mirror of
https://github.com/brain-hackers/u-boot-brain
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124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/*
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* (C) Copyright 2011
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* Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*
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* Driver for NXP's pca9698 40 bit I2C gpio expander
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*/
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#include <common.h>
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#include <i2c.h>
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#include <pca9698.h>
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/*
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* The pca9698 registers
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*/
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#define PCA9698_REG_INPUT 0x00
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#define PCA9698_REG_OUTPUT 0x08
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#define PCA9698_REG_POLARITY 0x10
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#define PCA9698_REG_CONFIG 0x18
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#define PCA9698_BUFFER_SIZE 5
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static int pca9698_read40(u8 chip, u8 offset, u8 *buffer)
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{
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u8 command = offset | 0x80; /* autoincrement */
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return i2c_read(chip, command, 1, buffer, PCA9698_BUFFER_SIZE);
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}
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static int pca9698_write40(u8 chip, u8 offset, u8 *buffer)
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{
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u8 command = offset | 0x80; /* autoincrement */
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return i2c_write(chip, command, 1, buffer, PCA9698_BUFFER_SIZE);
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}
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static void pca9698_set_bit(unsigned gpio, u8 *buffer, unsigned value)
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{
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unsigned byte = gpio / 8;
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unsigned bit = gpio % 8;
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if (value)
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buffer[byte] |= (1 << bit);
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else
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buffer[byte] &= ~(1 << bit);
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}
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int pca9698_direction_input(u8 chip, unsigned offset)
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{
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u8 data[PCA9698_BUFFER_SIZE];
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int res;
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res = pca9698_read40(chip, PCA9698_REG_CONFIG, data);
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if (res)
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return res;
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pca9698_set_bit(offset, data, 1);
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return pca9698_write40(chip, PCA9698_REG_CONFIG, data);
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}
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int pca9698_direction_output(u8 chip, unsigned offset)
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{
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u8 data[PCA9698_BUFFER_SIZE];
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int res;
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res = pca9698_read40(chip, PCA9698_REG_CONFIG, data);
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if (res)
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return res;
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pca9698_set_bit(offset, data, 0);
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return pca9698_write40(chip, PCA9698_REG_CONFIG, data);
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}
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int pca9698_get_input(u8 chip, unsigned offset)
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{
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unsigned config_byte = offset / 8;
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unsigned config_bit = offset % 8;
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unsigned value;
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u8 data[PCA9698_BUFFER_SIZE];
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int res;
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res = pca9698_read40(chip, PCA9698_REG_INPUT, data);
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if (res)
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return -1;
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value = data[config_byte] & (1 << config_bit);
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return !!value;
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}
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int pca9698_set_output(u8 chip, unsigned offset, int value)
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{
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u8 data[PCA9698_BUFFER_SIZE];
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int res;
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res = pca9698_read40(chip, PCA9698_REG_OUTPUT, data);
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if (res)
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return res;
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memset(data, sizeof(data), 0);
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pca9698_set_bit(offset, data, value);
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return pca9698_write40(chip, PCA9698_REG_OUTPUT, data);
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}
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