iio: hid-sensors: Added Pressure Sensor driver

Added usage id processing for Pressure Sensor. 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: Archana Patni <archana.patni@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 391 insertions, 0 deletions

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index a8b9cae..6215761 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -5,6 +5,20 @@
 
 menu "Pressure sensors"
 
+config HID_SENSOR_PRESS
+	depends on HID_SENSOR_HUB
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select HID_SENSOR_IIO_COMMON
+	select HID_SENSOR_IIO_TRIGGER
+	tristate "HID PRESS"
+	help
+	  Say yes here to build support for the HID SENSOR
+	  Pressure driver
+
+          To compile this driver as a module, choose M here: the module
+          will be called hid-sensor-press.
+
 config MPL3115
 	tristate "Freescale MPL3115A2 pressure sensor driver"
 	depends on I2C
diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index 42bb9fc..4a57bf6 100644
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -3,6 +3,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o
 obj-$(CONFIG_MPL3115) += mpl3115.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
diff --git a/drivers/iio/pressure/hid-sensor-press.c b/drivers/iio/pressure/hid-sensor-press.c
new file mode 100644
index 0000000..e0e6409
--- /dev/null
+++ b/drivers/iio/pressure/hid-sensor-press.c
@@ -0,0 +1,376 @@
+/*
+ * HID Sensors Driver
+ * Copyright (c) 2014, 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.
+ *
+ */
+#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-trigger.h"
+
+#define CHANNEL_SCAN_INDEX_PRESSURE 0
+
+struct press_state {
+	struct hid_sensor_hub_callbacks callbacks;
+	struct hid_sensor_common common_attributes;
+	struct hid_sensor_hub_attribute_info press_attr;
+	u32 press_data;
+};
+
+/* Channel definitions */
+static const struct iio_chan_spec press_channels[] = {
+	{
+		.type = IIO_PRESSURE,
+		.modified = 1,
+		.channel2 = IIO_NO_MOD,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS),
+		.scan_index = CHANNEL_SCAN_INDEX_PRESSURE,
+	}
+};
+
+/* Adjust channel real bits based on report descriptor */
+static void press_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 press_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int *val, int *val2,
+			      long mask)
+{
+	struct press_state *press_state = iio_priv(indio_dev);
+	int report_id = -1;
+	u32 address;
+	int ret;
+	int ret_type;
+
+	*val = 0;
+	*val2 = 0;
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->scan_index) {
+		case  CHANNEL_SCAN_INDEX_PRESSURE:
+			report_id = press_state->press_attr.report_id;
+			address =
+			HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE;
+			break;
+		default:
+			report_id = -1;
+			break;
+		}
+		if (report_id >= 0)
+			*val = sensor_hub_input_attr_get_raw_value(
+				press_state->common_attributes.hsdev,
+				HID_USAGE_SENSOR_PRESSURE, address,
+				report_id);
+		else {
+			*val = 0;
+			return -EINVAL;
+		}
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		*val = press_state->press_attr.units;
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = hid_sensor_convert_exponent(
+				press_state->press_attr.unit_expo);
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_read_samp_freq_value(
+				&press_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(
+				&press_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 press_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct press_state *press_state = iio_priv(indio_dev);
+	int ret = 0;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_write_samp_freq_value(
+				&press_state->common_attributes, val, val2);
+		break;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret = hid_sensor_write_raw_hyst_value(
+				&press_state->common_attributes, val, val2);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_info press_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &press_read_raw,
+	.write_raw = &press_write_raw,
+};
+
+/* Function to push data to buffer */
+static void hid_sensor_push_data(struct iio_dev *indio_dev, const void *data,
+					int len)
+{
+	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
+	iio_push_to_buffers(indio_dev, data);
+}
+
+/* Callback handler to send event after all samples are received and captured */
+static int press_proc_event(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct press_state *press_state = iio_priv(indio_dev);
+
+	dev_dbg(&indio_dev->dev, "press_proc_event [%d]\n",
+				press_state->common_attributes.data_ready);
+	if (press_state->common_attributes.data_ready)
+		hid_sensor_push_data(indio_dev,
+				&press_state->press_data,
+				sizeof(press_state->press_data));
+
+	return 0;
+}
+
+/* Capture samples in local storage */
+static int press_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 press_state *press_state = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	switch (usage_id) {
+	case HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE:
+		press_state->press_data = *(u32 *)raw_data;
+		ret = 0;
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+/* Parse report which is specific to an usage id*/
+static int press_parse_report(struct platform_device *pdev,
+				struct hid_sensor_hub_device *hsdev,
+				struct iio_chan_spec *channels,
+				unsigned usage_id,
+				struct press_state *st)
+{
+	int ret;
+
+	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
+			usage_id,
+			HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE,
+			&st->press_attr);
+	if (ret < 0)
+		return ret;
+	press_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_PRESSURE,
+					st->press_attr.size);
+
+	dev_dbg(&pdev->dev, "press %x:%x\n", st->press_attr.index,
+			st->press_attr.report_id);
+
+	/* Set Sensitivity field ids, when there is no individual modifier */
+	if (st->common_attributes.sensitivity.index < 0) {
+		sensor_hub_input_get_attribute_info(hsdev,
+			HID_FEATURE_REPORT, usage_id,
+			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
+			HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE,
+			&st->common_attributes.sensitivity);
+		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
+			st->common_attributes.sensitivity.index,
+			st->common_attributes.sensitivity.report_id);
+	}
+	return ret;
+}
+
+/* Function to initialize the processing for usage id */
+static int hid_press_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	static const char *name = "press";
+	struct iio_dev *indio_dev;
+	struct press_state *press_state;
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_chan_spec *channels;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+				sizeof(struct press_state));
+	if (!indio_dev)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, indio_dev);
+
+	press_state = iio_priv(indio_dev);
+	press_state->common_attributes.hsdev = hsdev;
+	press_state->common_attributes.pdev = pdev;
+
+	ret = hid_sensor_parse_common_attributes(hsdev,
+					HID_USAGE_SENSOR_PRESSURE,
+					&press_state->common_attributes);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup common attributes\n");
+		return ret;
+	}
+
+	channels = kmemdup(press_channels, sizeof(press_channels), GFP_KERNEL);
+	if (!channels) {
+		dev_err(&pdev->dev, "failed to duplicate channels\n");
+		return -ENOMEM;
+	}
+
+	ret = press_parse_report(pdev, hsdev, channels,
+				HID_USAGE_SENSOR_PRESSURE, press_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(press_channels);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &press_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;
+	}
+	press_state->common_attributes.data_ready = false;
+	ret = hid_sensor_setup_trigger(indio_dev, name,
+				&press_state->common_attributes);
+	if (ret) {
+		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;
+	}
+
+	press_state->callbacks.send_event = press_proc_event;
+	press_state->callbacks.capture_sample = press_capture_sample;
+	press_state->callbacks.pdev = pdev;
+	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_PRESSURE,
+					&press_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(&press_state->common_attributes);
+error_unreg_buffer_funcs:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_free_dev_mem:
+	kfree(indio_dev->channels);
+	return ret;
+}
+
+/* Function to deinitialize the processing for usage id */
+static int hid_press_remove(struct platform_device *pdev)
+{
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct press_state *press_state = iio_priv(indio_dev);
+
+	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PRESSURE);
+	iio_device_unregister(indio_dev);
+	hid_sensor_remove_trigger(&press_state->common_attributes);
+	iio_triggered_buffer_cleanup(indio_dev);
+	kfree(indio_dev->channels);
+
+	return 0;
+}
+
+static struct platform_device_id hid_press_ids[] = {
+	{
+		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
+		.name = "HID-SENSOR-200031",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, hid_press_ids);
+
+static struct platform_driver hid_press_platform_driver = {
+	.id_table = hid_press_ids,
+	.driver = {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= hid_press_probe,
+	.remove		= hid_press_remove,
+};
+module_platform_driver(hid_press_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor Pressure");
+MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
+MODULE_LICENSE("GPL");