working tx

.gitignore

@@ -1 +1,2 @@
+.vscode
 build/

.vscode/c_cpp_properties.json

@@ -0,0 +1,18 @@
+{
+    "configurations": [
+        {
+            "includePath": [
+                "${workspaceFolder}/**",
+                "${ZEPHYR_BASE}/include/**",
+                "${ZEPHYR_BASE}/kernel/include/**",
+                "${workspaceFolder}/build/zephyr/include/generated/**"
+            ],
+            //"compilerPath": "~/zephyr-sdk-0.17.4/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc",
+            "cStandard": "c11",
+            "cppStandard": "c++17",
+            "compileCommands": "${workspaceFolder}/build/compile_commands.json",
+            "intelliSenseMode": "gcc-arm"
+        }
+    ],
+    "version": 4
+}

.vscode/launch.json

@@ -0,0 +1,27 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Zephyr west debugserver",
+            "type": "cortex-debug",
+            "request": "attach",
+            "servertype": "external",
+            "cwd": "${workspaceFolder}",
+
+            "executable": "${workspaceFolder}/build/zephyr/zephyr.elf",
+            "gdbTarget": "localhost:3333",
+
+            "svdFile": "${env:ZEPHYR_BASE}/../modules/hal/nordic/nrfx/bsp/stable/mdk/nrf54l15_application.svd",
+            "rtos": "Zephyr",
+
+            "overrideAttachCommands": [
+                "monitor reset halt",
+            ],
+
+            "postAttachCommands": [
+                //"tbreak main",
+                "continue"
+            ],
+        }
+    ]
+}

boards/xiao_nrf54l15_nrf54l15_cpuapp.overlay

@@ -6,7 +6,7 @@
     test_uart: test_uart {
         compatible = "uart-interrupt-poll-bridge";
         uart = <&uart20>;
-        timer = <&timer00>;
+        counter = <&timer00>;
         interrupts = <1 2>; 
         interrupt-parent = <&nvic>;
         status = "okay";

modules/uart-interrupt-poll-bridge/drivers/serial/uart-interrupt-poll-bridge/Kconfig

@@ -1,6 +1,7 @@
 config UART_INTERRUPT_POLL_BRIDGE
     bool "UART interrupt/poll bridge driver"
     default y
+    select UART_USE_RUNTIME_CONFIGURE
 
 config UART_INTERRUPT_POLL_BRIDGE_QUEUE_SIZE
     int "UART interrupt/poll bridge driver rx / tx buffer size"

modules/uart-interrupt-poll-bridge/drivers/serial/uart-interrupt-poll-bridge/uart-interrupt-poll-bridge.c

@@ -1,31 +1,49 @@
 #define DT_DRV_COMPAT uart_interrupt_poll_bridge
 
 #include <zephyr/drivers/uart.h>
-#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+#include <zephyr/spinlock.h>
+#if IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)
+#include <zephyr/drivers/counter.h>
 #include <zephyr/sys/ring_buffer.h>
 #endif
 
+#define REDUCE_TO_BIT(obj) (!!obj)
+
 struct uart_pti_bridge_config {
 	const struct device *uart;
-#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+#if IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)
-	const struct device *timer;
+	const struct device *counter;
 	const uint8_t interrupt_line;
 #endif
 };
 
 struct uart_pti_bridge_data {
-#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+	struct k_spinlock lock;
+#if IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)
 	struct ring_buf *rx_buf;
 	struct ring_buf *tx_buf;
+	uart_irq_callback_user_data_t cb;
+	void *user_data;
+	union {
+		struct {
+			const uint8_t irq_triggered : 4;
+			const uint8_t irq_enabled : 4;
+		};
+		struct {
+			bool irq_tx_ready_triggered : 1;
+			bool irq_tx_complete_triggered: 1;
+			bool irq_rx_ready_triggered : 1;
+			bool irq_err_triggered : 1;
+			bool irq_tx_enabled : 1;
+			bool : 1;
+			bool irq_rx_enabled : 1;
+			bool irq_err_enabled : 1;
+
+		};
+	};
 #endif
 };
 
-int uart_pti_bridge_init(const struct device *dev) {
-	ARG_UNUSED(dev);
-	return 0;
-}
-
-
 static int uart_pti_bridge_poll_in(const struct device *dev, unsigned char *c) {
 	const struct uart_pti_bridge_config *config = dev->config;
 
@@ -48,7 +66,7 @@ static int uart_pti_bridge_err_check(const struct device *dev) {
 }
 
 
-#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
+#if IS_ENABLED(CONFIG_UART_USE_RUNTIME_CONFIGURE)
 static int uart_pti_bridge_configure(const struct device *dev,
 				  const struct uart_config *cfg) {
 	ARG_UNUSED(dev);
@@ -64,6 +82,213 @@ static int uart_pti_bridge_config_get(const struct device *dev,
 }
 #endif
 
+
+#if IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)
+int uart_pti_bridge_fifo_fill(const struct device *dev, const uint8_t *msg, int len) {
+	struct uart_pti_bridge_data *data = dev->data;
+	
+	k_spinlock_key_t key = k_spin_lock(&data->lock);
+	uint32_t bytes_written = ring_buf_put(data->tx_buf, msg, len);
+	k_spin_unlock(&data->lock, key);
+
+	return bytes_written;
+}
+
+
+int uart_pti_bridge_fifo_read(const struct device *dev, uint8_t *msg, const int size) {
+	struct uart_pti_bridge_data *data = dev->data;
+	
+	k_spinlock_key_t key = k_spin_lock(&data->lock);
+	uint32_t bytes_read = ring_buf_get(data->rx_buf, msg, size);
+	k_spin_unlock(&data->lock, key);
+
+	return bytes_read;
+}
+
+
+void uart_pti_bridge_irq_tx_enable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_tx_enabled = true;
+}
+
+
+void uart_pti_bridge_irq_tx_disable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_tx_enabled = false;
+}
+
+
+int uart_pti_bridge_irq_tx_ready(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	return data->irq_tx_ready_triggered; 
+}
+
+
+int uart_pti_bridge_irq_tx_complete(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	return data->irq_tx_complete_triggered; 
+}
+
+
+void uart_pti_bridge_irq_rx_enable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_rx_enabled = true;
+}
+
+
+void uart_pti_bridge_irq_rx_disable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_rx_enabled = false;
+}
+
+
+int uart_pti_bridge_irq_rx_ready(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	return data->irq_rx_ready_triggered; 
+}
+
+
+void uart_pti_bridge_irq_err_enable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_err_enabled = true;
+}
+
+
+void uart_pti_bridge_irq_err_disable(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	data->irq_err_enabled = false;
+}
+
+
+int uart_pti_bridge_irq_is_pending(const struct device *dev) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	return REDUCE_TO_BIT(data->irq_triggered);
+}
+
+
+int uart_pti_bridge_irq_update(const struct device *dev) {
+	ARG_UNUSED(dev);
+	return 1; // success
+}
+
+
+void uart_pti_bridge_callback_set(const struct device *dev, uart_irq_callback_user_data_t cb, void *user_data) {
+	struct uart_pti_bridge_data *data = dev->data;
+
+	k_spinlock_key_t key = k_spin_lock(&data->lock);
+	data->cb = cb;
+	data->user_data = user_data;
+	k_spin_unlock(&data->lock, key);
+}
+
+
+void uart_pti_bridge_timer_irq(const struct device *timer_dev, void *user_data) {
+	ARG_UNUSED(timer_dev);
+
+	const struct device *dev = user_data;
+	struct uart_pti_bridge_data *data = dev->data;
+
+	k_spinlock_key_t key = k_spin_lock(&data->lock);
+
+	data->irq_tx_ready_triggered = REDUCE_TO_BIT(ring_buf_space_get(data->tx_buf));
+	data->irq_tx_complete_triggered = REDUCE_TO_BIT(ring_buf_is_empty(data->tx_buf));
+	data->irq_rx_ready_triggered = REDUCE_TO_BIT(!ring_buf_is_empty(data->rx_buf));
+	data->irq_err_triggered = REDUCE_TO_BIT(uart_pti_bridge_err_check(dev));
+
+	if (data->irq_tx_ready_triggered && !data->irq_tx_complete_triggered) {
+		uint8_t chunk;
+		if (ring_buf_get(data->tx_buf, &chunk, 1)) {
+			uart_poll_out(dev, chunk);
+		}
+	}
+
+	if (data->irq_rx_enabled) {
+		uint32_t rx_buf_free_space = ring_buf_space_get(data->rx_buf);
+		uint8_t chunk;
+
+		for (uint32_t bytes_read = 0; bytes_read <= rx_buf_free_space; bytes_read++) {
+			if (uart_poll_in(dev, &chunk) < 0) {
+				break;
+			}
+			ring_buf_put(data->rx_buf, &chunk, 1);
+		}
+		
+	}
+
+	k_spin_unlock(&data->lock, key);
+
+	if (data->cb && data->irq_triggered) {
+		data->cb(dev, data->user_data);
+	}
+}
+
+static uint32_t uart_pti_bridge_us_per_byte(const struct uart_config *cfg)
+{
+    uint8_t bits = 1; // start bit
+
+    // data bits
+    switch (cfg->data_bits) {
+        case UART_CFG_DATA_BITS_5: bits += 5; break;
+        case UART_CFG_DATA_BITS_6: bits += 6; break;
+        case UART_CFG_DATA_BITS_7: bits += 7; break;
+        case UART_CFG_DATA_BITS_8: bits += 8; break;
+        case UART_CFG_DATA_BITS_9: bits += 9; break;
+    }
+
+    // parity bit
+    if (cfg->parity != UART_CFG_PARITY_NONE) {
+        bits += 1;
+    }
+
+    // stop bits
+    switch (cfg->stop_bits) {
+        case UART_CFG_STOP_BITS_0_5: break;          // rare, ignore
+        case UART_CFG_STOP_BITS_1:   bits += 1; break;
+        case UART_CFG_STOP_BITS_1_5: bits += 1; break; // round down
+        case UART_CFG_STOP_BITS_2:   bits += 2; break;
+    }
+
+    // round up to ensure buffer is always large enough
+    return (bits * 1000000 + cfg->baudrate - 1) / cfg->baudrate;
+}
+#endif
+
+
+int uart_pti_bridge_init(const struct device *dev) {
+#if IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)
+	const struct uart_pti_bridge_config *config = dev->config;
+
+	struct uart_config cfg;
+	uart_config_get(config->uart, &cfg);
+
+	const uint32_t us_per_byte = uart_pti_bridge_us_per_byte(&cfg);
+
+	struct counter_top_cfg top_cfg = {
+		.callback  = uart_pti_bridge_timer_irq,
+		.ticks     = counter_us_to_ticks(config->counter, us_per_byte),
+		.user_data = (struct device *)dev,
+		.flags     = 0,
+	};
+
+	counter_set_top_value(config->counter, &top_cfg);
+	counter_start(config->counter);
+#else
+	ARG_UNUSED(dev);
+#endif
+	return 0;
+}
+
+
 static DEVICE_API(uart, uart_interrupt_poll_bridge_api) = {
 	.poll_in = uart_pti_bridge_poll_in,
 	.poll_out = uart_pti_bridge_poll_out,
@@ -73,20 +298,20 @@ static DEVICE_API(uart, uart_interrupt_poll_bridge_api) = {
 	.config_get = uart_pti_bridge_config_get,
 #endif
 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
-	.fifo_fill = NULL,
+	.fifo_fill = uart_pti_bridge_fifo_fill,
-	.fifo_read = NULL,
+	.fifo_read = uart_pti_bridge_fifo_read,
-	.irq_tx_enable = NULL,
+	.irq_tx_enable = uart_pti_bridge_irq_tx_enable,
-	.irq_tx_disable = NULL,
+	.irq_tx_disable = uart_pti_bridge_irq_tx_disable,
-	.irq_tx_ready = NULL,
+	.irq_tx_ready = uart_pti_bridge_irq_tx_ready,
-	.irq_tx_complete = NULL,
+	.irq_tx_complete = uart_pti_bridge_irq_tx_complete,
-	.irq_rx_enable = NULL,
+	.irq_rx_enable = uart_pti_bridge_irq_rx_enable,
-	.irq_rx_disable = NULL,
+	.irq_rx_disable = uart_pti_bridge_irq_rx_disable,
-	.irq_rx_ready = NULL,
+	.irq_rx_ready = uart_pti_bridge_irq_rx_ready,
-	.irq_err_enable = NULL,
+	.irq_err_enable = uart_pti_bridge_irq_err_enable,
-	.irq_err_disable = NULL,
+	.irq_err_disable = uart_pti_bridge_irq_err_disable,
-	.irq_is_pending = NULL,
+	.irq_is_pending = uart_pti_bridge_irq_is_pending,
-	.irq_update = NULL,
+	.irq_update = uart_pti_bridge_irq_update,
-	.irq_callback_set = NULL,
+	.irq_callback_set = uart_pti_bridge_callback_set,
 #endif
 };
 
@@ -107,7 +332,7 @@ static DEVICE_API(uart, uart_interrupt_poll_bridge_api) = {
     static const struct uart_pti_bridge_config uart_pti_bridge_config_##inst = {						\
         .uart = DEVICE_DT_GET(DT_INST_PHANDLE(inst, uart)),												\
         COND_CODE_1(CONFIG_UART_INTERRUPT_DRIVEN, (														\
-            .timer = DEVICE_DT_GET(DT_INST_PHANDLE(inst, timer)),										\
+            .counter = DEVICE_DT_GET(DT_INST_PHANDLE(inst, counter)),									\
             .interrupt_line = DT_INST_IRQN(inst),														\
         ), ())																							\
     };																									\

modules/uart-interrupt-poll-bridge/dts/bindings/interrupt-poll-bridge.yaml

@@ -9,7 +9,7 @@ properties:
   interrupts:
     type: array
     required: true
-  timer:
+  counter:
     type: phandle
     required: true
   uart:

prj.conf

@@ -1,2 +1,8 @@
 CONFIG_UART_INTERRUPT_DRIVEN=y
 CONFIG_COUNTER=y
+
+# Disable compiler optimization
+CONFIG_DEBUG=y
+CONFIG_NO_OPTIMIZATIONS=y
+CONFIG_THREAD_RUNTIME_STATS=y
+CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS=y

src/main.cpp

@@ -5,17 +5,91 @@
 const struct device *test_uart = DEVICE_DT_GET(DT_ALIAS(testuart));
 
 
+// TEST GENERATED CODE START
+#include <zephyr/sys/ring_buffer.h>
+#include <zephyr/spinlock.h>
+
+#define RX_BUF_SIZE 256
+#define TX_BUF_SIZE 256
+
+RING_BUF_DECLARE(rx_buf, RX_BUF_SIZE);
+RING_BUF_DECLARE(tx_buf, TX_BUF_SIZE);
+
+static struct k_spinlock uart_lock;
+
+static void uart_isr(const struct device *dev, void *user_data)
+{
+    uart_irq_update(dev);
+
+    if (uart_irq_rx_ready(dev)) {
+        uint8_t byte;
+        while (uart_fifo_read(dev, &byte, 1) == 1) {
+            k_spinlock_key_t key = k_spin_lock(&uart_lock);
+            ring_buf_put(&rx_buf, &byte, 1);
+            k_spin_unlock(&uart_lock, key);
+        }
+    }
+
+    if (uart_irq_tx_ready(dev)) {
+        uint8_t byte;
+        k_spinlock_key_t key = k_spin_lock(&uart_lock);
+        if (ring_buf_get(&tx_buf, &byte, 1) == 1) {
+            k_spin_unlock(&uart_lock, key);
+            uart_fifo_fill(dev, &byte, 1);
+        } else {
+            k_spin_unlock(&uart_lock, key);
+            uart_irq_tx_disable(dev);  // nothing left, stop firing
+        }
+    }
+}
+
+/* Call once at init */
+void uart_init(const struct device *dev)
+{
+    uart_irq_callback_set(dev, uart_isr);
+    uart_irq_rx_enable(dev);
+    /* TX IRQ is enabled on demand when we have data to send */
+}
+
+/* Write bytes to TX — call from thread context */
+int uart_write(const struct device *dev, const uint8_t *data, size_t len)
+{
+    k_spinlock_key_t key = k_spin_lock(&uart_lock);
+    uint32_t written = ring_buf_put(&tx_buf, data, len);
+    k_spin_unlock(&uart_lock, key);
+
+    uart_irq_tx_enable(dev);  // kick off TX if not already running
+    return written;
+}
+
+/* Read bytes from RX — call from thread context */
+int uart_read(const struct device *dev, uint8_t *data, size_t len)
+{
+    k_spinlock_key_t key = k_spin_lock(&uart_lock);
+    uint32_t read = ring_buf_get(&rx_buf, data, len);
+    k_spin_unlock(&uart_lock, key);
+    return read;
+}
+// TEST GENERATED CODE END
+
 
 int main(void) {
     
-    const char msg [] = "Hello World";
+    const uint8_t msg [] = "Hello World\r\n";
+
+    uart_irq_callback_set(test_uart, uart_isr);
 
     while (1) {
-        for (char c : msg) {
+        uart_write(test_uart, msg, sizeof(msg));
-            uart_poll_out(test_uart, c);
-        }
 
-        k_sleep(K_MSEC(100));
+        
+        k_thread_runtime_stats_t stats;
+        
+        k_thread_runtime_stats_all_get(&stats);
+        uint8_t buff[32];
+        sprintf((char*)&buff, "total cycles: %15llu\r\n", stats.execution_cycles);
+        uart_write(test_uart, buff, sizeof(buff));
+        k_sleep(K_MSEC(1000));
     }
     return 0;
 }