Add support for RP2040-zero LED

CMakeLists.txt

@@ -11,6 +11,7 @@ add_executable(PicoMemcard)
 
 pico_set_linker_script(PicoMemcard ${CMAKE_SOURCE_DIR}/memmap.ld)
 pico_generate_pio_header(PicoMemcard ${CMAKE_CURRENT_LIST_DIR}/psxSPI.pio)
+pico_generate_pio_header(PicoMemcard ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio)
 
 
 # Example source

inc/config.h

@@ -8,20 +8,20 @@
 #define MEMCARD_FILE_NAME	"memcard.mcr"	// name of memory card file image
 
 /* Board targeted by build */
-#define TARGET_PICO
-//#define TARGET_RP2040ZERO
+#define PICO
+//#define RP2040ZERO
 
 
 /* PSX Interface Pinout */
-#ifdef TARGET_PICO
+#ifdef PICO
 	#define PIN_DAT 5
 	#define PIN_CMD PIN_DAT + 1		// must be immediately after PIN_DAT
 	#define PIN_SEL PIN_CMD + 1		// must be immediately after PIN_CMD
 	#define PIN_CLK PIN_SEL + 1		// must be immediately after PIN_SEL
 	#define PIN_ACK 9
 #endif
 
-#ifdef TARGET_RP2040ZERO
+#ifdef RP2040ZERO
 	#define PIN_DAT 9
 	#define PIN_CMD PIN_DAT + 1		// must be immediately after PIN_DAT
 	#define PIN_SEL PIN_CMD + 1		// must be immediately after PIN_CMD

inc/led.h

@@ -5,9 +5,6 @@
 
 void led_init();
 void led_output_sync_status(bool out_of_sync);
-void led_blink(int amount, int on_ms, int off_ms);
-void led_blink_fast(int amount);
-void led_blink_normal(int amount);
-void led_blink_slow(int amount);
+void led_blink_error(int amount);
 
 #endif

src/led.c

@@ -1,44 +1,72 @@
 #include "led.h"
+#include "config.h"
 #include "hardware/gpio.h"
+#include "hardware/pio.h"
+#ifdef RP2040ZERO
+#include "ws2812.pio.h"
+#endif
 
+#ifdef PICO
 #define PICO_LED_PIN 25
+#endif
 
-void led_init() {
+static uint smWs2813;
+static uint offsetWs2813;
+
+#ifdef RP2040ZERO
+void ws2812_put_pixel(uint32_t pixel_grb) {
+	pio_sm_put_blocking(pio1, smWs2813, pixel_grb << 8u);
+}
+void ws2812_put_rgb(uint8_t red, uint8_t green, uint8_t blue) {
+	uint32_t mask = (green << 16) | (red << 8) | (blue << 0);
+	ws2812_put_pixel(mask);
+}
+#endif
 
+void led_init() {
+	#ifdef RP2040ZERO
+	offsetWs2813 = pio_add_program(pio1, &ws2812_program);
+	smWs2813 = pio_claim_unused_sm(pio1, true);
+	ws2812_program_init(pio1, smWs2813, offsetWs2813, 16, 800000, true);
+	#endif
 }
 
 void led_output_sync_status(bool out_of_sync) {
+	#ifdef PICO
 	gpio_put(PICO_LED_PIN, !out_of_sync);
+	#endif
+	#ifdef RP2040ZERO
+	if(out_of_sync)
+		ws2812_put_rgb(255, 255, 0);
+	else
+		ws2812_put_rgb(0, 255, 0);
+	#endif
 }
 
-void led_blink(int amount, int on_ms, int off_ms) {
-	bool initial_state = gpio_get(PICO_LED_PIN);
-	if(initial_state) {
-		/* turn led off if already on */
-		gpio_put(PICO_LED_PIN, false);
-		sleep_ms(off_ms);
-		--amount;	// last blink is performed while restoring led state
-	}
+void led_blink_error(int amount) {
+	/* ensure led is off */
+	#ifdef PICO
+	gpio_put(PICO_LED_PIN, false);
+	#endif
+	#ifdef RP2040ZERO
+	ws2812_put_rgb(0, 0, 0);
+	#endif
+	sleep_ms(500);
+	/* start blinking */
 	for(int i = 0; i < amount; ++i) {
+		#ifdef PICO
 		gpio_put(PICO_LED_PIN, true);
-		sleep_ms(on_ms);
+		#endif
+		#ifdef RP2040ZERO
+		ws2812_put_rgb(255, 0, 0);
+		#endif
+		sleep_ms(500);
+		#ifdef PICO
 		gpio_put(PICO_LED_PIN, false);
-		sleep_ms(off_ms);
+		#endif
+		#ifdef RP2040ZERO
+		ws2812_put_rgb(0, 0, 0);
+		#endif
+		sleep_ms(500);
 	}
-	if(initial_state) {
-		/* restore led state */
-		gpio_put(PICO_LED_PIN, true);
-	}
-}
-
-void led_blink_fast(int amount) {
-	led_blink(amount, 250, 250);
-}
-
-void led_blink_normal(int amount) {
-	led_blink(amount, 500, 500);
-}
-
-void led_blink_slow(int amount) {
-	led_blink(amount, 1000, 1000);
 }

src/memcard_simulator.c

@@ -325,14 +325,14 @@ _Noreturn int simulate_memory_card() {
 	status = memory_card_init(&mc);
 	if(status != MC_OK) {
 		while(true) {
-			led_blink_normal(status);
+			led_blink_error(status);
 			sleep_ms(2000);
 		}
 	}
 	status = memory_card_import(&mc, MEMCARD_FILE_NAME);
 	if(status != MC_OK) {
 		while(true) {
-			led_blink_normal(status);
+			led_blink_error(status);
 			sleep_ms(2000);
 		}
 	}

ws2812.pio

@@ -0,0 +1,48 @@
+;
+; Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+;
+; SPDX-License-Identifier: BSD-3-Clause
+;
+
+.program ws2812
+.side_set 1
+
+.define public T1 2
+.define public T2 5
+.define public T3 3
+
+.lang_opt python sideset_init = pico.PIO.OUT_HIGH
+.lang_opt python out_init     = pico.PIO.OUT_HIGH
+.lang_opt python out_shiftdir = 1
+
+.wrap_target
+bitloop:
+    out x, 1       side 0 [T3 - 1] ; Side-set still takes place when instruction stalls
+    jmp !x do_zero side 1 [T1 - 1] ; Branch on the bit we shifted out. Positive pulse
+do_one:
+    jmp  bitloop   side 1 [T2 - 1] ; Continue driving high, for a long pulse
+do_zero:
+    nop            side 0 [T2 - 1] ; Or drive low, for a short pulse
+.wrap
+
+% c-sdk {
+#include "hardware/clocks.h"
+
+static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw) {
+
+    pio_gpio_init(pio, pin);
+    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
+
+    pio_sm_config c = ws2812_program_get_default_config(offset);
+    sm_config_set_sideset_pins(&c, pin);
+    sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
+    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+
+    int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3;
+    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
+    sm_config_set_clkdiv(&c, div);
+
+    pio_sm_init(pio, sm, offset, &c);
+    pio_sm_set_enabled(pio, sm, true);
+}
+%}