contiki/platform/galileo/drivers/cy8c9540a.c

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/*
* Copyright (C) 2016, Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "cy8c9540a.h"
#include <assert.h>
#include "i2c.h"
#include <stdio.h>
/* Change this to 0x21 if J2 is set to 1-2
* (covering the pin marked with the white triangle). */
#define I2C_ADDR 0x20
#define REG_PORT_SEL 0x18
#define REG_PORT_DIR 0x1C
#define PORT_CNT 6
/* Cache the current state of each port to obviate the need for reading before
* writing to output ports when simply updating a single pin.
*/
static uint8_t out_cache[PORT_CNT];
/*---------------------------------------------------------------------------*/
static void
write_reg(uint8_t reg, uint8_t data)
{
uint8_t pkt[] = { reg, data };
assert(quarkX1000_i2c_polling_write(pkt, sizeof(pkt), I2C_ADDR) == 0);
}
/*---------------------------------------------------------------------------*/
static uint8_t
read_reg(uint8_t reg)
{
uint8_t data;
assert(quarkX1000_i2c_polling_write(&reg, 1, I2C_ADDR) == 0);
assert(quarkX1000_i2c_polling_read(&data, 1, I2C_ADDR) == 0);
return data;
}
/*---------------------------------------------------------------------------*/
void
cy8c9540a_init(void)
{
uint8_t status;
/* has to init after I2C master */
assert(quarkX1000_i2c_is_available());
status = read_reg(0x2E);
if((status >> 4) != 4) {
fprintf(stderr, "Failed to communicate with CY8C9540A. Perhaps jumper J2 "
"is not set to 2-3? Halting.\n");
halt();
}
}
/*---------------------------------------------------------------------------*/
/**
* \brief Set the direction (in or out) for the indicated GPIO pin.
*/
void
cy8c9540a_set_port_dir(cy8c9540a_bit_addr_t addr, cy8c9540a_port_dir_t dir)
{
uint8_t mask;
assert(addr.port < PORT_CNT);
write_reg(REG_PORT_SEL, addr.port);
mask = read_reg(REG_PORT_DIR);
mask &= ~(1 << addr.pin);
mask |= ((uint8_t)dir) << addr.pin;
write_reg(REG_PORT_DIR, mask);
}
/*---------------------------------------------------------------------------*/
/**
* \brief Set the drive mode for the indicated GPIO pin.
*/
void
cy8c9540a_set_drive_mode(cy8c9540a_bit_addr_t addr,
cy8c9540a_drive_mode_t drv_mode)
{
assert(addr.port < PORT_CNT);
write_reg(REG_PORT_SEL, addr.port);
write_reg((uint8_t)drv_mode, 1 << addr.pin);
}
/*---------------------------------------------------------------------------*/
bool
cy8c9540a_read(cy8c9540a_bit_addr_t addr)
{
assert(addr.port < PORT_CNT);
return ((read_reg(addr.port) >> addr.pin) & 1) == 1;
}
/*---------------------------------------------------------------------------*/
void
cy8c9540a_write(cy8c9540a_bit_addr_t addr, bool val)
{
assert(addr.port < PORT_CNT);
out_cache[addr.port] &= ~(1 << addr.pin);
out_cache[addr.port] |= ((uint8_t)val) << addr.pin;
write_reg(8 + addr.port, out_cache[addr.port]);
}
/*---------------------------------------------------------------------------*/