On Tue, 27 Mar 2018 15:32:33 +0300 Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> wrote: > Hello, > > This patch series is a rework of my previous series named: > [PATCH 00/14] iio: triggers: add consumer support > > In few words, this is the implementation of splitting the functionality > of the IP block ADC device in SAMA5D2 SoC from ADC with touchscreen > support. In order to avoid having a MFD device, two separate > drivers that would work on same register base and split the IRQ,etc, > as advised on the mailing list, I created a consumer driver for the > channels, that will connect to the ADC as described in the device tree. > > I have collected feedback from everyone and here is the result: > I have added a new generic resistive touchscreen driver, which acts > as a iio consumer for the given channels and will create an input > device and report the events. It uses a callback buffer to register > to the IIO device and waits for data to be pushed. > Inside the IIO device, I have kept a similar approach with the first version > of the series, except that now the driver can take multiple buffers, and > will configure the touchscreen part of the hardware device if the specific > channels are requested. > > The SAMA5D2 ADC driver registers three new channels: two for the > position on the X and Y axis, and one for the touch pressure. > When channels are requested, it will check if the touchscreen channel mask > includes the requested channels (it is possible that the consumer driver > will not request pressure for example). If it's the case, it will work > in touchscreen mode, and will refuse to do usual analog-digital conversion, > because we have a single trigger and the touchscreen needs it. > When the scan mask will include only old channels, the driver will function > in the same way as before. If the scan mask somehow is a mix of the two (the > masks intersect), the driver will refuse to work whatsoever (cannot have both > in the same time). > The driver allows reading raw data for the new channels, if claim direct > mode works: no touchscreen driver requested anything. The new channels can > act like the old ones. However, when requesting these channels, the usual > trigger will not work and will not be enabled. The touchscreen channels > require special trigger and irq configuration: pen detect, no pen detect > and a periodic trigger to sample the touchscreen position and pressure. > If the user attempts to use another trigger while there is a buffer > that already requested the touchscreen channels (thus the trigger), the > driver will refuse to comply. > > In order to have defines for the channel numbers, I added a bindings include > file that goes on a separate commit : > dt-bindings: iio: adc: at91-sama5d2_adc: add channel specific consumer info > This should go in the same tree with the following commits : > ARM: dts: at91: sama5d2: add channel cells for ADC device > ARM: dts: at91: sama5d2: Add resistive touch device > > as build will break because these commits depend on the binding one > which creates the included header file. > > After the discussions earlier this year on the mailing list, I hope this > rework of the patches is much better and fulfills all the requirements > for this implementation. As I said in one of the later patches, I like this a lot. It is a good blend of the moderately nasty handling needed in the ADC driver with a lovely generic input driver. Very nice! Hope everyone else agrees ;) Jonathan > > Eugen Hristev (10): > MAINTAINERS: add generic resistive touchscreen adc > iio: Add channel for Position Relative > dt-bindings: input: touchscreen: touch_adc: create bindings > iio: inkern: add module put/get on iio dev module when requesting > channels > iio: adc: at91-sama5d2_adc: fix channel configuration for differential > channels > iio: adc: at91-sama5d2_adc: add support for position and pressure > channels > input: touchscreen: touch_adc: add generic resistive ADC touchscreen > dt-bindings: iio: adc: at91-sama5d2_adc: add channel specific consumer > info > ARM: dts: at91: sama5d2: add channel cells for ADC device > ARM: dts: at91: sama5d2: Add resistive touch device > > Documentation/ABI/testing/sysfs-bus-iio | 12 + > .../bindings/iio/adc/at91-sama5d2_adc.txt | 9 + > .../bindings/input/touchscreen/touch_adc.txt | 33 ++ > MAINTAINERS | 6 + > arch/arm/boot/dts/sama5d2.dtsi | 12 + > drivers/iio/adc/at91-sama5d2_adc.c | 491 ++++++++++++++++++++- > drivers/iio/industrialio-core.c | 1 + > drivers/iio/inkern.c | 8 +- > drivers/input/touchscreen/Kconfig | 13 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/touch_adc.c | 199 +++++++++ > include/dt-bindings/iio/adc/at91-sama5d2_adc.h | 16 + > include/uapi/linux/iio/types.h | 1 + > tools/iio/iio_event_monitor.c | 2 + > 14 files changed, 791 insertions(+), 13 deletions(-) > create mode 100644 Documentation/devicetree/bindings/input/touchscreen/touch_adc.txt > create mode 100644 drivers/input/touchscreen/touch_adc.c > create mode 100644 include/dt-bindings/iio/adc/at91-sama5d2_adc.h > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
