forked from Minki/linux
49316cbf0a
They tend to get not updated when files are moved around or copied and lack any obvious use. While at it zap some only too obvious comments and as per Shinya's suggestion, add a copyright header to extable.c. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
170 lines
3.5 KiB
C
170 lines
3.5 KiB
C
/*
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* Copyright (C) 2003 PMC-Sierra Inc.
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* Author: Manish Lachwani (lachwani@pmc-sierra.com)
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
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* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*
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* Description:
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*
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* This code reads the ATMEL 24CXX EEPROM. The PMC-Sierra Yosemite board uses the ATMEL
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* 24C32/24C64 which uses two byte addressing as compared to 24C16. Note that this program
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* uses the serial port like /dev/ttyS0, to communicate with the EEPROM. Hence, you are
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* expected to have a connectivity from the EEPROM to the serial port. This program does
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* __not__ communicate using the I2C protocol
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*/
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#include "atmel_read_eeprom.h"
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static void delay(int delay)
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{
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while (delay--);
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}
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static void send_bit(unsigned char bit)
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{
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scl_lo;
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delay(TXX);
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if (bit)
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sda_hi;
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else
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sda_lo;
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delay(TXX);
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scl_hi;
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delay(TXX);
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}
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static void send_ack(void)
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{
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send_bit(0);
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}
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static void send_byte(unsigned char byte)
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{
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int i = 0;
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for (i = 7; i >= 0; i--)
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send_bit((byte >> i) & 0x01);
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}
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static void send_start(void)
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{
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sda_hi;
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delay(TXX);
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scl_hi;
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delay(TXX);
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sda_lo;
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delay(TXX);
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}
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static void send_stop(void)
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{
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sda_lo;
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delay(TXX);
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scl_hi;
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delay(TXX);
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sda_hi;
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delay(TXX);
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}
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static void do_idle(void)
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{
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sda_hi;
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scl_hi;
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vcc_off;
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}
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static int recv_bit(void)
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{
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int status;
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scl_lo;
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delay(TXX);
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sda_hi;
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delay(TXX);
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scl_hi;
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delay(TXX);
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return 1;
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}
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static unsigned char recv_byte(void) {
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int i;
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unsigned char byte=0;
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for (i=7;i>=0;i--)
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byte |= (recv_bit() << i);
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return byte;
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}
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static int recv_ack(void)
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{
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unsigned int ack;
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ack = (unsigned int)recv_bit();
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scl_lo;
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if (ack) {
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do_idle();
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printk(KERN_ERR "Error reading the Atmel 24C32/24C64 EEPROM \n");
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return -1;
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}
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return ack;
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}
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/*
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* This function does the actual read of the EEPROM. It needs the buffer into which the
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* read data is copied, the size of the EEPROM being read and the buffer size
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*/
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int read_eeprom(char *buffer, int eeprom_size, int size)
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{
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int i = 0, err;
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send_start();
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send_byte(W_HEADER);
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recv_ack();
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/* EEPROM with size of more than 2K need two byte addressing */
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if (eeprom_size > 2048) {
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send_byte(0x00);
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recv_ack();
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}
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send_start();
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send_byte(R_HEADER);
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err = recv_ack();
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if (err == -1)
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return err;
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for (i = 0; i < size; i++) {
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*buffer++ = recv_byte();
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send_ack();
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}
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/* Note : We should do some check if the buffer contains correct information */
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send_stop();
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}
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