1 files changed, 94 insertions, 0 deletions

diff --git a/firmware/target/arm/samsung/yh925/lcd-yh925.c b/firmware/target/arm/samsung/yh925/lcd-yh925.c
index e2b3ae3694..93bfb3a5f2 100644
--- a/firmware/target/arm/samsung/yh925/lcd-yh925.c
+++ b/firmware/target/arm/samsung/yh925/lcd-yh925.c
@@ -37,6 +37,8 @@ static unsigned short disp_control_rev;
 /* Contrast setting << 8 */
 static int lcd_contrast;
 
+static unsigned lcd_yuv_options SHAREDBSS_ATTR = 0;
+
 /* Forward declarations */
 #if defined(HAVE_LCD_ENABLE) || defined(HAVE_LCD_SLEEP)
 static void lcd_display_off(void);
@@ -508,6 +510,98 @@ bool lcd_active(void)
 
 /*** update functions ***/
 
+void lcd_yuv_set_options(unsigned options)
+{
+    lcd_yuv_options = options;
+}
+
+/* Line write helper function for lcd_yuv_blit. Write two lines of yuv420. */
+extern void lcd_write_yuv420_lines(unsigned char const * const src[3],
+                                   int width,
+                                   int stride);
+extern void lcd_write_yuv420_lines_odither(unsigned char const * const src[3],
+                                           int width,
+                                           int stride,
+                                           int x_screen, /* To align dither pattern */
+                                           int y_screen);
+
+/* Performance function to blit a YUV bitmap directly to the LCD */
+void lcd_blit_yuv(unsigned char * const src[3],
+                  int src_x, int src_y, int stride,
+                  int x, int y, int width, int height)
+{
+    const unsigned char *yuv_src[3];
+    const unsigned char *ysrc_max;
+    int y0;
+    int options;
+
+    /* NOT MODIFIED FOR THE YH-925 */
+
+    if (!display_on)
+        return;
+
+    width &= ~1;
+    height &= ~1;
+
+    x += x_offset;
+
+    /* calculate the drawing region */
+
+    /* The 20GB LCD is actually 128x160 but rotated 90 degrees so the origin
+     * is actually the bottom left and horizontal and vertical are swapped. 
+     * Rockbox expects the origin to be the top left so we need to use 
+     * 127 - y instead of just y */
+    
+    /* max vert << 8 | start vert */
+    lcd_write_reg(R_VERT_RAM_ADDR_POS, ((x + width - 1) << 8) | x);
+
+    y0 = LCD_HEIGHT - 1 - y + y_offset;
+
+    /* DIT=0, BGR=1, HWM=0, I/D1-0=10, AM=0, LG2-0=000 */
+    lcd_write_reg(R_ENTRY_MODE, 0x1020);
+
+    yuv_src[0] = src[0] + src_y * stride + src_x;
+    yuv_src[1] = src[1] + (src_y * stride >> 2) + (src_x >> 1);
+    yuv_src[2] = src[2] + (yuv_src[1] - src[1]);
+    ysrc_max = yuv_src[0] + height * stride;
+
+    options = lcd_yuv_options;
+
+    do
+    {
+        /* max horiz << 8 | start horiz */
+        lcd_write_reg(R_HORIZ_RAM_ADDR_POS, (y0 << 8) | (y0 - 1));
+
+        /* position cursor (set AD0-AD15) */
+        /* start vert << 8 | start horiz */
+        lcd_write_reg(R_RAM_ADDR_SET, (x << 8) | y0);
+
+        /* start drawing */
+        lcd_send_cmd(R_WRITE_DATA_2_GRAM);
+
+        if (options & LCD_YUV_DITHER)
+        {
+            lcd_write_yuv420_lines_odither(yuv_src, width, stride,
+                                           x, y);
+            y -= 2;
+        }
+        else
+        {
+            lcd_write_yuv420_lines(yuv_src, width, stride);
+        }
+
+        y0 -= 2;
+        yuv_src[0] += stride << 1;
+        yuv_src[1] += stride >> 1;
+        yuv_src[2] += stride >> 1;
+    }
+    while (yuv_src[0] < ysrc_max);
+
+    /* DIT=0, BGR=1, HWM=0, I/D1-0=10, AM=1, LG2-0=000 */
+    lcd_write_reg(R_ENTRY_MODE, 0x1028);
+}
+
+
 /* Update a fraction of the display. */
 void lcd_update_rect(int x0, int y0, int width, int height)
 {