feat: add GT911 touch controller support (config packet 0x28)

src/opendisplay_ble.c

@@ -5,6 +5,7 @@
 #include "opendisplay_display.h"
 #include "opendisplay_button.h"
 #include "opendisplay_led.h"
+#include "opendisplay_touch.h"
 #include "opendisplay_buzzer.h"
 #include "opendisplay_pipe.h"
 #include "opendisplay_battery.h"
@@ -554,6 +555,7 @@ void opendisplay_ble_init(void)
 	}
 
 	opendisplay_button_init();
+	opendisplay_touch_init();
 	k_work_init_delayable(&s_adv_restart_work, adv_work_handler);
 	apply_tx_power(BT_HCI_VS_LL_HANDLE_TYPE_ADV, 0);
 	update_msd_payload();
@@ -569,6 +571,7 @@ void opendisplay_ble_process(void)
 	opendisplay_led_process();
 	opendisplay_buzzer_process();
 	opendisplay_button_process();
+	opendisplay_touch_process();
 	opendisplay_ble_advertising_tick();
 
 	/* Fallback if the delayed work restart fails or was cancelled. */

src/opendisplay_button.c

@@ -2,6 +2,7 @@
 #include "opendisplay_ble.h"
 #include "opendisplay_config_parser.h"
 #include "opendisplay_structs.h"
+#include "opendisplay_touch.h"
 #include "nrf54_gpio.h"
 
 #include <stdio.h>
@@ -67,6 +68,10 @@ void opendisplay_button_init(void)
       if (pin == 0xFFu || s_button_count >= MAX_BUTTONS) {
         continue;
       }
+      if (opendisplay_touch_gpio_is_touch_int(pin)) {
+        printf("[OD] button: skip pin 0x%02X (reserved for GT911 INT)\r\n", (unsigned)pin);
+        continue;
+      }
 
       ButtonState *btn = &s_buttons[s_button_count++];
       btn->button_id = (uint8_t)((input->instance_number * 8u) + pin_idx);

src/opendisplay_config_parser.c

@@ -376,6 +376,26 @@ bool parseConfigBytes(uint8_t* configData, uint32_t configLen, struct GlobalConf
                     return false;
                 }
                 break;
+
+            case CONFIG_PKT_TOUCH: // touch_controller (0x28) - parse but don't log
+                if (offset > configLen) {
+                    printf("Offset overflow before touch_controller\r\n");
+                    globalConfig->loaded = false;
+                    return false;
+                }
+                if (globalConfig->touch_controller_count < 4 && offset + sizeof(struct TouchController) <= configLen - 2) {
+                    memcpy(&globalConfig->touch_controllers[globalConfig->touch_controller_count], &configData[offset], sizeof(struct TouchController));
+                    offset += sizeof(struct TouchController);
+                    if (offset > configLen) {
+                        printf("Offset overflow after touch_controller\r\n");
+                        globalConfig->loaded = false;
+                        return false;
+                    }
+                    globalConfig->touch_controller_count++;
+                } else if (globalConfig->touch_controller_count >= 4) {
+                    offset += sizeof(struct TouchController);
+                    if (offset > configLen) {
+                        printf("Offset overflow after touch_controller (skipped)\r\n");
 
             case CONFIG_PKT_PASSIVE_BUZZER: // passive_buzzer (0x29) - parse but don't log
                 if (offset > configLen) {
@@ -400,6 +420,7 @@ bool parseConfigBytes(uint8_t* configData, uint32_t configLen, struct GlobalConf
                         return false;
                     }
                 } else {
+                    printf("touch_controller: need %zu, have %u\r\n", sizeof(struct TouchController), (unsigned)(configLen - 2 - offset));
                     printf("passive_buzzer: need %zu, have %u\r\n", sizeof(struct PassiveBuzzerConfig), (unsigned)(configLen - 2 - offset));
                     globalConfig->loaded = false;
                     return false;

src/opendisplay_constants.h

@@ -11,6 +11,7 @@
 #define CONFIG_PKT_BINARY_INPUT   0x25
 #define CONFIG_PKT_WIFI           0x26
 #define CONFIG_PKT_SECURITY       0x27
+#define CONFIG_PKT_TOUCH          0x28
 #define CONFIG_PKT_PASSIVE_BUZZER 0x29
 #define CONFIG_PKT_NFC            0x2A
 #define CONFIG_PKT_FLASH          0x2B

src/opendisplay_display.cpp

@@ -6,6 +6,7 @@
 #include "opendisplay_epd_map.h"
 #include "opendisplay_protocol.h"
 #include "opendisplay_structs.h"
+#include "opendisplay_touch.h"
 #include "board_nrf54.h"
 #include "boot_screen.h"
 #include "nrf54_gpio.h"
@@ -930,6 +931,9 @@ extern "C" int opendisplay_display_direct_write_end_refresh(const uint8_t *paylo
       *refresh_ok = ok;
     }
     partial_cleanup();
+    /* An EPD refresh can perturb a GT911 sharing the panel power rail; re-probe
+     * it (light probe first, full reset fallback) as the Arduino reference does. */
+    opendisplay_touch_resume_after_refresh();
     return 0;
   }
 
@@ -972,5 +976,7 @@ extern "C" int opendisplay_display_direct_write_end_refresh(const uint8_t *paylo
   if (refresh_ok != nullptr) {
     *refresh_ok = ok;
   }
+  /* See note above: re-probe touch after the full-refresh path too. */
+  opendisplay_touch_resume_after_refresh();
   return 0;
 }

src/opendisplay_structs.h

@@ -140,6 +140,29 @@ struct BinaryInputs {
   uint8_t reserved[14];
 } __attribute__((packed));
 
+/* 0x28: touch_controller (repeatable, max 4 instances). 32-byte fixed packet;
+ * on-wire layout matches OpenDisplay-Firmware src/structs.h TouchController and
+ * the py-opendisplay serializer (config_serializer.serialize_touch_controller).
+ * touch_ic_type: 0 = disabled / none, 1 = GT911. */
+#define TOUCH_IC_NONE   0u
+#define TOUCH_IC_GT911  1u
+#define TOUCH_FLAG_INVERT_X  (1u << 0)
+#define TOUCH_FLAG_INVERT_Y  (1u << 1)
+#define TOUCH_FLAG_SWAP_XY   (1u << 2)
+
+struct TouchController {
+  uint8_t instance_number;
+  uint16_t touch_ic_type;
+  uint8_t bus_id;             /* data_bus index for the I2C SCL/SDA pins */
+  uint8_t i2c_addr_7bit;      /* GT911: 0x5D or 0x14; 0 or 0xFF = auto */
+  uint8_t int_pin;            /* GT911 INT, 0xFF = poll only */
+  uint8_t rst_pin;            /* GT911 RST, 0xFF = skip hardware reset */
+  uint8_t display_instance;   /* clip/scale to displays[instance] pixel size */
+  uint8_t flags;              /* TOUCH_FLAG_* */
+  uint8_t poll_interval_ms;   /* 0 = default */
+  uint8_t touch_data_start_byte; /* first of 5 MSD dynamic bytes (0-6) */
+  uint8_t enable_pin;         /* optional touch panel power enable; 0/0xFF = unused */
+  uint8_t reserved[20];
 /* 0x29: passive_buzzer (repeatable, max 4 instances). On-wire layout matches the
  * Arduino reference Firmware src/structs.h PassiveBuzzerConfig exactly (32 bytes).
  * Frequency in the 0x0077 payload: 0 = silence/rest; 1-255 maps linearly to a
@@ -219,6 +242,8 @@ struct GlobalConfig {
   uint8_t data_bus_count;
   struct BinaryInputs binary_inputs[4];
   uint8_t binary_input_count;
+  struct TouchController touch_controllers[4];
+  uint8_t touch_controller_count;
   struct PassiveBuzzerConfig passive_buzzers[4];
   uint8_t passive_buzzer_count;
   struct NfcConfig nfc_configs[2];