poten.cpp

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/**
 * @file    poten.cpp
 * @brief   MCP42010 digital potentiometer driver
 *
 * @date Mar 16, 2013
 * @author Andrey Belomutskiy, (c) 2012-2020
 */
 
#include "pch.h"
 
#include "poten.h"
#include "eficonsole.h"
#include "hardware.h"
#include "mpu_util.h"
 
#if HAL_USE_SPI
 
/**
 * MCP42010 digital potentiometer driver
 *
 *
 * 1    CS      pin select                      PB12        PA10
 * 2    SCK     serial clock                    PA5         PC10
 * 3    SI      serial input        (MOSI)      PA7         PC12
 * 4    Vss     ground
 * 5    PB1
 * 6    PW1
 * 7    PA1
 * 8    PA0
 * 9    PW0
 * 10   PB0
 * 11   RS      Reset
 *
 * 14   Vdd     V input
 *
 * Rwa = 10000 * (256 - d) / 256 + 52
 * d = 256 - (Rwa - 52) * 256 / 10000
 *
 */
 
/* Low speed SPI configuration (281.250kHz, CPHA=0, CPOL=0, MSb first).*/
 
#if defined(STM32F7XX)
#define SPI_POT_CONFIG SPI_CR1_BR_2 | SPI_CR1_BR_1 | SPI_CR1_CRCL
#else /* defined(STM32F4XX) */
#define SPI_POT_CONFIG SPI_CR1_BR_2 | SPI_CR1_BR_1 | SPI_CR1_DFF
#endif /* defined(STM32F4XX) */
 
#if EFI_POTENTIOMETER
static Mcp42010Driver potConfig[DIGIPOT_COUNT];
 
void initPotentiometer(Mcp42010Driver *driver, SPIDriver *spi, brain_pin_e csPin) {
    driver->spiConfig.cr1 = SPI_POT_CONFIG;
    driver->spi = spi;
    initSpiCs(&driver->spiConfig, csPin);
}
 
static int getPotStep(int resistanceWA) {
    return 256 - (int) ((resistanceWA - 52) * 256 / 10000);
}
 
static void sendToPot(Mcp42010Driver *driver, int channel, int value) {
    lockSpi(SPI_NONE);
    spiStart(driver->spi, &driver->spiConfig);
    spiSelect(driver->spi);
    int word = (17 + channel) * 256 + value;
    spiSend(driver->spi, 1, &word);
    spiUnselect(driver->spi);
    spiStop(driver->spi);
    unlockSpi(SPI_NONE);
}
 
void setPotResistance(Mcp42010Driver *driver, int channel, int resistance) {
    int value = getPotStep(resistance);
 
    efiPrintf("Sending to potentiometer%d: %d for R=%d", channel, value, resistance);
    sendToPot(driver, channel, value);
}
 
static void setPotResistanceCommand(int index, int value) {
    setPotResistance(&potConfig[index / 2], index % 2, value);
}
 
static void setPotValue1(int value) {
    sendToPot(&potConfig[0], 1, value);
}
 
#endif /* EFI_POTENTIOMETER */
 
void initPotentiometers() {
#if EFI_POTENTIOMETER
    if (engineConfiguration->digitalPotentiometerSpiDevice == SPI_NONE) {
        efiPrintf("digiPot spi disabled");
        return;
    }
    // todo: we have centralized SPI management see other usages of 'turnOnSpi'
    //turnOnSpi(engineConfiguration->digitalPotentiometerSpiDevice);
 
    for (int i = 0; i < DIGIPOT_COUNT; i++) {
        brain_pin_e csPin = engineConfiguration->digitalPotentiometerChipSelect[i];
        if (!isBrainPinValid(csPin)) {
            continue;
                }
 
        SPIDriver *driver = getSpiDevice(engineConfiguration->digitalPotentiometerSpiDevice);
        if (driver == NULL) {
            // error already reported
            return;
        }
 
        initPotentiometer(&potConfig[i], driver, csPin);
    }
 
    addConsoleActionII("pot", setPotResistanceCommand);
 
    addConsoleActionI("potd1", setPotValue1);
 
    setPotResistance(&potConfig[0], 0, 3000);
    setPotResistance(&potConfig[0], 1, 7000);
#endif
}
 
#endif /* HAL_USE_SPI */