[BugFix] ClipZip Type1 Display init gamma correction

commit 32b8af98405e0d5fd6c06d9408ead7780523bb64
Author: William Wilgus <[email protected]>
Date:   Mon Jun 15 00:12:26 2026 -0400

    [BugFix] ClipZip Type1 Display init gamma correction
    
    Now that we have a datasheet for the type 1 display controller
    it turns out the gamma correction was not being applied
    the screen looks much better with it actually applied
    
    also lowers display refresh from 120 HZ to 90 Hz and applied a mentioned
    sleep mode (0x14) to save some power
    
    Adds comments for the LCD commands ala type 0
    
    Change-Id: I2d72df4d24b8bf9f3627bdb96ec9ce43ddd8b10a

diff --git a/firmware/target/arm/as3525/sansa-clipzip/lcd-clipzip.c b/firmware/target/arm/as3525/sansa-clipzip/lcd-clipzip.c
index 4f8ea2c863..2a5422601c 100644
--- a/firmware/target/arm/as3525/sansa-clipzip/lcd-clipzip.c
+++ b/firmware/target/arm/as3525/sansa-clipzip/lcd-clipzip.c
@@ -200,65 +200,67 @@ static void lcd_init_type1(void)
     };
     int i;
 
-    lcd_write(0x02, 0x00);
+    lcd_write(0x02, 0x00); /* DDISP OFF */
 
-    lcd_write_cmd(0x01);
+    lcd_write_cmd(0x01);  /* SOFTRESET */
 
-    lcd_write(0x03, 0x00);
+    lcd_write(0x03, 0x00); /* DSTBY ON */
 
-    lcd_write(0x04, 0x03);
+    lcd_write(0x04, 0x02); /* Set OSC Control 2 = 90Hz*/
 
-    lcd_write(0x05, 0x00);    /* 0x08 results in BGR colour */
+    lcd_write(0x05, 0x00); /* Write Direction 0x08 results in BGR colour */
 
-    lcd_write(0x06, 0x00);
+    lcd_write(0x06, 0x00); /* Set Row Scan Direction */
 
-    lcd_write(0x07, 0x00);
+    lcd_write(0x07, 0x00); /* Set Display Size */
     lcd_write_dat_word(0x00, 0x04);
     lcd_write_dat_word(0x1F, 0x00);
     lcd_write_dat_word(0x00, 0x05);
     lcd_write_dat(0x0F);
 
-    lcd_write(0x08, 0x01);
+    lcd_write(0x08, 0x01); /* Set Interface Bus Type 1 = 8-bit*/
 
-    lcd_write(0x09, 0x07);
+    lcd_write(0x09, 0x07); /* Set Masking Data */
 
-    lcd_write_cmd(0x0A);
+    lcd_write_cmd(0x0A); /* Set Read/Write Box Data */
     lcd_write_nibbles(0);
     lcd_write_nibbles(LCD_WIDTH - 1);
     lcd_write_nibbles(0);
     lcd_write_nibbles(LCD_HEIGHT - 1);
 
-    lcd_write(0x0B, 0x00);
+    lcd_write(0x0B, 0x00); /* Set Display Start Address */
     lcd_write_dat_word(0x00, 0x00);
     lcd_write_dat(0x00);
 
-    lcd_write_cmd(0x0E);
+    lcd_write_cmd(0x0E); /* Set Dot Matrix Current Level */
     lcd_write_nibbles(0x42);
     lcd_write_nibbles(0x25);
     lcd_write_nibbles(0x3F);
 
-    lcd_write(0x0F, 0x0A);
+    lcd_write(0x0F, 0x0A); /* Set Dot Matrix Peak Current Level */
     lcd_write_dat_word(0x0A, 0x0A);
 
-    lcd_write(0x1C, 0x08);
+    lcd_write(0x1C, 0x08); /* Set Pre-Charge Width */
 
-    lcd_write(0x1D, 0x00);
+    lcd_write(0x1D, 0x00); /* Set Peak Pulse Width */
     lcd_write_dat_word(0x00, 0x00);
 
-    lcd_write(0x1E, 0x05);
+    lcd_write(0x1E, 0x05); /* Set Peak Pulse Delay */
 
-    lcd_write(0x1F, 0x00);
+    lcd_write(0x1F, 0x00); /* Set Row Scan Operation 0=Mode 1 : Default scan mode */
 
-    lcd_write(0x30, 0x10);
+    lcd_write(0x30, 0x10); /* Set Internal Regulator for Row Scan*/
 
-    lcd_write_cmd(0x3A);
+    lcd_write_cmd(0x3A); /* Set Gamma Correction Table */
     for (i = 0; i < 128; i++) {
         lcd_write_nibbles(curve[i]);
     }
 
-    lcd_write(0x3C, 0x00);
+    lcd_write_cmd(0x3B); /* Set Gamma Correction Table Initialize */
 
-    lcd_write(0x3D, 0x00);
+    lcd_write(0x3C, 0x00); /* Set VDD Selection */
+
+    lcd_write(0x3D, 0x00); /* DMODE 0= 65K Color */
 }
 
 #ifdef HAVE_LCD_ENABLE
@@ -307,6 +309,8 @@ void lcd_enable(bool on)
             lcd_write(0x02, 0x00);
 
             lcd_write(0x03, 0x01);
+
+            lcd_write(0x14, 0x01); /* DSTBY ON */
         }
     }
 
@@ -357,13 +361,13 @@ static void lcd_setup_rect(int x, int x_end, int y, int y_end)
         lcd_write_cmd(0x08);    /* DDRAM_DATA_ACCESS_PORT */
     }
     else {
-        lcd_write_cmd(0x0A);
+        lcd_write_cmd(0x0A); /* Set Read/Write Box Data */
         lcd_write_nibbles(x);
         lcd_write_nibbles(x_end);
         lcd_write_nibbles(y);
         lcd_write_nibbles(y_end);
         
-        lcd_write_cmd(0x0C);
+        lcd_write_cmd(0x0C); /* Read/Write Display Data */
     }
 }
 
@@ -386,7 +390,7 @@ void oled_brightness(int brightness)
         g = 1 + 6*brightness;
         b = 3 + 10*brightness;
     
-        lcd_write_cmd(0x0E);
+        lcd_write_cmd(0x0E); /* Set Dot Matrix Current Level */
         lcd_write_nibbles(r);
         lcd_write_nibbles(g);
         lcd_write_nibbles(b);
-- 
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