rockbox/firmware/target/arm/imx233/sansa-fuzeplus/lcd-fuzeplus.c
Amaury Pouly 7d4fed53cc imx233:fuze+: major memory and usb rework
- now identity map dram uncached and have a cached and buffered virtual alias
- rework dma to handle virtual to physical pointers conversion
- fix lcd frame pointer
- implement usb detection properly
- implement bootloader usb properly
- allow the bootloader to disable MMC windowing (useful for recovery)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30432 a1c6a512-1295-4272-9138-f99709370657
2011-09-05 11:29:32 +00:00

593 lines
19 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (c) 2011 by Amaury Pouly
*
* 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.
*
****************************************************************************/
#include <sys/types.h> /* off_t */
#include <string.h>
#include "cpu.h"
#include "system.h"
#include "backlight-target.h"
#include "lcd.h"
#include "lcdif-imx233.h"
#include "clkctrl-imx233.h"
#include "pinctrl-imx233.h"
#define logf(...)
/* Copies a rectangle from one framebuffer to another. Can be used in
single transfer mode with width = num pixels, and height = 1 which
allows a full-width rectangle to be copied more efficiently. */
extern void lcd_copy_buffer_rect(fb_data *dst, const fb_data *src,
int width, int height);
static unsigned lcd_yuv_options = 0;
#ifdef HAVE_LCD_ENABLE
static bool lcd_on = false;
#endif
static enum lcd_kind_t
{
LCD_KIND_7783 = 0x7783,
LCD_KIND_9325 = 0x9325,
LCD_KIND_OTHER = 0,
} lcd_kind = LCD_KIND_OTHER;
static void setup_parameters(void)
{
imx233_lcdif_reset();
imx233_lcdif_set_lcd_databus_width(HW_LCDIF_CTRL__LCD_DATABUS_WIDTH_18_BIT);
imx233_lcdif_set_word_length(HW_LCDIF_CTRL__WORD_LENGTH_18_BIT);
imx233_lcdif_set_timings(1, 2, 2, 2);
}
static void setup_lcd_pins(bool use_lcdif)
{
if(use_lcdif)
{
imx233_set_pin_function(1, 25, PINCTRL_FUNCTION_GPIO); /* lcd_vsync */
imx233_set_pin_function(1, 21, PINCTRL_FUNCTION_MAIN); /* lcd_cs */
imx233_set_pin_function(1, 22, PINCTRL_FUNCTION_GPIO); /* lcd_dotclk */
imx233_set_pin_function(1, 23, PINCTRL_FUNCTION_GPIO); /* lcd_enable */
imx233_set_pin_function(1, 24, PINCTRL_FUNCTION_GPIO); /* lcd_hsync */
imx233_set_pin_function(1, 18, PINCTRL_FUNCTION_MAIN); /* lcd_reset */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_MAIN); /* lcd_rs */
imx233_set_pin_function(1, 16, PINCTRL_FUNCTION_MAIN); /* lcd_d16 */
imx233_set_pin_function(1, 17, PINCTRL_FUNCTION_MAIN); /* lcd_d17 */
imx233_set_pin_function(1, 20, PINCTRL_FUNCTION_MAIN); /* lcd_wr */
__REG_CLR(HW_PINCTRL_MUXSEL(2)) = 0xffffffff; /* lcd_d{0-15} */
}
else
{
__REG_SET(HW_PINCTRL_MUXSEL(2)) = 0xffffffff; /* lcd_d{0-15} */
imx233_enable_gpio_output_mask(1, 0x3ffffff, false); /* lcd_{d{0-17},reset,rs,wr,cs,dotclk,enable,hsync,vsync} */
imx233_set_pin_function(1, 16, PINCTRL_FUNCTION_GPIO); /* lcd_d16 */
imx233_set_pin_function(1, 17, PINCTRL_FUNCTION_GPIO); /* lcd_d17 */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_GPIO); /* lcd_rs */
imx233_set_pin_function(1, 20, PINCTRL_FUNCTION_GPIO); /* lcd_wr */
imx233_set_pin_function(1, 21, PINCTRL_FUNCTION_GPIO); /* lcd_cs */
imx233_set_pin_function(1, 22, PINCTRL_FUNCTION_GPIO); /* lcd_dotclk */
imx233_set_pin_function(1, 23, PINCTRL_FUNCTION_GPIO); /* lcd_enable */
imx233_set_pin_function(1, 24, PINCTRL_FUNCTION_GPIO); /* lcd_hsync */
imx233_set_pin_function(1, 25, PINCTRL_FUNCTION_GPIO); /* lcd_vsync */
}
}
static void setup_lcd_pins_i80(bool i80)
{
if(i80)
{
imx233_set_pin_drive_strength(1, 19, PINCTRL_DRIVE_12mA); /* lcd_rs */
imx233_set_pin_drive_strength(1, 20, PINCTRL_DRIVE_12mA); /* lcd_wr */
imx233_set_pin_drive_strength(1, 21, PINCTRL_DRIVE_12mA); /* lcd_cs */
imx233_set_pin_drive_strength(1, 23, PINCTRL_DRIVE_12mA); /* lcd_enable */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_GPIO); /* lcd_rs */
imx233_set_pin_function(1, 20, PINCTRL_FUNCTION_GPIO); /* lcd_wr */
imx233_set_pin_function(1, 21, PINCTRL_FUNCTION_GPIO); /* lcd_cs */
imx233_set_pin_function(1, 23, PINCTRL_FUNCTION_GPIO); /* lcd_enable */
/* lcd_{rs,wr,cs,enable} */
imx233_enable_gpio_output_mask(1, (1 << 19) | (1 << 20) | (1 << 21) | (1 << 23), true);
imx233_set_gpio_output_mask(1, (1 << 19) | (1 << 20) | (1 << 21) | (1 << 23), true);
imx233_enable_gpio_output_mask(1, 0x3ffff, false); /* lcd_d{0-17} */
__REG_SET(HW_PINCTRL_MUXSEL(2)) = 0xffffffff; /* lcd_d{0-15} as GPIO */
imx233_set_pin_function(1, 16, PINCTRL_FUNCTION_GPIO); /* lcd_d16 */
imx233_set_pin_function(1, 17, PINCTRL_FUNCTION_GPIO); /* lcd_d17 */
imx233_set_pin_function(1, 18, PINCTRL_FUNCTION_GPIO); /* lcd_reset */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_GPIO); /* lcd_rs */
}
else
{
imx233_set_gpio_output_mask(1, (1 << 19) | (1 << 20) | (1 << 21) | (1 << 23), true);
imx233_set_pin_drive_strength(1, 19, PINCTRL_DRIVE_4mA); /* lcd_rs */
imx233_set_pin_drive_strength(1, 20, PINCTRL_DRIVE_4mA); /* lcd_wr */
imx233_set_pin_drive_strength(1, 21, PINCTRL_DRIVE_4mA); /* lcd_cs */
imx233_set_pin_drive_strength(1, 23, PINCTRL_DRIVE_4mA); /* lcd_enable */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_MAIN); /* lcd_rs */
imx233_set_pin_function(1, 20, PINCTRL_FUNCTION_MAIN); /* lcd_wr */
imx233_set_pin_function(1, 21, PINCTRL_FUNCTION_MAIN); /* lcd_cs */
imx233_enable_gpio_output_mask(1, 0x3ffff, false); /* lcd_d{0-17} */
__REG_CLR(HW_PINCTRL_MUXSEL(2)) = 0xffffffff; /* lcd_d{0-15} as lcd_d{0-15} */
imx233_set_pin_function(1, 16, PINCTRL_FUNCTION_MAIN); /* lcd_d16 */
imx233_set_pin_function(1, 17, PINCTRL_FUNCTION_MAIN); /* lcd_d17 */
imx233_set_pin_function(1, 18, PINCTRL_FUNCTION_MAIN); /* lcd_reset */
imx233_set_pin_function(1, 19, PINCTRL_FUNCTION_MAIN); /* lcd_rs */
}
}
static void common_lcd_enable(bool enable)
{
imx233_lcdif_enable(enable);
setup_lcd_pins(enable); /* use GPIO pins when disable */
}
static void setup_lcdif(void)
{
setup_parameters();
common_lcd_enable(true);
imx233_lcdif_enable_bus_master(true);
//imx233_lcdif_enable_irqs(HW_LCDIF__CUR_FRAME_DONE_IRQ);
}
static inline uint32_t encode_16_to_18(uint32_t a)
{
return ((a & 0xff) << 1) | (((a >> 8) & 0xff) << 10);
}
static inline uint32_t decode_18_to_16(uint32_t a)
{
return ((a >> 1) & 0xff) | ((a >> 2) & 0xff00);
}
static void setup_lcdif_clock(void)
{
/* the LCD seems to works at 24Mhz, so use the xtal clock with no divider */
imx233_enable_clock(CLK_PIX, false);
imx233_set_clock_divisor(CLK_PIX, 1);
imx233_set_bypass_pll(CLK_PIX, true); /* use XTAL */
imx233_enable_clock(CLK_PIX, true);
}
static uint32_t i80_read_register(uint32_t data_out)
{
/* lcd_enable is mapped to the RD pin of the controller */
imx233_set_gpio_output(1, 21, true); /* lcd_cs */
imx233_set_gpio_output(1, 19, true); /* lcd_rs */
imx233_set_gpio_output(1, 23, true); /* lcd_enable */
imx233_set_gpio_output(1, 20, true); /* lcd_wr */
imx233_enable_gpio_output_mask(1, 0x3ffff, true); /* lcd_d{0-17} */
mdelay(2);
imx233_set_gpio_output(1, 19, false); /* lcd_rs */
mdelay(1);
imx233_set_gpio_output(1, 21, false); /* lcd_cs */
mdelay(1);
imx233_set_gpio_output(1, 20, false); /* lcd_wr */
mdelay(1);
imx233_set_gpio_output_mask(1, data_out & 0x3ffff, true); /* lcd_d{0-17} */
mdelay(1);
imx233_set_gpio_output(1, 20, true); /* lcd_wr */
mdelay(3);
imx233_enable_gpio_output_mask(1, 0x3ffff, false); /* lcd_d{0-17} */
mdelay(2);
imx233_set_gpio_output(1, 23, false); /* lcd_enable */
mdelay(1);
imx233_set_gpio_output(1, 19, true); /* lcd_rs */
mdelay(1);
imx233_set_gpio_output(1, 23, true); /* lcd_enable */
mdelay(3);
imx233_set_gpio_output(1, 23, false); /* lcd_enable */
mdelay(2);
uint32_t data_in = imx233_get_gpio_input_mask(1, 0x3ffff); /* lcd_d{0-17} */
mdelay(1);
imx233_set_gpio_output(1, 23, true); /* lcd_enable */
mdelay(1);
imx233_set_gpio_output(1, 21, true); /* lcd_cs */
mdelay(1);
return data_in;
}
static void lcd_write_reg(uint32_t reg, uint32_t data)
{
uint32_t old_reg = reg;
/* get back to 18-bit word length */
imx233_lcdif_set_word_length(HW_LCDIF_CTRL__WORD_LENGTH_18_BIT);
reg = encode_16_to_18(reg);
data = encode_16_to_18(data);
imx233_lcdif_pio_send(false, 2, &reg);
if(old_reg != 0x22)
imx233_lcdif_pio_send(true, 2, &data);
}
static uint32_t lcd_read_reg(uint32_t reg)
{
setup_lcd_pins_i80(true);
uint32_t data_in = i80_read_register(encode_16_to_18(reg));
setup_lcd_pins_i80(false);
lcd_write_reg(0x22, 0);
return decode_18_to_16(data_in);
}
#define REG_MDELAY 0xffffffff
struct lcd_sequence_entry_t
{
uint32_t reg, data;
};
static void lcd_send_sequence(struct lcd_sequence_entry_t *seq, unsigned count)
{
for(;count-- > 0; seq++)
{
if(seq->reg == REG_MDELAY)
mdelay(seq->data);
else
lcd_write_reg(seq->reg, seq->data);
}
}
#define _begin_seq() static struct lcd_sequence_entry_t __seq[] = {
#define _mdelay(a) {REG_MDELAY, a},
#define _lcd_write_reg(a, b) {a, b},
#define _end_seq() }; lcd_send_sequence(__seq, sizeof(__seq) / sizeof(__seq[0]));
static void lcd_init_seq_7783(void)
{
__REG_SET(HW_LCDIF_CTRL1) = HW_LCDIF_CTRL1__RESET;
mdelay(50);
__REG_CLR(HW_LCDIF_CTRL1) = HW_LCDIF_CTRL1__RESET;
mdelay(10);
__REG_SET(HW_LCDIF_CTRL1) = HW_LCDIF_CTRL1__RESET;
_begin_seq()
_mdelay(200)
_lcd_write_reg(1, 0x100)
_lcd_write_reg(2, 0x700)
_lcd_write_reg(3, 0x1030)
_lcd_write_reg(7, 0x121)
_lcd_write_reg(8, 0x302)
_lcd_write_reg(9, 0x200)
_lcd_write_reg(0xa, 0)
_lcd_write_reg(0x10, 0x790)
_lcd_write_reg(0x11, 5)
_lcd_write_reg(0x12, 0)
_lcd_write_reg(0x13, 0)
_mdelay(100)
_lcd_write_reg(0x10, 0x12b0)
_mdelay(100)
_lcd_write_reg(0x11, 7)
_mdelay(100)
_lcd_write_reg(0x12, 0x89)
_lcd_write_reg(0x13, 0x1d00)
_lcd_write_reg(0x29, 0x2f)
_mdelay(50)
_lcd_write_reg(0x30, 0)
_lcd_write_reg(0x31, 0x505)
_lcd_write_reg(0x32, 0x205)
_lcd_write_reg(0x35, 0x206)
_lcd_write_reg(0x36, 0x408)
_lcd_write_reg(0x37, 0)
_lcd_write_reg(0x38, 0x504)
_lcd_write_reg(0x39, 0x206)
_lcd_write_reg(0x3c, 0x206)
_lcd_write_reg(0x3d, 0x408)
_lcd_write_reg(0x50, 0) /* left X ? */
_lcd_write_reg(0x51, 0xef) /* right X ? */
_lcd_write_reg(0x52, 0) /* top Y ? */
_lcd_write_reg(0x53, 0x13f) /* bottom Y ? */
_lcd_write_reg(0x20, 0) /* left X ? */
_lcd_write_reg(0x21, 0) /* top Y ? */
_lcd_write_reg(0x60, 0xa700)
_lcd_write_reg(0x61, 1)
_lcd_write_reg(0x90, 0x33)
_lcd_write_reg(0x2b, 0xa)
_lcd_write_reg(9, 0)
_lcd_write_reg(7, 0x133)
_mdelay(50)
_lcd_write_reg(0x22, 0)
_end_seq()
}
static void lcd_init_seq_9325(void)
{
_begin_seq()
_lcd_write_reg(0xe5, 0x78f0)
_lcd_write_reg(0xe3, 0x3008)
_lcd_write_reg(0xe7, 0x12)
_lcd_write_reg(0xef, 0x1231)
_lcd_write_reg(0, 1)
_lcd_write_reg(1, 0x100)
_lcd_write_reg(2, 0x700)
_lcd_write_reg(3, 0x1030)
_lcd_write_reg(4, 0)
_lcd_write_reg(8, 0x207)
_lcd_write_reg(9, 0)
_lcd_write_reg(0xa, 0)
_lcd_write_reg(0xc, 0)
_lcd_write_reg(0xd, 0)
_lcd_write_reg(0xf, 0)
_lcd_write_reg(0x10, 0)
_lcd_write_reg(0x11, 7)
_lcd_write_reg(0x12, 0)
_lcd_write_reg(0x13, 0)
_mdelay(20)
_lcd_write_reg(0x10, 0x1290)
_lcd_write_reg(0x11, 7)
_mdelay(50)
_lcd_write_reg(0x12, 0x19)
_mdelay(50)
_lcd_write_reg(0x13, 0x1700)
_lcd_write_reg(0x29, 0x14)
_mdelay(50)
_lcd_write_reg(0x20, 0)
_lcd_write_reg(0x21, 0)
_lcd_write_reg(0x30, 0x504)
_lcd_write_reg(0x31, 7)
_lcd_write_reg(0x32, 6)
_lcd_write_reg(0x35, 0x106)
_lcd_write_reg(0x36, 0x202)
_lcd_write_reg(0x37, 0x504)
_lcd_write_reg(0x38, 0x500)
_lcd_write_reg(0x39, 0x706)
_lcd_write_reg(0x3c, 0x204)
_lcd_write_reg(0x3d, 0x202)
_lcd_write_reg(0x50, 0)
_lcd_write_reg(0x51, 0xef)
_lcd_write_reg(0x52, 0)
_lcd_write_reg(0x53, 0x13f)
_lcd_write_reg(0x60, 0xa700)
_lcd_write_reg(0x61, 1)
_lcd_write_reg(0x6a, 1)
_lcd_write_reg(0x2b, 0xd)
_mdelay(50)
_lcd_write_reg(0x90, 0x11)
_lcd_write_reg(0x92, 0x600)
_lcd_write_reg(0x93, 3)
_lcd_write_reg(0x95, 0x110)
_lcd_write_reg(0x97, 0)
_lcd_write_reg(0x98, 0)
_lcd_write_reg(7, 0x173)
_lcd_write_reg(0x22, 0)
_end_seq()
}
void lcd_init_device(void)
{
setup_lcdif();
setup_lcdif_clock();
for(int i = 0; i < 10; i++)
{
lcd_kind = lcd_read_reg(0);
if(lcd_kind == LCD_KIND_7783 || lcd_kind == LCD_KIND_9325)
break;
}
mdelay(5);
switch(lcd_kind)
{
case LCD_KIND_7783: lcd_init_seq_7783(); break;
case LCD_KIND_9325: lcd_init_seq_9325(); break;
default:
lcd_kind = LCD_KIND_9325;
lcd_init_seq_7783(); break;
}
}
#ifdef HAVE_LCD_ENABLE
static void lcd_enable_7783(bool enable)
{
if(!enable)
{
_begin_seq()
_lcd_write_reg(7, 0x131)
_mdelay(50)
_lcd_write_reg(7, 0x20)
_mdelay(50)
_lcd_write_reg(0x10, 0x82)
_mdelay(50)
_end_seq()
}
else
{
_begin_seq()
_lcd_write_reg(0x11, 5)
_lcd_write_reg(0x10, 0x12b0)
_mdelay(50)
_lcd_write_reg(7, 0x11)
_mdelay(50)
_lcd_write_reg(0x12, 0x89)
_mdelay(50)
_lcd_write_reg(0x13, 0x1d00)
_mdelay(50)
_lcd_write_reg(0x29, 0x2f)
_mdelay(50)
_lcd_write_reg(0x2b, 0xa)
_lcd_write_reg(7, 0x133)
_mdelay(50)
_lcd_write_reg(0x22, 0)
_end_seq()
}
}
static void lcd_enable_9325(bool enable)
{
if(!enable)
{
_begin_seq()
_lcd_write_reg(7, 0x131)
_mdelay(10)
_lcd_write_reg(7, 0x130)
_mdelay(10)
_lcd_write_reg(7, 0)
_lcd_write_reg(0x10, 0x80)
_lcd_write_reg(0x11, 0)
_lcd_write_reg(0x12, 0)
_lcd_write_reg(0x13, 0)
_mdelay(200)
_lcd_write_reg(0x10, 0x82)
_end_seq()
}
else
{
_begin_seq()
_lcd_write_reg(0x10, 0x80)
_lcd_write_reg(0x11, 0)
_lcd_write_reg(0x12, 0)
_lcd_write_reg(0x13, 0)
_lcd_write_reg(7, 1)
_mdelay(200)
_lcd_write_reg(0x10, 0x1290)
_lcd_write_reg(0x11, 7)
_mdelay(50)
_lcd_write_reg(0x12, 0x19)
_mdelay(50)
_lcd_write_reg(0x13, 0x1700)
_lcd_write_reg(0x29, 0x10)
_mdelay(50)
_lcd_write_reg(7, 0x133)
_lcd_write_reg(0x22, 0)
_end_seq()
}
}
void lcd_enable(bool enable)
{
if(lcd_on == enable)
return;
lcd_on = enable;
if(enable)
common_lcd_enable(true);
switch(lcd_kind)
{
case LCD_KIND_7783: lcd_enable_7783(enable); break;
case LCD_KIND_9325: lcd_enable_9325(enable); break;
default: lcd_enable_7783(enable); break;
}
if(!enable)
common_lcd_enable(false);
}
bool lcd_active(void)
{
return lcd_on;
}
#endif
void lcd_update(void)
{
#ifdef HAVE_LCD_ENABLE
if(!lcd_on)
return;
#endif
imx233_lcdif_wait_ready();
lcd_write_reg(0x50, 0);
lcd_write_reg(0x51, LCD_WIDTH - 1);
lcd_write_reg(0x52, 0);
lcd_write_reg(0x53, LCD_HEIGHT - 1);
lcd_write_reg(0x20, 0);
lcd_write_reg(0x21, 0);
lcd_write_reg(0x22, 0);
imx233_lcdif_wait_ready();
imx233_lcdif_set_word_length(HW_LCDIF_CTRL__WORD_LENGTH_16_BIT);
imx233_lcdif_set_byte_packing_format(0xf); /* two pixels per 32-bit word */
imx233_lcdif_set_data_format(false, false, false); /* RGB565, don't care, don't care */
lcd_copy_buffer_rect((fb_data *)FRAME, &lcd_framebuffer[0][0],
LCD_WIDTH * LCD_HEIGHT, 1);
imx233_lcdif_dma_send((void *)FRAME_PHYS_ADDR, LCD_WIDTH, LCD_HEIGHT);
}
void lcd_update_rect(int x, int y, int width, int height)
{
(void) x;
(void) y;
(void) width;
(void) height;
lcd_update();
}
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(fb_data *dst,
unsigned char const * const src[3],
int width,
int stride);
extern void lcd_write_yuv420_lines_odither(fb_data *dst,
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 */
/* So the LCD_WIDTH is now the height */
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)
{
/* Caches for chroma data so it only need be recaculated every other
line */
unsigned char const * yuv_src[3];
off_t z;
#ifdef HAVE_LCD_ENABLE
if (!lcd_on)
return;
#endif
/* Sorry, but width and height must be >= 2 or else */
width &= ~1;
height >>= 1;
y = LCD_WIDTH - 1 - y;
fb_data *dst = (fb_data*)FRAME + x * LCD_WIDTH + y;
z = stride*src_y;
yuv_src[0] = src[0] + z + src_x;
yuv_src[1] = src[1] + (z >> 2) + (src_x >> 1);
yuv_src[2] = src[2] + (yuv_src[1] - src[1]);
if (lcd_yuv_options & LCD_YUV_DITHER)
{
do
{
lcd_write_yuv420_lines_odither(dst, yuv_src, width, stride, y, x);
yuv_src[0] += stride << 1; /* Skip down two luma lines */
yuv_src[1] += stride >> 1; /* Skip down one chroma line */
yuv_src[2] += stride >> 1;
dst -= 2;
y -= 2;
}
while (--height > 0);
}
else
{
do
{
lcd_write_yuv420_lines(dst, yuv_src, width, stride);
yuv_src[0] += stride << 1; /* Skip down two luma lines */
yuv_src[1] += stride >> 1; /* Skip down one chroma line */
yuv_src[2] += stride >> 1;
dst -= 2;
}
while (--height > 0);
}
}