From 3561787ccefccec1ac56a9b0a588171f75030746 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 12 Apr 2026 23:37:28 +0000
Subject: [PATCH] Fix garbled OLED: send SSD1312 segment remap + charge pump
 via raw I2C

The vial-qmk-corne-choc-pro OLED driver does not support
OLED_IC_SSD1312, OLED_FLIP_SEGMENT, or configurable charge pump
(only the vial-qmk-keebart driver has these features). The previous
config defines were no-ops: OLED_IC_SSD1312 resolved to 0 (SSD1306),
OLED_FLIP_SEGMENT was never checked, and OLED_CHARGE_PUMP_VALUE was
ignored.

The driver hardcodes SEGMENT_REMAP_INV (0xA1) and CHARGE_PUMP 0x14,
but the SSD1312 needs SEGMENT_REMAP (0xA0) and 0x72 (9.0V). This
caused the garbled/mirrored text visible on the display.

Fix: Remove the no-op defines from config.h and send the correct
SSD1312 init commands as raw I2C overrides in oled_post_init().

Agent-Logs-Url: https://github.com/timfee/qmk_userspace/sessions/9ba5d3f7-eb8a-4121-978b-870c8401995c

Co-authored-by: timfee <3246342+timfee@users.noreply.github.com>
---
 users/timfee/config.h |  8 +++++---
 users/timfee/timfee.c | 13 +++++++++++++
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/users/timfee/config.h b/users/timfee/config.h
index 96d73f79..77c211ee 100644
--- a/users/timfee/config.h
+++ b/users/timfee/config.h
@@ -16,11 +16,13 @@
 #define COMBO_ONLY_FROM_LAYER 0
 
 // ── OLED (SSD1312 on Keebart Corne Choc Pro) ──
-#define OLED_IC OLED_IC_SSD1312
+// Note: The vial-qmk-corne-choc-pro driver lacks SSD1312 support
+// (no OLED_IC_SSD1312, OLED_FLIP_SEGMENT, or configurable charge pump).
+// We set what the driver honors here; the SSD1312-specific fixups
+// (segment remap + charge pump voltage) are sent via raw I2C commands
+// in oled_post_init() inside timfee.c.
 #define OLED_DISPLAY_128X64
-#define OLED_FLIP_SEGMENT
 #define OLED_DISPLAY_ADDRESS 0x3C
-#define OLED_CHARGE_PUMP_VALUE 0x72
 #define OLED_BRIGHTNESS 64
 #define OLED_TIMEOUT 0
 #define OLED_TIMEOUT_USER 60000
diff --git a/users/timfee/timfee.c b/users/timfee/timfee.c
index 27f9f7d4..cbfe7a2e 100644
--- a/users/timfee/timfee.c
+++ b/users/timfee/timfee.c
@@ -317,6 +317,19 @@ static bool oled_post_init(void) {
         pin_t pen = get_charge_pump_enable_pin();
         gpio_write_pin_high(pen);
         wait_ms(20);
+
+        // The vial-qmk-corne-choc-pro OLED driver does not support
+        // OLED_IC_SSD1312, OLED_FLIP_SEGMENT, or configurable charge pump.
+        // It hardcodes SEGMENT_REMAP_INV (0xA1) and CHARGE_PUMP 0x14,
+        // but the SSD1312 needs SEGMENT_REMAP (0xA0) and charge pump 0x72.
+        // Send the correct values as raw I2C commands after driver init.
+        static const uint8_t ssd1312_fixup[] = {
+            0x00,       // I2C command mode
+            0xA0,       // SEGMENT_REMAP: flip segment direction for SSD1312
+            0x8D, 0x72, // CHARGE_PUMP: 9.0 V for SSD1312
+        };
+        oled_send_cmd(ssd1312_fixup, sizeof(ssd1312_fixup));
+
         oled_clear();
 
         g_user_ontime = timer_read32();