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/* Copyright 2015 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* TI OPT3001 light sensor driver
*/
#include "driver/als_opt3001.h"
#include "i2c.h"
/**
* Read register from OPT3001 light sensor.
*/
static int opt3001_i2c_read(const int reg, int *data_ptr)
{
int ret;
ret = i2c_read16(I2C_PORT_ALS, OPT3001_I2C_ADDR, reg, data_ptr);
if (!ret)
*data_ptr = ((*data_ptr << 8) & 0xFF00) |
((*data_ptr >> 8) & 0x00FF);
return ret;
}
/**
* Write register to OPT3001 light sensor.
*/
static int opt3001_i2c_write(const int reg, int data)
{
data = ((data << 8) & 0xFF00) | ((data >> 8) & 0x00FF);
return i2c_write16(I2C_PORT_ALS, OPT3001_I2C_ADDR, reg, data);
}
/**
* Initialise OPT3001 light sensor.
*/
int opt3001_init(void)
{
int data;
int ret;
ret = opt3001_i2c_read(OPT3001_REG_MAN_ID, &data);
if (ret)
return ret;
if (data != OPT3001_MANUFACTURER_ID)
return EC_ERROR_UNKNOWN;
ret = opt3001_i2c_read(OPT3001_REG_DEV_ID, &data);
if (ret)
return ret;
if (data != OPT3001_DEVICE_ID)
return EC_ERROR_UNKNOWN;
/*
* [15:12]: 0101b Automatic full scale (1310.40lux, 0.32lux/lsb)
* [11] : 1b Conversion time 800ms
* [10:9] : 10b Continuous Mode of conversion operation
* [4] : 1b Latched window-style comparison operation
*/
return opt3001_i2c_write(OPT3001_REG_CONFIGURE, 0x5C10);
}
/**
* Read OPT3001 light sensor data.
*/
int opt3001_read_lux(int *lux, int af)
{
int ret;
int data;
ret = opt3001_i2c_read(OPT3001_REG_RESULT, &data);
if (ret)
return ret;
/*
* The default power-on values will give 12 bits of precision:
* 0x0000-0x0fff indicates 0 to 1310.40 lux. We multiply the sensor
* value by a scaling factor to account for attenuation by glass,
* tinting, etc.
*/
/*
* lux = 2EXP[3:0] × R[11:0] / 100
*/
*lux = (1 << ((data & 0xF000) >> 12)) * (data & 0x0FFF) * af / 100;
return EC_SUCCESS;
}
#ifdef CONFIG_CMD_I2C_STRESS_TEST_ALS
struct i2c_stress_test_dev opt3001_i2c_stress_test_dev = {
.reg_info = {
.read_reg = OPT3001_REG_DEV_ID,
.read_val = OPT3001_DEVICE_ID,
.write_reg = OPT3001_REG_INT_LIMIT_LSB,
},
.i2c_read_dev = &opt3001_i2c_read,
.i2c_write_dev = &opt3001_i2c_write,
};
#endif /* CONFIG_CMD_I2C_STRESS_TEST_ALS */
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