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/*
* MAX44000 Ambient and Infrared Proximity Sensor
*
* Copyright (c) 2016, Intel Corporation.
*
* 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.
*
* Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
*
* 7-bit I2C slave address 0x4a
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/acpi.h>
#define MAX44000_DRV_NAME "max44000"
/* Registers in datasheet order */
#define MAX44000_REG_STATUS 0x00
#define MAX44000_REG_CFG_MAIN 0x01
#define MAX44000_REG_CFG_RX 0x02
#define MAX44000_REG_CFG_TX 0x03
#define MAX44000_REG_ALS_DATA_HI 0x04
#define MAX44000_REG_ALS_DATA_LO 0x05
#define MAX44000_REG_PRX_DATA 0x16
#define MAX44000_REG_ALS_UPTHR_HI 0x06
#define MAX44000_REG_ALS_UPTHR_LO 0x07
#define MAX44000_REG_ALS_LOTHR_HI 0x08
#define MAX44000_REG_ALS_LOTHR_LO 0x09
#define MAX44000_REG_PST 0x0a
#define MAX44000_REG_PRX_IND 0x0b
#define MAX44000_REG_PRX_THR 0x0c
#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f
#define MAX44000_REG_TRIM_GAIN_IR 0x10
/* REG_CFG bits */
#define MAX44000_CFG_ALSINTE 0x01
#define MAX44000_CFG_PRXINTE 0x02
#define MAX44000_CFG_MASK 0x1c
#define MAX44000_CFG_MODE_SHUTDOWN 0x00
#define MAX44000_CFG_MODE_ALS_GIR 0x04
#define MAX44000_CFG_MODE_ALS_G 0x08
#define MAX44000_CFG_MODE_ALS_IR 0x0c
#define MAX44000_CFG_MODE_ALS_PRX 0x10
#define MAX44000_CFG_MODE_PRX 0x14
#define MAX44000_CFG_TRIM 0x20
/*
* Upper 4 bits are not documented but start as 1 on powerup
* Setting them to 0 causes proximity to misbehave so set them to 1
*/
#define MAX44000_REG_CFG_RX_DEFAULT 0xf0
/* REG_RX bits */
#define MAX44000_CFG_RX_ALSTIM_MASK 0x0c
#define MAX44000_CFG_RX_ALSTIM_SHIFT 2
#define MAX44000_CFG_RX_ALSPGA_MASK 0x03
#define MAX44000_CFG_RX_ALSPGA_SHIFT 0
/* REG_TX bits */
#define MAX44000_LED_CURRENT_MASK 0xf
#define MAX44000_LED_CURRENT_MAX 11
#define MAX44000_LED_CURRENT_DEFAULT 6
#define MAX44000_ALSDATA_OVERFLOW 0x4000
struct max44000_data {
struct mutex lock;
struct regmap *regmap;
};
/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
/* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */
static const int max44000_alspga_shift[] = {0, 2, 4, 7};
#define MAX44000_ALSPGA_MAX_SHIFT 7
/*
* Scale can be multiplied by up to 64x via ALSTIM because of lost resolution
*
* This scaling factor is hidden from userspace and instead accounted for when
* reading raw values from the device.
*
* This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and
* ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.
*
* Handling this internally is also required for buffer support because the
* channel's scan_type can't be modified dynamically.
*/
#define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))
/* Available integration times with pretty manual alignment: */
static const int max44000_int_time_avail_ns_array[] = {
100000000,
25000000,
6250000,
1562500,
};
static const char max44000_int_time_avail_str[] =
"0.100 "
"0.025 "
"0.00625 "
"0.0015625";
/* Available scales (internal to ulux) with pretty manual alignment: */
static const int max44000_scale_avail_ulux_array[] = {
31250,
125000,
500000,
4000000,
};
static const char max44000_scale_avail_str[] =
"0.03125 "
"0.125 "
"0.5 "
"4";
#define MAX44000_SCAN_INDEX_ALS 0
#define MAX44000_SCAN_INDEX_PRX 1
static const struct iio_chan_spec max44000_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_INT_TIME),
.scan_index = MAX44000_SCAN_INDEX_ALS,
.scan_type = {
.sign = 'u',
.realbits = 14,
.storagebits = 16,
}
},
{
.type = IIO_PROXIMITY,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.scan_index = MAX44000_SCAN_INDEX_PRX,
.scan_type = {
.sign = 'u',
.realbits = 8,
.storagebits = 16,
}
},
IIO_CHAN_SOFT_TIMESTAMP(2),
{
.type = IIO_CURRENT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.extend_name = "led",
.output = 1,
.scan_index = -1,
},
};
static int max44000_read_alstim(struct max44000_data *data)
{
unsigned int val;
int ret;
ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
if (ret < 0)
return ret;
return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;
}
static int max44000_write_alstim(struct max44000_data *data, int val)
{
return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
MAX44000_CFG_RX_ALSTIM_MASK,
val << MAX44000_CFG_RX_ALSTIM_SHIFT);
}
static int max44000_read_alspga(struct max44000_data *data)
{
unsigned int val;
int ret;
ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
if (ret < 0)
return ret;
return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;
}
static int max44000_write_alspga(struct max44000_data *data, int val)
{
return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
MAX44000_CFG_RX_ALSPGA_MASK,
val << MAX44000_CFG_RX_ALSPGA_SHIFT);
}
static int max44000_read_alsval(struct max44000_data *data)
{
u16 regval;
__be16 val;
int alstim, ret;
ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
&val, sizeof(val));
if (ret < 0)
return ret;
alstim = ret = max44000_read_alstim(data);
if (ret < 0)
return ret;
regval = be16_to_cpu(val);
/*
* Overflow is explained on datasheet page 17.
*
* It's a warning that either the G or IR channel has become saturated
* and that the value in the register is likely incorrect.
*
* The recommendation is to change the scale (ALSPGA).
* The driver just returns the max representable value.
*/
if (regval & MAX44000_ALSDATA_OVERFLOW)
return 0x3FFF;
return regval << MAX44000_ALSTIM_SHIFT(alstim);
}
static int max44000_write_led_current_raw(struct max44000_data *data, int val)
{
/* Maybe we should clamp the value instead? */
if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
return -ERANGE;
if (val >= 8)
val += 4;
return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
MAX44000_LED_CURRENT_MASK, val);
}
static int max44000_read_led_current_raw(struct max44000_data *data)
{
unsigned int regval;
int ret;
ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, ®val);
if (ret < 0)
return ret;
regval &= MAX44000_LED_CURRENT_MASK;
if (regval >= 8)
regval -= 4;
return regval;
}
static int max44000_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct max44000_data *data = iio_priv(indio_dev);
int alstim, alspga;
unsigned int regval;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_LIGHT:
mutex_lock(&data->lock);
ret = max44000_read_alsval(data);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_PROXIMITY:
mutex_lock(&data->lock);
ret
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