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pca9698.c 2.39 KiB
/*
 * (C) Copyright 2011
 * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * 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;