/*
 * hsdaoh - High Speed Data Acquisition over MS213x USB3 HDMI capture sticks
 * Implementation for the Raspberry Pi RP2350 HSTX peripheral
 *
 * External 12-bit ADC example, connected to the PIO
 *
 * Copyright (c) 2024 by Steve Markgraf <steve@steve-m.de>
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of its contributors may
 *    be used to endorse or promote products derived from this software
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "pico/stdlib.h"
#include "hardware/clocks.h"
#include "hardware/irq.h"
#include "hardware/sync.h"
#include "hardware/vreg.h"
#include "hardware/dma.h"
#include "hardware/pio.h"

#include "picohsdaoh.h"
#include "adc_12bit_input.pio.h"

/* The PIO is running with sys_clk/2, and needs 4 cycles per sample,
 * so the ADC clock is sys_clk/8 */
#define SYS_CLK		320000	// 40 MHz ADC clock
//#define SYS_CLK	384000	// 48 MHz ADC clock
//#define SYS_CLK	402000	// 50.25 MHz ADC clock, maximum that works on my Pico2 (with overvolting)

// ADC is attached to GP0 - GP11 with clock on GP22
#define PIO_INPUT_PIN_BASE 0
#define PIO_OUTPUT_CLK_PIN 22

#define DMACH_PIO_PING 0
#define DMACH_PIO_PONG 1

static bool pio_dma_pong = false;
uint16_t ringbuffer[RBUF_TOTAL_LEN];
int ringbuf_head = 0;

void __scratch_y("") pio_dma_irq_handler()
{
	uint ch_num = pio_dma_pong ? DMACH_PIO_PONG : DMACH_PIO_PING;
	dma_channel_hw_t *ch = &dma_hw->ch[ch_num];
	dma_hw->intr = 1u << ch_num;
	pio_dma_pong = !pio_dma_pong;

	ringbuf_head = (ringbuf_head + 1) % RBUF_SLICES;

	ch->write_addr = (uintptr_t)&ringbuffer[ringbuf_head * RBUF_SLICE_LEN];
	ch->transfer_count = RBUF_DATA_LEN;

	hsdaoh_update_head(ringbuf_head);
}

void init_pio_input(void)
{
	PIO pio = pio0;
	uint offset = pio_add_program(pio, &adc_12bit_input_program);
	uint sm_data = pio_claim_unused_sm(pio, true);
	adc_12bit_input_program_init(pio, sm_data, offset, PIO_INPUT_PIN_BASE, PIO_OUTPUT_CLK_PIN);

	dma_channel_config c;
	c = dma_channel_get_default_config(DMACH_PIO_PING);
	channel_config_set_chain_to(&c, DMACH_PIO_PONG);
	channel_config_set_dreq(&c, pio_get_dreq(pio, sm_data, false));
	channel_config_set_read_increment(&c, false);
	channel_config_set_write_increment(&c, true);
	channel_config_set_transfer_data_size(&c, DMA_SIZE_16);

	dma_channel_configure(
		DMACH_PIO_PING,
		&c,
		&ringbuffer[0 * RBUF_SLICE_LEN],
		&pio->rxf[sm_data],
		RBUF_DATA_LEN,
		false
	);
	c = dma_channel_get_default_config(DMACH_PIO_PONG);
	channel_config_set_chain_to(&c, DMACH_PIO_PING);
	channel_config_set_dreq(&c, pio_get_dreq(pio, sm_data, false));
	channel_config_set_read_increment(&c, false);
	channel_config_set_write_increment(&c, true);
	channel_config_set_transfer_data_size(&c, DMA_SIZE_16);

	dma_channel_configure(
		DMACH_PIO_PONG,
		&c,
		&ringbuffer[1 * RBUF_SLICE_LEN],
		&pio->rxf[sm_data],
		RBUF_DATA_LEN,
		false
	);

	dma_hw->ints0 |= (1u << DMACH_PIO_PING) | (1u << DMACH_PIO_PONG);
	dma_hw->inte0 |= (1u << DMACH_PIO_PING) | (1u << DMACH_PIO_PONG);
	irq_set_exclusive_handler(DMA_IRQ_0, pio_dma_irq_handler);
	irq_set_enabled(DMA_IRQ_0, true);

	dma_channel_start(DMACH_PIO_PING);
}

int main()
{
	/* set maximum 'allowed' voltage without voiding warranty */
	vreg_set_voltage(VREG_VOLTAGE_MAX);
	sleep_ms(1);

	set_sys_clock_khz(SYS_CLK, true);

	/* set HSTX clock to sysclk/2 */
	hw_write_masked(
		&clocks_hw->clk[clk_hstx].div,
		2 << CLOCKS_CLK_HSTX_DIV_INT_LSB,
		CLOCKS_CLK_HSTX_DIV_INT_BITS
	);

	stdio_init_all();

	hsdaoh_init(ringbuffer);
	hsdaoh_start();
	init_pio_input();

	while (1)
		__wfi();
}