iio: hid-sensors: Added Proximity Sensor Driver

Added usage id processing for Proximity (Human Presence).
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, 390 insertions, 0 deletions

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 3a7a5d9f03a3..c89740d4748f 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -73,6 +73,20 @@ config HID_SENSOR_ALS
           Say yes here to build support for the HID SENSOR
           Ambient light sensor.
 
+config HID_SENSOR_PROX
+        depends on HID_SENSOR_HUB
+        select IIO_BUFFER
+        select IIO_TRIGGERED_BUFFER
+        select HID_SENSOR_IIO_COMMON
+        select HID_SENSOR_IIO_TRIGGER
+        tristate "HID PROX"
+        help
+          Say yes here to build support for the HID SENSOR
+          Proximity sensor.
+
+          To compile this driver as a module, choose M here: the
+          module will be called hid-sensor-prox.
+
 config SENSORS_LM3533
         tristate "LM3533 ambient light sensor"
         depends on MFD_LM3533
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 924530597f83..3eb36e5151fa 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_CM32181)		+= cm32181.o
 obj-$(CONFIG_CM36651)           += cm36651.o
 obj-$(CONFIG_GP2AP020A00F)      += gp2ap020a00f.o
 obj-$(CONFIG_HID_SENSOR_ALS)    += hid-sensor-als.o
+obj-$(CONFIG_HID_SENSOR_PROX)   += hid-sensor-prox.o
 obj-$(CONFIG_SENSORS_LM3533)    += lm3533-als.o
 obj-$(CONFIG_LTR501)            += ltr501.o
 obj-$(CONFIG_SENSORS_TSL2563)   += tsl2563.o
diff --git a/drivers/iio/light/hid-sensor-prox.c b/drivers/iio/light/hid-sensor-prox.c
new file mode 100644
index 000000000000..1894ab196f97
--- /dev/null
+++ b/drivers/iio/light/hid-sensor-prox.c
@@ -0,0 +1,375 @@
+/*
+ * 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_PRESENCE 0
+
+struct prox_state {
+        struct hid_sensor_hub_callbacks callbacks;
+        struct hid_sensor_common common_attributes;
+        struct hid_sensor_hub_attribute_info prox_attr;
+        u32 human_presence;
+};
+
+/* Channel definitions */
+static const struct iio_chan_spec prox_channels[] = {
+        {
+                .type = IIO_PROXIMITY,
+                .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_PRESENCE,
+        }
+};
+
+/* Adjust channel real bits based on report descriptor */
+static void prox_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 prox_read_raw(struct iio_dev *indio_dev,
+                              struct iio_chan_spec const *chan,
+                              int *val, int *val2,
+                              long mask)
+{
+        struct prox_state *prox_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_PRESENCE:
+                        report_id = prox_state->prox_attr.report_id;
+                        address =
+                        HID_USAGE_SENSOR_HUMAN_PRESENCE;
+                        break;
+                default:
+                        report_id = -1;
+                        break;
+                }
+                if (report_id >= 0)
+                        *val = sensor_hub_input_attr_get_raw_value(
+                                prox_state->common_attributes.hsdev,
+                                HID_USAGE_SENSOR_PROX, address,
+                                report_id);
+                else {
+                        *val = 0;
+                        return -EINVAL;
+                }
+                ret_type = IIO_VAL_INT;
+                break;
+        case IIO_CHAN_INFO_SCALE:
+                *val = prox_state->prox_attr.units;
+                ret_type = IIO_VAL_INT;
+                break;
+        case IIO_CHAN_INFO_OFFSET:
+                *val = hid_sensor_convert_exponent(
+                                prox_state->prox_attr.unit_expo);
+                ret_type = IIO_VAL_INT;
+                break;
+        case IIO_CHAN_INFO_SAMP_FREQ:
+                ret = hid_sensor_read_samp_freq_value(
+                                &prox_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(
+                                &prox_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 prox_write_raw(struct iio_dev *indio_dev,
+                               struct iio_chan_spec const *chan,
+                               int val,
+                               int val2,
+                               long mask)
+{
+        struct prox_state *prox_state = iio_priv(indio_dev);
+        int ret = 0;
+
+        switch (mask) {
+        case IIO_CHAN_INFO_SAMP_FREQ:
+                ret = hid_sensor_write_samp_freq_value(
+                                &prox_state->common_attributes, val, val2);
+                break;
+        case IIO_CHAN_INFO_HYSTERESIS:
+                ret = hid_sensor_write_raw_hyst_value(
+                                &prox_state->common_attributes, val, val2);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
+static const struct iio_info prox_info = {
+        .driver_module = THIS_MODULE,
+        .read_raw = &prox_read_raw,
+        .write_raw = &prox_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 prox_proc_event(struct hid_sensor_hub_device *hsdev,
+                                unsigned usage_id,
+                                void *priv)
+{
+        struct iio_dev *indio_dev = platform_get_drvdata(priv);
+        struct prox_state *prox_state = iio_priv(indio_dev);
+
+        dev_dbg(&indio_dev->dev, "prox_proc_event [%d]\n",
+                                prox_state->common_attributes.data_ready);
+        if (prox_state->common_attributes.data_ready)
+                hid_sensor_push_data(indio_dev,
+                                &prox_state->human_presence,
+                                sizeof(prox_state->human_presence));
+
+        return 0;
+}
+
+/* Capture samples in local storage */
+static int prox_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 prox_state *prox_state = iio_priv(indio_dev);
+        int ret = -EINVAL;
+
+        switch (usage_id) {
+        case HID_USAGE_SENSOR_HUMAN_PRESENCE:
+                prox_state->human_presence = *(u32 *)raw_data;
+                ret = 0;
+                break;
+        default:
+                break;
+        }
+
+        return ret;
+}
+
+/* Parse report which is specific to an usage id*/
+static int prox_parse_report(struct platform_device *pdev,
+                                struct hid_sensor_hub_device *hsdev,
+                                struct iio_chan_spec *channels,
+                                unsigned usage_id,
+                                struct prox_state *st)
+{
+        int ret;
+
+        ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
+                        usage_id,
+                        HID_USAGE_SENSOR_HUMAN_PRESENCE,
+                        &st->prox_attr);
+        if (ret < 0)
+                return ret;
+        prox_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_PRESENCE,
+                                        st->prox_attr.size);
+
+        dev_dbg(&pdev->dev, "prox %x:%x\n", st->prox_attr.index,
+                        st->prox_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_PRESENCE,
+                        &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_prox_probe(struct platform_device *pdev)
+{
+        int ret = 0;
+        static const char *name = "prox";
+        struct iio_dev *indio_dev;
+        struct prox_state *prox_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 prox_state));
+        if (!indio_dev)
+                return -ENOMEM;
+        platform_set_drvdata(pdev, indio_dev);
+
+        prox_state = iio_priv(indio_dev);
+        prox_state->common_attributes.hsdev = hsdev;
+        prox_state->common_attributes.pdev = pdev;
+
+        ret = hid_sensor_parse_common_attributes(hsdev, HID_USAGE_SENSOR_PROX,
+                                        &prox_state->common_attributes);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to setup common attributes\n");
+                return ret;
+        }
+
+        channels = kmemdup(prox_channels, sizeof(prox_channels), GFP_KERNEL);
+        if (!channels) {
+                dev_err(&pdev->dev, "failed to duplicate channels\n");
+                return -ENOMEM;
+        }
+
+        ret = prox_parse_report(pdev, hsdev, channels,
+                                HID_USAGE_SENSOR_PROX, prox_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(prox_channels);
+        indio_dev->dev.parent = &pdev->dev;
+        indio_dev->info = &prox_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;
+        }
+        prox_state->common_attributes.data_ready = false;
+        ret = hid_sensor_setup_trigger(indio_dev, name,
+                                &prox_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;
+        }
+
+        prox_state->callbacks.send_event = prox_proc_event;
+        prox_state->callbacks.capture_sample = prox_capture_sample;
+        prox_state->callbacks.pdev = pdev;
+        ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_PROX,
+                                        &prox_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(&prox_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_prox_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 prox_state *prox_state = iio_priv(indio_dev);
+
+        sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_PROX);
+        iio_device_unregister(indio_dev);
+        hid_sensor_remove_trigger(&prox_state->common_attributes);
+        iio_triggered_buffer_cleanup(indio_dev);
+        kfree(indio_dev->channels);
+
+        return 0;
+}
+
+static struct platform_device_id hid_prox_ids[] = {
+        {
+                /* Format: HID-SENSOR-usage_id_in_hex_lowercase */
+                .name = "HID-SENSOR-200011",
+        },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, hid_prox_ids);
+
+static struct platform_driver hid_prox_platform_driver = {
+        .id_table = hid_prox_ids,
+        .driver = {
+                .name   = KBUILD_MODNAME,
+                .owner  = THIS_MODULE,
+        },
+        .probe          = hid_prox_probe,
+        .remove         = hid_prox_remove,
+};
+module_platform_driver(hid_prox_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor Proximity");
+MODULE_AUTHOR("Archana Patni <archana.patni@intel.com>");
+MODULE_LICENSE("GPL");