drv8860.cpp

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/*
 * drv8860.c
 *
 * DRV8860 Smart 8/16-Channel Low-Side Switch
 *
 * All channels are controlled via the serial interface (SPI).
 * <200 kHz SPI
 *
 * @date Apr 6, 2020
 *
 * @author andreika, (c) 2020
 * @author Andrey Belomutskiy, (c) 2012-2020
 */
 
#include "pch.h"
 
#include "gpio/gpio_ext.h"
#include "gpio/drv8860.h"
 
#if EFI_PROD_CODE && (BOARD_DRV8860_COUNT > 0)
 
/*==========================================================================*/
/* Driver local definitions.                                                */
/*==========================================================================*/
 
#define DRIVER_NAME             "drv8860"
 
static bool drv_task_ready = false;
 
typedef enum {
    DRV8860_DISABLED = 0,
    DRV8860_WAIT_INIT,
    DRV8860_READY,
    DRV8860_FAILED
} drv8860_drv_state;
 
/*==========================================================================*/
/* Driver exported variables.                                               */
/*==========================================================================*/
 
/*==========================================================================*/
/* Driver local variables and types.                                        */
/*==========================================================================*/
 
/* OS */
SEMAPHORE_DECL(drv8860_wake, 10 /* or BOARD_DRV8860_COUNT ? */);
static THD_WORKING_AREA(drv8860_thread_1_wa, 256);
 
/* Driver */
struct Drv8860 : public GpioChip {
    int init() override;
 
    int writePad(size_t pin, int value) override;
    brain_pin_diag_e getDiag(size_t pin) override;
 
    // Internal helpers
    int chip_init();
 
    void spi_send(uint16_t tx);
 
    void update_outputs();
    int wake_driver();
 
    const drv8860_config        *cfg;
    /* cached output state - state last send to chip */
    uint16_t                    o_state_cached;
    /* state to be sended to chip */
    uint16_t                    o_state;
 
    drv8860_drv_state           drv_state;
};
 
static Drv8860 chips[BOARD_DRV8860_COUNT];
 
static const char* drv8860_pin_names[DRV8860_OUTPUTS] = {
    "drv8860.OUT1",     "drv8860.OUT2",     "drv8860.OUT3",     "drv8860.OUT4",
    "drv8860.OUT5",     "drv8860.OUT6",     "drv8860.OUT7",     "drv8860.OUT8",
    "drv8860.OUT9",     "drv8860.OUT10",    "drv8860.OUT11",    "drv8860.OUT12",
    "drv8860.OUT13",    "drv8860.OUT14",    "drv8860.OUT15",    "drv8860.OUT16",
};
 
/*==========================================================================*/
/* Driver local functions.                                                  */
/*==========================================================================*/
 
/**
 * @brief DRV8860 send routine.
 * @details Sends 8/16 bits. CS asserted before and released after transaction.
 */
 
void Drv8860::spi_send(uint16_t tx) {
    SPIDriver *spi = cfg->spi_bus;
 
    /* Acquire ownership of the bus. */
    spiAcquireBus(spi);
    /* Setup transfer parameters. */
    spiStart(spi, &cfg->spi_config);
    /* Slave Select assertion. */
    spiSelect(spi);
    /* Atomic transfer operations. */
    spiPolledExchange(spi, tx);
    /* Slave Select de-assertion. */
    spiUnselect(spi);
    /* Ownership release. */
    spiReleaseBus(spi);
}
 
/**
 * @brief DRV8860 send output data.
 */
 
void Drv8860::update_outputs() {
    /* TODO: lock? */
 
    /* atomic */
    /* set value only for non-direct driven pins */
    spi_send(o_state & 0xffff);
 
    /* atomic */
    o_state_cached = o_state;
 
    /* TODO: unlock? */
}
 
/**
 * @brief DRV8860 chip init.
 * @details Marks all used pins.
 * @todo: Checks direct io signals integrity, read initial diagnostic state.
 */
 
int Drv8860::chip_init() {
    /* upload pin states */
    update_outputs();
 
    return 0;
}
 
/**
 * @brief DRV8860 chip driver wakeup.
 * @details Wake up driver. Will cause output register update.
 */
 
int Drv8860::wake_driver() {
    /* Entering a reentrant critical zone.*/
    chibios_rt::CriticalSectionLocker csl;
 
    chSemSignalI(&drv8860_wake);
 
    return 0;
}
 
/*==========================================================================*/
/* Driver thread.                                                           */
/*==========================================================================*/
 
static THD_FUNCTION(drv8860_driver_thread, p) {
    int i;
    msg_t msg;
 
    (void)p;
 
    chRegSetThreadName(DRIVER_NAME);
 
    while (1) {
        msg = chSemWaitTimeout(&drv8860_wake, TIME_MS2I(DRV8860_POLL_INTERVAL_MS));
 
        /* should we care about msg == MSG_TIMEOUT? */
        (void)msg;
 
        for (i = 0; i < BOARD_DRV8860_COUNT; i++) {
            auto chip = &chips[i];
            if ((chip->cfg == NULL) ||
                (chip->drv_state == DRV8860_DISABLED) ||
                (chip->drv_state == DRV8860_FAILED))
                continue;
 
            chip->update_outputs();
        }
    }
}
 
/*==========================================================================*/
/* Driver interrupt handlers.                                               */
/*==========================================================================*/
 
/* TODO: add IRQ support */
 
/*==========================================================================*/
/* Driver exported functions.                                               */
/*==========================================================================*/
 
int Drv8860::writePad(size_t pin, int value) {
    if (pin >= DRV8860_OUTPUTS)
        return -1;
 
    /* TODO: lock */
    if (value)
        o_state |=  (1 << pin);
    else
        o_state &= ~(1 << pin);
    /* TODO: unlock */
    wake_driver();
 
    return 0;
}
 
brain_pin_diag_e Drv8860::getDiag(size_t /*pin*/) {
    // todo: implement diag
    return PIN_OK;
}
 
int Drv8860::init() {
    int ret;
 
    ret = chip_init();
    if (ret)
        return ret;
 
    drv_state = DRV8860_READY;
 
    if (!drv_task_ready) {
        chThdCreateStatic(drv8860_thread_1_wa, sizeof(drv8860_thread_1_wa),
                          PRIO_GPIOCHIP, drv8860_driver_thread, NULL);
        drv_task_ready = true;
    }
 
    return 0;
}
 
/**
 * @brief DRV8860 driver add.
 * @details Checks for valid config
 */
 
int drv8860_add(brain_pin_e base, unsigned int index, const drv8860_config *cfg) {
    int ret;
 
    /* no config or no such chip */
    if ((!cfg) || (!cfg->spi_bus) || (index >= BOARD_DRV8860_COUNT))
        return -1;
 
    /* check for valid cs.
     * TODO: remove this check? CS can be driven by SPI */
    //if (cfg->spi_config.ssport == NULL)
    //  return -1;
 
    auto& chip = chips[index];
 
    /* already initted? */
    if (!chip.cfg)
        return -1;
 
    chip.cfg = cfg;
    chip.o_state = 0;
    chip.o_state_cached = 0;
    chip.drv_state = DRV8860_WAIT_INIT;
 
    /* register, return gpio chip base */
    ret = gpiochip_register(base, DRIVER_NAME, chip, DRV8860_OUTPUTS);
    if (ret < 0)
        return ret;
 
    /* set default pin names, board init code can rewrite */
    gpiochips_setPinNames(static_cast<brain_pin_e>(ret), drv8860_pin_names);
 
    return ret;
}
 
#else /* BOARD_DRV8860_COUNT > 0 */
 
int drv8860_add(brain_pin_e base, unsigned int index, const drv8860_config *cfg) {
    (void)base; (void)index; (void)cfg;
 
    return -1;
}
 
#endif /* BOARD_DRV8860_COUNT */