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hekate/bdk/input/als.c
CTCaer 185526d134 Introducing Bootloader Development Kit (BDK)
BDK will allow developers to use the full collection of drivers,
with limited editing, if any, for making payloads for Nintendo Switch.

Using a single source for everything will also help decoupling
Switch specific code and easily port it to other Tegra X1/X1+ platforms.
And maybe even to lower targets.

Everything is now centrilized into bdk folder.
Every module or project can utilize it by simply including it.

This is just the start and it will continue to improve.
2020-06-14 15:25:21 +03:00

118 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;
}