rk27xx lcd code rework

Use DMA engine for fullscreen updates and bypass mode for partial
updates. This gives major boost on rk27generic:
default ARM:AHB:APB 200:100:50
HEAD    1/1:  26.3fps 1/4: 105.0fps
patched 1/1: 116.5fps 1/4: 249.5fps

with freq scalling NORMAL mode ARM:AHB:APB 50:50:50
HEAD    1/1:  13.1fps 1/4: 52.5fps
patched 1/1:  54.5fps 1/4: 119.0fps

Tested on rk27generic noname DAP and on Hifimans.

Change-Id: Id9dd4d2d61542c7ea6b5c6336b170d6357cefde9

8 files changed, 352 insertions, 137 deletions

diff --git a/firmware/export/rk27xx.h b/firmware/export/rk27xx.h
index d1b9758f65..c75004c5f7 100644
--- a/firmware/export/rk27xx.h
+++ b/firmware/export/rk27xx.h
@@ -846,10 +846,10 @@
 #define VERT_PERIOD          (*(volatile unsigned long *)(AHB1_LCDC + 0x0C))
 #define HOR_PW               (*(volatile unsigned long *)(AHB1_LCDC + 0x10))
 #define VERT_PW              (*(volatile unsigned long *)(AHB1_LCDC + 0x14))
-#define HOR_ACT              (*(volatile unsigned long *)(AHB1_LCDC + 0x18))
-#define VERT_ACT             (*(volatile unsigned long *)(AHB1_LCDC + 0x1C))
-#define HOR_BP               (*(volatile unsigned long *)(AHB1_LCDC + 0x20))
-#define VERT_BP              (*(volatile unsigned long *)(AHB1_LCDC + 0x24))
+#define HOR_BP               (*(volatile unsigned long *)(AHB1_LCDC + 0x18))
+#define VERT_BP              (*(volatile unsigned long *)(AHB1_LCDC + 0x1C))
+#define HOR_ACT              (*(volatile unsigned long *)(AHB1_LCDC + 0x20))
+#define VERT_ACT             (*(volatile unsigned long *)(AHB1_LCDC + 0x24))
 #define LINE0_YADDR          (*(volatile unsigned long *)(AHB1_LCDC + 0x28))
 #define LINE_ALPHA_EN        (1<<14)
 #define LINE_SCALE_EN        (1<<13)
@@ -877,13 +877,23 @@
 #define INTR_MASK_VERT       (1<<1)
 #define INTR_MASK_HOR        (1<<0)
 
+#define ALPHA_ALX            (*(volatile unsigned long *)(AHB1_LCDC + 0x5C))
+#define ALPHA_ATY            (*(volatile unsigned long *)(AHB1_LCDC + 0x60))
+#define ALPHA_ARX            (*(volatile unsigned long *)(AHB1_LCDC + 0x64))
+#define ALPHA_ABY            (*(volatile unsigned long *)(AHB1_LCDC + 0x68))
+
+#define ALPHA_BLX            (*(volatile unsigned long *)(AHB1_LCDC + 0x6C))
+#define ALPHA_BTY            (*(volatile unsigned long *)(AHB1_LCDC + 0x70))
+#define ALPHA_BRX            (*(volatile unsigned long *)(AHB1_LCDC + 0x74))
+#define ALPHA_BBY            (*(volatile unsigned long *)(AHB1_LCDC + 0x78))
+
 #define LCDC_STA             (*(volatile unsigned long *)(AHB1_LCDC + 0x7C))
 #define LCDC_MCU_IDLE        (1<<12)
 
 #define LCD_COMMAND          (*(volatile unsigned long *)(AHB1_LCDC + 0x1000))
 #define LCD_DATA             (*(volatile unsigned long *)(AHB1_LCDC + 0x1004))
 
-#define LCD_BUFF             (*(volatile unsigned long *)(AHB1_LCDC + 0x2000))
+#define LCD_BUFF             ((volatile void *)(AHB1_LCDC + 0x2000))
 /* High speed ADC interface */
 #define AHB1_HS_ADC            0x186EC000
 #define HSADC_DATA           (*(volatile unsigned long *)(AHB1_HS_ADC + 0x00))
diff --git a/firmware/target/arm/rk27xx/hm60x/lcd-target.h b/firmware/target/arm/rk27xx/hm60x/lcd-target.h
new file mode 100644
index 0000000000..7c2f194e4c
--- /dev/null
+++ b/firmware/target/arm/rk27xx/hm60x/lcd-target.h
@@ -0,0 +1,27 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C)  2012 Andrew Ryabinin
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef LCD_TARGET_H
+#define LCD_TARGET_H
+
+#define LCD_DATABUS_WIDTH LCDIF_16BIT
+
+#endif
diff --git a/firmware/target/arm/rk27xx/hm801/lcd-target.h b/firmware/target/arm/rk27xx/hm801/lcd-target.h
new file mode 100644
index 0000000000..7c2f194e4c
--- /dev/null
+++ b/firmware/target/arm/rk27xx/hm801/lcd-target.h
@@ -0,0 +1,27 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C)  2012 Andrew Ryabinin
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef LCD_TARGET_H
+#define LCD_TARGET_H
+
+#define LCD_DATABUS_WIDTH LCDIF_16BIT
+
+#endif
diff --git a/firmware/target/arm/rk27xx/lcd-hifiman.c b/firmware/target/arm/rk27xx/lcd-hifiman.c
index aaf181690e..4ab04f7653 100644
--- a/firmware/target/arm/rk27xx/lcd-hifiman.c
+++ b/firmware/target/arm/rk27xx/lcd-hifiman.c
@@ -20,6 +20,7 @@
  *
  ****************************************************************************/
 
+
 #include "config.h"
 #include "kernel.h"
 #include "lcd.h"
@@ -29,7 +30,7 @@
 
 static bool display_on = false;
 
-static void lcd_v1_display_init(void)
+void lcd_v1_display_init(void)
 {
     unsigned int x, y;
 
@@ -84,7 +85,7 @@ static void lcd_v1_display_init(void)
     udelay(40);
 
     /* Memmory access setting */
-    lcd_write_reg(0x16, 0x48);
+    lcd_write_reg(0x16, 0x68);
     /* Setup 16bit mode */
     lcd_write_reg(0x17, 0x05);
 
@@ -92,11 +93,11 @@ static void lcd_v1_display_init(void)
     lcd_write_reg(0x02, 0x00);
     lcd_write_reg(0x03, 0x00);
     lcd_write_reg(0x04, 0x00);
-    lcd_write_reg(0x05, LCD_HEIGHT - 1);
+    lcd_write_reg(0x05, LCD_WIDTH - 1);
     lcd_write_reg(0x06, 0x00);
     lcd_write_reg(0x07, 0x00);
     lcd_write_reg(0x08, 0x00);
-    lcd_write_reg(0x09, LCD_WIDTH - 1);
+    lcd_write_reg(0x09, LCD_HEIGHT - 1);
 
     /* Start GRAM write */
     lcd_cmd(0x22);
@@ -110,6 +111,9 @@ static void lcd_v1_display_init(void)
 
 static void lcd_v1_enable (bool on)
 {
+    lcdctrl_bypass(1);
+    LCDC_CTRL |= RGB24B;
+
     if (on)
     {
         lcd_write_reg(0x18, 0x44);
@@ -139,23 +143,33 @@ static void lcd_v1_enable (bool on)
         lcd_write_reg(0x21, 0x00);
     }
     display_on = on;
+
+    LCDC_CTRL &= ~RGB24B;
+}
+static void lcd_v1_set_gram_area(int x, int y, int width, int height)
+{
+    lcdctrl_bypass(1);
+    LCDC_CTRL |= RGB24B;
+    
+    lcd_write_reg(0x03, x);
+    lcd_write_reg(0x05, width-1);
+    lcd_write_reg(0x07, y);
+    lcd_write_reg(0x09, height-1);
+    
+    lcd_cmd(0x22);
+    LCDC_CTRL &= ~RGB24B;
 }
 
 static void lcd_v1_update_rect(int x, int y, int width, int height)
 {
-     int px = x, py = y;
-     int pxmax = x + width, pymax = y + height;
- 
-     lcd_write_reg(0x03, y);
-     lcd_write_reg(0x05, pymax-1);
-     lcd_write_reg(0x07, x);
-     lcd_write_reg(0x09, pxmax-1);
-     
-     lcd_cmd(0x22);
-     
-     for (px=x; px<pxmax; px++)
-         for (py=y; py<pymax; py++)
-             lcd_data(*FBADDR(px, py));
+    int px = x, py = y;
+    int pxmax = x + width, pymax = y + height;
+
+    lcd_v1_set_gram_area(x, y, pxmax, pymax);
+
+    for (py=y; py<pymax; py++)
+        for (px=x; px<pxmax; px++)     
+            LCD_DATA = (*FBADDR(px, py));
 }
 
 
@@ -246,31 +260,34 @@ static void lcd_v2_enable (bool on)
     display_on = on;
 }
 
-static void lcd_v2_update_rect(int x, int y, int width, int height)
+static void lcd_v2_set_gram_area(int x, int y, int width, int height)
 {
-    int px, py;
     (void) x;
     (void) y;
     (void) width;
-    (void)height;
-
+    (void) height;
+    lcdctrl_bypass(1);
+    LCDC_CTRL |= RGB24B;
     lcd_cmd(0x22);
-    
-    for (py=0; py<LCD_HEIGHT; py++)
-        for (px=0; px<LCD_WIDTH; px++)
-            lcd_data(*FBADDR(px, py));
+    LCDC_CTRL &= ~RGB24B;
 }
 
-void lcd_init_device(void)
+static void lcd_v2_update_rect(int x, int y, int width, int height)
 {
-    lcdif_init(LCDIF_16BIT);
+    (void) x;
+    (void) y;
+    (void) width;
+    (void) height;
+    lcd_update();
+}
 
+void lcd_display_init(void)
+{
     identify_lcd();
     if (lcd_type == LCD_V1)
         lcd_v1_display_init();
     else
         lcd_v2_display_init();
-
 }
 
 void lcd_enable (bool on)
@@ -281,6 +298,14 @@ void lcd_enable (bool on)
         lcd_v2_enable(on);
 }
 
+void lcd_set_gram_area(int x, int y, int width, int height)
+{
+   if (lcd_type == LCD_V1)
+        lcd_v1_set_gram_area(x, y, width, height);
+    else
+        lcd_v2_set_gram_area(x, y, width, height);
+}
+
 void lcd_update_rect(int x, int y, int width, int height)
 {
     if (lcd_type == LCD_V1)
@@ -293,9 +318,8 @@ void lcd_update_rect(int x, int y, int width, int height)
 
 #else /* HM801 */
 
-void lcd_init_device(void)
+void lcd_display_init(void)
 {
-    lcdif_init(LCDIF_16BIT);
     lcd_v1_display_init();
 }
 
@@ -304,6 +328,11 @@ void lcd_enable (bool on)
     lcd_v1_enable(on);
 }
 
+void lcd_set_gram_area(int x, int y, int width, int height)
+{
+    lcd_v1_set_gram_area(x, y, width, height);
+}
+
 void lcd_update_rect(int x, int y, int width, int height)
 {
     lcd_v1_update_rect(x, y, width, height);
diff --git a/firmware/target/arm/rk27xx/lcdif-rk27xx.c b/firmware/target/arm/rk27xx/lcdif-rk27xx.c
index affc49b213..01b19603fd 100644
--- a/firmware/target/arm/rk27xx/lcdif-rk27xx.c
+++ b/firmware/target/arm/rk27xx/lcdif-rk27xx.c
@@ -5,9 +5,9 @@
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
- * $Id$
  *
  * Copyright (C) 2011 Marcin Bukat
+ * Copyright (C) 2012 Andrew Ryabinin
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -25,9 +25,28 @@
 #include "system.h"
 #include "cpu.h"
 #include "lcdif-rk27xx.h"
+#include "lcd-target.h"
+#include <string.h>
 
+/* dwdma linked list struct - hw defined
+ * we don't use __attribute__((packed)) just because
+ * all fields are 32bits and so are aligned
+ */
+struct llp_t {
+    uint32_t sar;
+    uint32_t dar;
+    struct llp_t *llp;
+    uint32_t ctl_l;
+    uint32_t ctl_h;
+    uint32_t dstat;
+};
+
+/* array of structs which describes full screen update
+ * each struct describes dma transfer for single line
+ */
+static struct llp_t scr_llp[LCD_HEIGHT];
 
-unsigned int lcd_data_transform(unsigned int data)
+static uint32_t lcd_data_transform(uint32_t data)
 {
     unsigned int r, g, b;
 
@@ -49,38 +68,10 @@ unsigned int lcd_data_transform(unsigned int data)
     return (r | g | b);
 }
 
-void lcd_cmd(unsigned int cmd)
-{
-    LCD_COMMAND = lcd_data_transform(cmd);
-}
-
-void lcd_data(unsigned int data)
-{
-    LCD_DATA = lcd_data_transform(data);
-}
-
-void lcd_write_reg(unsigned int reg, unsigned int val)
-{
-    lcd_cmd(reg);
-    lcd_data(val);
-}
-
-static void lcdctrl_bypass(unsigned int on_off)
-{
-    while (!(LCDC_STA & LCDC_MCU_IDLE));
-
-    if (on_off)
-        MCU_CTRL |= MCU_CTRL_BYPASS;
-    else
-        MCU_CTRL &= ~MCU_CTRL_BYPASS;
-}
-
-/* This part is unclear. I am unable to use buffered/FIFO based writes
- * to lcd. Depending on settings of IF I get various patterns on display
- * but not what I want to display apparently.
- */
 static void lcdctrl_init(void)
 {
+    int i;
+
     /* alpha b111
      * stop at current frame complete
      * MCU mode
@@ -89,37 +80,43 @@ static void lcdctrl_init(void)
     LCDC_CTRL = ALPHA(7) | LCDC_STOP | LCDC_MCU | RGB24B;
     MCU_CTRL = ALPHA_BASE(0x3f) | MCU_CTRL_BYPASS;
 
-    HOR_ACT = LCD_WIDTH + 3;    /* define horizonatal active region */
-    VERT_ACT = LCD_HEIGHT;       /* define vertical active region */
-    VERT_PERIOD = 0xfff;  /* CSn/WEn/RDn signal timings */
-
-    LINE0_YADDR = LINE_ALPHA_EN | 0x7fe;
-    LINE1_YADDR = LINE_ALPHA_EN | ((1 * LCD_WIDTH) - 2);
-    LINE2_YADDR = LINE_ALPHA_EN | ((2 * LCD_WIDTH) - 2);
-    LINE3_YADDR = LINE_ALPHA_EN | ((3 * LCD_WIDTH) - 2);
+    /* Warning: datasheet addresses and OF addresses
+     * don't match for HOR_ACT and VERT_ACT
+     */
+    HOR_ACT = LCD_WIDTH + 3;        /* define horizonatal active region */
+    VERT_ACT = LCD_HEIGHT;          /* define vertical active region */
+    VERT_PERIOD = (1<<7)|(1<<5)|1;  /* CSn/WEn/RDn signal timings */
 
-    LINE0_UVADDR = 0x7fe + 1;
-    LINE1_UVADDR = ((1 * LCD_WIDTH) - 2 + 1);
-    LINE2_UVADDR = ((2 * LCD_WIDTH) - 2 + 1);
-    LINE3_UVADDR = ((3 * LCD_WIDTH) - 2 + 1);
+    lcd_display_init();
+    lcdctrl_bypass(0);
 
-#if 0
+    /* This lines define layout of data in lcdif internal buffer
+     * LINEx_UVADDR = LINEx_YADDR + 1
+     * buffer is organized as 2048 x 32bit
+     * we use RGB565 (16 bits per pixel) so we pack 2 pixels
+     * in every lcdbuffer mem cell
+     */
     LINE0_YADDR = 0;
-    LINE1_YADDR = (1 * LCD_WIDTH);
-    LINE2_YADDR = (2 * LCD_WIDTH);
-    LINE3_YADDR = (3 * LCD_WIDTH);
+    LINE1_YADDR = 1 * LCD_WIDTH/2;
+    LINE2_YADDR = 2 * LCD_WIDTH/2;
+    LINE3_YADDR = 3 * LCD_WIDTH/2;
 
     LINE0_UVADDR = 1;
-    LINE1_UVADDR = (1 * LCD_WIDTH) + 1;
-    LINE2_UVADDR = (2 * LCD_WIDTH) + 1;
-    LINE3_UVADDR = (3 * LCD_WIDTH) + 1;
-
-    START_X = 0;
-    START_Y = 0;
-    DELTA_X = 0x200; /* no scaling */
-    DELTA_Y = 0x200; /* no scaling */
-#endif
-    LCDC_INTR_MASK = INTR_MASK_LINE; /* INTR_MASK_EVENLINE; */
+    LINE1_UVADDR = (1 * LCD_WIDTH/2) + 1;
+    LINE2_UVADDR = (2 * LCD_WIDTH/2) + 1;
+    LINE3_UVADDR = (3 * LCD_WIDTH/2) + 1;
+
+    LCDC_INTR_MASK = INTR_MASK_EVENLINE;
+
+    /* This loop seems to fix strange glitch where
+     * whole lcd content was shifted ~4 lines verticaly
+     * on second lcd_update call
+     */
+    for (i=0; i<2048; i++)
+        *((uint32_t *)LCD_BUFF + i) = 0;
+
+    /* Setup buffered writes to lcd controler */
+    MCU_CTRL = MCU_CTRL_RS_HIGH|MCU_CTRL_BUFF_WRITE|MCU_CTRL_BUFF_START;
 }
 
 /* configure pins to drive lcd in 18bit mode (16bit mode for HiFiMAN's) */
@@ -138,26 +135,133 @@ static void iomux_lcd(enum lcdif_mode_t mode)
     SCU_IOMUXB_CON |= IOMUX_LCD_D815;
 }
 
-void lcdif_init(enum lcdif_mode_t mode)
+static void dwdma_init(void)
 {
-    iomux_lcd(mode);   /* setup pins for lcd interface */
-    lcdctrl_init();    /* basic lcdc module configuration */
-    lcdctrl_bypass(1); /* run in bypass mode - all writes goes directly to lcd controller */
+    DWDMA_DMA_CHEN = 0xf00;
+    DWDMA_CLEAR_BLOCK = 0x0f;
+    DWDMA_DMA_CFG = 1;        /* global enable */
 }
 
-/* This is ugly hack. We drive lcd in bypass mode
- * where all writes goes directly to lcd controller.
- * This is suboptimal at best. IF module povides
- * FIFO, internal sram buffer, hardware scaller,
- * DMA signals, hardware alpha blending and more.
- * BUT the fact is that I have no idea how to use
- * this modes. Datasheet floating around is very
- * unclean in this regard and OF uses ackward
- * lcd update routines which are hard to understand.
- * Moreover OF sets some bits in IF module registers
- * which are referred as reseved in datasheet.
+static void llp_setup(void *src, void *dst, struct llp_t *llp, uint32_t size)
+{
+    llp->sar = (uint32_t)src;
+    llp->dar = (uint32_t)dst;
+    llp->llp = llp + 1;
+    llp->ctl_h = size;
+    llp->ctl_l = (1<<20) |
+                 (1<<23) |
+                 (1<<17) |
+                 (2<<1)  |
+                 (2<<4)  |
+                 (3<<11) |
+                 (3<<14) |
+                 (1<<27) |
+                 (1<<28) ;
+}
+
+static void llp_end(struct llp_t *llp)
+{
+    llp->ctl_l &= ~((1<<27)|(1<<28));
+}
+
+
+static void dwdma_start(uint8_t ch, struct llp_t *llp, uint8_t handshake)
+{
+    DWDMA_SAR(ch) = 0;
+    DWDMA_DAR(ch) = 0;
+    DWDMA_LLP(ch) = (uint32_t)llp;
+    DWDMA_CTL_L(ch) = (1<<20) |
+                      (1<<23) |
+                      (1<<17) |
+                      (2<<1)  |
+                      (2<<4)  |
+                      (3<<11) |
+                      (3<<14) |
+                      (1<<27) |
+                      (1<<28) ;
+              
+   DWDMA_CTL_H(ch) = 1;
+   DWDMA_CFG_L(ch) = (7<<5);
+   DWDMA_CFG_H(ch) = (handshake<<11)|(1<<2);
+   DWDMA_SGR(ch) = (13<<20);
+   DWDMA_DMA_CHEN = (0x101<<ch);
+}
+
+static void create_llp(void)
+{
+    int i;
+
+    /* build LLPs */
+    for (i=0; i<LCD_HEIGHT; i++)
+        llp_setup((void *)FBADDR(0,i),
+                  (void*)(LCD_BUFF+((i%4)*4*LCD_WIDTH/2)),
+                  &(scr_llp[i]),
+                  LCD_WIDTH/2);
+
+    llp_end(&scr_llp[LCD_HEIGHT-1]);
+}
+
+/* Public functions */
+
+/* Switch between lcdif bypass mode and buffered mode
+ * used in private implementations of lcd_set_gram_area()
+ */
+void lcdctrl_bypass(unsigned int on_off)
+{
+    while (!(LCDC_STA & LCDC_MCU_IDLE));
+
+    if (on_off)
+        MCU_CTRL |= MCU_CTRL_BYPASS;
+    else
+        MCU_CTRL &= ~MCU_CTRL_BYPASS;
+}
+
+/* Helper functions used to write commands
+ * to lcd controler in bypass mode
+ * used in controler specific implementations of:
+ * lcd_sleep()
+ * lcd_display_init()
  */
+void lcd_cmd(unsigned int cmd)
+{
+    LCD_COMMAND = lcd_data_transform(cmd);
+}
+
+void lcd_data(unsigned int data)
+{
+    LCD_DATA = lcd_data_transform(data);
+}
+
+void lcd_write_reg(unsigned int reg, unsigned int val)
+{
+    lcd_cmd(reg);
+    lcd_data(val);
+}
+
+/* rockbox API functions */
+void lcd_init_device(void)
+{
+    iomux_lcd(LCD_DATABUS_WIDTH);   /* setup pins for lcd interface */
+    dwdma_init();                   /* init dwdma module */
+    create_llp();                   /* build LLPs for screen update dma */
+    lcdctrl_init();                 /* basic lcdc module configuration */
+}
+
 void lcd_update()
 {
-    lcd_update_rect(0, 0, LCD_WIDTH, LCD_HEIGHT);
+    lcd_set_gram_area(0, 0, LCD_WIDTH, LCD_HEIGHT);
+    lcdctrl_bypass(0);
+
+    commit_discard_dcache_range(FBADDR(0,0), 2*LCD_WIDTH*LCD_HEIGHT);
+
+    while (!(LCDC_STA & LCDC_MCU_IDLE));
+
+    dwdma_start(0, scr_llp, 6);
+    udelay(10);
+
+    /* Setup buffered writes to lcd controler */
+    MCU_CTRL = MCU_CTRL_RS_HIGH|MCU_CTRL_BUFF_WRITE|MCU_CTRL_BUFF_START;
+
+    /* Wait for DMA transfer to finish */
+    while (DWDMA_CTL_L(0) & (1<<27));
 }
diff --git a/firmware/target/arm/rk27xx/lcdif-rk27xx.h b/firmware/target/arm/rk27xx/lcdif-rk27xx.h
index 1d7b810fa2..ea2dbea255 100644
--- a/firmware/target/arm/rk27xx/lcdif-rk27xx.h
+++ b/firmware/target/arm/rk27xx/lcdif-rk27xx.h
@@ -6,11 +6,12 @@ enum lcdif_mode_t {
     LCDIF_18BIT
 };
 
-unsigned int lcd_data_transform(unsigned int data);
-
 void lcd_cmd(unsigned int cmd);
 void lcd_data(unsigned int data);
 void lcd_write_reg(unsigned int reg, unsigned int val);
-void lcdif_init(enum lcdif_mode_t mode);
+void lcdctrl_bypass(unsigned int on_off);
+void lcd_display_init(void);
+
+void lcd_set_gram_area(int x, int y, int width, int height);
 
 #endif /* _LCDIF_RK27XX_H */
diff --git a/firmware/target/arm/rk27xx/rk27generic/lcd-rk27generic.c b/firmware/target/arm/rk27xx/rk27generic/lcd-rk27generic.c
index 5eca87c6d8..3e0eca1d6f 100644
--- a/firmware/target/arm/rk27xx/rk27generic/lcd-rk27generic.c
+++ b/firmware/target/arm/rk27xx/rk27generic/lcd-rk27generic.c
@@ -5,7 +5,6 @@
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
- * $Id$
  *
  * Copyright (C) 2011 Marcin Bukat
  *
@@ -37,17 +36,6 @@ static inline void delay_nop(int cycles)
 }
 
 
-/* converts RGB565 pixel into internal lcd bus format */
-static unsigned int lcd_pixel_transform(unsigned short rgb565)
-{
-    unsigned int r, g, b;
-    b = rgb565 & 0x1f;
-    g = (rgb565 >> 5) & 0x3f;
-    r = (rgb565 >> 11) & 0x1f;
-
-    return r<<19 | g<<10 | b<<3;
-}
-
 /* not tested */
 static void lcd_sleep(bool sleep)
 {
@@ -71,7 +59,7 @@ static void lcd_sleep(bool sleep)
     lcd_cmd(GRAM_WRITE);
 }
 
-static void lcd_display_init(void)
+void lcd_display_init(void)
 {
     unsigned int x, y;
 
@@ -173,31 +161,34 @@ static void lcd_display_init(void)
     lcd_sleep(false);
 }
 
-void lcd_init_device(void)
+void lcd_set_gram_area(int x, int y, int width, int height)
 {
-    lcdif_init(LCDIF_18BIT);
-    lcd_display_init();
-}
-
-void lcd_update_rect(int x, int y, int width, int height)
-{
-    int px = x, py = y;
-    int pxmax = x + width, pymax = y + height;
+    lcdctrl_bypass(1);
+    LCDC_CTRL |= RGB24B;
 
     /* addresses setup */
     lcd_write_reg(WINDOW_H_START,  y);
-    lcd_write_reg(WINDOW_H_END,    pymax-1);
+    lcd_write_reg(WINDOW_H_END,    height-1);
     lcd_write_reg(WINDOW_V_START,  x);
-    lcd_write_reg(WINDOW_V_END,    pxmax-1);
+    lcd_write_reg(WINDOW_V_END,    width-1);
     lcd_write_reg(GRAM_H_ADDR,     y);
     lcd_write_reg(GRAM_V_ADDR,     x);
 
     lcd_cmd(GRAM_WRITE);
+    LCDC_CTRL &= ~RGB24B;
+}
+
+void lcd_update_rect(int x, int y, int width, int height)
+{
+    int px = x, py = y;
+    int pxmax = x + width, pymax = y + height;
+
+    lcd_set_gram_area(x, y, pxmax, pymax);
 
     for (py=y; py<pymax; py++)
     {
         for (px=x; px<pxmax; px++)
-            LCD_DATA = lcd_pixel_transform(*FBADDR(px,py));
+            LCD_DATA = *FBADDR(px,py);
     }
 }
 
diff --git a/firmware/target/arm/rk27xx/rk27generic/lcd-target.h b/firmware/target/arm/rk27xx/rk27generic/lcd-target.h
new file mode 100644
index 0000000000..ec139e1002
--- /dev/null
+++ b/firmware/target/arm/rk27xx/rk27generic/lcd-target.h
@@ -0,0 +1,26 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (C)  2012 Andrew Ryabinin
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef LCD_TARGET_H
+#define LCD_TARGET_H
+
+#define LCD_DATABUS_WIDTH LCDIF_18BIT
+
+#endif