path: root/drivers/iio/light/tsl2591.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2021 Joe Sandom <joe.g.sandom@gmail.com>
 *
 * Datasheet: https://ams.com/tsl25911#tab/documents
 *
 * Device driver for the TAOS TSL2591. This is a very-high sensitivity
 * light-to-digital converter that transforms light intensity into a digital
 * signal.
 */

#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/sysfs.h>

#include <linux/unaligned.h>

#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

/* ADC integration time, field value to time in ms */
#define TSL2591_FVAL_TO_MSEC(x) (((x) + 1) * 100)
/* ADC integration time, field value to time in seconds */
#define TSL2591_FVAL_TO_SEC(x) ((x) + 1)
/* ADC integration time, time in seconds to field value */
#define TSL2591_SEC_TO_FVAL(x) ((x) - 1)

/* TSL2591 register set */
#define TSL2591_ENABLE      0x00
#define TSL2591_CONTROL     0x01
#define TSL2591_AILTL       0x04
#define TSL2591_AILTH       0x05
#define TSL2591_AIHTL       0x06
#define TSL2591_AIHTH       0x07
#define TSL2591_NP_AILTL    0x08
#define TSL2591_NP_AILTH    0x09
#define TSL2591_NP_AIHTL    0x0A
#define TSL2591_NP_AIHTH    0x0B
#define TSL2591_PERSIST     0x0C
#define TSL2591_PACKAGE_ID  0x11
#define TSL2591_DEVICE_ID   0x12
#define TSL2591_STATUS      0x13
#define TSL2591_C0_DATAL    0x14
#define TSL2591_C0_DATAH    0x15
#define TSL2591_C1_DATAL    0x16
#define TSL2591_C1_DATAH    0x17

/* TSL2591 command register definitions */
#define TSL2591_CMD_NOP             0xA0
#define TSL2591_CMD_SF_INTSET       0xE4
#define TSL2591_CMD_SF_CALS_I       0xE5
#define TSL2591_CMD_SF_CALS_NPI     0xE7
#define TSL2591_CMD_SF_CNP_ALSI     0xEA

/* TSL2591 enable register definitions */
#define TSL2591_PWR_ON              0x01
#define TSL2591_PWR_OFF             0x00
#define TSL2591_ENABLE_ALS          0x02
#define TSL2591_ENABLE_ALS_INT      0x10
#define TSL2591_ENABLE_SLEEP_INT    0x40
#define TSL2591_ENABLE_NP_INT       0x80

/* TSL2591 control register definitions */
#define TSL2591_CTRL_ALS_INTEGRATION_100MS  0x00
#define TSL2591_CTRL_ALS_INTEGRATION_200MS  0x01
#define TSL2591_CTRL_ALS_INTEGRATION_300MS  0x02
#define TSL2591_CTRL_ALS_INTEGRATION_400MS  0x03
#define TSL2591_CTRL_ALS_INTEGRATION_500MS  0x04
#define TSL2591_CTRL_ALS_INTEGRATION_600MS  0x05
#define TSL2591_CTRL_ALS_LOW_GAIN           0x00
#define TSL2591_CTRL_ALS_MED_GAIN           0x10
#define TSL2591_CTRL_ALS_HIGH_GAIN          0x20
#define TSL2591_CTRL_ALS_MAX_GAIN           0x30
#define TSL2591_CTRL_SYS_RESET              0x80

/* TSL2591 persist register definitions */
#define TSL2591_PRST_ALS_INT_CYCLE_0        0x00
#define TSL2591_PRST_ALS_INT_CYCLE_ANY      0x01
#define TSL2591_PRST_ALS_INT_CYCLE_2        0x02
#define TSL2591_PRST_ALS_INT_CYCLE_3        0x03
#define TSL2591_PRST_ALS_INT_CYCLE_5        0x04
#define TSL2591_PRST_ALS_INT_CYCLE_10       0x05
#define TSL2591_PRST_ALS_INT_CYCLE_15       0x06
#define TSL2591_PRST_ALS_INT_CYCLE_20       0x07
#define TSL2591_PRST_ALS_INT_CYCLE_25       0x08
#define TSL2591_PRST_ALS_INT_CYCLE_30       0x09
#define TSL2591_PRST_ALS_INT_CYCLE_35       0x0A
#define TSL2591_PRST_ALS_INT_CYCLE_40       0x0B
#define TSL2591_PRST_ALS_INT_CYCLE_45       0x0C
#define TSL2591_PRST_ALS_INT_CYCLE_50       0x0D
#define TSL2591_PRST_ALS_INT_CYCLE_55       0x0E
#define TSL2591_PRST_ALS_INT_CYCLE_60       0x0F
#define TSL2591_PRST_ALS_INT_CYCLE_MAX      (BIT(4) - 1)

/* TSL2591 PID register mask */
#define TSL2591_PACKAGE_ID_MASK  GENMASK(5, 4)

/* TSL2591 ID register mask */
#define TSL2591_DEVICE_ID_MASK   GENMASK(7, 0)

/* TSL2591 status register masks */
#define TSL2591_STS_ALS_VALID_MASK   BIT(0)
#define TSL2591_STS_ALS_INT_MASK     BIT(4)
#define TSL2591_STS_NPERS_INT_MASK   BIT(5)
#define TSL2591_STS_VAL_HIGH_MASK    BIT(0)

/* TSL2591 constant values */
#define TSL2591_PACKAGE_ID_VAL  0x00
#define TSL2591_DEVICE_ID_VAL   0x50

/* Power off suspend delay time MS */
#define TSL2591_POWER_OFF_DELAY_MS   2000

/* TSL2591 default values */
#define TSL2591_DEFAULT_ALS_INT_TIME          TSL2591_CTRL_ALS_INTEGRATION_300MS
#define TSL2591_DEFAULT_ALS_GAIN              TSL2591_CTRL_ALS_MED_GAIN
#define TSL2591_DEFAULT_ALS_PERSIST           TSL2591_PRST_ALS_INT_CYCLE_ANY
#define TSL2591_DEFAULT_ALS_LOWER_THRESH      100
#define TSL2591_DEFAULT_ALS_UPPER_THRESH      1500

/* TSL2591 number of data registers */
#define TSL2591_NUM_DATA_REGISTERS     4

/* TSL2591 number of valid status reads on ADC complete */
#define TSL2591_ALS_STS_VALID_COUNT    10

/* TSL2591 delay period between polls when checking for ALS valid flag */
#define TSL2591_DELAY_PERIOD_US        10000

/* TSL2591 maximum values */
#define TSL2591_MAX_ALS_INT_TIME_MS    600
#define TSL2591_ALS_MAX_VALUE	       (BIT(16) - 1)

/*
 * LUX calculations;
 * AGAIN values from Adafruit's TSL2591 Arduino library
 * https://github.com/adafruit/Adafruit_TSL2591_Library
 */
#define TSL2591_CTRL_ALS_LOW_GAIN_MULTIPLIER   1
#define TSL2591_CTRL_ALS_MED_GAIN_MULTIPLIER   25
#define TSL2591_CTRL_ALS_HIGH_GAIN_MULTIPLIER  428
#define TSL2591_CTRL_ALS_MAX_GAIN_MULTIPLIER   9876
#define TSL2591_LUX_COEFFICIENT                408

struct tsl2591_als_settings {
	u16 als_lower_thresh;
	u16 als_upper_thresh;
	u8 als_int_time;
	u8 als_persist;
	u8 als_gain;
};

struct tsl2591_chip {
	struct tsl2591_als_settings als_settings;
	struct i2c_client *client;
	/*
	 * Keep als_settings in sync with hardware state
	 * and ensure multiple readers are serialized.
	 */
	struct mutex als_mutex;
	bool events_enabled;
};

/*
 * Period table is ALS persist cycle x integration time setting
 * Integration times: 100ms, 200ms, 300ms, 400ms, 500ms, 600ms
 * ALS cycles: 1, 2, 3, 5, 10, 20, 25, 30, 35, 40, 45, 50, 55, 60
 */
static const char * const tsl2591_als_period_list[] = {
	"0.1 0.2 0.3 0.5 1.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0",
	"0.2 0.4 0.6 1.0 2.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0",
	"0.3 0.6 0.9 1.5 3.0 6.0 7.5 9.0 10.5 12.0 13.5 15.0 16.5 18.0",
	"0.4 0.8 1.2 2.0 4.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0",
	"0.5 1.0 1.5 2.5 5.0 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0",
	"0.6 1.2 1.8 3.0 6.0 12.0 15.0 18.0 21.0 24.0 27.0 30.0 33.0 36.0",
};

static const int tsl2591_int_time_available[] = {
	1, 2, 3, 4, 5, 6,
};

static const int tsl2591_calibscale_available[] = {