Re: [PATCH v2 2/3] Input: cyttsp - add device tree support
From: Rob Herring <robh@kernel.org>
Date: 2016-01-06 15:03:05
Also in:
linux-devicetree, lkml
On Tue, Jan 05, 2016 at 01:59:14PM +0100, Oreste Salerno wrote:
Add support for retrieving the platform data from the device tree.
Converting platform data to DT as is is typically not the right thing to do. There's some overlap, but it is not typically 1-1.
quoted hunk ↗ jump to hunk
Signed-off-by: Oreste Salerno <redacted> --- .../bindings/input/touchscreen/cyttsp.txt | 73 ++++++++++++++ drivers/input/touchscreen/cyttsp_core.c | 108 +++++++++++++++++++-- include/linux/input/cyttsp.h | 3 + 3 files changed, 177 insertions(+), 7 deletions(-) create mode 100644 Documentation/devicetree/bindings/input/touchscreen/cyttsp.txtdiff --git a/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt new file mode 100644 index 0000000..8e0bcc73 --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt@@ -0,0 +1,73 @@ +* Cypress cyttsp touchscreen controller + +Required properties: +- compatible : must be "cypress,cyttsp-i2c" or "cypress,cyttsp-spi" +- reg : Device address
...or SPI chip select number
+- spi-max-frequency : Maximum SPI clocking speed of the device (for cyttsp-spi) +- interrupt-parent : the phandle for the gpio controller + (see interrupt binding[0]). +- interrupts : (gpio) interrupt to which the chip is connected + (see interrupt binding[0]). +- reset-gpios : the reset gpio the chip is connected to + (see GPIO binding[1] for more details). +- maxx : horizontal resolution of touchscreen (in pixels) +- maxy : vertical resolution of touchscreen (in pixels)
IIRC, we have standard properties for these. Touchscreens don't really have pixels...
+- bootloader-key : the bootloader key used to exit bootloader mode
I don't understand what this is.
+ +Optional properties: +- use_hndshk : enable handshake bit +- act_dist : active distance +- act_intrvl : active refresh interval in ms
Is this sampling frequency?
+- tch_tmout : active touch timeout in ms +- lp_intrvl : low power refresh interval in ms
Look whether other touchscreens bindings have similar properties already and copy those. These need better definitions in general. Don't use '_' in property names and append units to the name of properties that have units (e.g. ms).
+Example:
+ &i2c1 {
+ /* ... */
+ cyttsp@a {
+ compatible = "cypress,cyttsp-i2c";
+ reg = <0xa>;
+ interrupt-parent = <&msm_gpio>;
+ interrupts = <13 0x2008>;
+ reset-gpios = <&msm_gpio 12 0x00>;
+
+ maxx = <800>;
+ maxy = <480>;
+ bootloader-key = /bits/ 8 <0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08>;
+
+ use_hndshk;
+ act_dist = /bits/ 8 <0xF8>;
+ act_intrvl = /bits/ 8 <0x00>;
+ tch_tmout = /bits/ 8 <0xFF>;
+ lp_intrvl = /bits/ 8 <0x0A>;If the size is not 32-bits, you need to state that in the description. There is not really much point in making these 8-bit though. Rob