Digitizer HID interface : absolute coordinates for mouse cursor (#12851)

* Add digitizer HID interface for setting the mouse cursor position at
absolute screen coordinates. Tested on Pro Micro, Proton C and
Blackpill.

* Update docs/feature_digitizer.md

Co-authored-by: Ryan <fauxpark@gmail.com>

* Update tmk_core/protocol/usb_descriptor.c

Co-authored-by: Ryan <fauxpark@gmail.com>

* Add missing copyrights
Add V-USB support

* Add support for digitizer dedicated endpoint for lufa and chibios.
Fix formatting issues
Move digitizer_task definition to the feature's base implementation file

* Run cformat on modified files

* Change digitizer report usage to Digitizer instead of Pen to avoid
pointer disappearing on Windows.

* Update tmk_core/protocol/vusb/vusb.c

Co-authored-by: Ryan <fauxpark@gmail.com>

* Run cformat from docker image

* Remove send_digitizer from host_driver_t and instead rely on the
declaration being the interface to the implementation in each
HW-specific usb implementation.

* Fix build : send_digitizer shouldn't be static in vusb and add
weak-linkage implementation for tests without usb implementation

* Change digitizer user interface to match pointing device's

* Update documentation with new API

Co-authored-by: a-chol <nothing@none.com>
Co-authored-by: Ryan <fauxpark@gmail.com>

4 files changed, 41 insertions, 1 deletions

diff --git a/tmk_core/common/host.c b/tmk_core/common/host.c
index a8b391e893..f0c396b189 100644
--- a/tmk_core/common/host.c
+++ b/tmk_core/common/host.c
@@ -22,6 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "host.h"
 #include "util.h"
 #include "debug.h"
+#include "digitizer.h"
 
 #ifdef NKRO_ENABLE
 #    include "keycode_config.h"
@@ -103,6 +104,24 @@ void host_consumer_send(uint16_t report) {
     (*driver->send_consumer)(report);
 }
 
+void host_digitizer_send(digitizer_t *digitizer) {
+    if (!driver) return;
+
+    report_digitizer_t report = {
+#ifdef DIGITIZER_SHARED_EP
+        .report_id = REPORT_ID_DIGITIZER,
+#endif
+        .tip     = digitizer->tipswitch & 0x1,
+        .inrange = digitizer->inrange & 0x1,
+        .x       = (uint16_t)(digitizer->x * 0x7FFF),
+        .y       = (uint16_t)(digitizer->y * 0x7FFF),
+    };
+
+    send_digitizer(&report);
+}
+
+__attribute__((weak)) void send_digitizer(report_digitizer_t *report) {}
+
 uint16_t host_last_system_report(void) { return last_system_report; }
 
 uint16_t host_last_consumer_report(void) { return last_consumer_report; }
diff --git a/tmk_core/common/host_driver.h b/tmk_core/common/host_driver.h
index f34a220530..2aebca043d 100644
--- a/tmk_core/common/host_driver.h
+++ b/tmk_core/common/host_driver.h
@@ -30,3 +30,5 @@ typedef struct {
     void (*send_system)(uint16_t);
     void (*send_consumer)(uint16_t);
 } host_driver_t;
+
+void send_digitizer(report_digitizer_t *report);
\ No newline at end of file
diff --git a/tmk_core/common/keyboard.c b/tmk_core/common/keyboard.c
index 28fa97bc8f..fcc51973fd 100644
--- a/tmk_core/common/keyboard.c
+++ b/tmk_core/common/keyboard.c
@@ -106,6 +106,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #if defined(CRC_ENABLE)
 #    include "crc.h"
 #endif
+#ifdef DIGITIZER_ENABLE
+#    include "digitizer.h"
+#endif
 
 static uint32_t last_input_modification_time = 0;
 uint32_t        last_input_activity_time(void) { return last_input_modification_time; }
@@ -537,6 +540,10 @@ MATRIX_LOOP_END:
     joystick_task();
 #endif
 
+#ifdef DIGITIZER_ENABLE
+    digitizer_task();
+#endif
+
     // update LED
     if (led_status != host_keyboard_leds()) {
         led_status = host_keyboard_leds();
diff --git a/tmk_core/common/report.h b/tmk_core/common/report.h
index db6370657d..f2223e8063 100644
--- a/tmk_core/common/report.h
+++ b/tmk_core/common/report.h
@@ -30,7 +30,8 @@ enum hid_report_ids {
     REPORT_ID_SYSTEM,
     REPORT_ID_CONSUMER,
     REPORT_ID_NKRO,
-    REPORT_ID_JOYSTICK
+    REPORT_ID_JOYSTICK,
+    REPORT_ID_DIGITIZER
 };
 
 /* Mouse buttons */
@@ -206,6 +207,17 @@ typedef struct {
 } __attribute__((packed)) report_mouse_t;
 
 typedef struct {
+#ifdef DIGITIZER_SHARED_EP
+    uint8_t report_id;
+#endif
+    uint8_t  tip : 1;
+    uint8_t  inrange : 1;
+    uint8_t  pad2 : 6;
+    uint16_t x;
+    uint16_t y;
+} __attribute__((packed)) report_digitizer_t;
+
+typedef struct {
 #if JOYSTICK_AXES_COUNT > 0
 #    if JOYSTICK_AXES_RESOLUTION > 8
     int16_t axes[JOYSTICK_AXES_COUNT];