/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2020-2021 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "py/runtime.h"
#include "py/mphal.h"
#include "shared/runtime/pyexec.h"
#include "extmod/machine_bitstream.h"
#include "extmod/machine_i2c.h"
#include "extmod/machine_mem.h"
#include "extmod/machine_pulse.h"
#include "extmod/machine_pwm.h"
#include "extmod/machine_signal.h"
#include "extmod/machine_spi.h"

#include "modmachine.h"
#include "uart.h"
#include "hardware/clocks.h"
#include "hardware/pll.h"
#include "hardware/structs/rosc.h"
#include "hardware/structs/scb.h"
#include "hardware/structs/syscfg.h"
#include "hardware/watchdog.h"
#include "hardware/xosc.h"
#include "pico/bootrom.h"
#include "pico/stdlib.h"
#include "pico/unique_id.h"

#if MICROPY_PY_MACHINE

#define RP2_RESET_PWRON (1)
#define RP2_RESET_WDT (3)

STATIC mp_obj_t machine_unique_id(void) {
    pico_unique_board_id_t id;
    pico_get_unique_board_id(&id);
    return mp_obj_new_bytes(id.id, sizeof(id.id));
}
MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);

STATIC mp_obj_t machine_soft_reset(void) {
    pyexec_system_exit = PYEXEC_FORCED_EXIT;
    mp_raise_type(&mp_type_SystemExit);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_soft_reset_obj, machine_soft_reset);

STATIC mp_obj_t machine_reset(void) {
    watchdog_reboot(0, SRAM_END, 0);
    for (;;) {
        __wfi();
    }
    return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);

STATIC mp_obj_t machine_reset_cause(void) {
    int reset_cause;
    if (watchdog_caused_reboot()) {
        reset_cause = RP2_RESET_WDT;
    } else {
        reset_cause = RP2_RESET_PWRON;
    }
    return MP_OBJ_NEW_SMALL_INT(reset_cause);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);

NORETURN mp_obj_t machine_bootloader(size_t n_args, const mp_obj_t *args) {
    MICROPY_BOARD_ENTER_BOOTLOADER(n_args, args);
    rosc_hw->ctrl = ROSC_CTRL_ENABLE_VALUE_ENABLE << ROSC_CTRL_ENABLE_LSB;
    reset_usb_boot(0, 0);
    for (;;) {
    }
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_bootloader_obj, 0, 1, machine_bootloader);

STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
    if (n_args == 0) {
        return MP_OBJ_NEW_SMALL_INT(mp_hal_get_cpu_freq());
    } else {
        mp_int_t freq = mp_obj_get_int(args[0]);
        if (!set_sys_clock_khz(freq / 1000, false)) {
            mp_raise_ValueError(MP_ERROR_TEXT("cannot change frequency"));
        }
        #if MICROPY_HW_ENABLE_UART_REPL
        setup_default_uart();
        mp_uart_init();
        #endif
        return mp_const_none;
    }
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);

STATIC mp_obj_t machine_idle(void) {
    best_effort_wfe_or_timeout(make_timeout_time_ms(1));
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_idle_obj, machine_idle);

STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
    mp_int_t delay_ms = 0;
    bool use_timer_alarm = false;

    if (n_args == 1) {
        delay_ms = mp_obj_get_int(args[0]);
        if (delay_ms <= 1) {
            // Sleep is too small, just use standard delay.
            mp_hal_delay_ms(delay_ms);
            return mp_const_none;
        }
        use_timer_alarm = delay_ms < (1ULL << 32) / 1000;
        if (use_timer_alarm) {
            // Use timer alarm to wake.
        } else {
            // TODO: Use RTC alarm to wake.
            mp_raise_ValueError(MP_ERROR_TEXT("sleep too long"));
        }
    }

    const uint32_t xosc_hz = XOSC_MHZ * 1000000;

    // Disable USB and ADC clocks.
    clock_stop(clk_usb);
    clock_stop(clk_adc);

    // CLK_REF = XOSC
    clock_configure(clk_ref, CLOCKS_CLK_REF_CTRL_SRC_VALUE_XOSC_CLKSRC, 0, xosc_hz, xosc_hz);

    // CLK_SYS = CLK_REF
    clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLK_REF, 0, xosc_hz, xosc_hz);

    // CLK_RTC = XOSC / 256
    clock_configure(clk_rtc, 0, CLOCKS_CLK_RTC_CTRL_AUXSRC_VALUE_XOSC_CLKSRC, xosc_hz, xosc_hz / 256);

    // CLK_PERI = CLK_SYS
    clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, xosc_hz, xosc_hz);

    // Disable PLLs.
    pll_deinit(pll_sys);
    pll_deinit(pll_usb);

    // Disable ROSC.
    rosc_hw->ctrl = ROSC_CTRL_ENABLE_VALUE_DISABLE << ROSC_CTRL_ENABLE_LSB;

    if (n_args == 0) {
        xosc_dormant();
    } else {
        uint32_t sleep_en0 = clocks_hw->sleep_en0;
        uint32_t sleep_en1 = clocks_hw->sleep_en1;
        clocks_hw->sleep_en0 = CLOCKS_SLEEP_EN0_CLK_RTC_RTC_BITS;
        if (use_timer_alarm) {
            // Use timer alarm to wake.
            clocks_hw->sleep_en1 = CLOCKS_SLEEP_EN1_CLK_SYS_TIMER_BITS;
            timer_hw->alarm[3] = timer_hw->timerawl + delay_ms * 1000;
        } else {
            // TODO: Use RTC alarm to wake.
            clocks_hw->sleep_en1 = 0;
        }
        scb_hw->scr |= M0PLUS_SCR_SLEEPDEEP_BITS;
        __wfi();
        scb_hw->scr &= ~M0PLUS_SCR_SLEEPDEEP_BITS;
        clocks_hw->sleep_en0 = sleep_en0;
        clocks_hw->sleep_en1 = sleep_en1;
    }

    // Enable ROSC.
    rosc_hw->ctrl = ROSC_CTRL_ENABLE_VALUE_ENABLE << ROSC_CTRL_ENABLE_LSB;

    // Bring back all clocks.
    clocks_init();

    return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);

STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
    machine_lightsleep(n_args, args);
    return machine_reset();
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);

STATIC mp_obj_t machine_disable_irq(void) {
    uint32_t state = MICROPY_BEGIN_ATOMIC_SECTION();
    return mp_obj_new_int(state);
}
MP_DEFINE_CONST_FUN_OBJ_0(machine_disable_irq_obj, machine_disable_irq);

STATIC mp_obj_t machine_enable_irq(mp_obj_t state_in) {
    uint32_t state = mp_obj_get_int(state_in);
    MICROPY_END_ATOMIC_SECTION(state);
    return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(machine_enable_irq_obj, machine_enable_irq);

STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
    { MP_ROM_QSTR(MP_QSTR___name__),            MP_ROM_QSTR(MP_QSTR_umachine) },
    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) },
    { MP_ROM_QSTR(MP_QSTR_soft_reset),          MP_ROM_PTR(&machine_soft_reset_obj) },
    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) },
    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) },
    { MP_ROM_QSTR(MP_QSTR_bootloader),          MP_ROM_PTR(&machine_bootloader_obj) },
    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) },

    { MP_ROM_QSTR(MP_QSTR_idle),                MP_ROM_PTR(&machine_idle_obj) },
    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) },
    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) },

    { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) },
    { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) },

    #if MICROPY_PY_MACHINE_BITSTREAM
    { MP_ROM_QSTR(MP_QSTR_bitstream),           MP_ROM_PTR(&machine_bitstream_obj) },
    #endif
    { MP_ROM_QSTR(MP_QSTR_time_pulse_us),       MP_ROM_PTR(&machine_time_pulse_us_obj) },

    { MP_ROM_QSTR(MP_QSTR_mem8),                MP_ROM_PTR(&machine_mem8_obj) },
    { MP_ROM_QSTR(MP_QSTR_mem16),               MP_ROM_PTR(&machine_mem16_obj) },
    { MP_ROM_QSTR(MP_QSTR_mem32),               MP_ROM_PTR(&machine_mem32_obj) },

    { MP_ROM_QSTR(MP_QSTR_ADC),                 MP_ROM_PTR(&machine_adc_type) },
    { MP_ROM_QSTR(MP_QSTR_I2C),                 MP_ROM_PTR(&machine_hw_i2c_type) },
    { MP_ROM_QSTR(MP_QSTR_SoftI2C),             MP_ROM_PTR(&mp_machine_soft_i2c_type) },
    { MP_ROM_QSTR(MP_QSTR_I2S),                 MP_ROM_PTR(&machine_i2s_type) },
    { MP_ROM_QSTR(MP_QSTR_Pin),                 MP_ROM_PTR(&machine_pin_type) },
    { MP_ROM_QSTR(MP_QSTR_PWM),                 MP_ROM_PTR(&machine_pwm_type) },
    { MP_ROM_QSTR(MP_QSTR_RTC),                 MP_ROM_PTR(&machine_rtc_type) },
    { MP_ROM_QSTR(MP_QSTR_Signal),              MP_ROM_PTR(&machine_signal_type) },
    { MP_ROM_QSTR(MP_QSTR_SPI),                 MP_ROM_PTR(&machine_spi_type) },
    { MP_ROM_QSTR(MP_QSTR_SoftSPI),             MP_ROM_PTR(&mp_machine_soft_spi_type) },
    { MP_ROM_QSTR(MP_QSTR_Timer),               MP_ROM_PTR(&machine_timer_type) },
    { MP_ROM_QSTR(MP_QSTR_UART),                MP_ROM_PTR(&machine_uart_type) },
    { MP_ROM_QSTR(MP_QSTR_WDT),                 MP_ROM_PTR(&machine_wdt_type) },

    { MP_ROM_QSTR(MP_QSTR_PWRON_RESET),         MP_ROM_INT(RP2_RESET_PWRON) },
    { MP_ROM_QSTR(MP_QSTR_WDT_RESET),           MP_ROM_INT(RP2_RESET_WDT) },
};
STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);

const mp_obj_module_t mp_module_machine = {
    .base = { &mp_type_module },
    .globals = (mp_obj_dict_t *)&machine_module_globals,
};

MP_REGISTER_MODULE(MP_QSTR_umachine, mp_module_machine);

#endif // MICROPY_PY_MACHINE
