M3 done: drop boot test, fold BOOT button into touch long-press

The Waveshare ESP32-P4-ETH board exposes BOOT on GPIO 35, but at runtime
that pin is owned by the EMAC TXD1 signal. No usable GPIO is wired to a
separate user button, so the BOOT-button task could never fire.

Move both BOOT-button behaviours onto the touch panel:
  - ≥1.5s hold → 15s identity overlay (was BOOT short-press)
  - ≥5s hold   → factory reset (was BOOT long-hold)
Short tap (<500ms) still toggles wake/sleep. Long-press fires while the
finger is still down so the user gets immediate feedback at each
threshold.

Also strip the R/G/B 6 s boot test sequence — the panel now renders
correctly, so it's no longer useful diagnostically.

Boot subsystem flags drop the trailing B column: [EMHDJT].

5 files changed, 66 insertions, 165 deletions

diff --git a/main/app_main.c b/main/app_main.c
index cc4c063..2cb395e 100644
--- a/main/app_main.c
+++ b/main/app_main.c
@@ -1,4 +1,3 @@
-#include "button.h"
 #include "display.h"
 #include "http_api.h"
 #include "jpeg_decoder.h"
@@ -47,7 +46,7 @@ void app_main(void)
     // don't get a DHCP lease. mDNS + HTTP advertise / bind anyway and will
     // start serving the moment the link comes up.
     // ------------------------------------------------------------------
-    char flags[8] = { '-','-','-','-','-','-','-', 0 };  // E M H D J T B
+    char flags[7] = { '-','-','-','-','-','-', 0 };  // E M H D J T
     esp_err_t eth_err = net_eth_init();
     mark(eth_err, 'E', &flags[0]);
 
@@ -73,10 +72,10 @@ void app_main(void)
     // config is even slightly off; keeping that off the main task means
     // a misconfigured panel can't take down networking + /state. The
     // task also brings up the JPEG decoder and touch (touch shares the
-    // panel I²C bus).
+    // panel I²C bus and also handles long-press → identity overlay and
+    // very-long-press → factory reset, since the board's BOOT button is
+    // wired to a strap pin (GPIO35) that the EMAC owns at runtime).
     // ------------------------------------------------------------------
-    mark(button_init(), 'B', &flags[6]);
-
     ESP_LOGI(TAG, "boot complete — net subsystems [%s] ip=%s; "
                   "display init deferred to dsp_init task",
              flags, got_ip ? net_eth_get_ip_str() : "(no link)");
@@ -92,16 +91,6 @@ static void display_setup_task(void *arg)
 
     if (dsp_err == ESP_OK) {
         local_screens_init();
-        // Show solid-color test sequence for ~6 s so we can characterize the
-        // garble: solid red, then solid green, then solid blue, each for 2s.
-        // If the panel paints a single uniform color (or close to it) for
-        // each, the issue is the text rendering only. If even solid colors
-        // are garbled, it's a stride / pixel-format bug deeper down.
-        display_wake();
-        display_fill(0xF800); vTaskDelay(pdMS_TO_TICKS(2000));   // red
-        display_fill(0x07E0); vTaskDelay(pdMS_TO_TICKS(2000));   // green
-        display_fill(0x001F); vTaskDelay(pdMS_TO_TICKS(2000));   // blue
-        display_sleep();
     }
 
     mark(jpeg_decoder_init(), 'J', &flags[1]);
diff --git a/main/button.c b/main/button.c
deleted file mode 100644
index 26e7cff..0000000
--- a/main/button.c
+++ /dev/null
@@ -1,96 +0,0 @@
-#include "button.h"
-
-#include "driver/gpio.h"
-#include "esp_log.h"
-#include "esp_system.h"
-#include "esp_timer.h"
-#include "freertos/FreeRTOS.h"
-#include "freertos/task.h"
-
-#include "display.h"
-#include "local_screens.h"
-#include "nvs_config.h"
-
-static const char *TAG = "button";
-
-// TODO confirm against the Waveshare ESP32-P4-ETH schematic. ESP32-P4's
-// strapping pin is GPIO35 but that's owned by RMII TXD1 at runtime. Most
-// Waveshare ESP32-P4 boards expose an additional user/BOOT button on a
-// free GPIO; GPIO0 is the conventional default if a separate button isn't
-// available. The button task fail-soft: if the pin reads stuck-high (no
-// button), it just never fires.
-#define PIN_BOOT_BUTTON      0
-
-#define POLL_PERIOD_MS       30
-#define LONG_HOLD_MS         5000
-#define OVERLAY_MS           15000
-
-static void start_overlay(void)
-{
-    if (!display_is_up()) return;
-    local_screens_overlay(OVERLAY_MS);
-    ESP_LOGI(TAG, "BOOT short-press → identity overlay for %dms", OVERLAY_MS);
-}
-
-static void factory_reset(void)
-{
-    ESP_LOGW(TAG, "BOOT held %dms → factory reset", LONG_HOLD_MS);
-    nvs_config_reset();
-    vTaskDelay(pdMS_TO_TICKS(200));   // let log flush
-    esp_restart();
-}
-
-static void button_task(void *arg)
-{
-    bool     was_pressed   = false;
-    uint64_t press_started = 0;
-    bool     long_fired    = false;
-
-    for (;;) {
-        vTaskDelay(pdMS_TO_TICKS(POLL_PERIOD_MS));
-
-        bool pressed = (gpio_get_level(PIN_BOOT_BUTTON) == 0);   // active-low
-
-        if (pressed && !was_pressed) {
-            press_started = (uint64_t)esp_timer_get_time();
-            long_fired = false;
-            was_pressed = true;
-        } else if (pressed && was_pressed) {
-            uint64_t held_ms = ((uint64_t)esp_timer_get_time() - press_started) / 1000ULL;
-            if (!long_fired && held_ms >= LONG_HOLD_MS) {
-                long_fired = true;
-                factory_reset();   // does not return
-            }
-        } else if (!pressed && was_pressed) {
-            uint64_t held_ms = ((uint64_t)esp_timer_get_time() - press_started) / 1000ULL;
-            was_pressed = false;
-            if (!long_fired && held_ms < LONG_HOLD_MS) {
-                start_overlay();
-            }
-        }
-    }
-}
-
-esp_err_t button_init(void)
-{
-    gpio_config_t cfg = {
-        .pin_bit_mask = 1ULL << PIN_BOOT_BUTTON,
-        .mode         = GPIO_MODE_INPUT,
-        .pull_up_en   = GPIO_PULLUP_ENABLE,
-        .pull_down_en = GPIO_PULLDOWN_DISABLE,
-        .intr_type    = GPIO_INTR_DISABLE,
-    };
-    esp_err_t err = gpio_config(&cfg);
-    if (err != ESP_OK) {
-        ESP_LOGW(TAG, "gpio_config GPIO%d failed: %s — button disabled",
-                 PIN_BOOT_BUTTON, esp_err_to_name(err));
-        return err;
-    }
-
-    BaseType_t ok = xTaskCreate(button_task, "boot_btn", 3072, NULL, 3, NULL);
-    if (ok != pdPASS) return ESP_FAIL;
-
-    ESP_LOGI(TAG, "BOOT button on GPIO%d (short=IP overlay 15s, hold 5s=factory reset)",
-             PIN_BOOT_BUTTON);
-    return ESP_OK;
-}
diff --git a/main/button.h b/main/button.h
deleted file mode 100644
index a6d1c80..0000000
--- a/main/button.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#pragma once
-
-#include "esp_err.h"
-
-// BOOT button polling task. Pin is hard-coded in button.c and may need
-// to be adjusted for the Waveshare ESP32-P4-ETH (see TODO in button.c).
-// Returns OK if the task started; the firmware keeps running either way.
-esp_err_t button_init(void);
diff --git a/main/local_screens.h b/main/local_screens.h
index f1e4876..e2d6ca1 100644
--- a/main/local_screens.h
+++ b/main/local_screens.h
@@ -15,7 +15,7 @@ esp_err_t local_screens_init(void);
 //   <current IP>                ("no network" if no DHCP lease)
 //   <state>                     ("awake" / "asleep" / "unconfigured")
 // Font scale is auto-picked to fit the longest line within 90% of width.
-// Shown on first boot, after factory reset, and as a 15s BOOT-button overlay.
+// Shown on first boot, after factory reset, and as a 15s touch-long-press overlay.
 esp_err_t local_screens_show_ip(void);
 
 // Render the loading screen — centered "Loading…" — shown on every wake
@@ -23,8 +23,7 @@ esp_err_t local_screens_show_ip(void);
 esp_err_t local_screens_show_loading(void);
 
 // Show the identity ("who am I") screen for `duration_ms`, then drop the
-// backlight off. Used by the BOOT button short-press (any state) and by
-// the touch handler when the device is unconfigured.
+// backlight off. Triggered by a ≥1.5s touch long-press in any state.
 esp_err_t local_screens_overlay(uint32_t duration_ms);
 
 // True while the identity overlay is currently shown (timer armed).
diff --git a/main/touch.c b/main/touch.c
index 4d8003f..6b4e035 100644
--- a/main/touch.c
+++ b/main/touch.c
@@ -5,12 +5,14 @@
 #include "driver/i2c_master.h"
 #include "esp_check.h"
 #include "esp_log.h"
+#include "esp_system.h"
 #include "esp_timer.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 
 #include "display.h"
 #include "local_screens.h"
+#include "nvs_config.h"
 #include "state_machine.h"
 #include "viewport_state.h"
 
@@ -19,18 +21,15 @@ static const char *TAG = "touch";
 #define FT5426_ADDR          0x38
 #define FT5426_I2C_FREQ_HZ   400000
 
-// FT5x06/FT5426 register map (subset).
 #define FT_REG_DEV_MODE      0x00
-#define FT_REG_GEST_ID       0x01
-#define FT_REG_TD_STATUS     0x02   // low 4 bits = touch count
-#define FT_REG_P1_XH         0x03   // X high (bits 0..3) + event flag (bits 6..7)
-#define FT_REG_P1_XL         0x04
-#define FT_REG_P1_YH         0x05
-#define FT_REG_P1_YL         0x06
+#define FT_REG_TD_STATUS     0x02
+#define FT_REG_P1_XH         0x03
 
 #define POLL_PERIOD_MS       30
-#define TAP_MAX_MS           500
-#define TAP_MAX_MOVE_PX      25
+#define TAP_MAX_MS           500     // < this on release = short tap (toggle)
+#define LONG_PRESS_MS        1500    // ≥ this while held = identity overlay
+#define FACTORY_RESET_MS     5000    // ≥ this while held = factory reset
+#define OVERLAY_MS           15000
 #define TAP_DEBOUNCE_MS      150
 
 static i2c_master_dev_handle_t s_dev;
@@ -41,12 +40,37 @@ static esp_err_t ft_read(uint8_t reg, uint8_t *buf, size_t n)
     return i2c_master_transmit_receive(s_dev, &reg, 1, buf, n, 50);
 }
 
+static void on_short_tap(void)
+{
+    if (local_screens_overlay_active()) local_screens_overlay_dismiss();
+    viewport_run_state_t target =
+        (state_machine_current() == VIEWPORT_STATE_AWAKE)
+            ? VIEWPORT_STATE_ASLEEP
+            : VIEWPORT_STATE_AWAKE;
+    ESP_LOGI(TAG, "tap -> %s", target == VIEWPORT_STATE_AWAKE ? "wake" : "sleep");
+    state_machine_set_local(target);
+}
+
+static void on_long_press(void)
+{
+    ESP_LOGI(TAG, "long-press → identity overlay for %dms", OVERLAY_MS);
+    if (display_is_up()) local_screens_overlay(OVERLAY_MS);
+}
+
+static void on_factory_reset(void)
+{
+    ESP_LOGW(TAG, "very-long-press %dms → factory reset", FACTORY_RESET_MS);
+    nvs_config_reset();
+    vTaskDelay(pdMS_TO_TICKS(200));
+    esp_restart();
+}
+
 static void touch_task(void *arg)
 {
     bool     was_down       = false;
     uint64_t down_us        = 0;
-    uint16_t down_x         = 0;
-    uint16_t down_y         = 0;
+    bool     long_fired     = false;
+    bool     reset_fired    = false;
     uint64_t last_tap_us    = 0;
     uint8_t  buf[7];
 
@@ -54,43 +78,36 @@ static void touch_task(void *arg)
         vTaskDelay(pdMS_TO_TICKS(POLL_PERIOD_MS));
 
         if (ft_read(FT_REG_DEV_MODE, buf, sizeof(buf)) != ESP_OK) continue;
-
         uint8_t touches = buf[FT_REG_TD_STATUS] & 0x0F;
+        uint64_t now    = (uint64_t)esp_timer_get_time();
+
         if (touches > 0) {
-            // Always capture P1; we only care about taps, not multi-touch.
-            uint16_t x = ((buf[FT_REG_P1_XH] & 0x0F) << 8) | buf[FT_REG_P1_XL];
-            uint16_t y = ((buf[FT_REG_P1_YH] & 0x0F) << 8) | buf[FT_REG_P1_YL];
             if (!was_down) {
-                was_down = true;
-                down_us  = (uint64_t)esp_timer_get_time();
-                down_x   = x;
-                down_y   = y;
+                was_down    = true;
+                down_us     = now;
+                long_fired  = false;
+                reset_fired = false;
+            } else {
+                uint64_t held_ms = (now - down_us) / 1000ULL;
+                if (!long_fired && held_ms >= LONG_PRESS_MS) {
+                    long_fired = true;
+                    on_long_press();
+                }
+                if (!reset_fired && held_ms >= FACTORY_RESET_MS) {
+                    reset_fired = true;
+                    on_factory_reset();   // does not return
+                }
             }
         } else if (was_down) {
-            // Release: was-down → up.
             was_down = false;
-            uint64_t now = (uint64_t)esp_timer_get_time();
-
+            uint64_t held_ms = (now - down_us) / 1000ULL;
             if (now - last_tap_us < (uint64_t)TAP_DEBOUNCE_MS * 1000ULL) continue;
 
-            uint64_t dt_ms = (now - down_us) / 1000ULL;
-            // No reliable last position from the burst; use down coordinates
-            // for the duration check, ignore movement check beyond the down
-            // capture. Good enough for tap-vs-press.
-            (void)down_x; (void)down_y; (void)TAP_MAX_MOVE_PX;
-
-            if (dt_ms > 0 && dt_ms <= TAP_MAX_MS) {
+            // Short tap only fires on release; long-press already fired
+            // while the finger was still down.
+            if (!long_fired && held_ms > 0 && held_ms <= TAP_MAX_MS) {
                 last_tap_us = now;
-                // Cancel any BOOT-button identity overlay so a tap-to-sleep
-                // doesn't fight the overlay timer trying to restore content.
-                if (local_screens_overlay_active()) local_screens_overlay_dismiss();
-                viewport_run_state_t target =
-                    (state_machine_current() == VIEWPORT_STATE_AWAKE)
-                        ? VIEWPORT_STATE_ASLEEP
-                        : VIEWPORT_STATE_AWAKE;
-                ESP_LOGI(TAG, "tap (%lu ms) -> %s", (unsigned long)dt_ms,
-                         target == VIEWPORT_STATE_AWAKE ? "wake" : "sleep");
-                state_machine_set_local(target);
+                on_short_tap();
             }
         }
     }
@@ -112,15 +129,15 @@ esp_err_t touch_init(void)
     ESP_RETURN_ON_ERROR(i2c_master_bus_add_device(bus, &cfg, &s_dev),
                        TAG, "i2c add FT5426");
 
-    // Sanity poll: read device mode.
     uint8_t dev_mode = 0;
     esp_err_t err = ft_read(FT_REG_DEV_MODE, &dev_mode, 1);
     if (err != ESP_OK) {
-        ESP_LOGE(TAG, "FT5426 @0x38 unreachable (%s) — check INT jumper",
-                 esp_err_to_name(err));
+        ESP_LOGE(TAG, "FT5426 @0x38 unreachable (%s)", esp_err_to_name(err));
         return err;
     }
-    ESP_LOGI(TAG, "FT5426 ack'd (dev_mode=0x%02x)", dev_mode);
+    ESP_LOGI(TAG, "FT5426 ack'd (dev_mode=0x%02x); "
+                  "tap=toggle, %dms hold=ID overlay, %dms hold=factory reset",
+             dev_mode, LONG_PRESS_MS, FACTORY_RESET_MS);
 
     BaseType_t ok = xTaskCreate(touch_task, "touch", 3072, NULL, 4, &s_task);
     return (ok == pdPASS) ? ESP_OK : ESP_FAIL;