text: /*
   * Copyright (c) 2019 Peter Bigot Consulting, LLC
   * Copyright (c) 2016 Intel Corporation
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  #define DT_DRV_COMPAT microchip_mcp9808
  
  #include <errno.h>
  
  #include <kernel.h>
  #include <drivers/i2c.h>
  #include <init.h>
  #include <sys/byteorder.h>
  #include <sys/__assert.h>
  #include <logging/log.h>
  
  #include "mcp9808.h"
  
  LOG_MODULE_REGISTER(MCP9808, CONFIG_SENSOR_LOG_LEVEL);
  
  int mcp9808_reg_read(struct device *dev, u8_t reg, u16_t *val)
  {
  	const struct mcp9808_data *data = dev->driver_data;
  	const struct mcp9808_config *cfg = dev->config->config_info;
  	int rc = i2c_write_read(data->i2c_master, cfg->i2c_addr,
  				&reg, sizeof(reg),
  				val, sizeof(*val));
  
  	if (rc == 0) {
  		*val = sys_be16_to_cpu(*val);
  	}
  
  	return rc;
  }
  
  static int mcp9808_sample_fetch(struct device *dev, enum sensor_channel chan)
  {
  	struct mcp9808_data *data = dev->driver_data;
  
  	__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_AMBIENT_TEMP);
  
  	return mcp9808_reg_read(dev, MCP9808_REG_TEMP_AMB, &data->reg_val);
  }
  
  static int mcp9808_channel_get(struct device *dev,
  			       enum sensor_channel chan,
  			       struct sensor_value *val)
  {
  	const struct mcp9808_data *data = dev->driver_data;
  	int temp = mcp9808_temp_signed_from_reg(data->reg_val);
  
  	__ASSERT_NO_MSG(chan == SENSOR_CHAN_AMBIENT_TEMP);
  
  	val->val1 = temp / MCP9808_TEMP_SCALE_CEL;
  	temp -= val->val1 * MCP9808_TEMP_SCALE_CEL;
  	val->val2 = (temp * 1000000) / MCP9808_TEMP_SCALE_CEL;
  
  	return 0;
  }
  
  static const struct sensor_driver_api mcp9808_api_funcs = {
  	.sample_fetch = mcp9808_sample_fetch,
  	.channel_get = mcp9808_channel_get,
  #ifdef CONFIG_MCP9808_TRIGGER
  	.attr_set = mcp9808_attr_set,
  	.trigger_set = mcp9808_trigger_set,
  #endif /* CONFIG_MCP9808_TRIGGER */
  };
  
  int mcp9808_init(struct device *dev)
  {
  	struct mcp9808_data *data = dev->driver_data;
  	const struct mcp9808_config *cfg = dev->config->config_info;
  	int rc = 0;
  
  	data->i2c_master = device_get_binding(cfg->i2c_bus);
  	if (!data->i2c_master) {
  		LOG_DBG("mcp9808: i2c master not found: %s", cfg->i2c_bus);
  		return -EINVAL;
  	}
  
  #ifdef CONFIG_MCP9808_TRIGGER
  	rc = mcp9808_setup_interrupt(dev);
  #endif /* CONFIG_MCP9808_TRIGGER */
  
  	return rc;
  }
  
  static struct mcp9808_data mcp9808_data;
  static const struct mcp9808_config mcp9808_cfg = {
  	.i2c_bus = DT_INST_BUS_LABEL(0),
  	.i2c_addr = DT_INST_REG_ADDR(0),
  #ifdef CONFIG_MCP9808_TRIGGER
  	.alert_pin = DT_INST_GPIO_PIN(0, int_gpios),
  	.alert_flags = DT_INST_GPIO_FLAGS(0, int_gpios),
  	.alert_controller = DT_INST_GPIO_LABEL(0, int_gpios),
  #endif /* CONFIG_MCP9808_TRIGGER */
  };
  
  DEVICE_AND_API_INIT(mcp9808, DT_INST_LABEL(0), mcp9808_init,
  		    &mcp9808_data, &mcp9808_cfg, POST_KERNEL,
  		    CONFIG_SENSOR_INIT_PRIORITY, &mcp9808_api_funcs);
  