Re: [PATCH 1/2] Input: bcm-keypad: add device tree bindings
From: Scott Branden
Date: Sat Feb 14 2015 - 11:49:35 EST
Hi Dmitry,
Comments inline. I still have an issue with vendor prefix as there are
not documented guidelines I can find in this area?
On 15-02-09 04:51 PM, Dmitry Torokhov wrote:
Hi Scott,
On Mon, Feb 09, 2015 at 04:07:40PM -0800, Scott Branden wrote:
Documents the Broadcom keypad controller device tree bindings.
Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx>
Signed-off-by: Scott Branden <sbranden@xxxxxxxxxxxx>
---
.../devicetree/bindings/input/brcm,bcm-keypad.txt | 118 +++++++++++++++++++++
1 file changed, 118 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt
diff --git a/Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt b/Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt
new file mode 100644
index 0000000..645829d
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt
@@ -0,0 +1,118 @@
+* Broadcom Keypad Controller device tree bindings
+
+Broadcom Keypad controller is used to interface a SoC with a matrix-type
+keypad device. The keypad controller supports multiple row and column lines.
+A key can be placed at each intersection of a unique row and a unique column.
+The keypad controller can sense a key-press and key-release and report the
+event using a interrupt to the cpu.
+
+This binding is based on the matrix-keymap binding with the following
+changes:
+
+keypad,num-rows and keypad,num-columns are required.
+
+Required SoC Specific Properties:
+- compatible: should be "brcm,bcm-keypad"
+
+- reg: physical base address of the controller and length of memory mapped
+ region.
+
+- interrupts: The interrupt number to the cpu.
+
+Board Specific Properties:
+- keypad,num-rows: Number of row lines connected to the keypad
+ controller.
+
+- keypad,num-columns: Number of column lines connected to the
+ keypad controller.
+
+- key-interrupt-trigger-type: The type of interrupt trigger asociated with the Keypad matrix.
+
+ KEYPAD_INTERRUPT_NO_TRIGGER = 0
+ KEYPAD_INTERRUPT_RISING_EDGE = 1
+ KEYPAD_INTERRUPT_FALLING_EDGE = 2
+ KEYPAD_INTERRUPT_BOTH_EDGES = 3
Can we get this data from the interrupt spec?
I don't understand your question. Could you elaborate?
But, looking at this closer this determines when the hardware should
generate interrupts. I think we would always need to set it to both
edges and this binding option can probably we removed?
+
+- col-debounce-filter-period: The debounce period for the Column filter.
+
+ KEYPAD_DEBOUNCE_1_ms = 0
+ KEYPAD_DEBOUNCE_2_ms = 1
+ KEYPAD_DEBOUNCE_4_ms = 2
+ KEYPAD_DEBOUNCE_8_ms = 3
+ KEYPAD_DEBOUNCE_16_ms = 4
+ KEYPAD_DEBOUNCE_32_ms = 5
+ KEYPAD_DEBOUNCE_64_ms = 6
+ KEYPAD_DEBOUNCE_128_ms = 7
+
+- status-debounce-filter-period: The debounce period for the Status filter.
+
+ KEYPAD_DEBOUNCE_1_ms = 0
+ KEYPAD_DEBOUNCE_2_ms = 1
+ KEYPAD_DEBOUNCE_4_ms = 2
+ KEYPAD_DEBOUNCE_8_ms = 3
+ KEYPAD_DEBOUNCE_16_ms = 4
+ KEYPAD_DEBOUNCE_32_ms = 5
+ KEYPAD_DEBOUNCE_64_ms = 6
+ KEYPAD_DEBOUNCE_128_ms = 7
I could swear device-specific properties should be in form of
<vendor-prefix>,<property-name> to ensure it won't clash with changes on
subsystem level later on. Device-tree folks, what say you?
I see examples with and without vendor-prefix.
qcom,pm8xxx-keypad.txt does not have prefixes
st-keyscan.txt does have a prefix
I can't find any documented guidelines for this.
Clash changes should not happen because as new standard properties are
added the drivers should be adjusted to use the new dt-bindings?
+
+- row-output-enabled: An optional property indicating whether the row or
+ column is being used as output. If specified the row is being used
+ as the output. Else defaults to column.
+
+- pull-up-enabled: An optional property indicating the Keypad scan mode.
+ If specified implies the keypad scan pull-up has been enabled.
+
+- Keys represented as child nodes: Each key connected to the keypad
+ controller is represented as a child node to the keypad controller
+ device node and should include the following properties.
+ - row: the row number to which the key is connected.
+ - column: the column number to which the key is connected.
+ - code: the key-code to be reported when the key is pressed
+ and released.
That does not seem to be right, linux,keymap is a list, not a subtree.
I'd simply refer to
Documentation/devicetree/bindings/input/matrix-keymap.txt for details.
Yes, we moved to matrix-keymap and forgot to update this documentation.
Will correct - thanks.
+
+Example:
+#include "dt-bindings/input/input.h"
+
+/ {
+ keypad: keypad@180ac000 {
+ /* Required SoC specific properties */
+ compatible = "brcm,bcm-keypad";
+
+ /* Required Board specific properties */
+ keypad,num-rows = <5>;
+ keypad,num-columns = <5>;
+ status = "okay";
+
+ linux,keymap = <MATRIX_KEY(0x00, 0x02, KEY_F) /* key_forward */
+ MATRIX_KEY(0x00, 0x03, KEY_HOME) /* key_home */
+ MATRIX_KEY(0x00, 0x04, KEY_M) /* key_message */
+ MATRIX_KEY(0x01, 0x00, KEY_A) /* key_contacts */
+ MATRIX_KEY(0x01, 0x01, KEY_1) /* key_1 */
+ MATRIX_KEY(0x01, 0x02, KEY_2) /* key_2 */
+ MATRIX_KEY(0x01, 0x03, KEY_3) /* key_3 */
+ MATRIX_KEY(0x01, 0x04, KEY_S) /* key_speaker */
+ MATRIX_KEY(0x02, 0x00, KEY_P) /* key_phone */
+ MATRIX_KEY(0x02, 0x01, KEY_4) /* key_4 */
+ MATRIX_KEY(0x02, 0x02, KEY_5) /* key_5 */
+ MATRIX_KEY(0x02, 0x03, KEY_6) /* key_6 */
+ MATRIX_KEY(0x02, 0x04, KEY_VOLUMEUP) /* key_vol_up */
+ MATRIX_KEY(0x03, 0x00, KEY_C) /* key_call_log */
+ MATRIX_KEY(0x03, 0x01, KEY_7) /* key_7 */
+ MATRIX_KEY(0x03, 0x02, KEY_8) /* key_8 */
+ MATRIX_KEY(0x03, 0x03, KEY_9) /* key_9 */
+ MATRIX_KEY(0x03, 0x04, KEY_VOLUMEDOWN) /* key_vol_down */
+ MATRIX_KEY(0x04, 0x00, KEY_H) /* key_headset */
+ MATRIX_KEY(0x04, 0x01, KEY_KPASTERISK) /* key_* */
+ MATRIX_KEY(0x04, 0x02, KEY_0) /* key_0 */
+ MATRIX_KEY(0x04, 0x03, KEY_GRAVE) /* key_# */
+ MATRIX_KEY(0x04, 0x04, KEY_MUTE) /* key_mute */
+ >;
+
+ /* Optional board specific properties */
+ key-interrupt-trigger-type = <3>;
+ col-debounce-filter-period = <5>;
+ row-output-enabled;
+ pull-up-enabled;
+
+ };
+};
--
2.2.2
Thanks.
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