144 lines
3.1 KiB
C
144 lines
3.1 KiB
C
/*
|
|
* (C) Copyright 2011
|
|
* Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/*
|
|
* Driver for NXP's pca9698 40 bit I2C gpio expander
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <i2c.h>
|
|
#include <asm/errno.h>
|
|
#include <pca9698.h>
|
|
|
|
/*
|
|
* The pca9698 registers
|
|
*/
|
|
|
|
#define PCA9698_REG_INPUT 0x00
|
|
#define PCA9698_REG_OUTPUT 0x08
|
|
#define PCA9698_REG_POLARITY 0x10
|
|
#define PCA9698_REG_CONFIG 0x18
|
|
|
|
#define PCA9698_BUFFER_SIZE 5
|
|
#define PCA9698_GPIO_COUNT 40
|
|
|
|
static int pca9698_read40(u8 addr, u8 offset, u8 *buffer)
|
|
{
|
|
u8 command = offset | 0x80; /* autoincrement */
|
|
|
|
return i2c_read(addr, command, 1, buffer, PCA9698_BUFFER_SIZE);
|
|
}
|
|
|
|
static int pca9698_write40(u8 addr, u8 offset, u8 *buffer)
|
|
{
|
|
u8 command = offset | 0x80; /* autoincrement */
|
|
|
|
return i2c_write(addr, command, 1, buffer, PCA9698_BUFFER_SIZE);
|
|
}
|
|
|
|
static void pca9698_set_bit(unsigned gpio, u8 *buffer, unsigned value)
|
|
{
|
|
unsigned byte = gpio / 8;
|
|
unsigned bit = gpio % 8;
|
|
|
|
if (value)
|
|
buffer[byte] |= (1 << bit);
|
|
else
|
|
buffer[byte] &= ~(1 << bit);
|
|
}
|
|
|
|
int pca9698_request(unsigned gpio, const char *label)
|
|
{
|
|
if (gpio >= PCA9698_GPIO_COUNT)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void pca9698_free(unsigned gpio)
|
|
{
|
|
}
|
|
|
|
int pca9698_direction_input(u8 addr, unsigned gpio)
|
|
{
|
|
u8 data[PCA9698_BUFFER_SIZE];
|
|
int res;
|
|
|
|
res = pca9698_read40(addr, PCA9698_REG_CONFIG, data);
|
|
if (res)
|
|
return res;
|
|
|
|
pca9698_set_bit(gpio, data, 1);
|
|
|
|
return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
|
|
}
|
|
|
|
int pca9698_direction_output(u8 addr, unsigned gpio, int value)
|
|
{
|
|
u8 data[PCA9698_BUFFER_SIZE];
|
|
int res;
|
|
|
|
res = pca9698_set_value(addr, gpio, value);
|
|
if (res)
|
|
return res;
|
|
|
|
res = pca9698_read40(addr, PCA9698_REG_CONFIG, data);
|
|
if (res)
|
|
return res;
|
|
|
|
pca9698_set_bit(gpio, data, 0);
|
|
|
|
return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
|
|
}
|
|
|
|
int pca9698_get_value(u8 addr, unsigned gpio)
|
|
{
|
|
unsigned config_byte = gpio / 8;
|
|
unsigned config_bit = gpio % 8;
|
|
unsigned value;
|
|
u8 data[PCA9698_BUFFER_SIZE];
|
|
int res;
|
|
|
|
res = pca9698_read40(addr, PCA9698_REG_INPUT, data);
|
|
if (res)
|
|
return -1;
|
|
|
|
value = data[config_byte] & (1 << config_bit);
|
|
|
|
return !!value;
|
|
}
|
|
|
|
int pca9698_set_value(u8 addr, unsigned gpio, int value)
|
|
{
|
|
u8 data[PCA9698_BUFFER_SIZE];
|
|
int res;
|
|
|
|
res = pca9698_read40(addr, PCA9698_REG_OUTPUT, data);
|
|
if (res)
|
|
return res;
|
|
|
|
pca9698_set_bit(gpio, data, value);
|
|
|
|
return pca9698_write40(addr, PCA9698_REG_OUTPUT, data);
|
|
}
|