path: root/drivers/iio/light/veml6030.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * VEML6030, VMEL6035 and VEML7700 Ambient Light Sensors
 *
 * Copyright (c) 2019, Rishi Gupta <gupt21@gmail.com>
 *
 * VEML6030:
 * Datasheet: https://www.vishay.com/docs/84366/veml6030.pdf
 * Appnote-84367: https://www.vishay.com/docs/84367/designingveml6030.pdf
 *
 * VEML6035:
 * Datasheet: https://www.vishay.com/docs/84889/veml6035.pdf
 * Appnote-84944: https://www.vishay.com/docs/84944/designingveml6035.pdf
 *
 * VEML7700:
 * Datasheet: https://www.vishay.com/docs/84286/veml7700.pdf
 * Appnote-84323: https://www.vishay.com/docs/84323/designingveml7700.pdf
 */

#include <linux/bitfield.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/regmap.h>
#include <linux/interrupt.h>
#include <linux/pm_runtime.h>
#include <linux/units.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/iio-gts-helper.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

/* Device registers */
#define VEML6030_REG_ALS_CONF   0x00
#define VEML6030_REG_ALS_WH     0x01
#define VEML6030_REG_ALS_WL     0x02
#define VEML6030_REG_ALS_PSM    0x03
#define VEML6030_REG_ALS_DATA   0x04
#define VEML6030_REG_WH_DATA    0x05
#define VEML6030_REG_ALS_INT    0x06
#define VEML6030_REG_DATA(ch)   (VEML6030_REG_ALS_DATA + (ch))

/* Bit masks for specific functionality */
#define VEML6030_ALS_IT       GENMASK(9, 6)
#define VEML6030_PSM          GENMASK(2, 1)
#define VEML6030_ALS_PERS     GENMASK(5, 4)
#define VEML6030_ALS_GAIN     GENMASK(12, 11)
#define VEML6030_PSM_EN       BIT(0)
#define VEML6030_INT_TH_LOW   BIT(15)
#define VEML6030_INT_TH_HIGH  BIT(14)
#define VEML6030_ALS_INT_EN   BIT(1)
#define VEML6030_ALS_SD       BIT(0)

#define VEML6035_GAIN_M       GENMASK(12, 10)
#define VEML6035_GAIN         BIT(10)
#define VEML6035_DG           BIT(11)
#define VEML6035_SENS         BIT(12)
#define VEML6035_INT_CHAN     BIT(3)
#define VEML6035_CHAN_EN      BIT(2)

/* Regfields */
#define VEML6030_GAIN_RF      REG_FIELD(VEML6030_REG_ALS_CONF, 11, 12)
#define VEML6030_IT_RF        REG_FIELD(VEML6030_REG_ALS_CONF, 6, 9)

#define VEML6035_GAIN_RF      REG_FIELD(VEML6030_REG_ALS_CONF, 10, 12)

/* Maximum scales x 10000 to work with integers */
#define VEML6030_MAX_SCALE    21504
#define VEML6035_MAX_SCALE    4096

enum veml6030_scan {
	VEML6030_SCAN_ALS,
	VEML6030_SCAN_WH,
	VEML6030_SCAN_TIMESTAMP,
};

struct veml6030_rf {
	struct regmap_field *it;
	struct regmap_field *gain;
};

struct veml603x_chip {
	const char *name;
	const struct iio_chan_spec *channels;
	const int num_channels;
	const struct reg_field gain_rf;
	const struct reg_field it_rf;
	const int max_scale;
	int (*hw_init)(struct iio_dev *indio_dev, struct device *dev);
	int (*set_info)(struct iio_dev *indio_dev);
};

/*
 * The resolution depends on both gain and integration time. The
 * cur_resolution stores one of the resolution mentioned in the
 * table during startup and gets updated whenever integration time
 * or gain is changed.
 *
 * Table 'resolution and maximum detection range' in the appnotes
 * is visualized as a 2D array. The cur_gain stores index of gain
 * in this table (0-3 for VEML6030, 0-5 for VEML6035) while the
 * cur_integration_time holds index of integration time (0-5).
 */
struct veml6030_data {
	struct i2c_client *client;
	struct regmap *regmap;
	struct veml6030_rf rf;
	const struct veml603x_chip *chip;
	struct iio_gts gts;

};

#define VEML6030_SEL_IT_25MS  0x0C
#define VEML6030_SEL_IT_50MS  0x08
#define VEML6030_SEL_IT_100MS 0x00
#define VEML6030_SEL_IT_200MS 0x01
#define VEML6030_SEL_IT_400MS 0x02
#define VEML6030_SEL_IT_800MS 0x03
static const struct iio_itime_sel_mul veml6030_it_sel[] = {
	GAIN_SCALE_ITIME_US(25000, VEML6030_SEL_IT_25MS, 1),
	GAIN_SCALE_ITIME_US(50000, VEML6030_SEL_IT_50MS, 2),
	GAIN_SCALE_ITIME_US(100000, VEML6030_SEL_IT_100MS, 4),
	GAIN_SCALE_ITIME_US(200000, VEML6030_SEL_IT_200MS, 8),
	GAIN_SCALE_ITIME_US(400000, VEML6030_SEL_IT_400MS, 16),
	GAIN_SCALE_ITIME_US(800000, VEML6030_SEL_IT_800MS, 32),
};

/* Gains are multiplied by 8 to work with integers. The values in the
 * iio-gts tables don't need corrections because the maximum value of
 * the scale refers to GAIN = x1, and the rest of the values are
 * obtained from the resulting linear function.
 */
#define VEML6030_SEL_MILLI_GAIN_X125  2
#define VEML6030_SEL_MILLI_GAIN_X250  3
#define VEML60