Some touchscreens are shipped with a physical layer on top of them where
a number of buttons and a resized touchscreen surface might be available.
In order to generate proper key events by overlay buttons and adjust the
touch events to a clipped surface, this series offers a documented,
device-tree-based solution by means of helper functions.
An implementation for a specific touchscreen driver is also included.
The functions in touch-overlay provide a simple workflow to acquire
physical objects from the device tree, map them into a list and generate
events according to the object descriptions.
This feature has been tested with a JT240MHQS-E3 display, which consists
of an st1624 as the base touchscreen and an overlay with two buttons and
a frame that clips its effective surface mounted on it.
Signed-off-by: Javier Carrasco <[email protected]>
---
Changes in v7:
- General: return to a single input device implementation.
- touchscreen bindings: segment instead of button in the label
description.
- touch-overlay.c: define button-specific data inside segment struct.
- touch-overlay.c: remove fwnode_property_present() and check return
value of fwnode_property_read_u32() in touch_overlay_get_segment().
- touch-overlay.c: simplify return path in touch_overlay_map().
- Link to v6: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v6-0-d8a605975153@wolfvision.net
Changes in v6:
- General: use a single list to manage a single type of object.
- General: swap patches to have bindings preceding the code.
- touch-overlay.c: minor code-sytle fixes.
- Link to v5: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v5-0-ff6b5c4db693@wolfvision.net
Changes in v5:
- touchscreen bindings: move overlay common properties to a $def entry (Rob Herring)
- st1232 bindings: move overlays to the existing example instead of
making a new one (Rob Herring)
- Link to v4: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v4-0-5c6c0fc1eed6@wolfvision.net
Changes in v4:
- General: rename "touchscreen" to "touch" to include other consumers.
- PATCH 1/4: move touch-overlay feature to input core.
- PATCH 1/4, 3/4: set key caps and report key events without consumer's
intervention.
- PATCH 2/4: add missing 'required' field with the required properties.
- Link to v3: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v3-0-b4fb7fc4bab7@wolfvision.net
Changes in v3:
- General: rename "virtobj" and "virtual" to "overlay"
- PATCH 1/4: Make feature bool instead of tristate (selected by
supported touchscreens)
- Link to v2: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v2-0-f68a6bfe7a0f@wolfvision.net
Changes in v2:
- PATCH 1/4: remove preprocessor directives (the module is selected by
the drivers that support the feature). Typo in the commit message.
- PATCH 2/4: more detailed documentation. Images and examples were added.
- PATCH 3/4: select ts-virtobj automatically.
- Link to v1: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v1-0-5ae5e81bc264@wolfvision.net
---
Javier Carrasco (4):
dt-bindings: touchscreen: add touch-overlay property
Input: touch-overlay - Add touchscreen overlay handling
dt-bindings: input: touchscreen: st1232: add touch-overlay example
Input: st1232 - add touch overlays handling
.../input/touchscreen/sitronix,st1232.yaml | 29 +++
.../bindings/input/touchscreen/touchscreen.yaml | 119 ++++++++++
MAINTAINERS | 7 +
drivers/input/Makefile | 2 +-
drivers/input/touch-overlay.c | 250 +++++++++++++++++++++
drivers/input/touchscreen/st1232.c | 48 ++--
include/linux/input/touch-overlay.h | 22 ++
7 files changed, 462 insertions(+), 15 deletions(-)
---
base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
change-id: 20230510-feature-ts_virtobj_patch-e267540aae74
Best regards,
--
Javier Carrasco <[email protected]>
The touch-overlay encompasses a number of touch areas that define a
clipped touchscreen area and/or buttons with a specific functionality.
A clipped touchscreen area avoids getting events from regions that are
physically hidden by overlay frames.
For touchscreens with printed overlay buttons, sub-nodes with a suitable
key code can be defined to report key events instead of the original
touch events.
Reviewed-by: Jeff LaBundy <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Javier Carrasco <[email protected]>
---
.../bindings/input/touchscreen/touchscreen.yaml | 119 +++++++++++++++++++++
1 file changed, 119 insertions(+)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
index 431c13335c40..eb1e86fa86c6 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
@@ -87,6 +87,125 @@ properties:
touchscreen-y-plate-ohms:
description: Resistance of the Y-plate in Ohms
+ touch-overlay:
+ description: list of nodes defining segments (touch areas) on the
+ touchscreen.
+
+ This object can be used to describe a series of segments to
+ restrict the region within touch events are reported or buttons
+ with a specific functionality.
+
+ This is of special interest if the touchscreen is shipped with a physical
+ overlay on top of it with a frame that hides some part of the original
+ touchscreen area. Printed buttons on that overlay are also a typical
+ use case.
+
+ A new touchscreen area is defined as a sub-node without a key code. If a
+ key code is defined in the sub-node, it will be interpreted as a button.
+
+ The x-origin and y-origin properties of a touchscreen area define the
+ offset of a new origin from where the touchscreen events are referenced.
+ This offset is applied to the events accordingly. The x-size and y-size
+ properties define the size of the touchscreen effective area.
+
+ The following example shows a new touchscreen area with the new origin
+ (0',0') for the touch events generated by the device.
+
+ Touchscreen (full area)
+ ┌────────────────────────────────────────┐
+ │ ┌───────────────────────────────┐ │
+ │ │ │ │
+ │ ├ y-size │ │
+ │ │ │ │
+ │ │ touchscreen area │ │
+ │ │ (no key code) │ │
+ │ │ │ │
+ │ │ x-size │ │
+ │ ┌└──────────────┴────────────────┘ │
+ │(0',0') │
+ ┌└────────────────────────────────────────┘
+ (0,0)
+
+ where (0',0') = (0+x-origin,0+y-origin)
+
+ Sub-nodes with key codes report the touch events on their surface as key
+ events instead.
+
+ The following example shows a touchscreen with a single button on it.
+
+ Touchscreen (full area)
+ ┌───────────────────────────────────┐
+ │ │
+ │ │
+ │ ┌─────────┐ │
+ │ │button 0 │ │
+ │ │KEY_POWER│ │
+ │ └─────────┘ │
+ │ │
+ │ │
+ ┌└───────────────────────────────────┘
+ (0,0)
+
+ Segments defining buttons and clipped toushcreen areas can be combined
+ as shown in the following example.
+ In that case only the events within the touchscreen area are reported
+ as touch events. Events within the button areas report their associated
+ key code. Any events outside the defined areas are ignored.
+
+ Touchscreen (full area)
+ ┌─────────┬──────────────────────────────┐
+ │ │ │
+ │ │ ┌───────────────────────┐ │
+ │ button 0│ │ │ │
+ │KEY_POWER│ │ │ │
+ │ │ │ │ │
+ ├─────────┤ │ touchscreen area │ │
+ │ │ │ (no key code) │ │
+ │ │ │ │ │
+ │ button 1│ │ │ │
+ │ KEY_INFO│ ┌└───────────────────────┘ │
+ │ │(0',0') │
+ ┌└─────────┴──────────────────────────────┘
+ (0,0)
+
+ type: object
+
+ patternProperties:
+ '^segment-':
+ type: object
+ description:
+ Each segment is represented as a sub-node.
+ properties:
+ x-origin:
+ description: horizontal origin of the node area
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ y-origin:
+ description: vertical origin of the node area
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ x-size:
+ description: horizontal resolution of the node area
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ y-size:
+ description: vertical resolution of the node area
+ $ref: /schemas/types.yaml#/definitions/uint32
+
+ label:
+ description: descriptive name of the segment
+ $ref: /schemas/types.yaml#/definitions/string
+
+ linux,code: true
+
+ required:
+ - x-origin
+ - y-origin
+ - x-size
+ - y-size
+
+ unevaluatedProperties: false
+
dependencies:
touchscreen-size-x: [ touchscreen-size-y ]
touchscreen-size-y: [ touchscreen-size-x ]
--
2.39.2
Some touch devices provide mechanical overlays with different objects
like buttons or clipped touchscreen surfaces.
In order to support these objects, add a series of helper functions
to the input subsystem to transform them into overlay objects via
device tree nodes.
These overlay objects consume the raw touch events and report the
expected input events depending on the object properties.
Note that the current implementation allows for multiple definitions
of touchscreen areas (regions that report touch events), but only the
first one will be used for the touchscreen device that the consumers
typically provide.
Should the need for multiple touchscreen areas arise, additional
touchscreen devices would be required at the consumer side.
There is no limitation in the number of touch areas defined as buttons.
Signed-off-by: Javier Carrasco <[email protected]>
---
MAINTAINERS | 7 +
drivers/input/Makefile | 2 +-
drivers/input/touch-overlay.c | 250 ++++++++++++++++++++++++++++++++++++
include/linux/input/touch-overlay.h | 22 ++++
4 files changed, 280 insertions(+), 1 deletion(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index a7c4cf8201e0..668687bf94df 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21961,6 +21961,13 @@ L: [email protected]
S: Maintained
F: drivers/platform/x86/toshiba-wmi.c
+TOUCH OVERLAY
+M: Javier Carrasco <[email protected]>
+L: [email protected]
+S: Maintained
+F: drivers/input/touch-overlay.c
+F: include/linux/input/touch-overlay.h
+
TPM DEVICE DRIVER
M: Peter Huewe <[email protected]>
M: Jarkko Sakkinen <[email protected]>
diff --git a/drivers/input/Makefile b/drivers/input/Makefile
index c78753274921..393e9f4d00dc 100644
--- a/drivers/input/Makefile
+++ b/drivers/input/Makefile
@@ -7,7 +7,7 @@
obj-$(CONFIG_INPUT) += input-core.o
input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o
-input-core-y += touchscreen.o
+input-core-y += touchscreen.o touch-overlay.o
obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
obj-$(CONFIG_INPUT_SPARSEKMAP) += sparse-keymap.o
diff --git a/drivers/input/touch-overlay.c b/drivers/input/touch-overlay.c
new file mode 100644
index 000000000000..42b6ad753a00
--- /dev/null
+++ b/drivers/input/touch-overlay.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Helper functions for overlay objects on touchscreens
+ *
+ * Copyright (c) 2023 Javier Carrasco <[email protected]>
+ */
+
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touch-overlay.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+struct touch_overlay_segment {
+ struct list_head list;
+ u32 x_origin;
+ u32 y_origin;
+ u32 x_size;
+ u32 y_size;
+ u32 key;
+ bool pressed;
+ int slot;
+};
+
+static int touch_overlay_get_segment(struct fwnode_handle *segment_node,
+ struct touch_overlay_segment *segment,
+ struct input_dev *input)
+{
+ int error;
+
+ error = fwnode_property_read_u32(segment_node, "x-origin",
+ &segment->x_origin);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "y-origin",
+ &segment->y_origin);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "x-size",
+ &segment->x_size);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "y-size",
+ &segment->y_size);
+ if (error)
+ return error;
+
+ error = fwnode_property_read_u32(segment_node, "linux,code",
+ &segment->key);
+ if (!error)
+ input_set_capability(input, EV_KEY, segment->key);
+ else if (error != -EINVAL)
+ return error;
+
+ return 0;
+}
+
+/**
+ * touch_overlay_map - map overlay objects from the device tree and set
+ * key capabilities if buttons are defined.
+ * @list: pointer to the list that will hold the segments
+ * @input: pointer to the already allocated input_dev
+ *
+ * Returns 0 on success and error number otherwise.
+ *
+ * If buttons are defined, key capabilities are set accordingly.
+ */
+int touch_overlay_map(struct list_head *list, struct input_dev *input)
+{
+ struct fwnode_handle *overlay, *fw_segment;
+ struct device *dev = input->dev.parent;
+ struct touch_overlay_segment *segment;
+ int error;
+
+ overlay = device_get_named_child_node(dev, "touch-overlay");
+ if (!overlay)
+ return 0;
+
+ fwnode_for_each_child_node(overlay, fw_segment) {
+ segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL);
+ if (!segment) {
+ error = -ENOMEM;
+ fwnode_handle_put(overlay);
+ break;
+ }
+ error = touch_overlay_get_segment(fw_segment, segment, input);
+ if (error) {
+ fwnode_handle_put(overlay);
+ break;
+ }
+ list_add_tail(&segment->list, list);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(touch_overlay_map);
+
+/**
+ * touch_overlay_get_touchscreen_abs - get abs size from the touchscreen area.
+ * @list: pointer to the list that holds the segments
+ * @x: horizontal abs
+ * @y: vertical abs
+ */
+void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (!segment->key) {
+ *x = segment->x_size - 1;
+ *y = segment->y_size - 1;
+ break;
+ }
+ }
+}
+EXPORT_SYMBOL(touch_overlay_get_touchscreen_abs);
+
+static bool touch_overlay_segment_event(struct touch_overlay_segment *seg,
+ u32 x, u32 y)
+{
+ if (!seg)
+ return false;
+
+ if (x >= seg->x_origin && x < (seg->x_origin + seg->x_size) &&
+ y >= seg->y_origin && y < (seg->y_origin + seg->y_size))
+ return true;
+
+ return false;
+}
+
+/**
+ * touch_overlay_mapped_touchscreen - check if a touchscreen area is mapped
+ * @list: pointer to the list that holds the segments
+ *
+ * Returns true if a touchscreen area is mapped or false otherwise.
+ */
+bool touch_overlay_mapped_touchscreen(struct list_head *list)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (!segment->key)
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(touch_overlay_mapped_touchscreen);
+
+static bool touch_overlay_event_on_ts(struct list_head *list, u32 *x, u32 *y)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+ bool valid_touch = true;
+
+ if (!x || !y)
+ return false;
+
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (segment->key)
+ continue;
+
+ if (touch_overlay_segment_event(segment, *x, *y)) {
+ *x -= segment->x_origin;
+ *y -= segment->y_origin;
+ return true;
+ }
+ /* ignore touch events outside the defined area */
+ valid_touch = false;
+ }
+
+ return valid_touch;
+}
+
+static bool touch_overlay_button_event(struct input_dev *input,
+ struct touch_overlay_segment *segment,
+ const u32 *x, const u32 *y, u32 slot)
+{
+ bool contact = x && y;
+
+ if (!contact && segment->pressed && segment->slot == slot) {
+ segment->pressed = false;
+ input_report_key(input, segment->key, false);
+ input_sync(input);
+ return true;
+ } else if (contact && touch_overlay_segment_event(segment, *x, *y)) {
+ segment->pressed = true;
+ segment->slot = slot;
+ input_report_key(input, segment->key, true);
+ input_sync(input);
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * touch_overlay_process_event - process input events according to the overlay
+ * mapping. This function acts as a filter to release the calling driver from
+ * the events that are either related to overlay buttons or out of the overlay
+ * touchscreen area, if defined.
+ * @list: pointer to the list that holds the segments
+ * @input: pointer to the input device associated to the event
+ * @x: pointer to the x coordinate (NULL if not available - no contact)
+ * @y: pointer to the y coordinate (NULL if not available - no contact)
+ * @slot: slot associated to the event
+ *
+ * Returns true if the event was processed (reported for valid key events
+ * and dropped for events outside the overlay touchscreen area) or false
+ * if the event must be processed by the caller. In that case this function
+ * shifts the (x,y) coordinates to the overlay touchscreen axis if required.
+ */
+bool touch_overlay_process_event(struct list_head *list,
+ struct input_dev *input,
+ u32 *x, u32 *y, u32 slot)
+{
+ struct touch_overlay_segment *segment;
+ struct list_head *ptr;
+
+ /*
+ * buttons must be prioritized over overlay touchscreens to account for
+ * overlappings e.g. a button inside the touchscreen area.
+ */
+ list_for_each(ptr, list) {
+ segment = list_entry(ptr, struct touch_overlay_segment, list);
+ if (segment->key &&
+ touch_overlay_button_event(input, segment, x, y, slot)) {
+ return true;
+ }
+ }
+
+ /*
+ * valid touch events on the overlay touchscreen are left for the client
+ * to be processed/reported according to its (possibly) unique features.
+ */
+ return !touch_overlay_event_on_ts(list, x, y);
+}
+EXPORT_SYMBOL(touch_overlay_process_event);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Helper functions for overlay objects on touch devices");
diff --git a/include/linux/input/touch-overlay.h b/include/linux/input/touch-overlay.h
new file mode 100644
index 000000000000..cef05c46000d
--- /dev/null
+++ b/include/linux/input/touch-overlay.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Javier Carrasco <[email protected]>
+ */
+
+#ifndef _TOUCH_OVERLAY
+#define _TOUCH_OVERLAY
+
+#include <linux/types.h>
+
+struct input_dev;
+
+int touch_overlay_map(struct list_head *list, struct input_dev *input);
+
+void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y);
+
+bool touch_overlay_mapped_touchscreen(struct list_head *list);
+
+bool touch_overlay_process_event(struct list_head *list, struct input_dev *input,
+ u32 *x, u32 *y, u32 slot);
+
+#endif
--
2.39.2
Use touch-overlay to support overlay objects such as buttons and a resized
frame defined in the device tree.
If buttons are provided, register an additional device to report key
events separately. A key event will be generated if the coordinates
of a touch event are within the area defined by the button properties.
Signed-off-by: Javier Carrasco <[email protected]>
---
drivers/input/touchscreen/st1232.c | 48 +++++++++++++++++++++++++++-----------
1 file changed, 34 insertions(+), 14 deletions(-)
diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 6475084aee1b..4fa31447dbc1 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -22,6 +22,7 @@
#include <linux/pm_qos.h>
#include <linux/slab.h>
#include <linux/types.h>
+#include <linux/input/touch-overlay.h>
#define ST1232_TS_NAME "st1232-ts"
#define ST1633_TS_NAME "st1633-ts"
@@ -57,6 +58,7 @@ struct st1232_ts_data {
struct dev_pm_qos_request low_latency_req;
struct gpio_desc *reset_gpio;
const struct st_chip_info *chip_info;
+ struct list_head touch_overlay_list;
int read_buf_len;
u8 *read_buf;
};
@@ -138,14 +140,20 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
for (i = 0; i < ts->chip_info->max_fingers; i++) {
u8 *buf = &ts->read_buf[i * 4];
+ bool contact = buf[0] & BIT(7);
+ unsigned int x, y;
- if (buf[0] & BIT(7)) {
- unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
- unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
-
- touchscreen_set_mt_pos(&pos[n_contacts],
- &ts->prop, x, y);
+ if (contact) {
+ x = ((buf[0] & 0x70) << 4) | buf[1];
+ y = ((buf[0] & 0x07) << 8) | buf[2];
+ }
+ if (touch_overlay_process_event(&ts->touch_overlay_list, input,
+ contact ? &x : NULL,
+ contact ? &y : NULL, i))
+ continue;
+ if (contact) {
+ touchscreen_set_mt_pos(&pos[n_contacts], &ts->prop, x, y);
/* st1232 includes a z-axis / touch strength */
if (ts->chip_info->have_z)
z[n_contacts] = ts->read_buf[i + 6];
@@ -292,18 +300,30 @@ static int st1232_ts_probe(struct i2c_client *client)
if (error)
return error;
- /* Read resolution from the chip */
- error = st1232_ts_read_resolution(ts, &max_x, &max_y);
- if (error) {
- dev_err(&client->dev,
- "Failed to read resolution: %d\n", error);
- return error;
- }
-
if (ts->chip_info->have_z)
input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
ts->chip_info->max_area, 0, 0);
+ /* map overlay objects if defined in the device tree */
+ INIT_LIST_HEAD(&ts->touch_overlay_list);
+ error = touch_overlay_map(&ts->touch_overlay_list, input_dev);
+ if (error)
+ return error;
+
+ if (touch_overlay_mapped_touchscreen(&ts->touch_overlay_list)) {
+ /* Read resolution from the overlay touchscreen if defined */
+ touch_overlay_get_touchscreen_abs(&ts->touch_overlay_list,
+ &max_x, &max_y);
+ } else {
+ /* Read resolution from the chip */
+ error = st1232_ts_read_resolution(ts, &max_x, &max_y);
+ if (error) {
+ dev_err(&client->dev,
+ "Failed to read resolution: %d\n", error);
+ return error;
+ }
+ }
+
input_set_abs_params(input_dev, ABS_MT_POSITION_X,
0, max_x, 0, 0);
input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
--
2.39.2
The touch-overaly feature adds support for segments (touch areas) on the
touchscreen surface that represent overlays with clipped touchscreen
areas and printed buttons.
Add nodes for a clipped touchscreen and overlay buttons to the existing
example.
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Javier Carrasco <[email protected]>
---
.../input/touchscreen/sitronix,st1232.yaml | 29 ++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml b/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
index 1d8ca19fd37a..e7ee7a0d74c4 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
@@ -37,6 +37,7 @@ unevaluatedProperties: false
examples:
- |
+ #include <dt-bindings/input/linux-event-codes.h>
i2c {
#address-cells = <1>;
#size-cells = <0>;
@@ -46,5 +47,33 @@ examples:
reg = <0x55>;
interrupts = <2 0>;
gpios = <&gpio1 166 0>;
+
+ touch-overlay {
+ segment-0 {
+ label = "Touchscreen";
+ x-origin = <0>;
+ x-size = <240>;
+ y-origin = <40>;
+ y-size = <280>;
+ };
+
+ segment-1a {
+ label = "Camera light";
+ linux,code = <KEY_LIGHTS_TOGGLE>;
+ x-origin = <40>;
+ x-size = <40>;
+ y-origin = <0>;
+ y-size = <40>;
+ };
+
+ segment-2a {
+ label = "Power";
+ linux,code = <KEY_POWER>;
+ x-origin = <160>;
+ x-size = <40>;
+ y-origin = <0>;
+ y-size = <40>;
+ };
+ };
};
};
--
2.39.2
On 19.01.24 08:43, Javier Carrasco wrote:
> Some touchscreens are shipped with a physical layer on top of them where
> a number of buttons and a resized touchscreen surface might be available.
>
> In order to generate proper key events by overlay buttons and adjust the
> touch events to a clipped surface, this series offers a documented,
> device-tree-based solution by means of helper functions.
> An implementation for a specific touchscreen driver is also included.
>
> The functions in touch-overlay provide a simple workflow to acquire
> physical objects from the device tree, map them into a list and generate
> events according to the object descriptions.
>
> This feature has been tested with a JT240MHQS-E3 display, which consists
> of an st1624 as the base touchscreen and an overlay with two buttons and
> a frame that clips its effective surface mounted on it.
>
> Signed-off-by: Javier Carrasco <[email protected]>
> ---
> Changes in v7:
> - General: return to a single input device implementation.
> - touchscreen bindings: segment instead of button in the label
> description.
> - touch-overlay.c: define button-specific data inside segment struct.
> - touch-overlay.c: remove fwnode_property_present() and check return
> value of fwnode_property_read_u32() in touch_overlay_get_segment().
> - touch-overlay.c: simplify return path in touch_overlay_map().
> - Link to v6: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v6-0-d8a605975153@wolfvision.net
>
> Changes in v6:
> - General: use a single list to manage a single type of object.
> - General: swap patches to have bindings preceding the code.
> - touch-overlay.c: minor code-sytle fixes.
> - Link to v5: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v5-0-ff6b5c4db693@wolfvision.net
>
> Changes in v5:
> - touchscreen bindings: move overlay common properties to a $def entry (Rob Herring)
> - st1232 bindings: move overlays to the existing example instead of
> making a new one (Rob Herring)
> - Link to v4: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v4-0-5c6c0fc1eed6@wolfvision.net
>
> Changes in v4:
> - General: rename "touchscreen" to "touch" to include other consumers.
> - PATCH 1/4: move touch-overlay feature to input core.
> - PATCH 1/4, 3/4: set key caps and report key events without consumer's
> intervention.
> - PATCH 2/4: add missing 'required' field with the required properties.
> - Link to v3: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v3-0-b4fb7fc4bab7@wolfvision.net
>
> Changes in v3:
> - General: rename "virtobj" and "virtual" to "overlay"
> - PATCH 1/4: Make feature bool instead of tristate (selected by
> supported touchscreens)
> - Link to v2: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v2-0-f68a6bfe7a0f@wolfvision.net
>
> Changes in v2:
> - PATCH 1/4: remove preprocessor directives (the module is selected by
> the drivers that support the feature). Typo in the commit message.
> - PATCH 2/4: more detailed documentation. Images and examples were added.
> - PATCH 3/4: select ts-virtobj automatically.
> - Link to v1: https://lore.kernel.org/r/20230510-feature-ts_virtobj_patch-v1-0-5ae5e81bc264@wolfvision.net
>
> ---
> Javier Carrasco (4):
> dt-bindings: touchscreen: add touch-overlay property
> Input: touch-overlay - Add touchscreen overlay handling
> dt-bindings: input: touchscreen: st1232: add touch-overlay example
> Input: st1232 - add touch overlays handling
>
> .../input/touchscreen/sitronix,st1232.yaml | 29 +++
> .../bindings/input/touchscreen/touchscreen.yaml | 119 ++++++++++
> MAINTAINERS | 7 +
> drivers/input/Makefile | 2 +-
> drivers/input/touch-overlay.c | 250 +++++++++++++++++++++
> drivers/input/touchscreen/st1232.c | 48 ++--
> include/linux/input/touch-overlay.h | 22 ++
> 7 files changed, 462 insertions(+), 15 deletions(-)
> ---
> base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
> change-id: 20230510-feature-ts_virtobj_patch-e267540aae74
>
> Best regards,
Gentle ping.
Best regards,
Javier Carrasco
Hi Javier,
On Fri, Jan 19, 2024 at 08:43:34AM +0100, Javier Carrasco wrote:
> Some touch devices provide mechanical overlays with different objects
> like buttons or clipped touchscreen surfaces.
>
> In order to support these objects, add a series of helper functions
> to the input subsystem to transform them into overlay objects via
> device tree nodes.
>
> These overlay objects consume the raw touch events and report the
> expected input events depending on the object properties.
>
> Note that the current implementation allows for multiple definitions
> of touchscreen areas (regions that report touch events), but only the
> first one will be used for the touchscreen device that the consumers
> typically provide.
> Should the need for multiple touchscreen areas arise, additional
> touchscreen devices would be required at the consumer side.
> There is no limitation in the number of touch areas defined as buttons.
>
> Signed-off-by: Javier Carrasco <[email protected]>
Apologies for the delay, but I think this looks great now. It can always
be extended later in case another touchscreen driver needs additional
functionality or visibility. You've addressed all of my feedback, and so:
Reviewed-by: Jeff LaBundy <[email protected]>
> ---
> MAINTAINERS | 7 +
> drivers/input/Makefile | 2 +-
> drivers/input/touch-overlay.c | 250 ++++++++++++++++++++++++++++++++++++
> include/linux/input/touch-overlay.h | 22 ++++
> 4 files changed, 280 insertions(+), 1 deletion(-)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a7c4cf8201e0..668687bf94df 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -21961,6 +21961,13 @@ L: [email protected]
> S: Maintained
> F: drivers/platform/x86/toshiba-wmi.c
>
> +TOUCH OVERLAY
> +M: Javier Carrasco <[email protected]>
> +L: [email protected]
> +S: Maintained
> +F: drivers/input/touch-overlay.c
> +F: include/linux/input/touch-overlay.h
> +
> TPM DEVICE DRIVER
> M: Peter Huewe <[email protected]>
> M: Jarkko Sakkinen <[email protected]>
> diff --git a/drivers/input/Makefile b/drivers/input/Makefile
> index c78753274921..393e9f4d00dc 100644
> --- a/drivers/input/Makefile
> +++ b/drivers/input/Makefile
> @@ -7,7 +7,7 @@
>
> obj-$(CONFIG_INPUT) += input-core.o
> input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o
> -input-core-y += touchscreen.o
> +input-core-y += touchscreen.o touch-overlay.o
>
> obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o
> obj-$(CONFIG_INPUT_SPARSEKMAP) += sparse-keymap.o
> diff --git a/drivers/input/touch-overlay.c b/drivers/input/touch-overlay.c
> new file mode 100644
> index 000000000000..42b6ad753a00
> --- /dev/null
> +++ b/drivers/input/touch-overlay.c
> @@ -0,0 +1,250 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Helper functions for overlay objects on touchscreens
> + *
> + * Copyright (c) 2023 Javier Carrasco <[email protected]>
> + */
> +
> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/input/touch-overlay.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +
> +struct touch_overlay_segment {
> + struct list_head list;
> + u32 x_origin;
> + u32 y_origin;
> + u32 x_size;
> + u32 y_size;
> + u32 key;
> + bool pressed;
> + int slot;
> +};
> +
> +static int touch_overlay_get_segment(struct fwnode_handle *segment_node,
> + struct touch_overlay_segment *segment,
> + struct input_dev *input)
> +{
> + int error;
> +
> + error = fwnode_property_read_u32(segment_node, "x-origin",
> + &segment->x_origin);
> + if (error)
> + return error;
> +
> + error = fwnode_property_read_u32(segment_node, "y-origin",
> + &segment->y_origin);
> + if (error)
> + return error;
> +
> + error = fwnode_property_read_u32(segment_node, "x-size",
> + &segment->x_size);
> + if (error)
> + return error;
> +
> + error = fwnode_property_read_u32(segment_node, "y-size",
> + &segment->y_size);
> + if (error)
> + return error;
> +
> + error = fwnode_property_read_u32(segment_node, "linux,code",
> + &segment->key);
> + if (!error)
> + input_set_capability(input, EV_KEY, segment->key);
> + else if (error != -EINVAL)
> + return error;
> +
> + return 0;
> +}
> +
> +/**
> + * touch_overlay_map - map overlay objects from the device tree and set
> + * key capabilities if buttons are defined.
> + * @list: pointer to the list that will hold the segments
> + * @input: pointer to the already allocated input_dev
> + *
> + * Returns 0 on success and error number otherwise.
> + *
> + * If buttons are defined, key capabilities are set accordingly.
> + */
> +int touch_overlay_map(struct list_head *list, struct input_dev *input)
> +{
> + struct fwnode_handle *overlay, *fw_segment;
> + struct device *dev = input->dev.parent;
> + struct touch_overlay_segment *segment;
> + int error;
> +
> + overlay = device_get_named_child_node(dev, "touch-overlay");
> + if (!overlay)
> + return 0;
> +
> + fwnode_for_each_child_node(overlay, fw_segment) {
> + segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL);
> + if (!segment) {
> + error = -ENOMEM;
> + fwnode_handle_put(overlay);
> + break;
> + }
> + error = touch_overlay_get_segment(fw_segment, segment, input);
> + if (error) {
> + fwnode_handle_put(overlay);
> + break;
> + }
> + list_add_tail(&segment->list, list);
> + }
> +
> + return error;
> +}
> +EXPORT_SYMBOL(touch_overlay_map);
> +
> +/**
> + * touch_overlay_get_touchscreen_abs - get abs size from the touchscreen area.
> + * @list: pointer to the list that holds the segments
> + * @x: horizontal abs
> + * @y: vertical abs
> + */
> +void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y)
> +{
> + struct touch_overlay_segment *segment;
> + struct list_head *ptr;
> +
> + list_for_each(ptr, list) {
> + segment = list_entry(ptr, struct touch_overlay_segment, list);
> + if (!segment->key) {
> + *x = segment->x_size - 1;
> + *y = segment->y_size - 1;
> + break;
> + }
> + }
> +}
> +EXPORT_SYMBOL(touch_overlay_get_touchscreen_abs);
> +
> +static bool touch_overlay_segment_event(struct touch_overlay_segment *seg,
> + u32 x, u32 y)
> +{
> + if (!seg)
> + return false;
> +
> + if (x >= seg->x_origin && x < (seg->x_origin + seg->x_size) &&
> + y >= seg->y_origin && y < (seg->y_origin + seg->y_size))
> + return true;
> +
> + return false;
> +}
> +
> +/**
> + * touch_overlay_mapped_touchscreen - check if a touchscreen area is mapped
> + * @list: pointer to the list that holds the segments
> + *
> + * Returns true if a touchscreen area is mapped or false otherwise.
> + */
> +bool touch_overlay_mapped_touchscreen(struct list_head *list)
> +{
> + struct touch_overlay_segment *segment;
> + struct list_head *ptr;
> +
> + list_for_each(ptr, list) {
> + segment = list_entry(ptr, struct touch_overlay_segment, list);
> + if (!segment->key)
> + return true;
> + }
> +
> + return false;
> +}
> +EXPORT_SYMBOL(touch_overlay_mapped_touchscreen);
> +
> +static bool touch_overlay_event_on_ts(struct list_head *list, u32 *x, u32 *y)
> +{
> + struct touch_overlay_segment *segment;
> + struct list_head *ptr;
> + bool valid_touch = true;
> +
> + if (!x || !y)
> + return false;
> +
> + list_for_each(ptr, list) {
> + segment = list_entry(ptr, struct touch_overlay_segment, list);
> + if (segment->key)
> + continue;
> +
> + if (touch_overlay_segment_event(segment, *x, *y)) {
> + *x -= segment->x_origin;
> + *y -= segment->y_origin;
> + return true;
> + }
> + /* ignore touch events outside the defined area */
> + valid_touch = false;
> + }
> +
> + return valid_touch;
> +}
> +
> +static bool touch_overlay_button_event(struct input_dev *input,
> + struct touch_overlay_segment *segment,
> + const u32 *x, const u32 *y, u32 slot)
> +{
> + bool contact = x && y;
> +
> + if (!contact && segment->pressed && segment->slot == slot) {
> + segment->pressed = false;
> + input_report_key(input, segment->key, false);
> + input_sync(input);
> + return true;
> + } else if (contact && touch_overlay_segment_event(segment, *x, *y)) {
> + segment->pressed = true;
> + segment->slot = slot;
> + input_report_key(input, segment->key, true);
> + input_sync(input);
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/**
> + * touch_overlay_process_event - process input events according to the overlay
> + * mapping. This function acts as a filter to release the calling driver from
> + * the events that are either related to overlay buttons or out of the overlay
> + * touchscreen area, if defined.
> + * @list: pointer to the list that holds the segments
> + * @input: pointer to the input device associated to the event
> + * @x: pointer to the x coordinate (NULL if not available - no contact)
> + * @y: pointer to the y coordinate (NULL if not available - no contact)
> + * @slot: slot associated to the event
> + *
> + * Returns true if the event was processed (reported for valid key events
> + * and dropped for events outside the overlay touchscreen area) or false
> + * if the event must be processed by the caller. In that case this function
> + * shifts the (x,y) coordinates to the overlay touchscreen axis if required.
> + */
> +bool touch_overlay_process_event(struct list_head *list,
> + struct input_dev *input,
> + u32 *x, u32 *y, u32 slot)
> +{
> + struct touch_overlay_segment *segment;
> + struct list_head *ptr;
> +
> + /*
> + * buttons must be prioritized over overlay touchscreens to account for
> + * overlappings e.g. a button inside the touchscreen area.
> + */
> + list_for_each(ptr, list) {
> + segment = list_entry(ptr, struct touch_overlay_segment, list);
> + if (segment->key &&
> + touch_overlay_button_event(input, segment, x, y, slot)) {
> + return true;
> + }
> + }
> +
> + /*
> + * valid touch events on the overlay touchscreen are left for the client
> + * to be processed/reported according to its (possibly) unique features.
> + */
> + return !touch_overlay_event_on_ts(list, x, y);
> +}
> +EXPORT_SYMBOL(touch_overlay_process_event);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Helper functions for overlay objects on touch devices");
> diff --git a/include/linux/input/touch-overlay.h b/include/linux/input/touch-overlay.h
> new file mode 100644
> index 000000000000..cef05c46000d
> --- /dev/null
> +++ b/include/linux/input/touch-overlay.h
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2023 Javier Carrasco <[email protected]>
> + */
> +
> +#ifndef _TOUCH_OVERLAY
> +#define _TOUCH_OVERLAY
> +
> +#include <linux/types.h>
> +
> +struct input_dev;
> +
> +int touch_overlay_map(struct list_head *list, struct input_dev *input);
> +
> +void touch_overlay_get_touchscreen_abs(struct list_head *list, u16 *x, u16 *y);
> +
> +bool touch_overlay_mapped_touchscreen(struct list_head *list);
> +
> +bool touch_overlay_process_event(struct list_head *list, struct input_dev *input,
> + u32 *x, u32 *y, u32 slot);
> +
> +#endif
>
> --
> 2.39.2
>
Kind regards,
Jeff LaBundy
Hi Javier,
On Fri, Jan 19, 2024 at 08:43:36AM +0100, Javier Carrasco wrote:
> Use touch-overlay to support overlay objects such as buttons and a resized
> frame defined in the device tree.
>
> If buttons are provided, register an additional device to report key
> events separately. A key event will be generated if the coordinates
> of a touch event are within the area defined by the button properties.
>
> Signed-off-by: Javier Carrasco <[email protected]>
Reviewed-by: Jeff LaBundy <[email protected]>
> ---
> drivers/input/touchscreen/st1232.c | 48 +++++++++++++++++++++++++++-----------
> 1 file changed, 34 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
> index 6475084aee1b..4fa31447dbc1 100644
> --- a/drivers/input/touchscreen/st1232.c
> +++ b/drivers/input/touchscreen/st1232.c
> @@ -22,6 +22,7 @@
> #include <linux/pm_qos.h>
> #include <linux/slab.h>
> #include <linux/types.h>
> +#include <linux/input/touch-overlay.h>
>
> #define ST1232_TS_NAME "st1232-ts"
> #define ST1633_TS_NAME "st1633-ts"
> @@ -57,6 +58,7 @@ struct st1232_ts_data {
> struct dev_pm_qos_request low_latency_req;
> struct gpio_desc *reset_gpio;
> const struct st_chip_info *chip_info;
> + struct list_head touch_overlay_list;
> int read_buf_len;
> u8 *read_buf;
> };
> @@ -138,14 +140,20 @@ static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
>
> for (i = 0; i < ts->chip_info->max_fingers; i++) {
> u8 *buf = &ts->read_buf[i * 4];
> + bool contact = buf[0] & BIT(7);
> + unsigned int x, y;
>
> - if (buf[0] & BIT(7)) {
> - unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
> - unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
> -
> - touchscreen_set_mt_pos(&pos[n_contacts],
> - &ts->prop, x, y);
> + if (contact) {
> + x = ((buf[0] & 0x70) << 4) | buf[1];
> + y = ((buf[0] & 0x07) << 8) | buf[2];
> + }
> + if (touch_overlay_process_event(&ts->touch_overlay_list, input,
> + contact ? &x : NULL,
> + contact ? &y : NULL, i))
> + continue;
>
> + if (contact) {
> + touchscreen_set_mt_pos(&pos[n_contacts], &ts->prop, x, y);
> /* st1232 includes a z-axis / touch strength */
> if (ts->chip_info->have_z)
> z[n_contacts] = ts->read_buf[i + 6];
> @@ -292,18 +300,30 @@ static int st1232_ts_probe(struct i2c_client *client)
> if (error)
> return error;
>
> - /* Read resolution from the chip */
> - error = st1232_ts_read_resolution(ts, &max_x, &max_y);
> - if (error) {
> - dev_err(&client->dev,
> - "Failed to read resolution: %d\n", error);
> - return error;
> - }
> -
> if (ts->chip_info->have_z)
> input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
> ts->chip_info->max_area, 0, 0);
>
> + /* map overlay objects if defined in the device tree */
> + INIT_LIST_HEAD(&ts->touch_overlay_list);
> + error = touch_overlay_map(&ts->touch_overlay_list, input_dev);
> + if (error)
> + return error;
> +
> + if (touch_overlay_mapped_touchscreen(&ts->touch_overlay_list)) {
> + /* Read resolution from the overlay touchscreen if defined */
> + touch_overlay_get_touchscreen_abs(&ts->touch_overlay_list,
> + &max_x, &max_y);
> + } else {
> + /* Read resolution from the chip */
> + error = st1232_ts_read_resolution(ts, &max_x, &max_y);
> + if (error) {
> + dev_err(&client->dev,
> + "Failed to read resolution: %d\n", error);
> + return error;
> + }
> + }
> +
> input_set_abs_params(input_dev, ABS_MT_POSITION_X,
> 0, max_x, 0, 0);
> input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
>
> --
> 2.39.2
>
Kind regards,
Jeff LaBundy
On 1/19/24 08:43, Javier Carrasco wrote:
> The touch-overlay encompasses a number of touch areas that define a
> clipped touchscreen area and/or buttons with a specific functionality.
>
> A clipped touchscreen area avoids getting events from regions that are
> physically hidden by overlay frames.
>
> For touchscreens with printed overlay buttons, sub-nodes with a suitable
> key code can be defined to report key events instead of the original
> touch events.
>
> Reviewed-by: Jeff LaBundy <[email protected]>
> Reviewed-by: Rob Herring <[email protected]>
> Signed-off-by: Javier Carrasco <[email protected]>
> ---
> .../bindings/input/touchscreen/touchscreen.yaml | 119 +++++++++++++++++++++
> 1 file changed, 119 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> index 431c13335c40..eb1e86fa86c6 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> @@ -87,6 +87,125 @@ properties:
> touchscreen-y-plate-ohms:
> description: Resistance of the Y-plate in Ohms
>
> + touch-overlay:
Even though it has already been reviewed, just in case before it gets
applied. Should it not be:
description: |
List of nodes...
instead, to keep formatting?
> + description: list of nodes defining segments (touch areas) on the
> + touchscreen.
> +
> + This object can be used to describe a series of segments to
> + restrict the region within touch events are reported or buttons
> + with a specific functionality.
> +
> + This is of special interest if the touchscreen is shipped with a physical
> + overlay on top of it with a frame that hides some part of the original
> + touchscreen area. Printed buttons on that overlay are also a typical
> + use case.
> +
> + A new touchscreen area is defined as a sub-node without a key code. If a
> + key code is defined in the sub-node, it will be interpreted as a button.
> +
> + The x-origin and y-origin properties of a touchscreen area define the
> + offset of a new origin from where the touchscreen events are referenced.
> + This offset is applied to the events accordingly. The x-size and y-size
> + properties define the size of the touchscreen effective area.
> +
> + The following example shows a new touchscreen area with the new origin
> + (0',0') for the touch events generated by the device.
> +
> + Touchscreen (full area)
> + ┌────────────────────────────────────────┐
> + │ ┌───────────────────────────────┐ │
> + │ │ │ │
> + │ ├ y-size │ │
> + │ │ │ │
> + │ │ touchscreen area │ │
> + │ │ (no key code) │ │
> + │ │ │ │
> + │ │ x-size │ │
> + │ ┌└──────────────┴────────────────┘ │
> + │(0',0') │
> + ┌└────────────────────────────────────────┘
> + (0,0)
> +
When at it, the following line could be aligned to match the rest of the
description.
> + where (0',0') = (0+x-origin,0+y-origin)
> +
> + Sub-nodes with key codes report the touch events on their surface as key
> + events instead.
> +
> + The following example shows a touchscreen with a single button on it.
> +
> + Touchscreen (full area)
> + ┌───────────────────────────────────┐
> + │ │
> + │ │
> + │ ┌─────────┐ │
> + │ │button 0 │ │
> + │ │KEY_POWER│ │
> + │ └─────────┘ │
> + │ │
> + │ │
> + ┌└───────────────────────────────────┘
> + (0,0)
> +
And the origin above too.
> + Segments defining buttons and clipped toushcreen areas can be combined
> + as shown in the following example.
> + In that case only the events within the touchscreen area are reported
> + as touch events. Events within the button areas report their associated
> + key code. Any events outside the defined areas are ignored.
> +
> + Touchscreen (full area)
> + ┌─────────┬──────────────────────────────┐
> + │ │ │
> + │ │ ┌───────────────────────┐ │
> + │ button 0│ │ │ │
> + │KEY_POWER│ │ │ │
> + │ │ │ │ │
> + ├─────────┤ │ touchscreen area │ │
> + │ │ │ (no key code) │ │
> + │ │ │ │ │
> + │ button 1│ │ │ │
> + │ KEY_INFO│ ┌└───────────────────────┘ │
> + │ │(0',0') │
> + ┌└─────────┴──────────────────────────────┘
> + (0,0)
> +
Same with this one.
> + type: object
> +
Best regards,
Javier Carrasco
On Tue, Mar 19, 2024 at 12:13:08PM +0100, Javier Carrasco wrote:
> On 1/19/24 08:43, Javier Carrasco wrote:
> > The touch-overlay encompasses a number of touch areas that define a
> > clipped touchscreen area and/or buttons with a specific functionality.
> >
> > A clipped touchscreen area avoids getting events from regions that are
> > physically hidden by overlay frames.
> >
> > For touchscreens with printed overlay buttons, sub-nodes with a suitable
> > key code can be defined to report key events instead of the original
> > touch events.
> >
> > Reviewed-by: Jeff LaBundy <[email protected]>
> > Reviewed-by: Rob Herring <[email protected]>
> > Signed-off-by: Javier Carrasco <[email protected]>
> > ---
> > .../bindings/input/touchscreen/touchscreen.yaml | 119 +++++++++++++++++++++
> > 1 file changed, 119 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> > index 431c13335c40..eb1e86fa86c6 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml
> > @@ -87,6 +87,125 @@ properties:
> > touchscreen-y-plate-ohms:
> > description: Resistance of the Y-plate in Ohms
> >
> > + touch-overlay:
>
> Even though it has already been reviewed, just in case before it gets
> applied. Should it not be:
>
> description: |
> List of nodes...
>
> instead, to keep formatting?
Yes.