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

From: Philippe Schenker
Date: Fri Nov 23 2018 - 09:24:29 EST

From: Stefan Agner <stefan@xxxxxxxx>

This adds the devicetree bindings for the STMPE ADC.

Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
Signed-off-by: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>
Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
---

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 {
+ 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

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:

--
2.19.1