[Core] Add Raspberry Pi RP2040 support (#14877)

* Disable RESET keycode because of naming conflicts

* Add Pico SDK as submodule

* Add RP2040 build support to QMK

* Adjust USB endpoint structs for RP2040

* Add RP2040 bootloader and double-tap reset routine

* Add generic and pro micro RP2040 boards

* Add RP2040 onekey keyboard

* Add WS2812 PIO DMA enabled driver and documentation

Supports regular and open-drain output configuration. RP2040 GPIOs are
sadly not 5V tolerant, so this is a bit use-less or needs extra hardware
or you take the risk to fry your hardware.

* Adjust SIO Driver for RP2040

* Adjust I2C Driver for RP2040

* Adjust SPI Driver for RP2040

* Add PIO serial driver and documentation

* Add general RP2040 documentation

* Apply suggestions from code review

Co-authored-by: Nick Brassel <nick@tzarc.org>

Co-authored-by: Nick Brassel <nick@tzarc.org>

1 files changed, 189 insertions, 0 deletions

diff --git a/platforms/chibios/drivers/vendor/RP/RP2040/ws2812_vendor.c b/platforms/chibios/drivers/vendor/RP/RP2040/ws2812_vendor.c
new file mode 100644
index 0000000000..bc34eded14
--- /dev/null
+++ b/platforms/chibios/drivers/vendor/RP/RP2040/ws2812_vendor.c
@@ -0,0 +1,189 @@
+// Copyright 2022 Stefan Kerkmann
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "quantum.h"
+#include "ws2812.h"
+#include "hardware/pio.h"
+#include "hardware/clocks.h"
+
+#if !defined(MCU_RP)
+#    error PIO Driver is only available for Raspberry Pi 2040 MCUs!
+#endif
+
+#if defined(WS2812_PIO_USE_PIO1)
+static const PIO pio = pio1;
+#else
+static const PIO pio = pio0;
+#endif
+
+#if !defined(RP_DMA_PRIORITY_WS2812)
+#    define RP_DMA_PRIORITY_WS2812 12
+#endif
+
+static int state_machine = -1;
+
+#define WS2812_WRAP_TARGET 0
+#define WS2812_WRAP 3
+
+#define WS2812_T1 2
+#define WS2812_T2 5
+#define WS2812_T3 3
+
+#if defined(WS2812_EXTERNAL_PULLUP)
+
+#    pragma message "The GPIOs of the RP2040 are NOT 5V tolerant! Make sure to NOT apply any voltage over 3.3V to the RGB data pin."
+
+// clang-format off
+static const uint16_t ws2812_program_instructions[] = {
+            //     .wrap_target
+    0x7221, //  0: out    x, 1            side 1 [2] 
+    0x0123, //  1: jmp    !x, 3           side 0 [1] 
+    0x0400, //  2: jmp    0               side 0 [4] 
+    0xb442, //  3: nop                    side 1 [4] 
+            //     .wrap
+};
+
+#else
+
+static const uint16_t ws2812_program_instructions[] = {
+             //     .wrap_target
+    0x6221,  //  0: out    x, 1            side 0 [2]
+    0x1123,  //  1: jmp    !x, 3           side 1 [1]
+    0x1400,  //  2: jmp    0               side 1 [4]
+    0xa442,  //  3: nop                    side 0 [4]
+             //     .wrap
+};
+// clang-format on
+#endif
+
+static const pio_program_t ws2812_program = {
+    .instructions = ws2812_program_instructions,
+    .length       = 4,
+    .origin       = -1,
+};
+
+static uint32_t                WS2812_BUFFER[RGBLED_NUM];
+static const rp_dma_channel_t* WS2812_DMA_CHANNEL;
+
+bool ws2812_init(void) {
+    uint pio_idx = pio_get_index(pio);
+    /* Get PIOx peripheral out of reset state. */
+    hal_lld_peripheral_unreset(pio_idx == 0 ? RESETS_ALLREG_PIO0 : RESETS_ALLREG_PIO1);
+
+    // clang-format off
+    iomode_t rgb_pin_mode = PAL_RP_PAD_SLEWFAST |
+                            PAL_RP_GPIO_OE |
+                            (pio_idx == 0 ? PAL_MODE_ALTERNATE_PIO0 : PAL_MODE_ALTERNATE_PIO1);
+    // clang-format on
+
+    palSetLineMode(RGB_DI_PIN, rgb_pin_mode);
+
+    state_machine = pio_claim_unused_sm(pio, true);
+    if (state_machine < 0) {
+        dprintln("ERROR: Failed to acquire state machine for WS2812 output!");
+        return false;
+    }
+
+    uint offset = pio_add_program(pio, &ws2812_program);
+
+    pio_sm_set_consecutive_pindirs(pio, state_machine, RGB_DI_PIN, 1, true);
+
+    pio_sm_config config = pio_get_default_sm_config();
+    sm_config_set_wrap(&config, offset + WS2812_WRAP_TARGET, offset + WS2812_WRAP);
+    sm_config_set_sideset_pins(&config, RGB_DI_PIN);
+    sm_config_set_fifo_join(&config, PIO_FIFO_JOIN_TX);
+
+#if defined(WS2812_EXTERNAL_PULLUP)
+    /* Instruct side-set to change the pin-directions instead of outputting
+     * a logic level. We generate our levels the following way:
+     *
+     * 1: Set RGB data pin to high impedance input and let the pull-up drive the
+     * signal high.
+     *
+     * 0: Set RGB data pin to low impedance output and drive the pin low.
+     */
+    sm_config_set_sideset(&config, 1, false, true);
+#else
+    sm_config_set_sideset(&config, 1, false, false);
+#endif
+
+#if defined(RGBW)
+    sm_config_set_out_shift(&config, false, true, 32);
+#else
+    sm_config_set_out_shift(&config, false, true, 24);
+#endif
+
+    int   cycles_per_bit = WS2812_T1 + WS2812_T2 + WS2812_T3;
+    float div            = clock_get_hz(clk_sys) / (800.0f * KHZ * cycles_per_bit);
+    sm_config_set_clkdiv(&config, div);
+
+    pio_sm_init(pio, state_machine, offset, &config);
+    pio_sm_set_enabled(pio, state_machine, true);
+
+    WS2812_DMA_CHANNEL = dmaChannelAlloc(RP_DMA_CHANNEL_ID_ANY, RP_DMA_PRIORITY_WS2812, NULL, NULL);
+
+    // clang-format off
+    uint32_t mode = DMA_CTRL_TRIG_INCR_READ |
+                    DMA_CTRL_TRIG_DATA_SIZE_WORD |
+                    DMA_CTRL_TRIG_IRQ_QUIET |
+                    DMA_CTRL_TRIG_TREQ_SEL(pio_idx == 0 ? state_machine : state_machine + 8);
+    // clang-format on
+
+    dmaChannelSetModeX(WS2812_DMA_CHANNEL, mode);
+    dmaChannelSetDestinationX(WS2812_DMA_CHANNEL, (uint32_t)&pio->txf[state_machine]);
+    return true;
+}
+
+/**
+ * @brief Convert RGBW value into WS2812 compatible 32-bit data word.
+ */
+__always_inline static uint32_t rgbw8888_to_u32(uint8_t red, uint8_t green, uint8_t blue, uint8_t white) {
+#if (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_GRB)
+    return ((uint32_t)green << 24) | ((uint32_t)red << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
+#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_RGB)
+    return ((uint32_t)red << 24) | ((uint32_t)green << 16) | ((uint32_t)blue << 8) | ((uint32_t)white);
+#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_BGR)
+    return ((uint32_t)blue << 24) | ((uint32_t)green << 16) | ((uint32_t)red << 8) | ((uint32_t)white);
+#endif
+}
+
+static inline void sync_ws2812_transfer(void) {
+    if (unlikely(dmaChannelIsBusyX(WS2812_DMA_CHANNEL) || !pio_sm_is_tx_fifo_empty(pio, state_machine))) {
+        fast_timer_t start = timer_read_fast();
+        do {
+            // Abort the synchronization if we have to wait longer than the total
+            // count of LEDs in millisecounds. This is safely much longer than it
+            // would take to push all the data out.
+            if (unlikely(timer_elapsed_fast(start) > RGBLED_NUM)) {
+                dprintln("ERROR: WS2812 DMA transfer has stalled, aborting!");
+                dmaChannelDisableX(WS2812_DMA_CHANNEL);
+                return;
+            }
+
+        } while (dmaChannelIsBusyX(WS2812_DMA_CHANNEL) || !pio_sm_is_tx_fifo_empty(pio, state_machine));
+        // We wait for the WS2812 chain to reset after all data has been pushed
+        // out.
+        wait_us(WS2812_TRST_US);
+    }
+}
+
+void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) {
+    static bool is_initialized = false;
+    if (unlikely(!is_initialized)) {
+        is_initialized = ws2812_init();
+    }
+
+    sync_ws2812_transfer();
+
+    for (int i = 0; i < leds; i++) {
+#if defined(RGBW)
+        WS2812_BUFFER[i] = rgbw8888_to_u32(ledarray[i].r, ledarray[i].g, ledarray[i].b, ledarray[i].w);
+#else
+        WS2812_BUFFER[i] = rgbw8888_to_u32(ledarray[i].r, ledarray[i].g, ledarray[i].b, 0);
+#endif
+    }
+
+    dmaChannelSetSourceX(WS2812_DMA_CHANNEL, (uint32_t)WS2812_BUFFER);
+    dmaChannelSetCounterX(WS2812_DMA_CHANNEL, leds);
+    dmaChannelEnableX(WS2812_DMA_CHANNEL);
+}