, this Linux driver wont be integrated into the generic Linux
- * I2C framework. And finally, the I2C interface is also known as the 2BI
- * interface. 2BI means 2-bit interface referring to SDA and SCL serial lines
- * respectively.
- *
- * - Manish Lachwani (12/09/2003)
- */
-
-#include "i2c-yosemite.h"
-
-/*
- * Poll the I2C interface for the BUSY bit.
- */
-static int titan_i2c_poll(void)
-{
- int i = 0;
- unsigned long val = 0;
-
- for (i = 0; i < TITAN_I2C_MAX_POLL; i++) {
- val = TITAN_I2C_READ(TITAN_I2C_COMMAND);
-
- if (!(val & 0x8000))
- return 0;
- }
-
- return TITAN_I2C_ERR_TIMEOUT;
-}
-
-/*
- * Execute the I2C command
- */
-int titan_i2c_xfer(unsigned int slave_addr, titan_i2c_command * cmd,
- int size, unsigned int *addr)
-{
- int loop, bytes = 0, i;
- unsigned int *write_data, data, *read_data;
- unsigned long reg_val, val;
-
- write_data = cmd->data;
- read_data = addr;
-
- TITAN_I2C_WRITE(TITAN_I2C_SLAVE_ADDRESS, slave_addr);
-
- if (cmd->type == TITAN_I2C_CMD_WRITE)
- loop = cmd->write_size;
- else
- loop = size;
-
- while (loop > 0) {
- if ((cmd->type == TITAN_I2C_CMD_WRITE) ||
- (cmd->type == TITAN_I2C_CMD_READ_WRITE)) {
-
- reg_val = TITAN_I2C_DATA;
- for (i = 0; i < TITAN_I2C_MAX_WORDS_PER_RW;
- ++i, write_data += 2, reg_val += 4) {
- if (bytes < cmd->write_size) {
- data = write_data[0];
- ++data;
- }
-
- if (bytes < cmd->write_size) {
- data = write_data[1];
- ++data;
- }
-
- TITAN_I2C_WRITE(reg_val, data);
- }
- }
-
- TITAN_I2C_WRITE(TITAN_I2C_COMMAND,
- (unsigned int) (cmd->type << 13));
- if (titan_i2c_poll() != TITAN_I2C_ERR_OK)
- return TITAN_I2C_ERR_TIMEOUT;
-
- if ((cmd->type == TITAN_I2C_CMD_READ) ||
- (cmd->type == TITAN_I2C_CMD_READ_WRITE)) {
-
- reg_val = TITAN_I2C_DATA;
- for (i = 0; i < TITAN_I2C_MAX_WORDS_PER_RW;
- ++i, read_data += 2, reg_val += 4) {
- data = TITAN_I2C_READ(reg_val);
-
- if (bytes < size) {
- read_data[0] = data & 0xff;
- ++bytes;
- }
-
- if (bytes < size) {
- read_data[1] =
- ((data >> 8) & 0xff);
- ++bytes;
- }
- }
- }
-
- loop -= (TITAN_I2C_MAX_WORDS_PER_RW * 2);
- }
-
- /*
- * Read the Interrupt status and then return the appropriate error code
- */
-
- val = TITAN_I2C_READ(TITAN_I2C_INTERRUPTS);
- if (val & 0x0020)
- return TITAN_I2C_ERR_ARB_LOST;
-
- if (val & 0x0040)
- return TITAN_I2C_ERR_NO_RESP;
-
- if (val & 0x0080)
- return TITAN_I2C_ERR_DATA_COLLISION;
-
- return TITAN_I2C_ERR_OK;
-}
-
-/*
- * Init the I2C subsystem of the PMC-Sierra Yosemite board
- */
-int titan_i2c_init(titan_i2c_config * config)
-{
- unsigned int val;
-
- /*
- * Reset the SCMB and program into the I2C mode
- */
- TITAN_I2C_WRITE(TITAN_I2C_SCMB_CONTROL, 0xA000);
- TITAN_I2C_WRITE(TITAN_I2C_SCMB_CONTROL, 0x2000);
-
- /*
- * Configure the filtera and clka values
- */
- val = TITAN_I2C_READ(TITAN_I2C_SCMB_CLOCK_A);
- val |= ((val & ~(0xF000)) | ((config->filtera << 12) & 0xF000));
- val |= ((val & ~(0x03FF)) | (config->clka & 0x03FF));
- TITAN_I2C_WRITE(TITAN_I2C_SCMB_CLOCK_A, val);
-
- /*
- * Configure the filterb and clkb values
- */
- val = TITAN_I2C_READ(TITAN_I2C_SCMB_CLOCK_B);
- val |= ((val & ~(0xF000)) | ((config->filterb << 12) & 0xF000));
- val |= ((val & ~(0x03FF)) | (config->clkb & 0x03FF));
- TITAN_I2C_WRITE(TITAN_I2C_SCMB_CLOCK_B, val);
-
- return TITAN_I2C_ERR_OK;
-}
projects / linux-2.6 / commitdiff