OpenRTX/platform/drivers/GPIO/gpio_shiftReg.h

86 wiersze
3.5 KiB
C

/***************************************************************************
* Copyright (C) 2024 - 2025 by Silvano Seva IU2KWO *
* *
* 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 3 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, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef GPIO_SHIFTREG_H
#define GPIO_SHIFTREG_H
#include <peripherals/gpio.h>
#include <peripherals/spi.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* Driver to use a chain of shift registers (e.g. 74HC595) as GPIO outputs.
* It requires an SPI interface, of which only the MOSI and SCK lines are used
* and an MCU gpio for shift register strobe signal.
*/
/**
* Private data of shift register gpio driver.
*/
struct gpioShiftRegPriv
{
const struct spiDevice *spi; ///< SPI interface device driver
const struct gpioPin strobe; ///< Gpio for output strobe line
const size_t numOutputs; ///< Number of actual outputs
uint8_t *const outData; ///< Pointer to gpio state storage
};
/**
* Instantiate a shift register gpio device driver.
*
* @param name: device name.
* @param spiDev: pointer to device driver managing the SPI bus.
* @param strb: gpioPin struct for strobe line management.
* @param numOuts: number of gpio outputs.
*/
#define GPIO_SHIFTREG_DEVICE_DEFINE(name, spiDev, strb, numOuts) \
extern const struct gpioApi gpioShiftReg_ops; \
static uint8_t srData_##name[(numOuts + 8 - 1) / 8]; \
static const struct gpioShiftRegPriv srGpioPriv_##name = \
{ \
.spi = spiDev, \
.strobe = strb, \
.numOutputs = numOuts, \
.outData = srData_##name \
}; \
const struct gpioDev name = \
{ \
.api = &gpioShiftReg_ops, \
.priv = &srGpioPriv_##name \
};
/**
* Initialize the GPIO shift register driver.
*/
void gpioShiftReg_init(const struct gpioDev *dev);
/**
* Shut down the GPIO shift register driver. Shift register outputs keep the last
* assigned state.
*/
void gpioShiftReg_terminate(const struct gpioDev *dev);
#ifdef __cplusplus
}
#endif
#endif /* GPIO_SHIFTREG_H */