Use new QSPI GPIO support in SDK

Removes the extra QSPI GPIO functions from the example, now just uses stdio

Author: will-v-pi

bootloaders/uart/CMakeLists.txt

@@ -26,6 +26,15 @@ add_executable(uart_binary
 # pull in common dependencies
 target_link_libraries(uart_binary pico_stdlib)
 
+# use the QSPI SD2 and SD3 pins as the default UART TX and RX (UART0), which are the same pins as the ROM UART bootloader
+target_compile_definitions(uart_binary PRIVATE
+    PICO_SUPPORT_QSPI_GPIOS=1
+    PICO_DEFAULT_UART=0
+    PICO_DEFAULT_UART_TX_PIN=QSPI_GPIO_SD2
+    PICO_DEFAULT_UART_RX_PIN=QSPI_GPIO_SD3
+    PICO_DEFAULT_UART_BAUD_RATE=1000000
+    )
+
 pico_set_binary_type(uart_binary no_flash)
 
 # package uf2 in flash

bootloaders/uart/uart_binary.c

@@ -4,10 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <stdio.h>
 #include "pico/stdlib.h"
-#include "hardware/uart.h"
-#include "hardware/structs/pads_qspi.h"
-#include "hardware/structs/io_qspi.h"
 
 #ifndef LED_DELAY_MS
 #define LED_DELAY_MS 500
@@ -31,53 +29,13 @@ void pico_set_led(bool led_on) {
 #endif
 }
 
-enum qspi_gpio {
-    // arbitrarily choose PAD register bank to set the order
-    QSPI_GPIO_SCLK = 0,
-    QSPI_GPIO_SD0 = 1,
-    QSPI_GPIO_SD1 = 2,
-    QSPI_GPIO_SD2 = 3,
-    QSPI_GPIO_SD3 = 4,
-    QSPI_GPIO_SS = 5,
-};
-
-// curiously the IO and PAD register banks for the QSPI GPIOs are not in the same order
-// This look up table will map the PAD offset to the IO offset for the same pin
-const uint QSPI_GPIO_PAD_TO_IO_OFFSET[] = {
-    0, // SCLK
-    2, // SD0
-    3, // SD1
-    4, // SD2
-    5, // SD3
-    1, // SS
-};
-
-// Set function for QSPI GPIO pin
-void qspi_gpio_set_function(enum qspi_gpio gpio, gpio_function1_t fn) {
-    // Set input enable on, output disable off
-    hw_write_masked(&pads_qspi_hw->io[gpio],
-                   PADS_QSPI_GPIO_QSPI_SD2_IE_BITS,
-                   PADS_QSPI_GPIO_QSPI_SD2_IE_BITS | PADS_QSPI_GPIO_QSPI_SD2_OD_BITS
-    );
-    // Zero all fields apart from fsel; we want this IO to do what the peripheral tells it.
-    // This doesn't affect e.g. pullup/pulldown, as these are in pad controls.
-    io_qspi_hw->io[QSPI_GPIO_PAD_TO_IO_OFFSET[gpio]].ctrl = fn << IO_QSPI_GPIO_QSPI_SD2_CTRL_FUNCSEL_LSB;
-
-    // Remove pad isolation now that the correct peripheral is in control of the pad
-    hw_clear_bits(&pads_qspi_hw->io[gpio], PADS_QSPI_GPIO_QSPI_SD2_ISO_BITS);
-}
-
 int main() {
     pico_led_init();
 
-    // SD2 is UART0 TX, SD3 is UART0 RX (same as the ROM UART bootloader)
-    qspi_gpio_set_function(QSPI_GPIO_SD2, GPIO_FUNC1_UART_AUX);
-    qspi_gpio_set_function(QSPI_GPIO_SD3, GPIO_FUNC1_UART_AUX);
-
-    uart_init(uart0, 1000000);
+    stdio_init_all();
 
     while (true) {
-        uart_puts(uart0, "Hello, world\n");
+        printf("Hello, world\n");
         pico_set_led(true);
         sleep_ms(LED_DELAY_MS);
         pico_set_led(false);