Xduoo X3 Tweak LCD settings

Adds contrast setting which actually sets the drive voltage

Change-Id: I173238e2efe9e50c6ef4cda9bf991e7ee5568ff5

firmware/export/config/xduoox3.h

@@ -45,6 +45,13 @@
 #define LCD_BL_DARKCOLOR     0x000000
 #define LCD_BL_BRIGHTCOLOR   0x0de2e5
 
+/* Define this if your LCD can set contrast */
+#define HAVE_LCD_CONTRAST
+
+#define MIN_CONTRAST_SETTING        -9
+#define MAX_CONTRAST_SETTING        -1
+#define DEFAULT_CONTRAST_SETTING    -6
+
 /* define this if you have LCD enable function */
 #define HAVE_LCD_ENABLE
 

firmware/target/mips/ingenic_jz47xx/xduoo_x3/lcd-xduoo_x3.c

@@ -148,11 +148,79 @@ void lcd_enable_power(bool onoff)
 static bool display_on = false; /* used by lcd_enable */
 
 /*** hardware configuration ***/
+int lcd_default_contrast(void)
+{
+    return DEFAULT_CONTRAST_SETTING;
+}
 
 void lcd_set_contrast(int val)
 {
-    lcd_write_command(LCD_CNTL_CONTRAST);
+    static int last_val = 0xFFFFFF;
-    lcd_write_command(val);
+    
+    if (val >= 0) /* brightness menu */
+    {
+        lcd_write_command(LCD_CNTL_CONTRAST);
+        lcd_write_command(val);
+    }
+    else if (val != last_val)
+    {
+        /* here we change the voltage level and drive times 
+         * longer precharge = dimmer display
+         * higher voltage = shorter precharge required
+         */
+        int precharge;
+        int vcomdsel;
+        switch (val)
+        {
+            case -9:
+                precharge = 0xFF;
+                vcomdsel  = 0x10;
+                break;
+            case -8:
+                precharge = 0xF9;
+                vcomdsel  = 0x10;
+                break;
+            case -7:
+                precharge = 0xF6;
+                vcomdsel  = 0x20;
+                break;
+            default:
+            case -6:
+                precharge = 0xF1;
+                vcomdsel  = 0x30;
+                break;
+            case -5:
+                precharge = 0xF1;
+                vcomdsel  = 0x40;
+                break;
+            case -4:
+                precharge = 0x91;
+                vcomdsel  = 0x50;
+                break;
+            case -3:
+                precharge = 0x61;
+                vcomdsel  = 0x60;
+                break;
+            case -2:
+                precharge = 0x31;
+                vcomdsel  = 0x65;
+                break;
+            case -1:
+                precharge = 0x11;
+                vcomdsel  = 0x70;
+                break;
+        }
+        last_val = val;
+        lcd_enable(false);
+        /* Set pre-charge period */
+        lcd_write_command(LCD_SET_PRECHARGE_PERIOD);
+        lcd_write_command(precharge); /* VCC Generated by Internal DC/DC Circuit */
+
+        /* Set VCOM deselect level */
+        lcd_write_command(LCD_SET_VCOM_DESELECT_LEVEL);
+        lcd_write_command(vcomdsel);
+        lcd_enable(true);
+    }
 }
 
 void lcd_set_invert_display(bool yesno)
@@ -252,7 +320,7 @@ void lcd_init_device(void)
 
     /* Set VCOM deselect level */
     lcd_write_command(LCD_SET_VCOM_DESELECT_LEVEL);
-    lcd_write_command(0x40);
+    lcd_write_command(0x20);
 
     /* Set normal display mode (not every pixel ON) */
     lcd_write_command(LCD_SET_ENTIRE_DISPLAY_OFF);
@@ -275,6 +343,22 @@ void lcd_init_device(void)
 
 /*** Update functions ***/
 
+/* returns LCD_CNTL_HIGHCOL or'd with higher 4 bits of
+   the 8-bit column address for the display data RAM.
+*/
+static inline int get_column_high_byte(const int x)
+{
+    return (LCD_CNTL_HIGHCOL | (((x+LCD_COL_OFFSET) >> 4) & 0xf));
+}
+
+/* returns LCD_CNTL_LOWCOL or'd with lower 4 bits of
+   the 8-bit column address for the display data RAM.
+*/
+static inline int get_column_low_byte(const int x)
+{
+     return (LCD_CNTL_LOWCOL | ((x+LCD_COL_OFFSET) & 0xf));
+}
+
 /* Performance function that works with an external buffer
    note that by and bheight are in 8-pixel units! */
 void lcd_blit_mono(const unsigned char *data, int x, int by, int width,
@@ -283,12 +367,15 @@ void lcd_blit_mono(const unsigned char *data, int x, int by, int width,
     if(!display_on)
         return;
 
+    const int column_high = get_column_high_byte(x);
+    const int column_low = get_column_low_byte(x);
+
     /* Copy display bitmap to hardware */
     while (bheight--)
     {
         lcd_write_command (LCD_CNTL_PAGE | (by++ & 0xf));
-        lcd_write_command (LCD_CNTL_HIGHCOL | (((x+LCD_COL_OFFSET)>>4) & 0xf));
+        lcd_write_command (column_high);
-        lcd_write_command (LCD_CNTL_LOWCOL | ((x+LCD_COL_OFFSET) & 0xf));
+        lcd_write_command (column_low);
 
         lcd_write_data(data, width);
         data += stride;
@@ -306,6 +393,7 @@ void lcd_grey_data(unsigned char *values, unsigned char *phases, int count)
     unsigned long *lpha = (unsigned long *)phases;
     const unsigned long mask = 0x80808080;
 
+    __gpio_set_pin(PIN_LCD_DC);
     while(count--)
     {
         /* calculate disp data from phase we only use the last byte (8bits) */
@@ -320,7 +408,12 @@ void lcd_grey_data(unsigned char *values, unsigned char *phases, int count)
         lpha[0] = lval[0] + (lpha[0] & ~mask);
         lpha[1] = lval[1] + (lpha[1] & ~mask);
 
-        lcd_write_data((const fb_data*) &ltmp, 1);
+        REG_GPIO_PXDATC(2) = 0x000030FC;
+        REG_GPIO_PXDATS(2) = ((ltmp & 0xC0) << 6) | ((ltmp & 0x3F) << 2);
+        __gpio_clear_pin(PIN_LCD_WR);
+        bitdelay();
+        __gpio_set_pin(PIN_LCD_WR);
+        bitdelay();
 
         lpha+=2;
         lval+=2;
@@ -335,13 +428,16 @@ void lcd_blit_grey_phase(unsigned char *values, unsigned char *phases,
     if(!display_on)
         return;
 
+    const int column_high = get_column_high_byte(x);
+    const int column_low = get_column_low_byte(x);
+
     stride <<= 3; /* 8 pixels per block */
     /* Copy display bitmap to hardware */
     while (bheight--)
     {
         lcd_write_command (LCD_CNTL_PAGE | (by++ & 0xf));
-        lcd_write_command (LCD_CNTL_HIGHCOL | (((x+LCD_COL_OFFSET)>>4) & 0xf));
+        lcd_write_command (column_high);
-        lcd_write_command (LCD_CNTL_LOWCOL | ((x+LCD_COL_OFFSET) & 0xf));
+        lcd_write_command (column_low);
 
         lcd_grey_data(values, phases, width);
 
@@ -361,12 +457,16 @@ void lcd_update(void)
     if(!display_on)
         return;
 
+
+    const int column_high = get_column_high_byte(0);
+    const int column_low = get_column_low_byte(0);
+
     /* Copy display bitmap to hardware */
     for (y = 0; y < LCD_FBHEIGHT; y++)
     {
         lcd_write_command (LCD_CNTL_PAGE | (y & 0xf));
-        lcd_write_command (LCD_CNTL_HIGHCOL | ((LCD_COL_OFFSET >> 4) & 0xf));
+        lcd_write_command (column_high);
-        lcd_write_command (LCD_CNTL_LOWCOL | (LCD_COL_OFFSET & 0xf));
+        lcd_write_command (column_low);
 
         lcd_write_data (FBADDR(0, y), LCD_WIDTH);
     }
@@ -381,6 +481,9 @@ void lcd_update_rect(int x, int y, int width, int height)
     if(!display_on)
         return;
 
+    const int column_high = get_column_high_byte(x);
+    const int column_low = get_column_low_byte(x);
+
     /* The Y coordinates have to work on even 8 pixel rows */
     if (x < 0)
     {
@@ -413,8 +516,8 @@ void lcd_update_rect(int x, int y, int width, int height)
     for (; y <= ymax; y++)
     {
         lcd_write_command (LCD_CNTL_PAGE | (y & 0xf));
-        lcd_write_command (LCD_CNTL_HIGHCOL | (((x+LCD_COL_OFFSET) >> 4) & 0xf));
+        lcd_write_command (column_high);
-        lcd_write_command (LCD_CNTL_LOWCOL | ((x+LCD_COL_OFFSET) & 0xf));
+        lcd_write_command (column_low);
 
         lcd_write_data (FBADDR(x,y), width);
     }