From 0d7ecbd8e2ffa109e8739da07bfe4593f98e61e5 Mon Sep 17 00:00:00 2001
From: CalcLoverHK <0v0katai@gmail.com>
Date: Sun, 29 Jun 2025 18:14:18 +0800
Subject: [PATCH] r61523: add r61523 backlight and display timing settings

---
 include/gint/drivers/r61523.h | 31 ++++++++++++++++++
 src/r61523/r61523.c           | 59 +++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)

diff --git a/include/gint/drivers/r61523.h b/include/gint/drivers/r61523.h
index 372cb9f..1daa124 100644
--- a/include/gint/drivers/r61523.h
+++ b/include/gint/drivers/r61523.h
@@ -13,6 +13,20 @@ extern "C" {
 
 #include <gint/defs/types.h>
 
+enum {
+    /* Normal/Partial mode (2^16 color) */
+    R61523_NORMAL,
+    /* Idle mode (2^3 color) */
+    R61523_IDLE
+};
+
+enum {
+    /* Frame inversion waveform (battery saver) */
+    R61523_FRAME,
+    /* Line inversion waveform (better display quality) */
+    R61523_LINE
+};
+
 /* r61523_display(): Update the entire display (320x528) */
 void r61523_display(uint16_t *vram);
 
@@ -20,6 +34,23 @@ void r61523_display(uint16_t *vram);
 void r61523_display_rect(
     uint16_t *vram, int xmin, int xmax, int ymin, int ymax);
 
+/* r61523_get_backlight() and r61523_set_backlight(): Backlight settings
+
+   @level       Brightness level (0-255)
+   @PWM_div     PWM frequency division
+   @dimming     Toggle dimming function */
+void r61523_get_backlight(int *level, int *PWM_div, bool *dimming);
+void r61523_set_backlight(int level, int PWM_div, bool dimming);
+
+/* r61523_get_display_timing() and r61523_set_display_timing(): Display timing settings
+
+   @mode        Normal/Partial or Idle mode
+   @waveform    Frame or Line waveform inversion
+   @CPL         Clocks per line (18-63)
+   @BP @FP      Number of back/front porch lines (4-128) */
+void r61523_get_display_timing(bool mode, bool *waveform, int *CPL, int *BP, int *FP);
+void r61523_set_display_timing(bool mode, bool waveform, int CPL, int BP, int FP);
+
 /* r61523_win_set(): Set the display window */
 void r61523_win_set(int x1, int x2, int y1, int y2);
 
diff --git a/src/r61523/r61523.c b/src/r61523/r61523.c
index 92cfa7e..644115a 100644
--- a/src/r61523/r61523.c
+++ b/src/r61523/r61523.c
@@ -16,6 +16,7 @@
 #define REG_HRANGE                0x2a
 #define REG_VRANGE                0x2b
 #define REG_DATA                  0x2c
+#define REG_BACKLIGHT_CONTROL     0xb9
 #define REG_DEVICE_CODE_READ      0xbf
 #define REG_DEVICE_CODE_VARIANT   0xda
 
@@ -96,6 +97,64 @@ void r61523_identify(
     }
 }
 
+//---
+// Display control
+//---
+
+void r61523_get_backlight(int *level, int *PWM_div, bool *dimming)
+{
+    uint16_t packets[5];
+    select(REG_BACKLIGHT_CONTROL);
+    read_Nu16(packets, 5);
+
+    *level = packets[2];
+    *PWM_div = packets[3];
+    *dimming = packets[4] & 1;
+}
+
+void r61523_set_backlight(int level, int PWM_div, bool dimming)
+{
+    select(REG_BACKLIGHT_CONTROL);
+
+    /* Default value of PWMON */
+    write(0);
+    synco();
+
+    write(level);
+    synco();
+    write(PWM_div);
+    synco();
+    write(0b1000 | dimming);
+    synco();
+}
+
+void r61523_get_display_timing(bool mode, bool *waveform, int *CPL, int *BP, int *FP)
+{
+    uint16_t packets[6];
+    select(mode ? 195 : 193);
+    read_Nu16(packets, 6);
+
+    *waveform = packets[1];
+    *CPL = packets[3];
+    *BP = packets[4];
+    *FP = packets[5];
+}
+
+void r61523_set_display_timing(bool mode, bool waveform, int CPL, int BP, int FP)
+{
+    select(mode ? 195 : 193);
+
+    write(waveform);
+    synco();
+    read();
+    write(CPL);
+    synco();
+    write(BP);
+    synco();
+    write(FP);
+    synco();
+}
+
 //---
 // Window management
 //---