pio_tx_rx_driver.c File Reference

#include "pio_tx_rx_driver.h"
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "hardware/gpio.h"
#include "hardware/pio.h"
#include "hardware/platform_defs.h"
#include "hardware/regs/pio.h"
#include "pico/time.h"
#include "pico/types.h"
#include "drivers/gpio_driver.h"
#include "drivers/v24_config.h"
#include "platform/pinmap.h"
#include "system/common.h"
#include "led_activity_mirror.pio.h"
#include "rck_rxd.pio.h"
#include "tck_txd.pio.h"
#include "xck_txd.pio.h"

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Macros
#define	V24_RTS_MIN_HOLDOFF   200U
	Minimum RTS holdoff in microseconds used as a safety floor.
#define	V24_RTS_HOLDOFF_MARGIN   41U
	RTS holdoff multiplier in bit-times. The final holdoff is: tx_rts_holdoff_us = margin * t_bit_us. This value was empirically determined to be the most stable for this system.
#define	LED_MIRROR_PIO   pio0

Functions
const v24_runtime_t *	get_v24_runtime (void)
	Returns a pointer to the v24 runtime.
uint32_t	tx_clock_get_cts_toggle_seq (void)
	Read current CTS edge sequence counter.
static void	cts_raw_irq_handler (void)
static void	cts_irq_init (void)
static gpio_function_t	pio_gpio_func (PIO pio)
static float	baud_to_clockdiv (V24_BAUDRATE_T baudrate)
void	led_mirror_init (void)
	Initialize optional LED activity mirror PIO program.
void	reinit_v24_config (V24_CONFIG_T *config, V24_BAUDRATE_T baudrate)
	Reinitialize V.24 runtime configuration and derived timing values.
void	init_v24_config (V24_CONFIG_T *config, V24_BAUDRATE_T baudrate)
	Initialize V.24 runtime configuration structure.
bool	rx_clock_poll_stall (void)
	Poll RX FIFO stall events and update the provided event counter.
bool	rx_get (uint8_t *data)
	Read one received byte from RX PIO FIFO.
void	rx_clock_update_settings (V24_RX_POLARITIES_T *polarities)
	Apply RX runtime settings to an already configured RX PIO SM. Take note that this function relies on tx_clock_init being called before. This is asserted in debug builds but otherwise UB in production.
void	rx_clock_hard_reset (void)
	Disable RX Path, clear fifos, restart SMs and CLKDIV and enable again.
void	rx_clock_init (PIO pio, uint pio_sm, V24_RX_POLARITIES_T *polarities)
	Initialize RX clock/data PIO state machine.
bool	tx_poll (void)
	Poll TX completion/holdoff state and manage RTS release.
bool	tx_put (uint8_t data)
	Queue one byte to the TX PIO FIFO.
void	tx_clock_hard_reset (void)
	Hard-reset TX SM state to discard queued/in-flight bytes.
void	tx_clock_update_settings (V24_CONFIG_T *config)
	Apply TX runtime settings to an already configured TX PIO SM. Take note that this function relies on tx_clock_init being called before. This is asserted in debug builds but otherwise UB in production.
static void	tx_clock_init_tck (PIO pio, uint pio_sm, V24_CONFIG_T *config)
static void	tx_clock_init_xck (PIO pio, uint pio_sm, V24_CONFIG_T *config)
void	tx_clock_init (PIO pio, uint pio_sm, V24_CONFIG_T *config)
	Initialize TX clock/data PIO state machine.

Variables
v24_runtime_t	v24_runtime

Macro Definition Documentation

LED_MIRROR_PIO

#define LED_MIRROR_PIO   pio0

Definition at line 112 of file pio_tx_rx_driver.c.

V24_RTS_HOLDOFF_MARGIN

#define V24_RTS_HOLDOFF_MARGIN   41U

RTS holdoff multiplier in bit-times. The final holdoff is: tx_rts_holdoff_us = margin * t_bit_us. This value was empirically determined to be the most stable for this system.

Definition at line 51 of file pio_tx_rx_driver.c.

V24_RTS_MIN_HOLDOFF

#define V24_RTS_MIN_HOLDOFF   200U

Minimum RTS holdoff in microseconds used as a safety floor.

Definition at line 45 of file pio_tx_rx_driver.c.

Function Documentation

baud_to_clockdiv()

static float baud_to_clockdiv ( V24_BAUDRATE_T  baudrate )

static

Definition at line 107 of file pio_tx_rx_driver.c.

References TX_PIO_CYCLES_PER_BIT.

Referenced by tx_clock_init_tck(), and tx_clock_update_settings().

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cts_irq_init()

static void cts_irq_init ( void  )

static

Definition at line 77 of file pio_tx_rx_driver.c.

References cts_raw_irq_handler(), and V24_CTS.

Referenced by tx_clock_init().

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cts_raw_irq_handler()

static void cts_raw_irq_handler ( void  )

static

Definition at line 66 of file pio_tx_rx_driver.c.

References v24_runtime_t::cts_toggle_seq, V24_CTS, and v24_runtime.

Referenced by cts_irq_init().

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get_v24_runtime()

const v24_runtime_t * get_v24_runtime

(

void

)

Returns a pointer to the v24 runtime.

Returns

Pointer to the v24 runtime.

Definition at line 56 of file pio_tx_rx_driver.c.

References v24_runtime.

Referenced by print_status_event().

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init_v24_config()

void init_v24_config	(	V24_CONFIG_T *	config,
		V24_BAUDRATE_T	baudrate
	)

Initialize V.24 runtime configuration structure.

Parameters

config	Destination configuration object.
baudrate	Initial baudrate.

Definition at line 164 of file pio_tx_rx_driver.c.

References init_polarities(), V24_CONFIG_T::polarities, and reinit_v24_config().

Referenced by init_app().

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led_mirror_init()

void led_mirror_init

(

void

)

Initialize optional LED activity mirror PIO program.

Definition at line 113 of file pio_tx_rx_driver.c.

References LED_MIRROR_PIO, LOG_ERROR, LOG_INFO, V24_RXD, V24_STATUS_LED, and V24_TXD.

pio_gpio_func()

static gpio_function_t pio_gpio_func ( PIO  pio )

static

Definition at line 93 of file pio_tx_rx_driver.c.

reinit_v24_config()

void reinit_v24_config	(	V24_CONFIG_T *	config,
		V24_BAUDRATE_T	baudrate
	)

Reinitialize V.24 runtime configuration and derived timing values.

Parameters

config	Destination configuration object.
baudrate	New baudrate.

Definition at line 152 of file pio_tx_rx_driver.c.

References V24_CONFIG_T::baudrate, v24_runtime_t::rts_set, v24_runtime_t::tx_rts_holdoff_us, US_PER_SECOND, V24_BAUD_1200, V24_RTS_HOLDOFF_MARGIN, V24_RTS_MIN_HOLDOFF, and v24_runtime.

Referenced by ev_set_v24_settings(), init_app(), and init_v24_config().

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rx_clock_hard_reset()

void rx_clock_hard_reset

(

void

)

Disable RX Path, clear fifos, restart SMs and CLKDIV and enable again.

Definition at line 213 of file pio_tx_rx_driver.c.

References v24_runtime_t::rx_pio, v24_runtime_t::rx_sm, and v24_runtime.

Referenced by poll_hdlc_no_progress().

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rx_clock_init()

void rx_clock_init	(	PIO	pio,
		uint	pio_sm,
		V24_RX_POLARITIES_T *	polarities
	)

Initialize RX clock/data PIO state machine.

Parameters

pio	PIO instance.
pio_sm	State machine index.
polarities	RX signal polarity configuration.

Definition at line 225 of file pio_tx_rx_driver.c.

References LOG_INFO, rx_clock_update_settings(), v24_runtime_t::rx_pio, v24_runtime_t::rx_sm, v24_runtime, V24_RXC, and V24_RXD.

Referenced by main().

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rx_clock_poll_stall()

bool rx_clock_poll_stall

(

void

)

Poll RX FIFO stall events and update the provided event counter.

Returns

True if stalled, false otherwise.

Definition at line 170 of file pio_tx_rx_driver.c.

References v24_runtime_t::rx_pio, v24_runtime_t::rx_sm, and v24_runtime.

Referenced by event_loop().

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rx_clock_update_settings()

void rx_clock_update_settings

(

V24_RX_POLARITIES_T *

polarities

)

Apply RX runtime settings to an already configured RX PIO SM. Take note that this function relies on tx_clock_init being called before. This is asserted in debug builds but otherwise UB in production.

Parameters

polarities

RX polarity settings.

Definition at line 195 of file pio_tx_rx_driver.c.

References V24_RX_POLARITIES_T::dcd_inverted, v24_runtime_t::rx_pio, v24_runtime_t::rx_sm, V24_RX_POLARITIES_T::rxc_inverted, V24_RX_POLARITIES_T::rxd_inverted, V24_DCD, v24_runtime, V24_RXC, and V24_RXD.

Referenced by ev_set_v24_settings(), and rx_clock_init().

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rx_get()

bool rx_get

(

uint8_t *

data

)

Read one received byte from RX PIO FIFO.

Parameters

data	Destination pointer for the received byte.

Returns

true if a byte was read, false if RX FIFO is empty.

Definition at line 184 of file pio_tx_rx_driver.c.

References v24_runtime_t::rx_pio, RX_SHIFT_TO_LSB, v24_runtime_t::rx_sm, and v24_runtime.

Referenced by drain_rx_until_empty().

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tx_clock_get_cts_toggle_seq()

uint32_t tx_clock_get_cts_toggle_seq

(

void

)

Read current CTS edge sequence counter.

Returns

Monotonic CTS edge sequence value.

Definition at line 61 of file pio_tx_rx_driver.c.

References v24_runtime_t::cts_toggle_seq, and v24_runtime.

Referenced by tx_queue_drain().

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tx_clock_hard_reset()

void tx_clock_hard_reset

(

void

)

Hard-reset TX SM state to discard queued/in-flight bytes.

Definition at line 322 of file pio_tx_rx_driver.c.

References v24_runtime_t::tx_pio, v24_runtime_t::tx_sm, and v24_runtime.

Referenced by tx_queue_drain().

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tx_clock_init()

void tx_clock_init	(	PIO	pio,
		uint	pio_sm,
		V24_CONFIG_T *	config
	)

Initialize TX clock/data PIO state machine.

Parameters

pio	PIO instance.
pio_sm	State machine index.
config	V.24 configuration.

Definition at line 453 of file pio_tx_rx_driver.c.

References cts_irq_init(), V24_CONFIG_T::external_clock, tx_clock_init_tck(), and tx_clock_init_xck().

Referenced by main().

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tx_clock_init_tck()

static void tx_clock_init_tck ( PIO  pio, uint  pio_sm, V24_CONFIG_T *  config  )

static

Definition at line 376 of file pio_tx_rx_driver.c.

References baud_to_clockdiv(), V24_CONFIG_T::baudrate, LOG_DEBUG, LOG_INFO, tx_clock_update_settings(), v24_runtime_t::tx_pio, v24_runtime_t::tx_rts_holdoff_us, v24_runtime_t::tx_sm, V24_CTS, v24_runtime, V24_TXC_DTE, and V24_TXD.

Referenced by tx_clock_init().

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tx_clock_init_xck()

static void tx_clock_init_xck ( PIO  pio, uint  pio_sm, V24_CONFIG_T *  config  )

static

Definition at line 415 of file pio_tx_rx_driver.c.

References LOG_DEBUG, LOG_INFO, tx_clock_update_settings(), v24_runtime_t::tx_pio, v24_runtime_t::tx_rts_holdoff_us, v24_runtime_t::tx_sm, V24_CTS, v24_runtime, V24_TXC_DCE, and V24_TXD.

Referenced by tx_clock_init().

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tx_clock_update_settings()

void tx_clock_update_settings

(

V24_CONFIG_T *

config

)

Apply TX runtime settings to an already configured TX PIO SM. Take note that this function relies on tx_clock_init being called before. This is asserted in debug builds but otherwise UB in production.

Parameters

config

V.24 configuration.

Definition at line 337 of file pio_tx_rx_driver.c.

References baud_to_clockdiv(), V24_CONFIG_T::baudrate, V24_TX_POLARITIES_T::cts_inverted, V24_TX_POLARITIES_T::dtr_inverted, V24_CONFIG_T::external_clock, V24_CONFIG_T::polarities, V24_TX_POLARITIES_T::rts_inverted, v24_runtime_t::tx_pio, V24_POLARITIES_T::tx_polarities, v24_runtime_t::tx_sm, V24_TX_POLARITIES_T::txc_inverted, V24_TX_POLARITIES_T::txd_inverted, V24_CTS, V24_DTR, V24_RTS, v24_runtime, V24_TXC_DCE, V24_TXC_DTE, and V24_TXD.

Referenced by ev_set_v24_settings(), tx_clock_init_tck(), and tx_clock_init_xck().

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tx_poll()

bool tx_poll

(

void

)

Poll TX completion/holdoff state and manage RTS release.

Returns

true if TX path is idle after polling, false otherwise.

Definition at line 257 of file pio_tx_rx_driver.c.

References v24_runtime_t::rts_set, v24_runtime_t::tx_pio, v24_runtime_t::tx_rts_holdoff_us, v24_runtime_t::tx_sm, V24_RTS, and v24_runtime.

Referenced by poll_tx_pipeline().

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tx_put()

bool tx_put

(

uint8_t

data

)

Queue one byte to the TX PIO FIFO.

Parameters

data	Byte to transmit.

Returns

true if accepted, false if FIFO/full-state prevents enqueue.

Definition at line 299 of file pio_tx_rx_driver.c.

References v24_runtime_t::rts_set, v24_runtime_t::tx_pio, v24_runtime_t::tx_sm, V24_RTS, and v24_runtime.

Referenced by tx_queue_drain_bytes().

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Variable Documentation

v24_runtime

v24_runtime_t v24_runtime

Definition at line 54 of file pio_tx_rx_driver.c.

Referenced by cts_raw_irq_handler(), get_v24_runtime(), print_status_event(), reinit_v24_config(), rx_clock_hard_reset(), rx_clock_init(), rx_clock_poll_stall(), rx_clock_update_settings(), rx_get(), tx_clock_get_cts_toggle_seq(), tx_clock_hard_reset(), tx_clock_init_tck(), tx_clock_init_xck(), tx_clock_update_settings(), tx_poll(), and tx_put().