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hekate/nyx/nyx_gui/input/als.c
2019-10-18 18:02:06 +03:00

117 lines
3.8 KiB
C

/*
* Ambient light sensor driver for Nintendo Switch's Rohm BH1730
*
* Copyright (c) 2018 CTCaer
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "als.h"
#include "../power/max77620.h"
#include "../soc/clock.h"
#include "../soc/i2c.h"
#include "../soc/pinmux.h"
#include "../utils/util.h"
#define HOS_GAIN BH1730_GAIN_64X
#define HOS_ITIME 38
void set_als_cfg(als_table_t *als_val, u8 gain, u8 itime)
{
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_GAIN_REG), gain);
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_TIMING_REG), (256 - itime));
als_val->gain = gain;
als_val->itime = itime;
}
void get_als_lux(als_table_t *als_val)
{
u32 data[2];
float pre_gain_lux;
float visible_light;
float ir_light;
float light_ratio;
u8 adc_ready = 0;
u8 retries = 100;
const float als_gain_idx_tbl[4] = { 1.0, 2.0, 64.0, 128.0 };
const float als_norm_res = 100.0;
const float als_multiplier = 3.6;
const float als_tint = 2.7;
// Wait for ADC to prepare new data.
while (!(adc_ready & BH1730_CTL_ADC_VALID) && retries)
{
retries--;
adc_ready = i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_CONTROL_REG));
}
// Get visible and ir light raw data.
data[0] = i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_DATA0LOW_REG)) +
(i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_DATA0HIGH_REG)) << 8);
data[1] = i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_DATA1LOW_REG)) +
(i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_DATA1HIGH_REG)) << 8);
als_val->over_limit = data[0] > 65534 || data[1] > 65534;
als_val->vi_light = data[0];
als_val->ir_light = data[1];
if (!data[0] || !retries)
{
als_val->lux = 0.0;
return;
}
visible_light = (float)data[0];
ir_light = (float)data[1];
light_ratio = (float)data[1] / (float)data[0];
// The following are specific to the light filter Switch uses.
if (light_ratio < 0.5)
pre_gain_lux = visible_light * 5.002 - ir_light * 7.502;
else if (light_ratio < 0.754)
pre_gain_lux = visible_light * 2.250 - ir_light * 2.000;
else if (light_ratio < 1.029)
pre_gain_lux = visible_light * 1.999 - ir_light * 1.667;
else if (light_ratio < 1.373)
pre_gain_lux = visible_light * 0.884 - ir_light * 0.583;
else if (light_ratio < 1.879)
pre_gain_lux = visible_light * 0.309 - ir_light * 0.165;
else pre_gain_lux = 0.0;
als_val->lux = (pre_gain_lux / als_gain_idx_tbl[als_val->gain]) * (als_norm_res / ((float)als_val->itime * als_tint)) * als_multiplier;
}
u8 als_init(als_table_t *als_val)
{
pinmux_config_i2c(I2C_2);
clock_enable_i2c(I2C_2);
i2c_init(I2C_2);
max77620_regulator_set_volt_and_flags(REGULATOR_LDO6, 2900000, MAX77620_POWER_MODE_NORMAL);
i2c_send_byte(I2C_5, MAX77620_I2C_ADDR, MAX77620_REG_LDO6_CFG2, 0xD8 | MAX77620_LDO_CFG2_ADE_MASK);
u8 id = i2c_recv_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(0x12));
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_SPEC(BH1730_SPECCMD_RESET), 0);
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_GAIN_REG), HOS_GAIN);
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_TIMING_REG), (256 - HOS_ITIME));
i2c_send_byte(I2C_2, BH1730_I2C_ADDR, BH1730_ADDR(BH1730_CONTROL_REG), BH1730_CTL_POWER_ON | BH1730_CTL_ADC_EN);
als_val->gain = HOS_GAIN;
als_val->itime = HOS_ITIME;
return id;
}