Fix some pio examples to work with gpios >= 32

Use pio_claim_free_sm_and_add_program_for_gpio_range as a good example
of how you should find a free pio and state machine that's compatible
with a particular gpio.

Author: peterharperuk

pio/hello_pio/hello.c

@@ -17,6 +17,11 @@
 #define HELLO_PIO_LED_PIN PICO_DEFAULT_LED_PIN
 #endif
 
+// Check the pin is compatible with the platform
+#if HELLO_PIO_LED_PIN >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
 int main() {
 #ifndef HELLO_PIO_LED_PIN
 #warning pio/hello_pio example requires a board with a regular LED

pio/uart_rx/uart_rx.c

@@ -26,6 +26,11 @@
 #define HARD_UART_TX_PIN 4
 #define PIO_RX_PIN 3
 
+// Check the pin is compatible with the platform
+#if PIO_RX_PIN >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
 // Ask core 1 to print a string, to make things easier on core 0
 void core1_main() {
     const char *s = (const char *) multicore_fifo_pop_blocking();
@@ -42,10 +47,17 @@ int main() {
     gpio_set_function(HARD_UART_TX_PIN, GPIO_FUNC_UART);
 
     // Set up the state machine we're going to use to receive them.
-    PIO pio = pio0;
-    uint sm = 0;
-    uint offset = pio_add_program(pio, &uart_rx_program);
+    PIO pio;
+    uint sm;
+    uint offset;
+
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range so we can address gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&uart_rx_program, &pio, &sm, &offset, PIO_RX_PIN, 1, true);
+    hard_assert(success);
+
     uart_rx_program_init(pio, sm, offset, PIO_RX_PIN, SERIAL_BAUD);
+    //uart_rx_mini_program_init(pio, sm, offset, PIO_RX_PIN, SERIAL_BAUD);
 
     // Tell core 1 to print some text to uart1 as fast as it can
     multicore_launch_core1(core1_main);
@@ -57,4 +69,7 @@ int main() {
         char c = uart_rx_program_getc(pio, sm);
         putchar(c);
     }
+
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&uart_rx_program, pio, sm, offset);
 }

pio/uart_rx/uart_rx_intr.c

@@ -35,6 +35,11 @@
 #define FIFO_SIZE 64
 #define MAX_COUNTER 10
 
+// Check the pin is compatible with the platform
+#if PIO_RX_PIN >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
 static PIO pio;
 static uint sm;
 static int8_t pio_irq;
@@ -84,27 +89,6 @@ static void async_worker_func(__unused async_context_t *async_context, __unused
     }
 }
 
-// Find a free pio and state machine and load the program into it.
-// Returns false if this fails
-static bool init_pio(const pio_program_t *program, PIO *pio_hw, uint *sm, uint *offset) {
-    // Find a free pio
-    *pio_hw = pio1;
-    if (!pio_can_add_program(*pio_hw, program)) {
-        *pio_hw = pio0;
-        if (!pio_can_add_program(*pio_hw, program)) {
-            *offset = -1;
-            return false;
-        }
-    }
-    *offset = pio_add_program(*pio_hw, program);
-    // Find a state machine
-    *sm = (int8_t)pio_claim_unused_sm(*pio_hw, false);
-    if (*sm < 0) {
-        return false;
-    }
-    return true;
-}
-
 int main() {
     // Console output (also a UART, yes it's confusing)
     setup_default_uart();
@@ -123,16 +107,15 @@ int main() {
     }
     async_context_add_when_pending_worker(&async_context.core, &worker);
 
-    // Set up the state machine we're going to use to receive them.
-    // In real code you need to find a free pio and state machine in case pio resources are used elsewhere
-    if (!init_pio(&uart_rx_program, &pio, &sm, &offset)) {
-        panic("failed to setup pio");
-    }
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range so we can address gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&uart_rx_program, &pio, &sm, &offset, PIO_RX_PIN, 1, true);
+    hard_assert(success);
+
     uart_rx_program_init(pio, sm, offset, PIO_RX_PIN, SERIAL_BAUD);
 
     // Find a free irq
-    static_assert(PIO0_IRQ_1 == PIO0_IRQ_0 + 1 && PIO1_IRQ_1 == PIO1_IRQ_0 + 1, "");
-    pio_irq = (pio == pio0) ? PIO0_IRQ_0 : PIO1_IRQ_0;
+    pio_irq = pio_get_irq_num(pio, 0);
     if (irq_get_exclusive_handler(pio_irq)) {
         pio_irq++;
         if (irq_get_exclusive_handler(pio_irq)) {
@@ -143,8 +126,8 @@ int main() {
     // Enable interrupt
     irq_add_shared_handler(pio_irq, pio_irq_func, PICO_SHARED_IRQ_HANDLER_DEFAULT_ORDER_PRIORITY); // Add a shared IRQ handler
     irq_set_enabled(pio_irq, true); // Enable the IRQ
-    const uint irq_index = pio_irq - ((pio == pio0) ? PIO0_IRQ_0 : PIO1_IRQ_0); // Get index of the IRQ
-    pio_set_irqn_source_enabled(pio, irq_index, pis_sm0_rx_fifo_not_empty + sm, true); // Set pio to tell us when the FIFO is NOT empty
+    const uint irq_index = pio_irq - pio_get_irq_num(pio, 0); // Get index of the IRQ
+    pio_set_irqn_source_enabled(pio, irq_index, pio_get_rx_fifo_not_empty_interrupt_source(sm), true); // Set pio to tell us when the FIFO is NOT empty
 
     // Tell core 1 to print text to uart1
     multicore_launch_core1(core1_main);
@@ -160,14 +143,12 @@ int main() {
     }
 
     // Disable interrupt
-    pio_set_irqn_source_enabled(pio, irq_index, pis_sm0_rx_fifo_not_empty + sm, false);
+    pio_set_irqn_source_enabled(pio, irq_index, pio_get_rx_fifo_not_empty_interrupt_source(sm), false);
     irq_set_enabled(pio_irq, false);
     irq_remove_handler(pio_irq, pio_irq_func);
 
-    // Cleanup pio
-    pio_sm_set_enabled(pio, sm, false);
-    pio_remove_program(pio, &uart_rx_program, offset);
-    pio_sm_unclaim(pio, sm);
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&uart_rx_program, pio, sm, offset);
 
     async_context_remove_when_pending_worker(&async_context.core, &worker);
     async_context_deinit(&async_context.core);

pio/uart_tx/uart_tx.c

@@ -8,20 +8,35 @@
 #include "hardware/pio.h"
 #include "uart_tx.pio.h"
 
+// We're going to use PIO to print "Hello, world!" on the same GPIO which we
+// normally attach UART0 to.
+#define PIO_TX_PIN 0
+
+// Check the pin is compatible with the platform
+#if PIO_TX_PIN >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
 int main() {
-    // We're going to use PIO to print "Hello, world!" on the same GPIO which we
-    // normally attach UART0 to.
-    const uint PIN_TX = 0;
     // This is the same as the default UART baud rate on Pico
     const uint SERIAL_BAUD = 115200;
 
-    PIO pio = pio0;
-    uint sm = 0;
-    uint offset = pio_add_program(pio, &uart_tx_program);
-    uart_tx_program_init(pio, sm, offset, PIN_TX, SERIAL_BAUD);
+    PIO pio;
+    uint sm;
+    uint offset;
+
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range so we can address gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&uart_tx_program, &pio, &sm, &offset, PIO_TX_PIN, 1, true);
+    hard_assert(success);
+
+    uart_tx_program_init(pio, sm, offset, PIO_TX_PIN, SERIAL_BAUD);
 
     while (true) {
-        uart_tx_program_puts(pio, sm, "Hello, world! (from PIO!)\n");
+        uart_tx_program_puts(pio, sm, "Hello, world! (from PIO!)\r\n");
         sleep_ms(1000);
     }
+
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&uart_tx_program, pio, sm, offset);
 }

pio/uart_tx/uart_tx.pio

@@ -24,8 +24,8 @@ bitloop:                   ; This loop will run 8 times (8n1 UART)
 static inline void uart_tx_program_init(PIO pio, uint sm, uint offset, uint pin_tx, uint baud) {
     // Tell PIO to initially drive output-high on the selected pin, then map PIO
     // onto that pin with the IO muxes.
-    pio_sm_set_pins_with_mask(pio, sm, 1u << pin_tx, 1u << pin_tx);
-    pio_sm_set_pindirs_with_mask(pio, sm, 1u << pin_tx, 1u << pin_tx);
+    pio_sm_set_pins_with_mask64(pio, sm, 1ull << pin_tx, 1ull << pin_tx);
+    pio_sm_set_pindirs_with_mask64(pio, sm, 1ull << pin_tx, 1ull << pin_tx);
     pio_gpio_init(pio, pin_tx);
 
     pio_sm_config c = uart_tx_program_get_default_config(offset);

pio/ws2812/ws2812.c

@@ -35,8 +35,13 @@
 #define WS2812_PIN 2
 #endif
 
-static inline void put_pixel(uint32_t pixel_grb) {
-    pio_sm_put_blocking(pio0, 0, pixel_grb << 8u);
+// Check the pin is compatible with the platform
+#if WS2812_PIN >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
+static inline void put_pixel(PIO pio, uint sm, uint32_t pixel_grb) {
+    pio_sm_put_blocking(pio, sm, pixel_grb << 8u);
 }
 
 static inline uint32_t urgb_u32(uint8_t r, uint8_t g, uint8_t b) {
@@ -54,44 +59,44 @@ static inline uint32_t urgbw_u32(uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
             (uint32_t) (b);
 }
 
-void pattern_snakes(uint len, uint t) {
+void pattern_snakes(PIO pio, uint sm, uint len, uint t) {
     for (uint i = 0; i < len; ++i) {
         uint x = (i + (t >> 1)) % 64;
         if (x < 10)
-            put_pixel(urgb_u32(0xff, 0, 0));
+            put_pixel(pio, sm, urgb_u32(0xff, 0, 0));
         else if (x >= 15 && x < 25)
-            put_pixel(urgb_u32(0, 0xff, 0));
+            put_pixel(pio, sm, urgb_u32(0, 0xff, 0));
         else if (x >= 30 && x < 40)
-            put_pixel(urgb_u32(0, 0, 0xff));
+            put_pixel(pio, sm, urgb_u32(0, 0, 0xff));
         else
-            put_pixel(0);
+            put_pixel(pio, sm, 0);
     }
 }
 
-void pattern_random(uint len, uint t) {
+void pattern_random(PIO pio, uint sm, uint len, uint t) {
     if (t % 8)
         return;
     for (uint i = 0; i < len; ++i)
-        put_pixel(rand());
+        put_pixel(pio, sm, rand());
 }
 
-void pattern_sparkle(uint len, uint t) {
+void pattern_sparkle(PIO pio, uint sm, uint len, uint t) {
     if (t % 8)
         return;
     for (uint i = 0; i < len; ++i)
-        put_pixel(rand() % 16 ? 0 : 0xffffffff);
+        put_pixel(pio, sm, rand() % 16 ? 0 : 0xffffffff);
 }
 
-void pattern_greys(uint len, uint t) {
+void pattern_greys(PIO pio, uint sm, uint len, uint t) {
     uint max = 100; // let's not draw too much current!
     t %= max;
     for (uint i = 0; i < len; ++i) {
-        put_pixel(t * 0x10101);
+        put_pixel(pio, sm, t * 0x10101);
         if (++t >= max) t = 0;
     }
 }
 
-typedef void (*pattern)(uint len, uint t);
+typedef void (*pattern)(PIO pio, uint sm, uint len, uint t);
 const struct {
     pattern pat;
     const char *name;
@@ -105,12 +110,17 @@ const struct {
 int main() {
     //set_sys_clock_48();
     stdio_init_all();
-    printf("WS2812 Smoke Test, using pin %d", WS2812_PIN);
+    printf("WS2812 Smoke Test, using pin %d\n", WS2812_PIN);
 
     // todo get free sm
-    PIO pio = pio0;
-    int sm = 0;
-    uint offset = pio_add_program(pio, &ws2812_program);
+    PIO pio;
+    uint sm;
+    uint offset;
+
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range so we can address gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&ws2812_program, &pio, &sm, &offset, WS2812_PIN, 1, true);
+    hard_assert(success);
 
     ws2812_program_init(pio, sm, offset, WS2812_PIN, 800000, IS_RGBW);
 
@@ -121,9 +131,12 @@ int main() {
         puts(pattern_table[pat].name);
         puts(dir == 1 ? "(forward)" : "(backward)");
         for (int i = 0; i < 1000; ++i) {
-            pattern_table[pat].pat(NUM_PIXELS, t);
+            pattern_table[pat].pat(pio, sm, NUM_PIXELS, t);
             sleep_ms(10);
             t += dir;
         }
     }
+
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&ws2812_program, pio, sm, offset);
 }

pio/ws2812/ws2812_parallel.c

@@ -19,6 +19,11 @@
 #define NUM_PIXELS 64
 #define WS2812_PIN_BASE 2
 
+// Check the pin is compatible with the platform
+#if WS2812_PIN_BASE >= NUM_BANK0_GPIOS
+#error Attempting to use a pin>=32 on a platform that does not support it
+#endif
+
 // horrible temporary hack to avoid changing pattern code
 static uint8_t *current_strip_out;
 static bool current_strip_4color;
@@ -278,12 +283,16 @@ void output_strips_dma(value_bits_t *bits, uint value_length) {
 int main() {
     //set_sys_clock_48();
     stdio_init_all();
-    puts("WS2812 parallel");
+    printf("WS2812 parallel using pin %d\n", WS2812_PIN_BASE);
+
+    PIO pio;
+    uint sm;
+    uint offset;
 
-    // todo get free sm
-    PIO pio = pio0;
-    int sm = 0;
-    uint offset = pio_add_program(pio, &ws2812_parallel_program);
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range so we can address gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&ws2812_parallel_program, &pio, &sm, &offset, WS2812_PIN_BASE, count_of(strips), true);
+    hard_assert(success);
 
     ws2812_parallel_program_init(pio, sm, offset, WS2812_PIN_BASE, count_of(strips), 800000);
 
@@ -318,4 +327,7 @@ int main() {
         }
         memset(&states, 0, sizeof(states)); // clear out errors
     }
+
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&ws2812_parallel_program, pio, sm, offset);
 }