From: "Baluta, Teodora" <teodora.baluta@intel.com>
To: "jic23@kernel.org" <jic23@kernel.org>
Cc: "m.chehab@samsung.com" <m.chehab@samsung.com>,
"lars@metafoo.de" <lars@metafoo.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"hverkuil@xs4all.nl" <hverkuil@xs4all.nl>
Subject: Re: [RFC PATCH 0/3] Introduce IIO interface for fingerprint sensors
Date: Wed, 14 Jan 2015 17:14:03 +0000 [thread overview]
Message-ID: <1421255642.31900.4.camel@bebop> (raw)
In-Reply-To: <549D42BD.1050901@kernel.org>
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WARNING: multiple messages have this Message-ID (diff)
From: "Baluta, Teodora" <teodora.baluta@intel.com>
To: "jic23@kernel.org" <jic23@kernel.org>
Cc: "m.chehab@samsung.com" <m.chehab@samsung.com>,
"lars@metafoo.de" <lars@metafoo.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"hverkuil@xs4all.nl" <hverkuil@xs4all.nl>
Subject: Re: [RFC PATCH 0/3] Introduce IIO interface for fingerprint sensors
Date: Wed, 14 Jan 2015 17:14:03 +0000 [thread overview]
Message-ID: <1421255642.31900.4.camel@bebop> (raw)
In-Reply-To: <549D42BD.1050901@kernel.org>
On Vi, 2014-12-26 at 11:13 +0000, Jonathan Cameron wrote:
> On 18/12/14 16:51, Lars-Peter Clausen wrote:
> > Adding V4L folks to Cc for more input.
> Thanks Lars - we definitely would need the v4l guys to agree to a driver like
> this going in IIO. (not that I'm convinced it should!)
> >
> > On 12/08/2014 03:10 PM, Baluta, Teodora wrote:
> >> Hello,
> >>
> >> On Vi, 2014-12-05 at 02:15 +0000, Jonathan Cameron wrote:
> >>> On 04/12/14 13:00, Teodora Baluta wrote:
> >>>> This patchset adds support for fingerprint sensors through the IIO interface.
> >>>> This way userspace applications collect information in a uniform way. All
> >>>> processing would be done in the upper layers as suggested in [0].
> >>>>
> >>>> In order to test out this proposal, a minimal implementation for UPEK's
> >>>> TouchChip Fingerprint Sensor via USB is also available. Although there is an
> >>>> existing implementation in userspace for USB fingerprint devices, including this
> >>>> particular device, the driver represents a proof of concept of how fingerprint
> >>>> sensors could be integrated in the IIO framework regardless of the used bus. For
> >>>> lower power requirements, the SPI bus is preferred and a kernel driver
> >>>> implementation makes more sense.
> >>>
> >>> So why not v4l? These are effectively image sensors..
> >>
> >> Well, here's why I don't think v4l would be the best option:
> >>
> >> - an image scanner could be implemented in the v4l subsystem, but it
> >> seems far more complicated for a simple fingerprint scanner - it usually
> >> has drivers for webcams, TVs or video streaming devices. The v4l
> >> subsystem (with all its support for colorspace, decoders, image
> >> compression, frame control) seems a bit of an overkill for a very
> >> straightforward fingerprint imaging sensor.
> Whilst those are there, I would doubt the irrelevant bits would put much
> burden on a fingerprint scanning driver. Been a while since I did
> anything in that area though so I could be wrong!
> >>
> >> - a fingerprint device could also send out a processed information, not
> >> just the image of a fingerprint. This means that the processing is done
> >> in hardware - the UPEK TouchStrip chipset in libfprint has this behavior
> >> (see [0]). So, the IIO framework would support a uniform way of handling
> >> fingerprint devices that either do processing in software or in
> >> hardware.
> This is more interesting, but does that map well to IIO style
> channels anyway? If not we are going to end up with a whole new
> interface which ever subsystem is used for the image side of things.
> >>
> >> The way I see it now, for processed fingerprint information, an IIO
> >> device could have an IIO_FINGERPRINT channel with a modifier and only
> >> the sensitivity threshold attribute set. We would also need two
> >> triggers: one for enrollment and one for the verification mode to
> >> control the device from a userspace application.
> Sure - what you proposed would work. The question is whether it is
> the best way to do it.
Any thoughts on this from the v4l community?
Thanks,
Teodora
>
>
> >>
> >> Thanks,
> >> Teodora
> >>
> >> [0] http://www.freedesktop.org/wiki/Software/fprint/libfprint/upekts/
> >>
> >>
> >>>>
> >>>> A sysfs trigger is enabled and the device starts scanning. As soon as an image
> >>>> is available it is written in the character device /dev/iio:deviceX.
> >>>>
> >>>> Userspace applications will be able to calculate the expected image size using
> >>>> the fingerprint attributes height, width and bit depth. Other attributes
> >>>> introduced for the fingerprint channel in IIO represent information that aids in
> >>>> the fingerprint image processing. Besides these, the proposed interface offers
> >>>> userspace a way to read a feedback after a scan (like the swipe was too slow or
> >>>> too fast) through a modified fingerprint_status channel.
> >>>>
> >>>> [0] http://www.spinics.net/lists/linux-iio/msg11463.html
> >>>>
> >>>> Teodora Baluta (3):
> >>>> iio: core: add support for fingerprint devices
> >>>> iio: core: change channel's storagebits/realbits to u32
> >>>> iio: fingerprint: add fingerprint sensor via USB
> >>>>
> >>>> Documentation/ABI/testing/sysfs-bus-iio | 51 +++
> >>>> drivers/iio/Kconfig | 1 +
> >>>> drivers/iio/Makefile | 1 +
> >>>> drivers/iio/fingerprint/Kconfig | 15 +
> >>>> drivers/iio/fingerprint/Makefile | 5 +
> >>>> drivers/iio/fingerprint/fp_tc.c | 162 +++++++++
> >>>> drivers/iio/fingerprint/fp_tc.h | 22 ++
> >>>> drivers/iio/fingerprint/fp_tc_usb.c | 618 ++++++++++++++++++++++++++++++++
> >>>> drivers/iio/fingerprint/fp_tc_usb.h | 144 ++++++++
> >>>> drivers/iio/industrialio-core.c | 9 +
> >>>> include/linux/iio/iio.h | 11 +-
> >>>> include/linux/iio/types.h | 10 +
> >>>> 12 files changed, 1047 insertions(+), 2 deletions(-)
> >>>> create mode 100644 drivers/iio/fingerprint/Kconfig
> >>>> create mode 100644 drivers/iio/fingerprint/Makefile
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc.c
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc.h
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc_usb.c
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc_usb.h
> >>>>
> >>>
> >>
> >> N�����r��y���b�X��ǧv�^�){.n�+����{��*"��^n�r���z�\x1a��h����&��\x1e�G���h�\x03(�階�ݢj"��\x1a�^[m�����z�ޖ���f���h���~�mml==
> >>
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WARNING: multiple messages have this Message-ID (diff)
From: "Baluta, Teodora" <teodora.baluta@intel.com>
To: "jic23@kernel.org" <jic23@kernel.org>
Cc: "m.chehab@samsung.com" <m.chehab@samsung.com>,
"lars@metafoo.de" <lars@metafoo.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"hverkuil@xs4all.nl" <hverkuil@xs4all.nl>
Subject: Re: [RFC PATCH 0/3] Introduce IIO interface for fingerprint sensors
Date: Wed, 14 Jan 2015 17:14:03 +0000 [thread overview]
Message-ID: <1421255642.31900.4.camel@bebop> (raw)
In-Reply-To: <549D42BD.1050901@kernel.org>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 6016 bytes --]
On Vi, 2014-12-26 at 11:13 +0000, Jonathan Cameron wrote:
> On 18/12/14 16:51, Lars-Peter Clausen wrote:
> > Adding V4L folks to Cc for more input.
> Thanks Lars - we definitely would need the v4l guys to agree to a driver like
> this going in IIO. (not that I'm convinced it should!)
> >
> > On 12/08/2014 03:10 PM, Baluta, Teodora wrote:
> >> Hello,
> >>
> >> On Vi, 2014-12-05 at 02:15 +0000, Jonathan Cameron wrote:
> >>> On 04/12/14 13:00, Teodora Baluta wrote:
> >>>> This patchset adds support for fingerprint sensors through the IIO interface.
> >>>> This way userspace applications collect information in a uniform way. All
> >>>> processing would be done in the upper layers as suggested in [0].
> >>>>
> >>>> In order to test out this proposal, a minimal implementation for UPEK's
> >>>> TouchChip Fingerprint Sensor via USB is also available. Although there is an
> >>>> existing implementation in userspace for USB fingerprint devices, including this
> >>>> particular device, the driver represents a proof of concept of how fingerprint
> >>>> sensors could be integrated in the IIO framework regardless of the used bus. For
> >>>> lower power requirements, the SPI bus is preferred and a kernel driver
> >>>> implementation makes more sense.
> >>>
> >>> So why not v4l? These are effectively image sensors..
> >>
> >> Well, here's why I don't think v4l would be the best option:
> >>
> >> - an image scanner could be implemented in the v4l subsystem, but it
> >> seems far more complicated for a simple fingerprint scanner - it usually
> >> has drivers for webcams, TVs or video streaming devices. The v4l
> >> subsystem (with all its support for colorspace, decoders, image
> >> compression, frame control) seems a bit of an overkill for a very
> >> straightforward fingerprint imaging sensor.
> Whilst those are there, I would doubt the irrelevant bits would put much
> burden on a fingerprint scanning driver. Been a while since I did
> anything in that area though so I could be wrong!
> >>
> >> - a fingerprint device could also send out a processed information, not
> >> just the image of a fingerprint. This means that the processing is done
> >> in hardware - the UPEK TouchStrip chipset in libfprint has this behavior
> >> (see [0]). So, the IIO framework would support a uniform way of handling
> >> fingerprint devices that either do processing in software or in
> >> hardware.
> This is more interesting, but does that map well to IIO style
> channels anyway? If not we are going to end up with a whole new
> interface which ever subsystem is used for the image side of things.
> >>
> >> The way I see it now, for processed fingerprint information, an IIO
> >> device could have an IIO_FINGERPRINT channel with a modifier and only
> >> the sensitivity threshold attribute set. We would also need two
> >> triggers: one for enrollment and one for the verification mode to
> >> control the device from a userspace application.
> Sure - what you proposed would work. The question is whether it is
> the best way to do it.
Any thoughts on this from the v4l community?
Thanks,
Teodora
>
>
> >>
> >> Thanks,
> >> Teodora
> >>
> >> [0] http://www.freedesktop.org/wiki/Software/fprint/libfprint/upekts/
> >>
> >>
> >>>>
> >>>> A sysfs trigger is enabled and the device starts scanning. As soon as an image
> >>>> is available it is written in the character device /dev/iio:deviceX.
> >>>>
> >>>> Userspace applications will be able to calculate the expected image size using
> >>>> the fingerprint attributes height, width and bit depth. Other attributes
> >>>> introduced for the fingerprint channel in IIO represent information that aids in
> >>>> the fingerprint image processing. Besides these, the proposed interface offers
> >>>> userspace a way to read a feedback after a scan (like the swipe was too slow or
> >>>> too fast) through a modified fingerprint_status channel.
> >>>>
> >>>> [0] http://www.spinics.net/lists/linux-iio/msg11463.html
> >>>>
> >>>> Teodora Baluta (3):
> >>>> iio: core: add support for fingerprint devices
> >>>> iio: core: change channel's storagebits/realbits to u32
> >>>> iio: fingerprint: add fingerprint sensor via USB
> >>>>
> >>>> Documentation/ABI/testing/sysfs-bus-iio | 51 +++
> >>>> drivers/iio/Kconfig | 1 +
> >>>> drivers/iio/Makefile | 1 +
> >>>> drivers/iio/fingerprint/Kconfig | 15 +
> >>>> drivers/iio/fingerprint/Makefile | 5 +
> >>>> drivers/iio/fingerprint/fp_tc.c | 162 +++++++++
> >>>> drivers/iio/fingerprint/fp_tc.h | 22 ++
> >>>> drivers/iio/fingerprint/fp_tc_usb.c | 618 ++++++++++++++++++++++++++++++++
> >>>> drivers/iio/fingerprint/fp_tc_usb.h | 144 ++++++++
> >>>> drivers/iio/industrialio-core.c | 9 +
> >>>> include/linux/iio/iio.h | 11 +-
> >>>> include/linux/iio/types.h | 10 +
> >>>> 12 files changed, 1047 insertions(+), 2 deletions(-)
> >>>> create mode 100644 drivers/iio/fingerprint/Kconfig
> >>>> create mode 100644 drivers/iio/fingerprint/Makefile
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc.c
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc.h
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc_usb.c
> >>>> create mode 100644 drivers/iio/fingerprint/fp_tc_usb.h
> >>>>
> >>>
> >>
> >> N�����r��y���b�X��ǧv�^�)޺{.n�+����{��*"��^n�r���z�\x1a��h����&��\x1e�G���h�\x03(�階�ݢj"��\x1a�^[m�����z�ޖ���f���h���~�mml==
> >>
> >
> > --
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>
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next prev parent reply other threads:[~2015-01-14 17:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-04 13:00 [RFC PATCH 0/3] Introduce IIO interface for fingerprint sensors Teodora Baluta
2014-12-04 13:00 ` [RFC PATCH 1/3] iio: core: add support for fingerprint devices Teodora Baluta
2014-12-04 13:00 ` [RFC PATCH 2/3] iio: core: change channel's storagebits/realbits to u32 Teodora Baluta
2014-12-04 13:00 ` [RFC PATCH 3/3] iio: fingerprint: add fingerprint sensor via USB Teodora Baluta
2014-12-05 2:15 ` [RFC PATCH 0/3] Introduce IIO interface for fingerprint sensors Jonathan Cameron
2014-12-08 14:10 ` Baluta, Teodora
2014-12-08 14:10 ` Baluta, Teodora
2014-12-18 16:51 ` Lars-Peter Clausen
2014-12-26 11:13 ` Jonathan Cameron
2015-01-14 17:14 ` Baluta, Teodora [this message]
2015-01-14 17:14 ` Baluta, Teodora
2015-01-14 17:14 ` Baluta, Teodora
2015-01-15 17:37 ` Sylwester Nawrocki
2015-01-23 13:05 ` Baluta, Teodora
2015-01-23 13:05 ` Baluta, Teodora
2015-01-23 13:05 ` Baluta, Teodora
2015-01-23 16:46 ` Florian Echtler
2015-01-26 10:24 ` Baluta, Teodora
2015-01-26 10:24 ` Baluta, Teodora
2015-01-26 10:24 ` Baluta, Teodora
2015-01-27 11:32 ` Sylwester Nawrocki
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