iio: hid-sensors: Added ALS

Added usage id processing for ALS. This uses IIO
interfaces for triggered buffer to present data to user
mode.This uses HID sensor framework for registering callback
events from the sensor hub.
Signed-off-by: Nsrinivas pandruvada <srinivas.pandruvada@intel.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/iio/Kconfig

@@ -62,6 +62,7 @@ source "drivers/iio/frequency/Kconfig"
 source "drivers/iio/dac/Kconfig"
 source "drivers/iio/common/Kconfig"
 source "drivers/iio/gyro/Kconfig"
+source "drivers/iio/light/Kconfig"
 source "drivers/iio/magnetometer/Kconfig"
 
 endif # IIO

drivers/iio/Makefile

@@ -18,4 +18,5 @@ obj-y += frequency/
 obj-y += dac/
 obj-y += common/
 obj-y += gyro/
+obj-y += light/
 obj-y += magnetometer/

drivers/iio/light/Kconfig

@@ -42,4 +42,14 @@ config VCNL4000
 	 To compile this driver as a module, choose M here: the
 	 module will be called vcnl4000.
 
+config HID_SENSOR_ALS
+	depends on HID_SENSOR_HUB
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select HID_SENSOR_IIO_COMMON
+	tristate "HID ALS"
+	help
+	  Say yes here to build support for the HID SENSOR
+	  Ambient light sensor.
+
 endmenu

drivers/iio/light/Makefile

@@ -5,3 +5,4 @@
 obj-$(CONFIG_ADJD_S311)		+= adjd_s311.o
 obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
+obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o

drivers/iio/light/hid-sensor-als.c

+/*
+ * HID Sensors Driver
+ * Copyright (c) 2012, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/hid-sensor-hub.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 "../common/hid-sensors/hid-sensor-attributes.h"
+#include "../common/hid-sensors/hid-sensor-trigger.h"
+
+/*Format: HID-SENSOR-usage_id_in_hex*/
+/*Usage ID from spec for Accelerometer-3D: 0x200041*/
+#define DRIVER_NAME "HID-SENSOR-200041"
+
+#define CHANNEL_SCAN_INDEX_ILLUM 0
+
+struct als_state {
+	struct hid_sensor_hub_callbacks callbacks;
+	struct hid_sensor_iio_common common_attributes;
+	struct hid_sensor_hub_attribute_info als_illum;
+	u32 illum;
+};
+
+/* Channel definitions */
+static const struct iio_chan_spec als_channels[] = {
+	{
+		.type = IIO_INTENSITY,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_BOTH,
+		.info_mask = IIO_CHAN_INFO_OFFSET_SHARED_BIT |
+		IIO_CHAN_INFO_SCALE_SHARED_BIT |
+		IIO_CHAN_INFO_SAMP_FREQ_SHARED_BIT |
+		IIO_CHAN_INFO_HYSTERESIS_SHARED_BIT,
+		.scan_index = CHANNEL_SCAN_INDEX_ILLUM,
+	}
+};
+
+/* Adjust channel real bits based on report descriptor */
+static void als_adjust_channel_bit_mask(struct iio_chan_spec *channels,
+					int channel, int size)
+{
+	channels[channel].scan_type.sign = 's';
+	/* Real storage bits will change based on the report desc. */
+	channels[channel].scan_type.realbits = size * 8;
+	/* Maximum size of a sample to capture is u32 */
+	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
+}
+
+/* Channel read_raw handler */
+static int als_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int *val, int *val2,
+			      long mask)
+{
+	struct als_state *als_state = iio_priv(indio_dev);
+	int report_id = -1;
+	u32 address;
+	int ret;
+	int ret_type;
+
+	*val = 0;
+	*val2 = 0;
+	switch (mask) {
+	case 0:
+		switch (chan->scan_index) {
+		case  CHANNEL_SCAN_INDEX_ILLUM:
+			report_id = als_state->als_illum.report_id;
+			address =
+			HID_USAGE_SENSOR_LIGHT_ILLUM;
+			break;
+		default:
+			report_id = -1;
+			break;
+		}
+		if (report_id >= 0)
+			*val = sensor_hub_input_attr_get_raw_value(
+				als_state->common_attributes.hsdev,
+				HID_USAGE_SENSOR_ALS, address,
+				report_id);
+		else {
+			*val = 0;
+			return -EINVAL;
+		}
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		*val = als_state->als_illum.units;
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = hid_sensor_convert_exponent(
+				als_state->als_illum.unit_expo);
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_read_samp_freq_value(
+				&als_state->common_attributes, val, val2);
+		ret_type = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret = hid_sensor_read_raw_hyst_value(
+				&als_state->common_attributes, val, val2);
+		ret_type = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	default:
+		ret_type = -EINVAL;
+		break;
+	}
+
+	return ret_type;
+}
+
+/* Channel write_raw handler */
+static int als_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct als_state *als_state = iio_priv(indio_dev);
+	int ret = 0;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_write_samp_freq_value(
+				&als_state->common_attributes, val, val2);
+		break;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret = hid_sensor_write_raw_hyst_value(
+				&als_state->common_attributes, val, val2);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int als_write_raw_get_fmt(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       long mask)
+{
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static const struct iio_info als_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &als_read_raw,
+	.write_raw = &als_write_raw,
+	.write_raw_get_fmt = &als_write_raw_get_fmt,
+};
+
+/* Function to push data to buffer */
+static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
+{
+	struct iio_buffer *buffer = indio_dev->buffer;
+	s64 timestamp = iio_get_time_ns();
+	int datum_sz;
+
+	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
+	if (!buffer) {
+		dev_err(&indio_dev->dev, "Buffer == NULL\n");
+		return;
+	}
+	datum_sz = buffer->access->get_bytes_per_datum(buffer);
+	if (len > datum_sz) {
+		dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
+				datum_sz);
+		return;
+	}
+	buffer->access->store_to(buffer, (u8 *)data, timestamp);
+}
+
+/* Callback handler to send event after all samples are received and captured */
+static int als_proc_event(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct als_state *als_state = iio_priv(indio_dev);
+
+	dev_dbg(&indio_dev->dev, "als_proc_event [%d]\n",
+				als_state->common_attributes.data_ready);
+	if (als_state->common_attributes.data_ready)
+		hid_sensor_push_data(indio_dev,
+				(u8 *)&als_state->illum,
+				sizeof(als_state->illum));
+
+	return 0;
+}
+
+/* Capture samples in local storage */
+static int als_capture_sample(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				size_t raw_len, char *raw_data,
+				void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct als_state *als_state = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	switch (usage_id) {
+	case HID_USAGE_SENSOR_LIGHT_ILLUM:
+		als_state->illum = *(u32 *)raw_data;
+		ret = 0;
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+/* Parse report which is specific to an usage id*/
+static int als_parse_report(struct platform_device *pdev,
+				struct hid_sensor_hub_device *hsdev,
+				struct iio_chan_spec *channels,
+				unsigned usage_id,
+				struct als_state *st)
+{
+	int ret;
+
+	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
+			usage_id,
+			HID_USAGE_SENSOR_LIGHT_ILLUM,
+			&st->als_illum);
+	if (ret < 0)
+		return ret;
+	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_ILLUM,
+					st->als_illum.size);
+
+	dev_dbg(&pdev->dev, "als %x:%x\n", st->als_illum.index,
+			st->als_illum.report_id);
+
+	return ret;
+}
+
+/* Function to initialize the processing for usage id */
+static int __devinit hid_als_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	static const char *name = "als";
+	struct iio_dev *indio_dev;
+	struct als_state *als_state;
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_chan_spec *channels;
+
+	indio_dev = iio_device_alloc(sizeof(struct als_state));
+	if (indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	platform_set_drvdata(pdev, indio_dev);
+
+	als_state = iio_priv(indio_dev);
+	als_state->common_attributes.hsdev = hsdev;
+	als_state->common_attributes.pdev = pdev;
+
+	ret = hid_sensor_parse_common_attributes(hsdev, HID_USAGE_SENSOR_ALS,
+					&als_state->common_attributes);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup common attributes\n");
+		goto error_free_dev;
+	}
+
+	channels = kmemdup(als_channels,
+					sizeof(als_channels),
+					GFP_KERNEL);
+	if (!channels) {
+		dev_err(&pdev->dev, "failed to duplicate channels\n");
+		goto error_free_dev;
+	}
+
+	ret = als_parse_report(pdev, hsdev, channels,
+				HID_USAGE_SENSOR_ALS, als_state);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup attributes\n");
+		goto error_free_dev_mem;
+	}
+
+	indio_dev->channels = channels;
+	indio_dev->num_channels =
+				ARRAY_SIZE(als_channels);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &als_info;
+	indio_dev->name = name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+		NULL, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
+		goto error_free_dev_mem;
+	}
+	als_state->common_attributes.data_ready = false;
+	ret = hid_sensor_setup_trigger(indio_dev, name,
+				&als_state->common_attributes);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "trigger setup failed\n");
+		goto error_unreg_buffer_funcs;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "device register failed\n");
+		goto error_remove_trigger;
+	}
+
+	als_state->callbacks.send_event = als_proc_event;
+	als_state->callbacks.capture_sample = als_capture_sample;
+	als_state->callbacks.pdev = pdev;
+	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_ALS,
+					&als_state->callbacks);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "callback reg failed\n");
+		goto error_iio_unreg;
+	}
+
+	return ret;
+
+error_iio_unreg:
+	iio_device_unregister(indio_dev);
+error_remove_trigger:
+	hid_sensor_remove_trigger(indio_dev);
+error_unreg_buffer_funcs:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_free_dev_mem:
+	kfree(indio_dev->channels);
+error_free_dev:
+	iio_device_free(indio_dev);
+error_ret:
+	return ret;
+}
+
+/* Function to deinitialize the processing for usage id */
+static int __devinit hid_als_remove(struct platform_device *pdev)
+{
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_ALS);
+	iio_device_unregister(indio_dev);
+	hid_sensor_remove_trigger(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	kfree(indio_dev->channels);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static struct platform_driver hid_als_platform_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= hid_als_probe,
+	.remove		= hid_als_remove,
+};
+module_platform_driver(hid_als_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor ALS");
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
+MODULE_LICENSE("GPL");