| Message ID | 20240626-feature-ts_virtobj_patch-v10-2-873ad79bb2c9@wolfvision.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Input: support overlay objects on touchscreens | expand |
Hi Javier, On Wed, Jun 26, 2024 at 11:56:14AM +0200, Javier Carrasco wrote: > Some touch devices provide mechanical overlays with different objects > like buttons or clipped touchscreen surfaces. Thank you for your work. I think it is pretty much ready to be merged, just a few small comments: > > 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. So if we have overlays and also want to invert/swap axis then the overlays should be processed first and only then touchscreen_set_mt_pos() or touchscreen_report_pos() should be called? But then it will not work if we need help frm the input core to assign slots in cases when touch controller does not implement [reliable] contact tracing/identification. I think this all needs to be clarified. > > 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. > > Reviewed-by: Jeff LaBundy <jeff@labundy.com> > Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net> > +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 = 0; > + > + overlay = device_get_named_child_node(dev, "touch-overlay"); We can annotate this as struct fwnode_handle *overlay __free(fwnode_handle) = device_get_named_child_node(dev, "touch-overlay"); > + if (!overlay) > + return 0; > + > + fwnode_for_each_available_child_node(overlay, fw_segment) { > + segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL); > + if (!segment) { > + fwnode_handle_put(fw_segment); > + error = -ENOMEM; return -ENOMEM; > + break; > + } > + error = touch_overlay_get_segment(fw_segment, segment, input); > + if (error) { > + fwnode_handle_put(fw_segment); return error; > + break; > + } > + list_add_tail(&segment->list, list); > + } > + fwnode_handle_put(overlay); Drop. > + > + return error; return 0; > +} > +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; This is a static function in the module, we are not passing NULL segments to it ever. Such tests should be done on API boundary. > + > + 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 (segment->slot == slot && segment->pressed) { > + /* button release */ > + if (!contact) { > + segment->pressed = false; > + input_report_key(input, segment->key, false); > + input_sync(input); Do we really need to emit sync here? Can we require/rely on the driver calling us to emit input_sync() once it's done processing current frame/packet? > + return true; > + } > + > + /* sliding out of the button releases it */ > + if (!touch_overlay_segment_event(segment, *x, *y)) { > + segment->pressed = false; > + input_report_key(input, segment->key, false); > + input_sync(input); > + /* keep available for a possible touch event */ > + return false; > + } > + /* ignore sliding on the button while pressed */ > + 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) Would it be better to have a separate argument communicating slot state (contact/no contact)? > + * @slot: slot associated to the event What if we are not dealing with an MT device? Can we say that they should use slot 0 or maybe -1? > + * > + * 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 <javier.carrasco@wolfvision.net> > + */ > + > +#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 > > -- > 2.40.1 > Thanks.
On 09/07/2024 02:08, Dmitry Torokhov wrote: > Hi Javier, > > On Wed, Jun 26, 2024 at 11:56:14AM +0200, Javier Carrasco wrote: >> Some touch devices provide mechanical overlays with different objects >> like buttons or clipped touchscreen surfaces. > > Thank you for your work. I think it is pretty much ready to be merged, > just a few small comments: > >> >> 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. > > So if we have overlays and also want to invert/swap axis then the > overlays should be processed first and only then > touchscreen_set_mt_pos() or touchscreen_report_pos() should be called? > > But then it will not work if we need help frm the input core to assign > slots in cases when touch controller does not implement [reliable] > contact tracing/identification. > > I think this all needs to be clarified. > I think this is the most critical point from your feedback. So far, touch-overlay processes the coordinates of input_mt_pos elements before passing them to touchscreen_set_mt_pos(). As you pointed out, that means that it does not act on the slots i.e. it assumes that the controller does the contact tracing and pos[i] is assigned to slot[i], which is wrong. Current status: [Sensor]->[touch-overlay(filter + button events)]->[touchscreen_set_mt_pos()]->[input_mt_assign_slots()]->[report MT events] If I am not mistaken, I would need a solution that processes the coordinates associated to assigned slots via input_mt_assign_slots(). Then I would have to avoid generating MT events from slots whose coordinates are outside of the overlay frame (ignored) or on overlay buttons (generating button press/release events instead). But once input_mt_assign_slots() is called, it is already too late for that processing, isn't it? Unless assigned slots filtered by touch-overlay are kept from generating MT events somehow, but still used to keep contact tracing. Any suggestion on this respect would be more than welcome. >> >> 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. >> >> Reviewed-by: Jeff LaBundy <jeff@labundy.com> >> Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net> > >> +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 = 0; >> + >> + overlay = device_get_named_child_node(dev, "touch-overlay"); > > We can annotate this as > > struct fwnode_handle *overlay __free(fwnode_handle) = > device_get_named_child_node(dev, "touch-overlay"); > That's right. A scoped version of the loop would have been nice too, but there is still no such variant for this particular one. I am pushing that somewhere else, though. >> + if (!overlay) >> + return 0; >> + >> + fwnode_for_each_available_child_node(overlay, fw_segment) { >> + segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL); >> + if (!segment) { >> + fwnode_handle_put(fw_segment); >> + error = -ENOMEM; > > return -ENOMEM; > >> + break; >> + } >> + error = touch_overlay_get_segment(fw_segment, segment, input); >> + if (error) { >> + fwnode_handle_put(fw_segment); > > return error; > >> + break; >> + } >> + list_add_tail(&segment->list, list); >> + } >> + fwnode_handle_put(overlay); > > Drop. > >> + >> + return error; > > return 0; > Ack. >> +} >> +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; > > This is a static function in the module, we are not passing NULL > segments to it ever. Such tests should be done on API boundary. > Ack. >> + >> + 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 (segment->slot == slot && segment->pressed) { >> + /* button release */ >> + if (!contact) { >> + segment->pressed = false; >> + input_report_key(input, segment->key, false); >> + input_sync(input); > > Do we really need to emit sync here? Can we require/rely on the driver > calling us to emit input_sync() once it's done processing current > frame/packet? > I will test it without it, but that might change anyway depending on the outcome of your first comment. >> + return true; >> + } >> + >> + /* sliding out of the button releases it */ >> + if (!touch_overlay_segment_event(segment, *x, *y)) { >> + segment->pressed = false; >> + input_report_key(input, segment->key, false); >> + input_sync(input); >> + /* keep available for a possible touch event */ >> + return false; >> + } >> + /* ignore sliding on the button while pressed */ >> + 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) > > Would it be better to have a separate argument communicating slot state > (contact/no contact)? > Passing NULL would be ok to save one extra argument, but I have no strong feelings about it. >> + * @slot: slot associated to the event > > What if we are not dealing with an MT device? Can we say that they > should use slot 0 or maybe -1? > slot 0 would be ok. I will document it. >> + * >> + * 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 <javier.carrasco@wolfvision.net> >> + */ >> + >> +#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 >> >> -- >> 2.40.1 >> > > Thanks. > Thanks a lot for your feedback. Best regards, Javier Carrasco
On Wed, Jul 10, 2024 at 02:16:13PM +0200, Javier Carrasco wrote: > On 09/07/2024 02:08, Dmitry Torokhov wrote: > > Hi Javier, > > > > On Wed, Jun 26, 2024 at 11:56:14AM +0200, Javier Carrasco wrote: > >> Some touch devices provide mechanical overlays with different objects > >> like buttons or clipped touchscreen surfaces. > > > > Thank you for your work. I think it is pretty much ready to be merged, > > just a few small comments: > > > >> > >> 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. > > > > So if we have overlays and also want to invert/swap axis then the > > overlays should be processed first and only then > > touchscreen_set_mt_pos() or touchscreen_report_pos() should be called? > > > > But then it will not work if we need help frm the input core to assign > > slots in cases when touch controller does not implement [reliable] > > contact tracing/identification. > > > > I think this all needs to be clarified. > > > > I think this is the most critical point from your feedback. > > So far, touch-overlay processes the coordinates of input_mt_pos elements > before passing them to touchscreen_set_mt_pos(). As you pointed out, > that means that it does not act on the slots i.e. it assumes that the > controller does the contact tracing and pos[i] is assigned to slot[i], > which is wrong. > > Current status: > [Sensor]->[touch-overlay(filter + button > events)]->[touchscreen_set_mt_pos()]->[input_mt_assign_slots()]->[report > MT events] > > If I am not mistaken, I would need a solution that processes the > coordinates associated to assigned slots via input_mt_assign_slots(). > Then I would have to avoid generating MT events from slots whose > coordinates are outside of the overlay frame (ignored) or on overlay > buttons (generating button press/release events instead). > > But once input_mt_assign_slots() is called, it is already too late for > that processing, isn't it? Unless assigned slots filtered by > touch-overlay are kept from generating MT events somehow, but still used > to keep contact tracing. > > Any suggestion on this respect would be more than welcome. The driver is in control which slots to emit the events for, so it can skip reporting if it wants. Consider the st1232 for which you are making these adjustments: for (i = 0; i < ts->chip_info->max_fingers; i++) { u8 *buf = &ts->read_buf[i * 4]; 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); /* st1232 includes a z-axis / touch strength */ if (ts->chip_info->have_z) z[n_contacts] = ts->read_buf[i + 6]; n_contacts++; } } input_mt_assign_slots(input, slots, pos, n_contacts, 0); for (i = 0; i < n_contacts; i++) { input_mt_slot(input, slots[i]); input_mt_report_slot_state(input, MT_TOOL_FINGER, true); input_report_abs(input, ABS_MT_POSITION_X, pos[i].x); input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y); if (ts->chip_info->have_z) input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]); } Can you call touch_overlay_process_event() from the 2nd for() loop, something like this: for (i = 0; i < n_contacts; i++) { if (touch_overlay_process_event(&ts->touch_overlay_list, input, &pos[i].x, &pos[i].y)) continue; input_mt_slot(input, slots[i]); ... } Note that you will no longer able to rely on the input core to drop "unused" slots because you may need to generate "key up" events for them, but you do have access to input_mt_is_active() and input_mt_is_used() so you can implement what you need. Thanks.
diff --git a/MAINTAINERS b/MAINTAINERS index 2ca8f35dfe03..fbe2824d99c1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22739,6 +22739,13 @@ L: platform-driver-x86@vger.kernel.org S: Maintained F: drivers/platform/x86/toshiba-wmi.c +TOUCH OVERLAY +M: Javier Carrasco <javier.carrasco@wolfvision.net> +L: linux-input@vger.kernel.org +S: Maintained +F: drivers/input/touch-overlay.c +F: include/linux/input/touch-overlay.h + TPM DEVICE DRIVER M: Peter Huewe <peterhuewe@gmx.de> M: Jarkko Sakkinen <jarkko@kernel.org> 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..5f839b206358 --- /dev/null +++ b/drivers/input/touch-overlay.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Helper functions for overlay objects on touchscreens + * + * Copyright (c) 2023 Javier Carrasco <javier.carrasco@wolfvision.net> + */ + +#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 = 0; + + overlay = device_get_named_child_node(dev, "touch-overlay"); + if (!overlay) + return 0; + + fwnode_for_each_available_child_node(overlay, fw_segment) { + segment = devm_kzalloc(dev, sizeof(*segment), GFP_KERNEL); + if (!segment) { + fwnode_handle_put(fw_segment); + error = -ENOMEM; + break; + } + error = touch_overlay_get_segment(fw_segment, segment, input); + if (error) { + fwnode_handle_put(fw_segment); + break; + } + list_add_tail(&segment->list, list); + } + fwnode_handle_put(overlay); + + 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 (segment->slot == slot && segment->pressed) { + /* button release */ + if (!contact) { + segment->pressed = false; + input_report_key(input, segment->key, false); + input_sync(input); + return true; + } + + /* sliding out of the button releases it */ + if (!touch_overlay_segment_event(segment, *x, *y)) { + segment->pressed = false; + input_report_key(input, segment->key, false); + input_sync(input); + /* keep available for a possible touch event */ + return false; + } + /* ignore sliding on the button while pressed */ + 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 <javier.carrasco@wolfvision.net> + */ + +#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