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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ACPI Ambient Light Sensor Driver
*
* Based on ALS driver:
* Copyright (C) 2009 Zhang Rui <rui.zhang@intel.com>
*
* Rework for IIO subsystem:
* Copyright (C) 2012-2013 Martin Liska <marxin.liska@gmail.com>
*
* Final cleanup and debugging:
* Copyright (C) 2013-2014 Marek Vasut <marex@denx.de>
* Copyright (C) 2015 Gabriele Mazzotta <gabriele.mzt@gmail.com>
*/
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/kfifo_buf.h>
#define ACPI_ALS_CLASS "als"
#define ACPI_ALS_DEVICE_NAME "acpi-als"
#define ACPI_ALS_NOTIFY_ILLUMINANCE 0x80
ACPI_MODULE_NAME("acpi-als");
/*
* So far, there's only one channel in here, but the specification for
* ACPI0008 says there can be more to what the block can report. Like
* chromaticity and such. We are ready for incoming additions!
*/
static const struct iio_chan_spec acpi_als_channels[] = {
{
.type = IIO_LIGHT,
.scan_type = {
.sign = 's',
.realbits = 32,
.storagebits = 32,
},
/* _RAW is here for backward ABI compatibility */
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_PROCESSED),
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
/*
* The event buffer contains timestamp and all the data from
* the ACPI0008 block. There are multiple, but so far we only
* support _ALI (illuminance): One channel, padding and timestamp.
*/
#define ACPI_ALS_EVT_BUFFER_SIZE \
(sizeof(s32) + sizeof(s32) + sizeof(s64))
struct acpi_als {
struct acpi_device *device;
struct mutex lock;
s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE / sizeof(s32)] __aligned(8);
};
/*
* All types of properties the ACPI0008 block can report. The ALI, ALC, ALT
* and ALP can all be handled by acpi_als_read_value() below, while the ALR is
* special.
*
* The _ALR property returns tables that can be used to fine-tune the values
* reported by the other props based on the particular hardware type and it's
* location (it contains tables for "rainy", "bright inhouse lighting" etc.).
*
* So far, we support only ALI (illuminance).
*/
#define ACPI_ALS_ILLUMINANCE "_ALI"
#define ACPI_ALS_CHROMATICITY "_ALC"
#define ACPI_ALS_COLOR_TEMP "_ALT"
#define ACPI_ALS_POLLING "_ALP"
#define ACPI_ALS_TABLES "_ALR"
static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val)
{
unsigned long long temp_val;
acpi_status status;
status = acpi_evaluate_integer(als->device->handle, prop, NULL,
&temp_val);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop));
return -EIO;
}
*val = temp_val;
return 0;
}
static void acpi_als_notify(struct acpi_device *device, u32 event)
{
struct iio_dev *indio_dev = acpi_driver_data(device);
struct acpi_als *als = iio_priv(indio_dev);
s32 *buffer = als->evt_buffer;
s64 time_ns = iio_get_time_ns(indio_dev);
s32 val;
int ret;
mutex_lock(&als->lock);
memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE);
switch (event) {
case ACPI_ALS_NOTIFY_ILLUMINANCE:
ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
if (ret < 0)
goto out;
*buffer++ = val;
break;
default:
/* Unhandled event */
dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n",
event);
goto out;
}
iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns);
out:
mutex_unlock(&als->lock);
}
static int acpi_als_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct acpi_als *als = iio_priv(indio_dev);
s32 temp_val;
int ret;
if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW))
return -EINVAL;
/* we support only illumination (_ALI) so far. */
if (chan->type != IIO_LIGHT)
return -EINVAL;
ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val);
if (ret < 0)
return ret;
*val = temp_val;
return IIO_VAL_INT;
}
static const struct iio_info acpi_als_info = {
.read_raw = acpi_als_read_raw,
};
static int acpi_als_add(struct acpi_device *device)
{
struct acpi_als *als;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als));
if (!indio_dev)
return -ENOMEM;
als = iio_priv(indio_dev);
device->driver_data = indio_dev;
als->device = device;
mutex_init(&als->lock);
indio_dev->name = ACPI_ALS_DEVICE_NAME;
indio_dev->info = &acpi_als_info;
indio_dev->channels = acpi_als_channels;
indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);
ret = devm_iio_kfifo_buffer_setup(&device->dev, indio_dev,
INDIO_BUFFER_SOFTWARE, NULL);
if (ret)
return ret;
return devm_iio_device_register(&device->dev, indio_dev);
}
static const struct acpi_device_id acpi_als_device_ids[] = {
{"ACPI0008", 0},
{},
};
MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids);
static struct acpi_driver acpi_als_driver = {
.name = "acpi_als",
.class = ACPI_ALS_CLASS,
.ids = acpi_als_device_ids,
.ops = {
.add = acpi_als_add,
.notify = acpi_als_notify,
},
};
module_acpi_driver(acpi_als_driver);
MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>");
MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
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