/*
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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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* SPDX-License-Identifier: GPL-2.0+
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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 <linux/errno.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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#define PCA9698_GPIO_COUNT 40
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static int pca9698_read40(u8 addr, u8 offset, u8 *buffer)
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{
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u8 command = offset | 0x80; /* autoincrement */
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return i2c_read(addr, command, 1, buffer, PCA9698_BUFFER_SIZE);
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}
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static int pca9698_write40(u8 addr, u8 offset, u8 *buffer)
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{
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u8 command = offset | 0x80; /* autoincrement */
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return i2c_write(addr, 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_request(unsigned gpio, const char *label)
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{
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if (gpio >= PCA9698_GPIO_COUNT)
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return -EINVAL;
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return 0;
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}
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void pca9698_free(unsigned gpio)
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{
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}
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int pca9698_direction_input(u8 addr, unsigned gpio)
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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(addr, PCA9698_REG_CONFIG, data);
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if (res)
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return res;
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pca9698_set_bit(gpio, data, 1);
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return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
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}
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int pca9698_direction_output(u8 addr, unsigned gpio, 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_set_value(addr, gpio, value);
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if (res)
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return res;
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res = pca9698_read40(addr, PCA9698_REG_CONFIG, data);
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if (res)
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return res;
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pca9698_set_bit(gpio, data, 0);
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return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
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}
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int pca9698_get_value(u8 addr, unsigned gpio)
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{
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unsigned config_byte = gpio / 8;
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unsigned config_bit = gpio % 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(addr, 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_value(u8 addr, unsigned gpio, 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(addr, PCA9698_REG_OUTPUT, data);
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if (res)
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return res;
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pca9698_set_bit(gpio, data, value);
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return pca9698_write40(addr, PCA9698_REG_OUTPUT, data);
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}
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