Merge pull request #568 from Paciente8159/74hc595-pio

RP2040 custom 74hc595 via PIO

uCNC/src/hal/boards/rp2040/boardmap_rpi_pico.h

@@ -50,7 +50,7 @@ extern "C"
 // Setup control input pins
 // #define ESTOP_BIT 0
 // #define ESTOP_PORT A
-//#define ESTOP_ISR
+// #define ESTOP_ISR
 
 // Setup com pins
 #define RX_BIT 1
@@ -85,7 +85,44 @@ extern "C"
 #define I2C_CLK_BIT 27
 #define I2C_DATA_BIT 26
 #define I2C_PORT 1
-// #define I2C_ADDRESS 1
+#define I2C_ADDRESS 1
+
+/**
+ * This is an example of how to use RP2040 PIO to control
+ * up to 4 chainned 74hc595 (32 output pins) using only 3 pins
+ * from the board.
+ * The 3 pins should be sequential (for example GPIO's 26, 27 and 28)
+ * 
+ * RP2040 does not yet support software generate PWM
+ * 
+ * **/
+
+// // Use PIO to shift data to 74HC595 shift registers (up to 4)
+// // IO pins should be sequencial GPIO pins starting by data, then clock then the latch pin
+// #define IC74HC595_CUSTOM_SHIFT_IO //Enables custom MCU data shift transmission. In RP2040 that is via a PIO
+// #define IC74HC595_PIO_DATA 26
+// #define IC74HC595_PIO_CLK 27
+// #define IC74HC595_PIO_LATCH 28
+// // enabling IC74HC595_CUSTOM_SHIFT_IO will force IC74HC595_COUNT to be set to 4 no matter what
+// // support up to 4 chained 74HC595. Less can be used (overflow bits will be discarded like in the ESP32 I2S implementation)
+// #define IC74HC595_COUNT 4
+
+// #define STEP0_EN_IO_OFFSET 0
+// #define STEP0_IO_OFFSET 1
+// #define DIR0_IO_OFFSET 2
+// #define STEP1_EN_IO_OFFSET 3
+// #define STEP1_IO_OFFSET 4
+// #define DIR1_IO_OFFSET 5
+// #define STEP2_EN_IO_OFFSET 6
+// #define STEP2_IO_OFFSET 7
+// #define DIR2_IO_OFFSET 8
+// #define STEP3_EN_IO_OFFSET 9
+// #define STEP3_IO_OFFSET 10
+// #define DIR3_IO_OFFSET 11
+// #define STEP4_EN_IO_OFFSET 12
+// #define STEP4_IO_OFFSET 13
+// #define DIR4_IO_OFFSET 14
+// #define DOUT0_IO_OFFSET 15
 
 #ifdef __cplusplus
 }

uCNC/src/hal/mcus/rp2040/ic74hc595.pio

@@ -0,0 +1,57 @@
+;
+;Name: ic74hc595.pio
+;Description: Implements a custom PIO for 74HC595 shift register in µCNC for RP2040.
+;
+;Copyright: Copyright (c) João Martins
+;Author: João Martins
+;Date: 02-11-2023
+;
+;µCNC is free software: you can redistribute it and/or modify
+;it under the terms of the GNU General Public License as published by
+;the Free Software Foundation, either version 3 of the License, or
+;(at your option) any later version. Please see <http://www.gnu.org/licenses/>
+;
+;µCNC is distributed WITHOUT ANY WARRANTY;
+;Also without the implied warranty of	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+;See the	GNU General Public License for more details.
+;
+
+.program ic74hc595
+.side_set 1 opt
+
+pull						; shift TX to OSR
+set x, 31					; load loop counter
+set pins, 0 				; set all pins low (latch)
+bitloop:                   	; loop bits
+out pins, 1 side 0        	; Shift 1 bit from OSR to the data pin and the remaining down
+jmp x-- bitloop side 1		; decrement loop and bring clock up
+set pins, 2 				; set 3rd pin (4=0b100) up (latch)
+
+% c-sdk {
+#include "hardware/clocks.h"
+
+static inline void ic74hc595_program_init(PIO pio, uint sm, uint offset, uint pin_data, uint pin_clk, uint pin_latch, uint freq) {
+	pio_sm_config c = ic74hc595_program_get_default_config(offset);
+	sm_config_set_out_pins(&c, pin_data, 1); // define one pin to respond to the out instruction
+	sm_config_set_set_pins(&c, pin_clk, 2);	 // define all pins to respond to the set instruction
+	sm_config_set_sideset_pins(&c, pin_clk); // define clock as the side set base pin (and only)
+	// Only support MSB-first in this example code (shift to left, no auto push/pull, threshold=nbits)
+	sm_config_set_out_shift(&c, false, false, 32);
+	// All pins output
+	pio_sm_set_consecutive_pindirs(pio, sm, pin_data, 3, true);
+	pio_gpio_init(pio, pin_data);
+	pio_gpio_init(pio, pin_clk);
+	pio_gpio_init(pio, pin_latch);
+	// We only need TX, so get an 8-deep FIFO!
+	sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+	// SM transmits 1 bit per 8 execution cycles.
+	float div = (float)clock_get_hz(clk_sys) / (freq << 1);
+	sm_config_set_clkdiv(&c, div);
+	pio_sm_init(pio, sm, offset, &c);
+	pio_sm_set_enabled(pio, sm, true);
+}
+
+static inline void ic74hc595_program_write(PIO pio, uint sm, uint out) {
+    pio_sm_put_blocking(pio, sm, out);
+}
+%}

uCNC/src/hal/mcus/rp2040/ic74hc595.pio.h

@@ -0,0 +1,68 @@
+// -------------------------------------------------- //
+// This file is autogenerated by pioasm; do not edit! //
+// -------------------------------------------------- //
+
+#pragma once
+
+#if !PICO_NO_HARDWARE
+#include "hardware/pio.h"
+#endif
+
+// --------- //
+// ic74hc595 //
+// --------- //
+
+#define ic74hc595_wrap_target 0
+#define ic74hc595_wrap 5
+
+static const uint16_t ic74hc595_program_instructions[] = {
+            //     .wrap_target
+    0x80a0, //  0: pull   block                      
+    0xe03f, //  1: set    x, 31                      
+    0xe000, //  2: set    pins, 0                    
+    0x7001, //  3: out    pins, 1         side 0     
+    0x1843, //  4: jmp    x--, 3          side 1     
+    0xe002, //  5: set    pins, 2                    
+            //     .wrap
+};
+
+#if !PICO_NO_HARDWARE
+static const struct pio_program ic74hc595_program = {
+    .instructions = ic74hc595_program_instructions,
+    .length = 6,
+    .origin = -1,
+};
+
+static inline pio_sm_config ic74hc595_program_get_default_config(uint offset) {
+    pio_sm_config c = pio_get_default_sm_config();
+    sm_config_set_wrap(&c, offset + ic74hc595_wrap_target, offset + ic74hc595_wrap);
+    sm_config_set_sideset(&c, 2, true, false);
+    return c;
+}
+
+#include "hardware/clocks.h"
+static inline void ic74hc595_program_init(PIO pio, uint sm, uint offset, uint pin_data, uint pin_clk, uint pin_latch, uint freq) {
+	pio_sm_config c = ic74hc595_program_get_default_config(offset);
+	sm_config_set_out_pins(&c, pin_data, 1); // define one pin to respond to the out instruction
+	sm_config_set_set_pins(&c, pin_clk, 2);	 // define all pins to respond to the set instruction
+	sm_config_set_sideset_pins(&c, pin_clk); // define clock as the side set base pin (and only)
+	// Only support MSB-first in this example code (shift to left, no auto push/pull, threshold=nbits)
+	sm_config_set_out_shift(&c, false, false, 32);
+	// All pins output
+	pio_sm_set_consecutive_pindirs(pio, sm, pin_data, 3, true);
+	pio_gpio_init(pio, pin_data);
+	pio_gpio_init(pio, pin_clk);
+	pio_gpio_init(pio, pin_latch);
+	// We only need TX, so get an 8-deep FIFO!
+	sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+	// SM transmits 1 bit per 8 execution cycles.
+	float div = (float)clock_get_hz(clk_sys) / (freq << 1);
+	sm_config_set_clkdiv(&c, div);
+	pio_sm_init(pio, sm, offset, &c);
+	pio_sm_set_enabled(pio, sm, true);
+}
+static inline void ic74hc595_program_write(PIO pio, uint sm, uint out) {
+    pio_sm_put_blocking(pio, sm, out);
+}
+
+#endif

uCNC/src/hal/mcus/rp2040/mcu_rp2040.c

@@ -35,6 +35,44 @@ extern void rp2040_eeprom_flush(void);
 
 uint8_t rp2040_pwm[16];
 
+#ifdef IC74HC595_CUSTOM_SHIFT_IO
+
+#ifndef IC74HC595_PIO_FREQ
+#define IC74HC595_PIO_FREQ 20000000UL
+#endif
+
+#if IC74HC595_COUNT != 4
+#error "IC74HC595_COUNT must be 4 to use ESP32 I2S mode for IO shifting"
+#endif
+
+#ifdef IC74HC595_HAS_PWMS
+#warning "IC74HC595 on RP2040 does not support soft PWM yet!"
+#endif
+
+#include "pico/stdlib.h"
+#include "hardware/pio.h"
+#include "ic74hc595.pio.h"
+
+static PIO pio_ic74hc595;
+static uint sm_ic74hc595;
+
+void ic74hc595_pio_init()
+{
+	pio_ic74hc595 = pio0;
+	sm_ic74hc595 = 0;
+	uint offset = pio_add_program(pio_ic74hc595, &ic74hc595_program);
+	ic74hc595_program_init(pio_ic74hc595, sm_ic74hc595, offset, IC74HC595_PIO_DATA, IC74HC595_PIO_CLK, IC74HC595_PIO_LATCH, IC74HC595_PIO_FREQ);
+}
+
+// disable this function
+// IO will be updated at a fixed rate
+MCU_CALLBACK void ic74hc595_shift_io_pins(void)
+{
+	ic74hc595_program_write(pio_ic74hc595, sm_ic74hc595, *((volatile uint32_t *)&ic74hc595_io_pins[0]));
+}
+
+#endif
+
 void mcu_din_isr(void)
 {
 	mcu_inputs_changed_cb();
@@ -266,6 +304,10 @@ static void mcu_usart_init(void)
 void mcu_init(void)
 {
 	mcu_io_init();
+
+#ifdef IC74HC595_CUSTOM_SHIFT_IO
+	ic74hc595_pio_init();
+#endif
 	mcu_usart_init();
 
 	pinMode(LED_BUILTIN, OUTPUT);

uCNC/src/hal/mcus/rp2040/mcumap_rp2040.h

@@ -1096,6 +1096,14 @@ extern "C"
 #define SERVO_ALARM 1
 #define ONESHOT_ALARM 2
 
+#ifdef IC74HC595_CUSTOM_SHIFT_IO
+#ifdef IC74HC595_COUNT
+#undef IC74HC595_COUNT
+#endif
+// forces IC74HC595_COUNT to 4 to prevent errors
+#define IC74HC595_COUNT 4
+#endif
+
 #define __timer_irq__(X) TIMER_IRQ_##X
 #define _timer_irq_(X) __timer_irq__(X)
 

uCNC/src/modules/ic74hc595.c

@@ -44,6 +44,7 @@
 #define ic74hc595_delay() mcu_delay_cycles(IC74HC595_DELAY_CYCLES)
 #if (IC74HC595_COUNT != 0)
 volatile uint8_t ic74hc595_io_pins[IC74HC595_COUNT];
+#ifndef IC74HC595_CUSTOM_SHIFT_IO
 MCU_CALLBACK void __attribute__((weak)) ic74hc595_shift_io_pins(void)
 {
 
@@ -53,7 +54,7 @@ MCU_CALLBACK void __attribute__((weak)) ic74hc595_shift_io_pins(void)
 	{
 		do
 		{
-			memcpy(pins, (const void*)ic74hc595_io_pins, IC74HC595_COUNT);
+			memcpy(pins, (const void *)ic74hc595_io_pins, IC74HC595_COUNT);
 			mcu_clear_output(IC74HC595_LATCH);
 			for (uint8_t i = IC74HC595_COUNT; i != 0;)
 			{
@@ -92,3 +93,4 @@ MCU_CALLBACK void __attribute__((weak)) ic74hc595_shift_io_pins(void)
 {
 }
 #endif
+#endif