text: /*
   * Copyright (c) 2018 Nordic Semiconductor ASA
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  #include <logging/log_backend.h>
  #include <logging/log_core.h>
  #include <logging/log_msg.h>
  #include <logging/log_output.h>
  #include <logging/log_backend_std.h>
  #include <device.h>
  #include <drivers/uart.h>
  #include <sys/__assert.h>
  
  static const struct device *uart_dev;
  
  static int char_out(uint8_t *data, size_t length, void *ctx)
  {
  	ARG_UNUSED(ctx);
  
  	for (size_t i = 0; i < length; i++) {
  		uart_poll_out(uart_dev, data[i]);
  	}
  
  	return length;
  }
  
  static uint8_t uart_output_buf;
  
  LOG_OUTPUT_DEFINE(log_output_uart, char_out, &uart_output_buf, 1);
  
  static void put(const struct log_backend *const backend,
  		struct log_msg *msg)
  {
  	uint32_t flag = IS_ENABLED(CONFIG_LOG_BACKEND_UART_SYST_ENABLE) ?
  		LOG_OUTPUT_FLAG_FORMAT_SYST : 0;
  
  	log_backend_std_put(&log_output_uart, flag, msg);
  }
  
  static void process(const struct log_backend *const backend,
  		union log_msg2_generic *msg)
  {
  	uint32_t flags = log_backend_std_get_flags();
  
  	log_output_msg2_process(&log_output_uart, &msg->log, flags);
  }
  
  static void log_backend_uart_init(struct log_backend const *const backend)
  {
  	uart_dev = device_get_binding(CONFIG_UART_CONSOLE_ON_DEV_NAME);
  	__ASSERT_NO_MSG((void *)uart_dev);
  }
  
  static void panic(struct log_backend const *const backend)
  {
  	log_backend_std_panic(&log_output_uart);
  }
  
  static void dropped(const struct log_backend *const backend, uint32_t cnt)
  {
  	ARG_UNUSED(backend);
  
  	log_backend_std_dropped(&log_output_uart, cnt);
  }
  
  static void sync_string(const struct log_backend *const backend,
  		     struct log_msg_ids src_level, uint32_t timestamp,
  		     const char *fmt, va_list ap)
  {
  	uint32_t flag = IS_ENABLED(CONFIG_LOG_BACKEND_UART_SYST_ENABLE) ?
  		LOG_OUTPUT_FLAG_FORMAT_SYST : 0;
  
  	log_backend_std_sync_string(&log_output_uart, flag, src_level,
  				    timestamp, fmt, ap);
  }
  
  static void sync_hexdump(const struct log_backend *const backend,
  			 struct log_msg_ids src_level, uint32_t timestamp,
  			 const char *metadata, const uint8_t *data, uint32_t length)
  {
  	uint32_t flag = IS_ENABLED(CONFIG_LOG_BACKEND_UART_SYST_ENABLE) ?
  		LOG_OUTPUT_FLAG_FORMAT_SYST : 0;
  
  	log_backend_std_sync_hexdump(&log_output_uart, flag, src_level,
  				     timestamp, metadata, data, length);
  }
  
  const struct log_backend_api log_backend_uart_api = {
  	.process = IS_ENABLED(CONFIG_LOG2) ? process : NULL,
  	.put = IS_ENABLED(CONFIG_LOG_MODE_DEFERRED) ? put : NULL,
  	.put_sync_string = IS_ENABLED(CONFIG_LOG_MODE_IMMEDIATE) ?
  			sync_string : NULL,
  	.put_sync_hexdump = IS_ENABLED(CONFIG_LOG_MODE_IMMEDIATE) ?
  			sync_hexdump : NULL,
  	.panic = panic,
  	.init = log_backend_uart_init,
  	.dropped = IS_ENABLED(CONFIG_LOG_IMMEDIATE) ? NULL : dropped,
  };
  
  LOG_BACKEND_DEFINE(log_backend_uart, log_backend_uart_api, true);
  