On Wed, 2015-01-21 at 21:53 +0000, Jonathan Cameron wrote:
> On 07/01/15 18:24, Srinivas Pandruvada wrote:
> > HID sensor hub exports several sensor which are fusion sensors, where
> > data is interpreted from one or more sensors. Some of them can't be
> > exported via IIO like sysfs as the user space download some firmware,
> > which defines what sensor will look like. They can be a part of a
> > collection.
> This functionality is beginning to turn up on a number of devices.
> I'd argue that where at all possible, we should try for standard
> interfaces on the resulting 'fused sensors'. Still you do indeed
> always need a means of uploading the firmware!
I will submitted RFCs, once I see in production releases.
Currently planning to use misc driver for FW update.
What do you think about using dev/iio:deviceX for such case to download
FW for each sensor? We also need mechanism to initiate and reset after
FW download.
Thanks,
Srinivas
> > Creating a MFD cell for a collection to write a standalone driver
> > to manage collections. Most of the time they will be propritery drivers
> > may not be even upstreamed. This patch allows framework to have
> > capability to write such drivers.
> >
> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> >
>
> A few comments inline...
>
> How does userspace download a firmware?
>
>
> ---
> > drivers/hid/hid-sensor-hub.c | 50 ++++++++++++++++++++++++++++++++++++++----
> > include/linux/hid-sensor-ids.h | 2 ++
> > 2 files changed, 48 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
> > index 865cd56..83b6e15 100644
> > --- a/drivers/hid/hid-sensor-hub.c
> > +++ b/drivers/hid/hid-sensor-hub.c
> > @@ -119,11 +119,12 @@ static struct hid_sensor_hub_callbacks *sensor_hub_get_callback(
> >
> > spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> > list_for_each_entry(callback, &pdata->dyn_callback_list, list)
> > - if (callback->usage_id == usage_id &&
> > + if (callback->usage_id == HID_USAGE_SENSOR_TYPE_COLLECTION ||
> > + (callback->usage_id == usage_id &&
> > (collection_index >=
> > callback->hsdev->start_collection_index) &&
> > (collection_index <
> > - callback->hsdev->end_collection_index)) {
> > + callback->hsdev->end_collection_index))) {
> > *priv = callback->priv;
> > *hsdev = callback->hsdev;
> > spin_unlock_irqrestore(&pdata->dyn_callback_lock,
> > @@ -159,7 +160,12 @@ int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
> > callback->usage_callback = usage_callback;
> > callback->usage_id = usage_id;
> > callback->priv = NULL;
> > - list_add_tail(&callback->list, &pdata->dyn_callback_list);
> > + /* Give higher priority to collection device, so add to front */
> Comment should probably state why we want to give them higher priorities.
>
> > + if (usage_id == HID_USAGE_SENSOR_TYPE_COLLECTION)
> > + list_add(&callback->list, &pdata->dyn_callback_list);
> > + else
> > + list_add_tail(&callback->list, &pdata->dyn_callback_list);
> > +
> > spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> > return 0;
> > @@ -547,6 +553,37 @@ static __u8 *sensor_hub_report_fixup(struct hid_device *hdev, __u8 *rdesc,
> > return rdesc;
> > }
> >
> > +static int sensor_hub_add_collection_device(struct hid_device *hdev,
> > + struct sensor_hub_data *sd)
> > +{
> > + struct hid_sensor_hub_device *hsdev;
> > + char *name;
> > +
> > + hsdev = devm_kzalloc(&hdev->dev, sizeof(*hsdev), GFP_KERNEL);
> > + if (!hsdev)
> > + return -ENOMEM;
> > +
> > + hsdev->hdev = hdev;
> > + hsdev->vendor_id = hdev->vendor;
> > + hsdev->product_id = hdev->product;
> > + hsdev->usage = HID_USAGE_SENSOR_TYPE_COLLECTION;
> > + mutex_init(&hsdev->mutex);
> > + name = devm_kasprintf(&hdev->dev, GFP_KERNEL, "HID-SENSOR-%x",
> > + HID_USAGE_SENSOR_TYPE_COLLECTION);
> > + if (name == NULL) {
> > + hid_err(hdev, "Failed MFD device name\n");
> > + return -ENOMEM;
> > + }
> > + sd->hid_sensor_hub_client_devs[sd->hid_sensor_client_cnt].name = name;
> > + sd->hid_sensor_hub_client_devs[
> > + sd->hid_sensor_client_cnt].platform_data = hsdev;
> Odd breaking up of the line... Perhaps break before .platform_data instead?
> > + sd->hid_sensor_hub_client_devs[
> > + sd->hid_sensor_client_cnt].pdata_size = sizeof(*hsdev);
> > + sd->hid_sensor_client_cnt++;
> > +
> > + return 0;
> > +}
> > +
> > static int sensor_hub_probe(struct hid_device *hdev,
> > const struct hid_device_id *id)
> > {
> > @@ -591,7 +628,8 @@ static int sensor_hub_probe(struct hid_device *hdev,
> > ret = -EINVAL;
> > goto err_stop_hw;
> > }
> > - sd->hid_sensor_hub_client_devs = devm_kzalloc(&hdev->dev, dev_cnt *
> > + sd->hid_sensor_hub_client_devs = devm_kzalloc(&hdev->dev,
> > + (dev_cnt + 1) *
> > sizeof(struct mfd_cell),
> > GFP_KERNEL);
> > if (sd->hid_sensor_hub_client_devs == NULL) {
> > @@ -645,6 +683,10 @@ static int sensor_hub_probe(struct hid_device *hdev,
> > if (last_hsdev)
> > last_hsdev->end_collection_index = i;
> >
> > + ret = sensor_hub_add_collection_device(hdev, sd);
> > + if (ret)
> > + goto err_stop_hw;
> > +
> > ret = mfd_add_hotplug_devices(&hdev->dev,
> > sd->hid_sensor_hub_client_devs,
> > sd->hid_sensor_client_cnt);
> > diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
> > index 109f0e6..300ffea 100644
> > --- a/include/linux/hid-sensor-ids.h
> > +++ b/include/linux/hid-sensor-ids.h
> > @@ -21,6 +21,8 @@
> >
> > #define HID_MAX_PHY_DEVICES 0xFF
> >
> > +#define HID_USAGE_SENSOR_TYPE_COLLECTION 0x200001
> > +
> > /* Accel 3D (200073) */
> > #define HID_USAGE_SENSOR_ACCEL_3D 0x200073
> > #define HID_USAGE_SENSOR_DATA_ACCELERATION 0x200452
> >
>
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