From 3376d52d8e0b96d22649cd902336696bf8e22b0c Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@devjustinian.com>
Date: Sun, 30 Mar 2025 12:26:16 -0700
Subject: [PATCH] Parameterize gpio expander settings into constants

---
 src/edmfd/main.cc     | 50 ++++++++++++++++++++++++++++++++-----------
 src/edmfd/mcp23017.cc | 10 ++++-----
 2 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/src/edmfd/main.cc b/src/edmfd/main.cc
index 91dc977..25196b3 100644
--- a/src/edmfd/main.cc
+++ b/src/edmfd/main.cc
@@ -17,7 +17,6 @@
 
 using mcp23017::reg;
 
-static constexpr unsigned i2c_baud = 1200 * 1000;
 
 extern "C" {
     // TinyUSB callbacks
@@ -27,14 +26,15 @@ extern "C" {
     void tud_resume_cb();
 }
 
-static constexpr unsigned bank_leds = 0;
-static constexpr unsigned bank_buttons = 1;
+static constexpr unsigned i2c_baud = 400 * 1000;
 
 static constexpr unsigned hid_update_ms = 1000/20; // 20Hz
 
+static constexpr unsigned bank_leds = 0;
+static constexpr unsigned bank_buttons = 1;
 static constexpr unsigned buttons_per_group = 5;
 static constexpr unsigned button_group_count = 2;
-static const unsigned button_group_irqs[] = {5, 6};
+static const unsigned button_group_irqs[] = {4, 7};
 mcp23017::extender button_groups[] ={ {0x20}, {0x21} };
 uint8_t button_states[] = {0, 0};
 uint8_t button_leds[] = {0, 0};
@@ -68,6 +68,16 @@ void set_leds_callback(uint32_t leds) {
             button_leds[i] = desired;
         }
     }
+    log::trace("set leds to %02x %02x", button_leds[0], button_leds[1]);
+}
+
+void test_irq_handler(unsigned pin, uint32_t events) {
+    log::debug("irq received on %d", pin);
+    irq_handler(pin, events);
+    uint32_t leds = 0;
+    for (unsigned i = 0; i < button_group_count; ++i)
+        leds |= (uint32_t(button_states[i]) << (i*8));
+    set_leds_callback(leds);
 }
 
 int main(void)
@@ -98,6 +108,7 @@ int main(void)
     }
 
     bool have_any_buttons = false;
+    bool start_test_mode = false;
     for (unsigned i = 0; i < button_group_count; ++i) {
         if (!button_groups[i].init()) {
             log::warn("failed to initialize button group %d", i);
@@ -110,12 +121,21 @@ int main(void)
 
         using mcp23017::direction;
         for (unsigned i = 0; i < buttons_per_group; ++i)
-            buttons.set_direction(0, i, direction::out);
+            buttons.set_direction(bank_leds, i, direction::out);
 
-        buttons.set_direction(1, 0, direction::in);
-        buttons.set_polarity(1, 0, true);
-        buttons.set_pullup(1, 0, true);
-        buttons.set_irq(1, 0, true);
+        for (unsigned i = 0; i < buttons_per_group; ++i) {
+            buttons.set_direction(bank_buttons, i, direction::in);
+            buttons.set_polarity(bank_buttons, i, true);
+            buttons.set_pullup(bank_buttons, i, true);
+            buttons.set_irq(bank_buttons, i, true);
+        }
+
+        button_states[i] = buttons.get_gpios(bank_buttons);
+        if (button_states[i] != 0) {
+            log::debug("button group %d has pressed buttons %02x, enabling test mode.",
+                    i, button_states[i]);
+            start_test_mode = true;
+        }
     }
 
     if (!have_any_buttons) {
@@ -123,10 +143,16 @@ int main(void)
         return 1;
     }
 
-    hid::init(set_leds_callback);
-
     repeating_timer hid_timer;
-    add_repeating_timer_ms(hid_update_ms, hid_update_callback, nullptr, &hid_timer);
+    if (start_test_mode) {
+        // Replace IRQ handlers
+        for (int pin : button_group_irqs)
+            gpio_set_irq_enabled_with_callback(pin, GPIO_IRQ_EDGE_FALL, true, test_irq_handler);
+    } else {
+        // Regular mode
+        hid::init(set_leds_callback);
+        add_repeating_timer_ms(hid_update_ms, hid_update_callback, nullptr, &hid_timer);
+    }
 
     // Let timers and iterrupts handle most things
     while (1) {
diff --git a/src/edmfd/mcp23017.cc b/src/edmfd/mcp23017.cc
index 2633d62..0c5eb54 100644
--- a/src/edmfd/mcp23017.cc
+++ b/src/edmfd/mcp23017.cc
@@ -42,11 +42,11 @@ extender::init()
         sleep_ms(10);
     }
 
-    if (read(reg::iodira, m_direction, 2) > 0) {
-        //log::info("initialized directions to %02x %02x", m_direction[0], m_direction[1]);
-        return true;
-    }
-    return false;
+    if (read(reg::iodira, m_direction, 2) < 0)
+        return false;
+
+    uint8_t config = (1 << 6);  // mirror interrupt lines
+    return write(reg::iocona, config) >= 0;
 }
 
 template<reg base_reg, typename Value>