path: root/drivers/iio/light/ltr501.c

/*
 * ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
 *
 * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * 7-bit I2C slave address 0x23
 *
 * TODO: IR LED characteristics
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/acpi.h>

#include <linux/iio/iio.h>
#include <linux/iio/events.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>

#define LTR501_DRV_NAME "ltr501"

#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
#define LTR501_PS_CONTR 0x81 /* PS operation mode */
#define LTR501_PS_MEAS_RATE 0x84 /* measurement rate*/
#define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/
#define LTR501_PART_ID 0x86
#define LTR501_MANUFAC_ID 0x87
#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
#define LTR501_ALS_PS_STATUS 0x8c
#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
#define LTR501_INTR 0x8f /* output mode, polarity, mode */
#define LTR501_PS_THRESH_UP 0x90 /* 11 bit, ps upper threshold */
#define LTR501_PS_THRESH_LOW 0x92 /* 11 bit, ps lower threshold */
#define LTR501_ALS_THRESH_UP 0x97 /* 16 bit, ALS upper threshold */
#define LTR501_ALS_THRESH_LOW 0x99 /* 16 bit, ALS lower threshold */
#define LTR501_INTR_PRST 0x9e /* ps thresh, als thresh */
#define LTR501_MAX_REG 0x9f

#define LTR501_ALS_CONTR_SW_RESET BIT(2)
#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
#define LTR501_CONTR_PS_GAIN_SHIFT 2
#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
#define LTR501_CONTR_ACTIVE BIT(1)

#define LTR501_STATUS_ALS_INTR BIT(3)
#define LTR501_STATUS_ALS_RDY BIT(2)
#define LTR501_STATUS_PS_INTR BIT(1)
#define LTR501_STATUS_PS_RDY BIT(0)

#define LTR501_PS_DATA_MASK 0x7ff
#define LTR501_PS_THRESH_MASK 0x7ff
#define LTR501_ALS_THRESH_MASK 0xffff

#define LTR501_ALS_DEF_PERIOD 500000
#define LTR501_PS_DEF_PERIOD 100000

#define LTR501_REGMAP_NAME "ltr501_regmap"

#define LTR501_LUX_CONV(vis_coeff, vis_data, ir_coeff, ir_data) \
			((vis_coeff * vis_data) - (ir_coeff * ir_data))

static const int int_time_mapping[] = {100000, 50000, 200000, 400000};

static const struct reg_field reg_field_it =
				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
static const struct reg_field reg_field_als_intr =
				REG_FIELD(LTR501_INTR, 1, 1);
static const struct reg_field reg_field_ps_intr =
				REG_FIELD(LTR501_INTR, 0, 0);
static const struct reg_field reg_field_als_rate =
				REG_FIELD(LTR501_ALS_MEAS_RATE, 0, 2);
static const struct reg_field reg_field_ps_rate =
				REG_FIELD(LTR501_PS_MEAS_RATE, 0, 3);
static const struct reg_field reg_field_als_prst =
				REG_FIELD(LTR501_INTR_PRST, 0, 3);
static const struct reg_field reg_field_ps_prst =
				REG_FIELD(LTR501_INTR_PRST, 4, 7);

struct ltr501_samp_table {
	int freq_val;  /* repetition frequency in micro HZ*/
	int time_val; /* repetition rate in micro seconds */
};

#define LTR501_RESERVED_GAIN -1

enum {
	ltr501 = 0,
	ltr559,
	ltr301,
};

struct ltr501_gain {
	int scale;
	int uscale;
};

static struct ltr501_gain ltr501_als_gain_tbl[] = {
	{1, 0},
	{0, 5000},
};

static struct ltr501_gain ltr559_als_gain_tbl[] = {
	{1, 0},
	{0, 500000},
	{0, 250000},
	{0, 125000},
	{LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
	{LTR501_RESERVED_GAIN, LTR501_RESERVED_GAIN},
	{0, 20000},
	{0, 10000},
};

static struct ltr501_gain ltr501_ps_gain_tbl[] = {
	{1, 0},
	{0, 250000},
	{0, 125000},
	{0, 62500},
};

static struct ltr501_gain ltr559_ps_gain_tbl[] = {
	{0, 62500}, /* x16 gain */
	{0, 31250}, /* x32 gain */
	{0, 15625}, /* bits X1 are for x64 gain */
	{0, 15624},
};

struct ltr501_chip_info {
	u8 partid;
	struct ltr501_gain *als_gain;
	int als_gain_tbl_size;
	struct ltr501_gain *ps_gain;
	int ps_gain_tbl_size;
	u8 als_mode_active;
	u8 als_gain_mask;
	u8 als_gain_shift;
	struct iio_chan_spec const *channels;
	const int no_channels;
	const struct iio_info *info;
	const struct iio_info *info_no_irq;
};

struct ltr501_data {
	struct i2c_client *client;
	struct mutex lock_als, lock_ps;
	struct ltr501_chip_info *chip_info;
	u8 als_contr, ps_contr;
	int als_period, ps_period; /* period in micro seconds */
	struct regmap *regmap;
	struct regmap_field *reg_it;
	struct regmap_field *reg_als_intr;
	struct regmap_field *reg_ps_intr;
	struct regmap_field *reg_als_rate;
	struct regmap_field *reg_ps_rate;
	struct regmap_field *reg_als_prst;
	struct regmap_field *reg_ps_prst;
};

static const struct ltr501_samp_table ltr501_als_samp_table[] = {
			{20000000, 50000}, {10000000, 100000},
			{5000000, 200000}, {2000000, 500000},
			{1000000, 1000000}, {500000, 2000000},
			{500000, 2000000}, {500000, 2000000}
};

static const struct ltr501_samp_table ltr501_ps_samp_table[] = {
			{20000000, 50000}, {14285714, 70000},
			{10000000, 100000}, {5000000, 2