pwm.h

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/*
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef _HARDWARE_PWM_H
#define _HARDWARE_PWM_H

#include "pico.h"
#include "hardware/structs/pwm.h"
#include "hardware/regs/dreq.h"

#ifdef __cplusplus
extern "C" {
#endif

// PICO_CONFIG: PARAM_ASSERTIONS_ENABLED_PWM, Enable/disable assertions in the PWM module, type=bool, default=0, group=hardware_pwm
#ifndef PARAM_ASSERTIONS_ENABLED_PWM
#define PARAM_ASSERTIONS_ENABLED_PWM 0
#endif

enum pwm_clkdiv_mode
{
    PWM_DIV_FREE_RUNNING = 0, 
    PWM_DIV_B_HIGH = 1,       
    PWM_DIV_B_RISING = 2,     
    PWM_DIV_B_FALLING = 3    
};

enum pwm_chan
{
    PWM_CHAN_A = 0,
    PWM_CHAN_B = 1
};

typedef struct {
    uint32_t csr;
    uint32_t div;
    uint32_t top;
} pwm_config;

static inline void check_slice_num_param(__unused uint slice_num) {
    valid_params_if(PWM, slice_num < NUM_PWM_SLICES);
}

static inline uint pwm_gpio_to_slice_num(uint gpio) {
    valid_params_if(PWM, gpio < NUM_BANK0_GPIOS);
    return (gpio >> 1u) & 7u;
}

static inline uint pwm_gpio_to_channel(uint gpio) {
    valid_params_if(PWM, gpio < NUM_BANK0_GPIOS);
    return gpio & 1u;
}

static inline void pwm_config_set_phase_correct(pwm_config *c, bool phase_correct) {
    c->csr = (c->csr & ~PWM_CH0_CSR_PH_CORRECT_BITS)
        | (bool_to_bit(phase_correct) << PWM_CH0_CSR_PH_CORRECT_LSB);
}

static inline void pwm_config_set_clkdiv(pwm_config *c, float div) {
    valid_params_if(PWM, div >= 1.f && div < 256.f);
    c->div = (uint32_t)(div * (float)(1u << PWM_CH0_DIV_INT_LSB));
}

static inline void pwm_config_set_clkdiv_int_frac(pwm_config *c, uint8_t integer, uint8_t fract) {
    valid_params_if(PWM, integer >= 1);
    valid_params_if(PWM, fract < 16);
    c->div = (((uint)integer) << PWM_CH0_DIV_INT_LSB) | (((uint)fract) << PWM_CH0_DIV_FRAC_LSB);
}

static inline void pwm_config_set_clkdiv_int(pwm_config *c, uint div) {
    valid_params_if(PWM, div >= 1 && div < 256);
    pwm_config_set_clkdiv_int_frac(c, (uint8_t)div, 0);
}

static inline void pwm_config_set_clkdiv_mode(pwm_config *c, enum pwm_clkdiv_mode mode) {
    valid_params_if(PWM, mode == PWM_DIV_FREE_RUNNING ||
            mode == PWM_DIV_B_RISING ||
            mode == PWM_DIV_B_HIGH ||
            mode == PWM_DIV_B_FALLING);
    c->csr = (c->csr & ~PWM_CH0_CSR_DIVMODE_BITS)
        | (((uint)mode) << PWM_CH0_CSR_DIVMODE_LSB);
}

static inline void pwm_config_set_output_polarity(pwm_config *c, bool a, bool b) {
    c->csr = (c->csr & ~(PWM_CH0_CSR_A_INV_BITS | PWM_CH0_CSR_B_INV_BITS))
        | ((bool_to_bit(a) << PWM_CH0_CSR_A_INV_LSB) | (bool_to_bit(b) << PWM_CH0_CSR_B_INV_LSB));
}

static inline void pwm_config_set_wrap(pwm_config *c, uint16_t wrap) {
    c->top = wrap;
}

static inline void pwm_init(uint slice_num, pwm_config *c, bool start) {
    check_slice_num_param(slice_num);
    pwm_hw->slice[slice_num].csr = 0;

    pwm_hw->slice[slice_num].ctr = PWM_CH0_CTR_RESET;
    pwm_hw->slice[slice_num].cc = PWM_CH0_CC_RESET;
    pwm_hw->slice[slice_num].top = c->top;
    pwm_hw->slice[slice_num].div = c->div;
    pwm_hw->slice[slice_num].csr = c->csr | (bool_to_bit(start) << PWM_CH0_CSR_EN_LSB);
}

static inline pwm_config pwm_get_default_config(void) {
    pwm_config c = {0, 0, 0};
    pwm_config_set_phase_correct(&c, false);
    pwm_config_set_clkdiv_int(&c, 1);
    pwm_config_set_clkdiv_mode(&c, PWM_DIV_FREE_RUNNING);
    pwm_config_set_output_polarity(&c, false, false);
    pwm_config_set_wrap(&c, 0xffffu);
    return c;
}

static inline void pwm_set_wrap(uint slice_num, uint16_t wrap) {
    check_slice_num_param(slice_num);
    pwm_hw->slice[slice_num].top = wrap;
}

static inline void pwm_set_chan_level(uint slice_num, uint chan, uint16_t level) {
    check_slice_num_param(slice_num);
    hw_write_masked(
        &pwm_hw->slice[slice_num].cc,
        ((uint)level) << (chan ? PWM_CH0_CC_B_LSB : PWM_CH0_CC_A_LSB),
        chan ? PWM_CH0_CC_B_BITS : PWM_CH0_CC_A_BITS
    );
}

static inline void pwm_set_both_levels(uint slice_num, uint16_t level_a, uint16_t level_b) {
    check_slice_num_param(slice_num);
    pwm_hw->slice[slice_num].cc = (((uint)level_b) << PWM_CH0_CC_B_LSB) | (((uint)level_a) << PWM_CH0_CC_A_LSB);
}

static inline void pwm_set_gpio_level(uint gpio, uint16_t level) {
    valid_params_if(PWM, gpio < NUM_BANK0_GPIOS);
    pwm_set_chan_level(pwm_gpio_to_slice_num(gpio), pwm_gpio_to_channel(gpio), level);
}

static inline uint16_t pwm_get_counter(uint slice_num) {
    check_slice_num_param(slice_num);
    return (uint16_t)(pwm_hw->slice[slice_num].ctr);
}

static inline void pwm_set_counter(uint slice_num, uint16_t c) {
    check_slice_num_param(slice_num);
    pwm_hw->slice[slice_num].ctr = c;
}

static inline void pwm_advance_count(uint slice_num) {
    check_slice_num_param(slice_num);
    hw_set_bits(&pwm_hw->slice[slice_num].csr, PWM_CH0_CSR_PH_ADV_BITS);
    while (pwm_hw->slice[slice_num].csr & PWM_CH0_CSR_PH_ADV_BITS) {
        tight_loop_contents();
    }
}

static inline void pwm_retard_count(uint slice_num) {
    check_slice_num_param(slice_num);
    hw_set_bits(&pwm_hw->slice[slice_num].csr, PWM_CH0_CSR_PH_RET_BITS);
    while (pwm_hw->slice[slice_num].csr & PWM_CH0_CSR_PH_RET_BITS) {
        tight_loop_contents();
    }
}

static inline void pwm_set_clkdiv_int_frac(uint slice_num, uint8_t integer, uint8_t fract) {
    check_slice_num_param(slice_num);
    valid_params_if(PWM, integer >= 1);
    valid_params_if(PWM, fract < 16);
    pwm_hw->slice[slice_num].div = (((uint)integer) << PWM_CH0_DIV_INT_LSB) | (((uint)fract) << PWM_CH0_DIV_FRAC_LSB);
}

static inline void pwm_set_clkdiv(uint slice_num, float divider) {
    check_slice_num_param(slice_num);
    valid_params_if(PWM, divider >= 1.f && divider < 256.f);
    uint8_t i = (uint8_t)divider;
    uint8_t f = (uint8_t)((divider - i) * (0x01 << 4));
    pwm_set_clkdiv_int_frac(slice_num, i, f);
}

static inline void pwm_set_output_polarity(uint slice_num, bool a, bool b) {
    check_slice_num_param(slice_num);
    hw_write_masked(&pwm_hw->slice[slice_num].csr, bool_to_bit(a) << PWM_CH0_CSR_A_INV_LSB | bool_to_bit(b) << PWM_CH0_CSR_B_INV_LSB,
                     PWM_CH0_CSR_A_INV_BITS | PWM_CH0_CSR_B_INV_BITS);
}


static inline void pwm_set_clkdiv_mode(uint slice_num, enum pwm_clkdiv_mode mode) {
    check_slice_num_param(slice_num);
    valid_params_if(PWM, mode == PWM_DIV_FREE_RUNNING ||
                         mode == PWM_DIV_B_RISING ||
                         mode == PWM_DIV_B_HIGH ||
                         mode == PWM_DIV_B_FALLING);
    hw_write_masked(&pwm_hw->slice[slice_num].csr, ((uint)mode) << PWM_CH0_CSR_DIVMODE_LSB, PWM_CH0_CSR_DIVMODE_BITS);
}

static inline void pwm_set_phase_correct(uint slice_num, bool phase_correct) {
    check_slice_num_param(slice_num);
    hw_write_masked(&pwm_hw->slice[slice_num].csr, bool_to_bit(phase_correct) << PWM_CH0_CSR_PH_CORRECT_LSB, PWM_CH0_CSR_PH_CORRECT_BITS);
}

static inline void pwm_set_enabled(uint slice_num, bool enabled) {
    check_slice_num_param(slice_num);
    hw_write_masked(&pwm_hw->slice[slice_num].csr, bool_to_bit(enabled) << PWM_CH0_CSR_EN_LSB, PWM_CH0_CSR_EN_BITS);
}

static inline void pwm_set_mask_enabled(uint32_t mask) {
    pwm_hw->en = mask;
}

static inline void pwm_set_irq_enabled(uint slice_num, bool enabled) {
    check_slice_num_param(slice_num);
    if (enabled) {
        hw_set_bits(&pwm_hw->inte, 1u << slice_num);
    } else {
        hw_clear_bits(&pwm_hw->inte, 1u << slice_num);
    }
}

static inline void pwm_set_irq_mask_enabled(uint32_t slice_mask, bool enabled) {
    valid_params_if(PWM, slice_mask < 256);
    if (enabled) {
        hw_set_bits(&pwm_hw->inte, slice_mask);
    } else {
        hw_clear_bits(&pwm_hw->inte, slice_mask);
    }
}

static inline void pwm_clear_irq(uint slice_num) {
    pwm_hw->intr = 1u << slice_num;
}

static inline uint32_t pwm_get_irq_status_mask(void) {
    return pwm_hw->ints;
}

static inline void pwm_force_irq(uint slice_num) {
    pwm_hw->intf = 1u << slice_num;
}

static inline uint pwm_get_dreq(uint slice_num) {
    static_assert(DREQ_PWM_WRAP1 == DREQ_PWM_WRAP0 + 1, "");
    static_assert(DREQ_PWM_WRAP7 == DREQ_PWM_WRAP0 + 7, "");
    check_slice_num_param(slice_num);
    return DREQ_PWM_WRAP0 + slice_num;
}

#ifdef __cplusplus
}
#endif

#endif