Re: [PATCH v3 3/4] iio: adc: add STMPE ADC devicetree bindings

Jonathan Cameron
2018-11-25T10:04:25Z

On Fri, 23 Nov 2018 15:24:10 +0100
Philippe Schenker <dev@pschenker.ch> wrote:

> From: Stefan Agner <stefan@agner.ch>
>
> This adds the devicetree bindings for the STMPE ADC.
>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Clearly this will need review from input and mfd.

I've suggested inline that you split the realignment out to a
separate patch for reviewability reasons.

> ---
>
> Changes in v3:
> - Reformatted documentation for touchscreen to use tabs and have a better
> overview of the settings.
> - Added note which adc-settings will take precedence.
> - changed typo in sample-time setting from 144 clocks to 124 clocks, as stated
> in the datasheet.
>
> Changes in v2:
> - Moved the bindings for ADC to the overlying mfd.
> - Reformatted for better readability
>
> .../devicetree/bindings/iio/adc/stmpe-adc.txt | 21 +++++++
> .../bindings/input/touchscreen/stmpe.txt | 60 ++++++++++++-------
> .../devicetree/bindings/mfd/stmpe.txt | 28 ++++++---
> 3 files changed, 80 insertions(+), 29 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt b/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
> new file mode 100644
> index 000000000000..480e66422625
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
> @@ -0,0 +1,21 @@
> +STMPE ADC driver
> +----------------
> +
> +Required properties:
> + - compatible: "st,stmpe-adc"
> +
> +Optional properties:
> +Note that the ADC is shared with the STMPE touchscreen. ADC related settings
> +have to be done in the mfd.
> +- st,norequest-mask: bitmask specifying which ADC channels should _not_ be
> + requestable due to different usage (e.g. touch)
> +
> +Node name must be stmpe_adc and should be child node of stmpe node to
> +which it belongs.
> +
> +Example:
> +
> + stmpe_adc {

Can we use adc { here to match standard naming?

> + compatible = "st,stmpe-adc";
> + st,norequest-mask = <0x0F>; /* dont use ADC CH3-0 */
> + };
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> index 127baa31a77a..414586513a02 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> @@ -5,36 +5,52 @@ Required properties:
> - compatible: "st,stmpe-ts"
>
> Optional properties:
> -- st,sample-time: ADC converstion time in number of clock. (0 -> 36 clocks, 1 ->
> - 44 clocks, 2 -> 56 clocks, 3 -> 64 clocks, 4 -> 80 clocks, 5 -> 96 clocks, 6
> - -> 144 clocks), recommended is 4.
> -- st,mod-12b: ADC Bit mode (0 -> 10bit ADC, 1 -> 12bit ADC)
> -- st,ref-sel: ADC reference source (0 -> internal reference, 1 -> external
> - reference)
> -- st,adc-freq: ADC Clock speed (0 -> 1.625 MHz, 1 -> 3.25 MHz, 2 || 3 -> 6.5 MHz)
> -- st,ave-ctrl: Sample average control (0 -> 1 sample, 1 -> 2 samples, 2 -> 4
> - samples, 3 -> 8 samples)
> -- st,touch-det-delay: Touch detect interrupt delay (0 -> 10 us, 1 -> 50 us, 2 ->
> - 100 us, 3 -> 500 us, 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) recommended
> - is 3
> -- st,settling: Panel driver settling time (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3
> - -> 1 ms, 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) recommended is 2
> -- st,fraction-z: Length of the fractional part in z (fraction-z ([0..7]) = Count of
> - the fractional part) recommended is 7
> -- st,i-drive: current limit value of the touchscreen drivers (0 -> 20 mA typical 35
> - mA max, 1 -> 50 mA typical 80 mA max)
> +- st,ave-ctrl : Sample average control
> + 0 -> 1 sample
> + 1 -> 2 samples
> + 2 -> 4 samples
> + 3 -> 8 samples
> +- st,touch-det-delay : Touch detect interrupt delay (recommended is 3)
> + 0 -> 10 us 5 -> 5 ms
> + 1 -> 50 us 6 -> 10 ms
> + 2 -> 100 us 7 -> 50 ms
> + 3 -> 500 us
> + 4-> 1 ms
> +- st,settling : Panel driver settling time (recommended is 2)
> + 0 -> 10 us 5 -> 10 ms
> + 1 -> 100 us 6 for 50 ms
> + 2 -> 500 us 7 -> 100 ms
> + 3 -> 1 ms
> + 4 -> 5 ms
> +- st,fraction-z : Length of the fractional part in z (recommended is 7)
> + (fraction-z ([0..7]) = Count of the fractional part)
> +- st,i-drive : current limit value of the touchscreen drivers
> + 0 -> 20 mA (typical 35mA max)
> + 1 -> 50 mA (typical 80 mA max)
> +
> +Optional properties common with MFD (deprecated):
> + - st,sample-time : ADC conversion time in number of clock.
> + 0 -> 36 clocks 4 -> 80 clocks (recommended)
> + 1 -> 44 clocks 5 -> 96 clocks
> + 2 -> 56 clocks 6 -> 124 clocks
> + 3 -> 64 clocks
> + - st,mod-12b : ADC Bit mode
> + 0 -> 10bit ADC 1 -> 12bit ADC
> + - st,ref-sel : ADC reference source
> + 0 -> internal 1 -> external
> + - st,adc-freq : ADC Clock speed
> + 0 -> 1.625 MHz 2 || 3 -> 6.5 MHz
> + 1 -> 3.25 MHz
>
> Node name must be stmpe_touchscreen and should be child node of stmpe node to
> which it belongs.
>
> +Note that common ADC settings of stmpe_touchscreen will take precedence.
> +
> Example:
>
> stmpe_touchscreen {
> compatible = "st,stmpe-ts";
> - st,sample-time = <4>;
> - st,mod-12b = <1>;
> - st,ref-sel = <0>;
> - st,adc-freq = <1>;
> st,ave-ctrl = <1>;
> st,touch-det-delay = <2>;
> st,settling = <2>;
> diff --git a/Documentation/devicetree/bindings/mfd/stmpe.txt b/Documentation/devicetree/bindings/mfd/stmpe.txt
> index c797c05cd3c2..d4408a417193 100644
> --- a/Documentation/devicetree/bindings/mfd/stmpe.txt
> +++ b/Documentation/devicetree/bindings/mfd/stmpe.txt
> @@ -4,15 +4,29 @@ STMPE is an MFD device which may expose the following inbuilt devices: gpio,
> keypad, touchscreen, adc, pwm, rotator.
>
> Required properties:
> - - compatible : "st,stmpe[610|801|811|1600|1601|2401|2403]"
> - - reg : I2C/SPI address of the device
> + - compatible : "st,stmpe[610|801|811|1600|1601|2401|2403]"
> + - reg : I2C/SPI address of the device

Nothing wrong with correcting alignment, but it shouldn't be in the same patch
as a fundamental change lie this. Just adds noise.

If that means you first have to introduce the new block missaligned, then
fix up the alignment in a follow up patch, then do that as we can then
effectively ignore the realignment as obviously correct and focus on
the real changes.

>
> Optional properties:
> - - interrupts : The interrupt outputs from the controller
> - - interrupt-controller : Marks the device node as an interrupt controller
> - - wakeup-source : Marks the input device as wakable
> - - st,autosleep-timeout : Valid entries (ms); 4, 16, 32, 64, 128, 256, 512 and 1024
> - - irq-gpio : If present, which GPIO to use for event IRQ
> + - interrupts : The interrupt outputs from the controller
> + - interrupt-controller : Marks the device node as an interrupt controller
> + - wakeup-source : Marks the input device as wakable
> + - st,autosleep-timeout : Valid entries (ms); 4, 16, 32, 64, 128, 256, 512 and 1024
> + - irq-gpio : If present, which GPIO to use for event IRQ
> +
> +Optional properties for devices with touch and ADC (STMPE811|STMPE610):
> + - st,sample-time : ADC conversion time in number of clock.
> + 0 -> 36 clocks 4 -> 80 clocks (recommended)
> + 1 -> 44 clocks 5 -> 96 clocks
> + 2 -> 56 clocks 6 -> 124 clocks
> + 3 -> 64 clocks
> + - st,mod-12b : ADC Bit mode
> + 0 -> 10bit ADC 1 -> 12bit ADC
> + - st,ref-sel : ADC reference source
> + 0 -> internal 1 -> external
> + - st,adc-freq : ADC Clock speed
> + 0 -> 1.625 MHz 2 || 3 -> 6.5 MHz
> + 1 -> 3.25 MHz
>
> Example:
>