| /* sensor_mcp9808.c - Driver for MCP9808 temperature sensor */ |
| |
| /* |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <errno.h> |
| |
| #include <nanokernel.h> |
| #include <i2c.h> |
| #include <init.h> |
| #include <misc/byteorder.h> |
| #include <misc/__assert.h> |
| |
| #include "sensor_mcp9808.h" |
| |
| |
| int mcp9808_reg_read(struct mcp9808_data *data, uint8_t reg, uint16_t *val) |
| { |
| struct i2c_msg msgs[2] = { |
| { |
| .buf = ®, |
| .len = 1, |
| .flags = I2C_MSG_WRITE | I2C_MSG_RESTART, |
| }, |
| { |
| .buf = (uint8_t *)val, |
| .len = 2, |
| .flags = I2C_MSG_READ | I2C_MSG_STOP, |
| }, |
| }; |
| |
| if (i2c_transfer(data->i2c_master, msgs, 2, data->i2c_slave_addr) |
| < 0) { |
| return -EIO; |
| } |
| |
| *val = sys_be16_to_cpu(*val); |
| |
| return 0; |
| } |
| |
| static int mcp9808_sample_fetch(struct device *dev, enum sensor_channel chan) |
| { |
| struct mcp9808_data *data = dev->driver_data; |
| |
| __ASSERT(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_TEMP); |
| |
| return mcp9808_reg_read(data, MCP9808_REG_TEMP_AMB, &data->reg_val); |
| } |
| |
| static int mcp9808_channel_get(struct device *dev, |
| enum sensor_channel chan, |
| struct sensor_value *val) |
| { |
| struct mcp9808_data *data = dev->driver_data; |
| |
| __ASSERT(chan == SENSOR_CHAN_TEMP); |
| |
| val->type = SENSOR_VALUE_TYPE_INT_PLUS_MICRO; |
| |
| val->val1 = (data->reg_val & MCP9808_TEMP_INT_MASK) >> |
| MCP9808_TEMP_INT_SHIFT; |
| val->val2 = (data->reg_val & MCP9808_TEMP_FRAC_MASK) * 62500; |
| |
| if (data->reg_val & MCP9808_SIGN_BIT) { |
| val->val1 -= 256; |
| } |
| |
| return 0; |
| } |
| |
| static struct sensor_driver_api mcp9808_api_funcs = { |
| .sample_fetch = mcp9808_sample_fetch, |
| .channel_get = mcp9808_channel_get, |
| .attr_set = mcp9808_attr_set, |
| .trigger_set = mcp9808_trigger_set, |
| }; |
| |
| int mcp9808_init(struct device *dev) |
| { |
| struct mcp9808_data *data = dev->driver_data; |
| |
| data->i2c_master = device_get_binding(CONFIG_MCP9808_I2C_DEV_NAME); |
| if (!data->i2c_master) { |
| SYS_LOG_DBG("mcp9808: i2c master not found: %s", |
| CONFIG_MCP9808_I2C_DEV_NAME); |
| return -EINVAL; |
| } |
| |
| data->i2c_slave_addr = CONFIG_MCP9808_I2C_ADDR; |
| |
| mcp9808_setup_interrupt(dev); |
| |
| dev->driver_api = &mcp9808_api_funcs; |
| |
| return 0; |
| } |
| |
| struct mcp9808_data mcp9808_data; |
| |
| DEVICE_INIT(mcp9808, CONFIG_MCP9808_DEV_NAME, mcp9808_init, &mcp9808_data, |
| NULL, SECONDARY, CONFIG_MCP9808_INIT_PRIORITY); |