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SubjectRe: [PATCH 3/3] iio: light: Add support for ltrf216a sensor
From
On 25/03/2022 11:30, Shreeya Patel wrote:
> From: Zhigang Shi <Zhigang.Shi@liteon.com>
>
> Add initial support for ltrf216a ambient light sensor.
>
> Datasheet :-
> https://gitlab.steamos.cloud/shreeya/iio/-/blob/main/LTR-F216A-QT.pdf
>
>
> Co-developed-by: Shreeya Patel <shreeya.patel@collabora.com>
> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
> Signed-off-by: Zhigang Shi <Zhigang.Shi@liteon.com>
> ---
> drivers/iio/light/Kconfig | 10 ++
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/ltrf216a.c | 334 +++++++++++++++++++++++++++++++++++
> 3 files changed, 345 insertions(+)
> create mode 100644 drivers/iio/light/ltrf216a.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index a62c7b4b8678..08fa383a8ca7 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -318,6 +318,16 @@ config SENSORS_LM3533
> changes. The ALS-control output values can be set per zone for the
> three current output channels.
>
> +config LTRF216A
> + tristate "Liteon LTRF216A Light Sensor"
> + depends on I2C
> + help
> + If you say Y or M here, you get support for Liteon LTRF216A
> + Ambient Light Sensor.
> +
> + If built as a dynamically linked module, it will be called
> + ltrf216a.
> +
> config LTR501
> tristate "LTR-501ALS-01 light sensor"
> depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index d10912faf964..8fa91b9fe5b6 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_SENSORS_ISL29028) += isl29028.o
> obj-$(CONFIG_ISL29125) += isl29125.o
> obj-$(CONFIG_JSA1212) += jsa1212.o
> obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
> +obj-$(CONFIG_LTRF216A) += ltrf216a.o
> obj-$(CONFIG_LTR501) += ltr501.o
> obj-$(CONFIG_LV0104CS) += lv0104cs.o
> obj-$(CONFIG_MAX44000) += max44000.o
> diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c
> new file mode 100644
> index 000000000000..99295358a7fe
> --- /dev/null
> +++ b/drivers/iio/light/ltrf216a.c
> @@ -0,0 +1,334 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * LTRF216A Ambient Light Sensor
> + *
> + * Copyright (C) 2021 Lite-On Technology Corp (Singapore)
> + * Author: Shi Zhigang <Zhigang.Shi@liteon.com>
> + *
> + * IIO driver for LTRF216A (7-bit I2C slave address 0x53).
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/mutex.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/pm.h>
> +#include <linux/delay.h>
> +
> +#define LTRF216A_DRV_NAME "ltrf216a"
> +
> +#define LTRF216A_MAIN_CTRL 0x00
> +
> +#define LTRF216A_ALS_MEAS_RATE 0x04
> +#define LTRF216A_MAIN_STATUS 0x07
> +#define LTRF216A_CLEAR_DATA_0 0x0A
> +
> +#define LTRF216A_ALS_DATA_0 0x0D
> +
> +static const int int_time_mapping[] = { 400000, 200000, 100000 };
> +
> +struct ltrf216a_data {
> + struct i2c_client *client;
> + u32 int_time;
> + u8 int_time_fac;
> + u8 als_gain_fac;
> + struct mutex mutex;
> +};
> +
> +/* open air. need to update based on TP transmission rate. */
> +#define WIN_FAC 1
> +
> +static const struct iio_chan_spec ltrf216a_channels[] = {
> + {
> + .type = IIO_LIGHT,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_PROCESSED) |
> + BIT(IIO_CHAN_INFO_INT_TIME),
> + }
> +};
> +
> +static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.2 0.4");
> +
> +static struct attribute *ltrf216a_attributes[] = {
> + &iio_const_attr_integration_time_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group ltrf216a_attribute_group = {
> + .attrs = ltrf216a_attributes,
> +};
> +
> +static int ltrf216a_init(struct iio_dev *indio_dev)
> +{
> + int ret;
> + struct ltrf216a_data *data = iio_priv(indio_dev);
> +
> + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL);
> + if (ret < 0) {
> + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n");
> + return ret;
> + }
> +
> + /* enable sensor */
> + ret |= 0x02;
> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret);
> + if (ret < 0) {
> + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ltrf216a_disable(struct iio_dev *indio_dev)
> +{
> + int ret;
> + struct ltrf216a_data *data = iio_priv(indio_dev);
> +
> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, 0);
> + if (ret < 0)
> + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n");
> +
> + return ret;
> +}
> +
> +static int ltrf216a_set_it_time(struct ltrf216a_data *data, int itime)
> +{
> + int i, ret, index = -1;
> + u8 reg;
> +
> + for (i = 0; i < ARRAY_SIZE(int_time_mapping); i++) {
> + if (int_time_mapping[i] == itime) {
> + index = i;
> + break;
> + }
> + }
> + /* Make sure integration time index is valid */
> + if (index < 0)
> + return -EINVAL;
> +
> + if (index == 0) {
> + reg = 0x03;
> + data->int_time_fac = 4;
> + } else if (index == 1) {
> + reg = 0x13;
> + data->int_time_fac = 2;
> + } else {
> + reg = (index << 4) | 0x02;
> + data->int_time_fac = 1;
> + }
> +
> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RATE, reg);
> + if (ret < 0)
> + return ret;
> +
> + data->int_time = itime;
> +
> + return 0;
> +}
> +
> +static int ltrf216a_get_it_time(struct ltrf216a_data *data, int *val, int *val2)
> +{
> + *val = 0;
> + *val2 = data->int_time;
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int ltrf216a_read_data(struct ltrf216a_data *data, u8 addr)
> +{
> + int ret;
> + int tries = 25;
> + int val_0, val_1, val_2;
> +
> + while (tries--) {
> + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_STATUS);
> + if (ret < 0)
> + return ret;
> + if (ret & 0x08)
> + break;
> + msleep(20);
> + }
> +
> + val_0 = i2c_smbus_read_byte_data(data->client, addr);
> + val_1 = i2c_smbus_read_byte_data(data->client, addr + 1);
> + val_2 = i2c_smbus_read_byte_data(data->client, addr + 2);
> + ret = (val_2 << 16) + (val_1 << 8) + val_0;
> +
> + return ret;
> +}
> +
> +static int ltrf216a_get_lux(struct ltrf216a_data *data)
> +{
> + int greendata, cleardata, lux;
> +
> + greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
> + cleardata = ltrf216a_read_data(data, LTRF216A_CLEAR_DATA_0);
> +
> + if (greendata < 0 || cleardata < 0)
> + lux = 0;
> + else
> + lux = greendata * 8 * WIN_FAC / data->als_gain_fac / data->int_time_fac / 10;
> +
> + return lux;
> +}
> +
> +static int ltrf216a_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + int ret;
> + struct ltrf216a_data *data = iio_priv(indio_dev);
> +
> + mutex_lock(&data->mutex);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_PROCESSED:
> + ret = ltrf216a_get_lux(data);
> + *val = ret;
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + ret = ltrf216a_get_it_time(data, val, val2);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + mutex_unlock(&data->mutex);
> +
> + return ret;
> +}
> +
> +static int ltrf216a_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int val,
> + int val2, long mask)
> +{
> + struct ltrf216a_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_INT_TIME:
> + if (val != 0)
> + return -EINVAL;
> + mutex_lock(&data->mutex);
> + ret = ltrf216a_set_it_time(data, val2);
> + mutex_unlock(&data->mutex);
> + return ret;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct iio_info ltrf216a_info = {
> + .read_raw = ltrf216a_read_raw,
> + .write_raw = ltrf216a_write_raw,
> + .attrs = &ltrf216a_attribute_group,
> +};
> +
> +static int ltrf216a_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct ltrf216a_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> +
> + mutex_init(&data->mutex);
> +
> + indio_dev->info = &ltrf216a_info;
> + indio_dev->name = LTRF216A_DRV_NAME;
> + indio_dev->channels = ltrf216a_channels;
> + indio_dev->num_channels = ARRAY_SIZE(ltrf216a_channels);
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + ret = ltrf216a_init(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev, "ltrf216a chip init failed\n");
> + return ret;
> + }
> + data->int_time = 100000;
> + data->int_time_fac = 1;
> + data->als_gain_fac = 3;
> +
> + ret = iio_device_register(indio_dev);

Use devm- function, assuming no issues with removal-steps (disable will
be before iio unregister).

> + if (ret < 0) {
> + dev_err(&client->dev, "failed to register iio dev\n");
> + goto err_init;
> + }
> +
> + return 0;

Blank line.

> +err_init:
> + ltrf216a_disable(indio_dev);
> + return ret;
> +}
> +



Best regards,
Krzysztof

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