--- /dev/null
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#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),
+ },
+};
+
+/*
+ * The event buffer contains timestamp and all the data from
+ * the ACPI0008 block. There are multiple, but so far we only
+ * support _ALI (illuminance). Once someone adds new channels
+ * to acpi_als_channels[], the evt_buffer below will grow
+ * automatically.
+ */
+#define ACPI_ALS_EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels)
+#define ACPI_ALS_EVT_BUFFER_SIZE \
+ (sizeof(s64) + (ACPI_ALS_EVT_NR_SOURCES * sizeof(s32)))
+
+struct acpi_als {
+ struct acpi_device *device;
+ struct mutex lock;
+
+ s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE];
+};
+
+/*
+ * 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();
+ 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 = {
+ .driver_module = THIS_MODULE,
+ .read_raw = acpi_als_read_raw,
+};
+
+static int acpi_als_add(struct acpi_device *device)
+{
+ struct acpi_als *als;
+ struct iio_dev *indio_dev;
+ struct iio_buffer *buffer;
+
+ 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->dev.parent = &device->dev;
+ indio_dev->info = &acpi_als_info;
+ indio_dev->modes = INDIO_BUFFER_SOFTWARE;
+ indio_dev->channels = acpi_als_channels;
+ indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);
+
+ buffer = devm_iio_kfifo_allocate(&device->dev);
+ if (!buffer)
+ return -ENOMEM;
+
+ iio_device_attach_buffer(indio_dev, buffer);
+
+ 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");
Code Review / kvmfornfv.git / blobdiff