rgbled.cpp

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/**
 * @file rgbled.cpp
 *
 * Driver for the onboard RGB LED controller (TCA62724FMG) connected via I2C.
 *
 * @author Julian Oes <julian@px4.io>
 * @author Anton Babushkin <anton.babushkin@me.com>
 */

#include <string.h>

#include <drivers/device/i2c.h>
#include <lib/led/led.h>
#include <lib/parameters/param.h>
#include <px4_platform_common/getopt.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <uORB/Subscription.hpp>
#include <uORB/topics/parameter_update.h>

#define ADDR            0x55    /**< I2C adress of TCA62724FMG */
#define SUB_ADDR_START      0x01    /**< write everything (with auto-increment) */
#define SUB_ADDR_PWM0       0x81    /**< blue     (without auto-increment) */
#define SUB_ADDR_PWM1       0x82    /**< green    (without auto-increment) */
#define SUB_ADDR_PWM2       0x83    /**< red      (without auto-increment) */
#define SUB_ADDR_SETTINGS   0x84    /**< settings (without auto-increment)*/

#define SETTING_NOT_POWERSAVE   0x01    /**< power-save mode not off */
#define SETTING_ENABLE      0x02    /**< on */

class RGBLED : public device::I2C, public px4::ScheduledWorkItem
{
public:
    RGBLED(int bus, int rgbled);
    virtual ~RGBLED();

    virtual int     init();
    virtual int     probe();
    int         status();

private:

    float           _brightness{1.0f};
    float           _max_brightness{1.0f};

    uint8_t         _r{0};
    uint8_t         _g{0};
    uint8_t         _b{0};
    volatile bool       _running{false};
    volatile bool       _should_run{true};
    bool            _leds_enabled{true};

    uORB::Subscription  _parameter_update_sub{ORB_ID(parameter_update)};

    LedController       _led_controller;

    void            Run() override;

    int         send_led_enable(bool enable);
    int         send_led_rgb();
    int         get(bool &on, bool &powersave, uint8_t &r, uint8_t &g, uint8_t &b);
    void            update_params();
};

/* for now, we only support one RGBLED */
namespace
{
RGBLED *g_rgbled = nullptr;
}

void rgbled_usage();

extern "C" __EXPORT int rgbled_main(int argc, char *argv[]);

RGBLED::RGBLED(int bus, int rgbled) :
    I2C("rgbled", RGBLED0_DEVICE_PATH, bus, rgbled, 100000),
    ScheduledWorkItem(MODULE_NAME, px4::device_bus_to_wq(get_device_id()))
{
}

RGBLED::~RGBLED()
{
    _should_run = false;
    int counter = 0;

    while (_running && ++counter < 10) {
        px4_usleep(100000);
    }
}

int
RGBLED::init()
{
    int ret = I2C::init();

    if (ret != OK) {
        return ret;
    }

    /* switch off LED on start */
    send_led_enable(false);
    send_led_rgb();

    update_params();

    _running = true;

    // kick off work queue
    ScheduleNow();

    return OK;
}

int
RGBLED::probe()
{
    int ret;
    bool on, powersave;
    uint8_t r, g, b;

    /**
       this may look strange, but is needed. There is a serial
       EEPROM (Microchip-24aa01) that responds to a bunch of I2C
       addresses, including the 0x55 used by this LED device. So
       we need to do enough operations to be sure we are talking
       to the right device. These 3 operations seem to be enough,
       as the 3rd one consistently fails if no RGBLED is on the bus.
     */

    unsigned prevretries = _retries;
    _retries = 4;

    if ((ret = get(on, powersave, r, g, b)) != OK ||
        (ret = send_led_enable(false) != OK) ||
        (ret = send_led_enable(false) != OK)) {
        return ret;
    }

    _retries = prevretries;

    return ret;
}

int
RGBLED::status()
{
    bool on, powersave;
    uint8_t r, g, b;

    int ret = get(on, powersave, r, g, b);

    if (ret == OK) {
        /* we don't care about power-save mode */
        DEVICE_LOG("state: %s", on ? "ON" : "OFF");
        DEVICE_LOG("red: %u, green: %u, blue: %u", (unsigned)r, (unsigned)g, (unsigned)b);

    } else {
        PX4_WARN("failed to read led");
    }

    return ret;
}

/**
 * Main loop function
 */
void
RGBLED::Run()
{
    if (!_should_run) {
        _running = false;
        return;
    }

    // check for parameter updates
    if (_parameter_update_sub.updated()) {
        // clear update
        parameter_update_s pupdate;
        _parameter_update_sub.copy(&pupdate);

        // update parameters from storage
        update_params();

        // Immediately update to change brightness
        send_led_rgb();
    }

    LedControlData led_control_data;

    if (_led_controller.update(led_control_data) == 1) {
        switch (led_control_data.leds[0].color) {
        case led_control_s::COLOR_RED:
            _r = 255; _g = 0; _b = 0;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_GREEN:
            _r = 0; _g = 255; _b = 0;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_BLUE:
            _r = 0; _g = 0; _b = 255;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_AMBER: //make it the same as yellow
        case led_control_s::COLOR_YELLOW:
            _r = 255; _g = 255; _b = 0;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_PURPLE:
            _r = 255; _g = 0; _b = 255;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_CYAN:
            _r = 0; _g = 255; _b = 255;
            send_led_enable(true);
            break;

        case led_control_s::COLOR_WHITE:
            _r = 255; _g = 255; _b = 255;
            send_led_enable(true);
            break;

        default: // led_control_s::COLOR_OFF
            _r = 0; _g = 0; _b = 0;
            send_led_enable(false);
            break;
        }

        _brightness = (float)led_control_data.leds[0].brightness / 255.f;

        send_led_rgb();
    }

    /* re-queue ourselves to run again later */
    ScheduleDelayed(_led_controller.maximum_update_interval());
}

/**
 * Sent ENABLE flag to LED driver
 */
int
RGBLED::send_led_enable(bool enable)
{
    if (_leds_enabled && enable) {
        // already enabled
        return 0;
    }

    _leds_enabled = enable;
    uint8_t settings_byte = 0;

    if (enable) {
        settings_byte |= SETTING_ENABLE;
    }

    settings_byte |= SETTING_NOT_POWERSAVE;

    const uint8_t msg[2] = { SUB_ADDR_SETTINGS, settings_byte};

    return transfer(msg, sizeof(msg), nullptr, 0);
}

/**
 * Send RGB PWM settings to LED driver according to current color and brightness
 */
int
RGBLED::send_led_rgb()
{
    /* To scale from 0..255 -> 0..15 shift right by 4 bits */
    const uint8_t msg[6] = {
        SUB_ADDR_PWM0, static_cast<uint8_t>((_b >> 4) * _brightness * _max_brightness + 0.5f),
        SUB_ADDR_PWM1, static_cast<uint8_t>((_g >> 4) * _brightness * _max_brightness + 0.5f),
        SUB_ADDR_PWM2, static_cast<uint8_t>((_r >> 4) * _brightness * _max_brightness + 0.5f)
    };
    return transfer(msg, sizeof(msg), nullptr, 0);
}

int
RGBLED::get(bool &on, bool &powersave, uint8_t &r, uint8_t &g, uint8_t &b)
{
    uint8_t result[2] = {0, 0};
    int ret;

    ret = transfer(nullptr, 0, &result[0], 2);

    if (ret == OK) {
        on = ((result[0] >> 4) & SETTING_ENABLE);
        powersave = !((result[0] >> 4) & SETTING_NOT_POWERSAVE);
        /* XXX check, looks wrong */
        r = (result[0] & 0x0f) << 4;
        g = (result[1] & 0xf0);
        b = (result[1] & 0x0f) << 4;
    }

    return ret;
}

void
RGBLED::update_params()
{
    int32_t maxbrt = 15;
    param_get(param_find("LED_RGB_MAXBRT"), &maxbrt);
    maxbrt = maxbrt > 15 ? 15 : maxbrt;
    maxbrt = maxbrt <  0 ?  0 : maxbrt;

    // A minimum of 2 "on" steps is required for breathe effect
    if (maxbrt == 1) {
        maxbrt = 2;
    }

    _max_brightness = maxbrt / 15.0f;
}

void
rgbled_usage()
{
    PX4_INFO("missing command: try 'start', 'status', 'stop'");
    PX4_INFO("options:");
    PX4_INFO("    -b i2cbus (%d)", PX4_I2C_BUS_LED);
    PX4_INFO("    -a addr (0x%x)", ADDR);
}

int
rgbled_main(int argc, char *argv[])
{
    int i2cdevice = -1;
    int rgbledadr = ADDR; /* 7bit */

    int ch;

    /* jump over start/off/etc and look at options first */
    int myoptind = 1;
    const char *myoptarg = nullptr;

    while ((ch = px4_getopt(argc, argv, "a:b:", &myoptind, &myoptarg)) != EOF) {
        switch (ch) {
        case 'a':
            rgbledadr = strtol(myoptarg, nullptr, 0);
            break;

        case 'b':
            i2cdevice = strtol(myoptarg, nullptr, 0);
            break;

        default:
            rgbled_usage();
            return 1;
        }
    }

    if (myoptind >= argc) {
        rgbled_usage();
        return 1;
    }

    const char *verb = argv[myoptind];

    if (!strcmp(verb, "start")) {
        if (g_rgbled != nullptr) {
            PX4_WARN("already started");
            return 1;
        }

        if (i2cdevice == -1) {
            // try the external bus first
            i2cdevice = PX4_I2C_BUS_EXPANSION;
            g_rgbled = new RGBLED(PX4_I2C_BUS_EXPANSION, rgbledadr);

            if (g_rgbled != nullptr && OK != g_rgbled->init()) {
                delete g_rgbled;
                g_rgbled = nullptr;
            }

            if (g_rgbled == nullptr) {
                // fall back to default bus
                if (PX4_I2C_BUS_LED == PX4_I2C_BUS_EXPANSION) {
                    PX4_WARN("no RGB led on bus #%d", i2cdevice);
                    return 1;
                }

                i2cdevice = PX4_I2C_BUS_LED;
            }
        }

        if (g_rgbled == nullptr) {
            g_rgbled = new RGBLED(i2cdevice, rgbledadr);

            if (g_rgbled == nullptr) {
                PX4_WARN("alloc failed");
                return 1;
            }

            if (OK != g_rgbled->init()) {
                delete g_rgbled;
                g_rgbled = nullptr;
                PX4_WARN("no RGB led on bus #%d", i2cdevice);
                return 1;
            }
        }

        return 0;
    }

    /* need the driver past this point */
    if (g_rgbled == nullptr) {
        PX4_WARN("not started");
        rgbled_usage();
        return 1;
    }

    if (!strcmp(verb, "status")) {
        g_rgbled->status();
        return 0;
    }

    if (!strcmp(verb, "stop")) {
        delete g_rgbled;
        g_rgbled = nullptr;
        return 0;
    }

    rgbled_usage();
    return 1;
}