summaryrefslogtreecommitdiffstats
path: root/firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S
diff options
context:
space:
mode:
authorMark Arigo <markarigo@gmail.com>2009-02-13 04:10:57 +0000
committerMark Arigo <markarigo@gmail.com>2009-02-13 04:10:57 +0000
commit8e5c4ce097526f7668d9ebe89b6cae40b756ed8b (patch)
treefe64f362d7f87c5cb783e2cbbc0f7db9b5b2e838 /firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S
parent802b57ccd7676a9f619e93a4d326cf6f524f2079 (diff)
downloadrockbox-8e5c4ce097526f7668d9ebe89b6cae40b756ed8b.tar.gz
rockbox-8e5c4ce097526f7668d9ebe89b6cae40b756ed8b.tar.bz2
rockbox-8e5c4ce097526f7668d9ebe89b6cae40b756ed8b.zip
Philips HDD1630 - add LCD YUV functions so mpegplayer works.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19997 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S')
-rw-r--r--firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S570
1 files changed, 570 insertions, 0 deletions
diff --git a/firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S b/firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S
new file mode 100644
index 0000000000..8f3d12e727
--- /dev/null
+++ b/firmware/target/arm/philips/hdd1630/lcd-as-hdd1630.S
@@ -0,0 +1,570 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2007-2008 by Michael Sevakis
+ *
+ * H10 20GB LCD assembly routines
+ *
+ * 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 "config.h"
+#include "cpu.h"
+
+/****************************************************************************
+ * void lcd_write_yuv_420_lines(unsigned char const * const src[3],
+ * int width,
+ * int stride);
+ *
+ * |R| |1.000000 -0.000001 1.402000| |Y'|
+ * |G| = |1.000000 -0.334136 -0.714136| |Pb|
+ * |B| |1.000000 1.772000 0.000000| |Pr|
+ * Scaled, normalized, rounded and tweaked to yield RGB 565:
+ * |R| |74 0 101| |Y' - 16| >> 9
+ * |G| = |74 -24 -51| |Cb - 128| >> 8
+ * |B| |74 128 0| |Cr - 128| >> 9
+ *
+ * Write four RGB565 pixels in the following order on each loop:
+ * 1 3 + > down
+ * 2 4 \/ left
+ */
+ .section .icode, "ax", %progbits
+ .align 2
+ .global lcd_write_yuv420_lines
+ .type lcd_write_yuv420_lines, %function
+lcd_write_yuv420_lines:
+ @ r0 = yuv_src
+ @ r1 = width
+ @ r2 = stride
+ stmfd sp!, { r4-r12, lr } @ save non-scratch
+ ldmia r0, { r4, r5, r6 } @ r4 = yuv_src[0] = Y'_p
+ @ r5 = yuv_src[1] = Cb_p
+ @ r6 = yuv_src[2] = Cr_p
+ @
+ mov r0, #0x7000000c @ r0 = &LCD2_PORT = 0x70008a0c
+ add r0, r0, #0x8a00 @
+ mov r14, #LCD2_DATA_MASK @
+ @
+ sub r2, r2, #1 @ Adjust stride because of increment
+10: @ loop line @
+ ldrb r7, [r4], #1 @ r7 = *Y'_p++;
+ ldrb r8, [r5], #1 @ r8 = *Cb_p++;
+ ldrb r9, [r6], #1 @ r9 = *Cr_p++;
+ @
+ sub r7, r7, #16 @ r7 = Y = (Y' - 16)*74
+ add r12, r7, r7, asl #2 @ actually (Y' - 16)*37 and shift right
+ add r7, r12, r7, asl #5 @ by one less when adding - same for all
+ @
+ sub r8, r8, #128 @ Cb -= 128
+ sub r9, r9, #128 @ Cr -= 128
+ @
+ add r10, r9, r9, asl #1 @ r10 = Cr*51 + Cb*24
+ add r10, r10, r10, asl #4 @
+ add r10, r10, r8, asl #3 @
+ add r10, r10, r8, asl #4 @
+ @
+ add r11, r9, r9, asl #2 @ r9 = Cr*101
+ add r11, r11, r9, asl #5 @
+ add r9, r11, r9, asl #6 @
+ @
+ add r8, r8, #2 @ r8 = bu = (Cb*128 + 128) >> 8
+ mov r8, r8, asr #2 @
+ add r9, r9, #256 @ r9 = rv = (r8 + 256) >> 9
+ mov r9, r9, asr #9 @
+ rsb r10, r10, #128 @ r10 = guv = (-r9 + 128) >> 8
+ mov r10, r10, asr #8 @
+ @ compute R, G, and B
+ add r3, r8, r7, asr #8 @ r3 = b = (Y >> 9) + bu
+ add r11, r9, r7, asr #8 @ r11 = r = (Y >> 9) + rv
+ add r7, r10, r7, asr #7 @ r7 = g = (Y >> 8) + guv
+ @
+ orr r12, r3, r11 @ check if clamping is needed...
+ orr r12, r12, r7, asr #1 @ ...at all
+ cmp r12, #31 @
+ bls 15f @ no clamp @
+ cmp r3, #31 @ clamp b
+ mvnhi r3, r3, asr #31 @
+ andhi r3, r3, #31 @
+ cmp r11, #31 @ clamp r
+ mvnhi r11, r11, asr #31 @
+ andhi r11, r11, #31 @
+ cmp r7, #63 @ clamp g
+ mvnhi r7, r7, asr #31 @
+ andhi r7, r7, #63 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4, r2] @ r12 = Y' = *(Y'_p + stride)
+ @
+ orr r3, r3, r11, lsl #11 @ r3 = b | (r << 11)
+ orr r3, r3, r7, lsl #5 @ r3 |= (g << 5)
+ @
+ orr r7, r14, r3, lsr #8 @ store pixel
+ orr r11, r14, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*74
+ add r12, r7, r7, asl #2 @
+ add r7, r12, r7, asl #5 @
+ @ compute R, G, and B
+ add r3, r8, r7, asr #8 @ r3 = b = (Y >> 9) + bu
+ add r11, r9, r7, asr #8 @ r11 = r = (Y >> 9) + rv
+ add r7, r10, r7, asr #7 @ r7 = g = (Y >> 8) + guv
+ @
+ orr r12, r3, r11 @ check if clamping is needed...
+ orr r12, r12, r7, asr #1 @ ...at all
+ cmp r12, #31 @
+ bls 15f @ no clamp @
+ cmp r3, #31 @ clamp b
+ mvnhi r3, r3, asr #31 @
+ andhi r3, r3, #31 @
+ cmp r11, #31 @ clamp r
+ mvnhi r11, r11, asr #31 @
+ andhi r11, r11, #31 @
+ cmp r7, #63 @ clamp g
+ mvnhi r7, r7, asr #31 @
+ andhi r7, r7, #63 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4], #1 @ r12 = Y' = *(Y'_p++)
+ @
+ orr r3, r3, r11, lsl #11 @ r3 = b | (r << 11)
+ orr r3, r3, r7, lsl #5 @ r3 |= (g << 5)
+ @
+ orr r7, r14, r3, lsr #8 @ store pixel
+ orr r11, r14, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*74
+ add r12, r7, r7, asl #2 @
+ add r7, r12, r7, asl #5 @
+ @ compute R, G, and B
+ add r3, r8, r7, asr #8 @ r3 = b = (Y >> 9) + bu
+ add r11, r9, r7, asr #8 @ r11 = r = (Y >> 9) + rv
+ add r7, r10, r7, asr #7 @ r7 = g = (Y >> 8) + guv
+ @
+ orr r12, r3, r11 @ check if clamping is needed...
+ orr r12, r12, r7, asr #1 @ ...at all
+ cmp r12, #31 @
+ bls 15f @ no clamp @
+ cmp r3, #31 @ clamp b
+ mvnhi r3, r3, asr #31 @
+ andhi r3, r3, #31 @
+ cmp r11, #31 @ clamp r
+ mvnhi r11, r11, asr #31 @
+ andhi r11, r11, #31 @
+ cmp r7, #63 @ clamp g
+ mvnhi r7, r7, asr #31 @
+ andhi r7, r7, #63 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4, r2] @ r12 = Y' = *(Y'_p + stride)
+ @
+ orr r3, r3, r7, lsl #5 @ r3 = b | (g << 5)
+ orr r3, r3, r11, lsl #11 @ r3 |= (r << 11)
+ @
+ orr r7, r14, r3, lsr #8 @ store pixel
+ orr r11, r14, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*74
+ add r12, r7, r7, asl #2 @
+ add r7, r12, r7, asl #5 @
+ @ compute R, G, and B
+ add r3, r8, r7, asr #8 @ r3 = b = (Y >> 9) + bu
+ add r11, r9, r7, asr #8 @ r11 = r = (Y >> 9) + rv
+ add r7, r10, r7, asr #7 @ r7 = g = (Y >> 8) + guv
+ @
+ orr r12, r3, r11 @ check if clamping is needed...
+ orr r12, r12, r7, asr #1 @ ...at all
+ cmp r12, #31 @
+ bls 15f @ no clamp @
+ cmp r3, #31 @ clamp b
+ mvnhi r3, r3, asr #31 @
+ andhi r3, r3, #31 @
+ cmp r11, #31 @ clamp r
+ mvnhi r11, r11, asr #31 @
+ andhi r11, r11, #31 @
+ cmp r7, #63 @ clamp g
+ mvnhi r7, r7, asr #31 @
+ andhi r7, r7, #63 @
+15: @ no clamp @
+ @
+ orr r3, r3, r11, lsl #11 @ r3 = b | (r << 11)
+ orr r3, r3, r7, lsl #5 @ r3 |= (g << 5)
+ @
+ orr r7, r14, r3, lsr #8 @ store pixel
+ orr r11, r14, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ subs r1, r1, #2 @ subtract block from width
+ bgt 10b @ loop line @
+ @
+ ldmfd sp!, { r4-r12, pc } @ restore registers and return
+ .ltorg @ dump constant pool
+ .size lcd_write_yuv420_lines, .-lcd_write_yuv420_lines
+
+
+/****************************************************************************
+ * void lcd_write_yuv_420_lines_odither(unsigned char const * const src[3],
+ * int width,
+ * int stride,
+ * int x_screen,
+ * int y_screen);
+ *
+ * |R| |1.000000 -0.000001 1.402000| |Y'|
+ * |G| = |1.000000 -0.334136 -0.714136| |Pb|
+ * |B| |1.000000 1.772000 0.000000| |Pr|
+ * Red scaled at twice g & b but at same precision to place it in correct
+ * bit position after multiply and leave instruction count lower.
+ * |R| |258 0 408| |Y' - 16|
+ * |G| = |149 -49 -104| |Cb - 128|
+ * |B| |149 258 0| |Cr - 128|
+ *
+ * Write four RGB565 pixels in the following order on each loop:
+ * 1 3 + > down
+ * 2 4 \/ left
+ *
+ * Kernel pattern (raw|use order):
+ * 5 3 4 2 row0 row2 > down
+ * 1 7 0 6 | 5 1 3 7 4 0 2 6 col0 left
+ * 4 2 5 3 | 4 0 2 6 5 1 3 7 col2 \/
+ * 0 6 1 7
+ */
+ .section .icode, "ax", %progbits
+ .align 2
+ .global lcd_write_yuv420_lines_odither
+ .type lcd_write_yuv420_lines_odither, %function
+lcd_write_yuv420_lines_odither:
+ @ r0 = yuv_src
+ @ r1 = width
+ @ r2 = stride
+ @ r3 = x_screen
+ @ [sp] = y_screen
+ stmfd sp!, { r4-r12, lr } @ save non-scratch
+ ldmia r0, { r4, r5, r6 } @ r4 = yuv_src[0] = Y'_p
+ @ r5 = yuv_src[1] = Cb_p
+ @ r6 = yuv_src[2] = Cr_p
+ @
+ ldr r0, [sp, #40] @ Line up pattern and kernel quadrant
+ eor r14, r3, r0 @
+ and r14, r14, #0x2 @
+ mov r14, r14, lsl #6 @ 0x00 or 0x80
+ @
+ mov r0, #0x7000000c @ r0 = &LCD2_PORT = 0x70008a0c
+ add r0, r0, #0x8a00 @
+ @
+ sub r2, r2, #1 @ Adjust stride because of increment
+10: @ loop line @
+ @
+ ldrb r7, [r4], #1 @ r7 = *Y'_p++;
+ ldrb r8, [r5], #1 @ r8 = *Cb_p++;
+ ldrb r9, [r6], #1 @ r9 = *Cr_p++;
+ @
+ eor r14, r14, #0x80 @ flip pattern quadrant
+ @
+ sub r7, r7, #16 @ r7 = Y = (Y' - 16)*149
+ add r12, r7, r7, asl #2 @
+ add r12, r12, r12, asl #4 @
+ add r7, r12, r7, asl #6 @
+ @
+ sub r8, r8, #128 @ Cb -= 128
+ sub r9, r9, #128 @ Cr -= 128
+ @
+ add r10, r8, r8, asl #4 @ r10 = guv = Cr*104 + Cb*49
+ add r10, r10, r8, asl #5 @
+ add r10, r10, r9, asl #3 @
+ add r10, r10, r9, asl #5 @
+ add r10, r10, r9, asl #6 @
+ @
+ mov r8, r8, asl #1 @ r8 = bu = Cb*258
+ add r8, r8, r8, asl #7 @
+ @
+ add r9, r9, r9, asl #1 @ r9 = rv = Cr*408
+ add r9, r9, r9, asl #4 @
+ mov r9, r9, asl #3 @
+ @
+ @ compute R, G, and B
+ add r3, r8, r7 @ r3 = b' = Y + bu
+ add r11, r9, r7, asl #1 @ r11 = r' = Y*2 + rv
+ rsb r7, r10, r7 @ r7 = g' = Y + guv
+ @
+ @ r8 = bu, r9 = rv, r10 = guv
+ @
+ sub r12, r3, r3, lsr #5 @ r3 = 31/32*b + b/256
+ add r3, r12, r3, lsr #8 @
+ @
+ sub r12, r11, r11, lsr #5 @ r11 = 31/32*r + r/256
+ add r11, r12, r11, lsr #8 @
+ @
+ sub r12, r7, r7, lsr #6 @ r7 = 63/64*g + g/256
+ add r7, r12, r7, lsr #8 @
+ @
+ add r12, r14, #0x200 @
+ @
+ add r3, r3, r12 @ b = r3 + delta
+ add r11, r11, r12, lsl #1 @ r = r11 + delta*2
+ add r7, r7, r12, lsr #1 @ g = r7 + delta/2
+ @
+ orr r12, r3, r11, asr #1 @ check if clamping is needed...
+ orr r12, r12, r7 @ ...at all
+ movs r12, r12, asr #15 @
+ beq 15f @ no clamp @
+ movs r12, r3, asr #15 @ clamp b
+ mvnne r3, r12, lsr #15 @
+ andne r3, r3, #0x7c00 @ mask b only if clamped
+ movs r12, r11, asr #16 @ clamp r
+ mvnne r11, r12, lsr #16 @
+ movs r12, r7, asr #15 @ clamp g
+ mvnne r7, r12, lsr #15 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4, r2] @ r12 = Y' = *(Y'_p + stride)
+ @
+ and r11, r11, #0xf800 @ pack pixel
+ and r7, r7, #0x7e00 @ r3 = pixel = (r & 0xf800) |
+ orr r11, r11, r7, lsr #4 @ ((g & 0x7e00) >> 4) |
+ orr r3, r11, r3, lsr #10 @ (b >> 10)
+ @
+ mov r11, #LCD2_DATA_MASK @ store pixel
+ orr r7, r11, r3, lsr #8 @
+ orr r11, r11, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*149
+ add r12, r7, r7, asl #2 @
+ add r12, r12, r12, asl #4 @
+ add r7, r12, r7, asl #6 @
+ @ compute R, G, and B
+ add r3, r8, r7 @ r3 = b' = Y + bu
+ add r11, r9, r7, asl #1 @ r11 = r' = Y*2 + rv
+ rsb r7, r10, r7 @ r7 = g' = Y + guv
+ @
+ sub r12, r3, r3, lsr #5 @ r3 = 31/32*b' + b'/256
+ add r3, r12, r3, lsr #8 @
+ @
+ sub r12, r11, r11, lsr #5 @ r11 = 31/32*r' + r'/256
+ add r11, r12, r11, lsr #8 @
+ @
+ sub r12, r7, r7, lsr #6 @ r7 = 63/64*g' + g'/256
+ add r7, r12, r7, lsr #8 @
+ @
+ @ This element is zero - use r14 @
+ @
+ add r3, r3, r14 @ b = r3 + delta
+ add r11, r11, r14, lsl #1 @ r = r11 + delta*2
+ add r7, r7, r14, lsr #1 @ g = r7 + delta/2
+ @
+ orr r12, r3, r11, asr #1 @ check if clamping is needed...
+ orr r12, r12, r7 @ ...at all
+ movs r12, r12, asr #15 @
+ beq 15f @ no clamp @
+ movs r12, r3, asr #15 @ clamp b
+ mvnne r3, r12, lsr #15 @
+ andne r3, r3, #0x7c00 @ mask b only if clamped
+ movs r12, r11, asr #16 @ clamp r
+ mvnne r11, r12, lsr #16 @
+ movs r12, r7, asr #15 @ clamp g
+ mvnne r7, r12, lsr #15 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4], #1 @ r12 = Y' = *(Y'_p++)
+ @
+ and r11, r11, #0xf800 @ pack pixel
+ and r7, r7, #0x7e00 @ r3 = pixel = (r & 0xf800) |
+ orr r11, r11, r7, lsr #4 @ ((g & 0x7e00) >> 4) |
+ orr r3, r11, r3, lsr #10 @ (b >> 10)
+ @
+ mov r11, #LCD2_DATA_MASK @ store pixel
+ orr r7, r11, r3, lsr #8 @
+ orr r11, r11, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*149
+ add r12, r7, r7, asl #2 @
+ add r12, r12, r12, asl #4 @
+ add r7, r12, r7, asl #6 @
+ @ compute R, G, and B
+ add r3, r8, r7 @ r3 = b' = Y + bu
+ add r11, r9, r7, asl #1 @ r11 = r' = Y*2 + rv
+ rsb r7, r10, r7 @ r7 = g' = Y + guv
+ @
+ @ r8 = bu, r9 = rv, r10 = guv
+ @
+ sub r12, r3, r3, lsr #5 @ r3 = 31/32*b' + b'/256
+ add r3, r12, r3, lsr #8 @
+ @
+ sub r12, r11, r11, lsr #5 @ r11 = 31/32*r' + r'/256
+ add r11, r12, r11, lsr #8 @
+ @
+ sub r12, r7, r7, lsr #6 @ r7 = 63/64*g' + g'/256
+ add r7, r12, r7, lsr #8 @
+ @
+ add r12, r14, #0x100 @
+ @
+ add r3, r3, r12 @ b = r3 + delta
+ add r11, r11, r12, lsl #1 @ r = r11 + delta*2
+ add r7, r7, r12, lsr #1 @ g = r7 + delta/2
+ @
+ orr r12, r3, r11, asr #1 @ check if clamping is needed...
+ orr r12, r12, r7 @ ...at all
+ movs r12, r12, asr #15 @
+ beq 15f @ no clamp @
+ movs r12, r3, asr #15 @ clamp b
+ mvnne r3, r12, lsr #15 @
+ andne r3, r3, #0x7c00 @ mask b only if clamped
+ movs r12, r11, asr #16 @ clamp r
+ mvnne r11, r12, lsr #16 @
+ movs r12, r7, asr #15 @ clamp g
+ mvnne r7, r12, lsr #15 @
+15: @ no clamp @
+ @
+ ldrb r12, [r4, r2] @ r12 = Y' = *(Y'_p + stride)
+ @
+ and r11, r11, #0xf800 @ pack pixel
+ and r7, r7, #0x7e00 @ r3 = pixel = (r & 0xf800) |
+ orr r11, r11, r7, lsr #4 @ ((g & 0x7e00) >> 4) |
+ orr r3, r11, r3, lsr #10 @ (b >> 10)
+ @
+ mov r11, #LCD2_DATA_MASK @ store pixel
+ orr r7, r11, r3, lsr #8 @
+ orr r11, r11, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ sub r7, r12, #16 @ r7 = Y = (Y' - 16)*149
+ add r12, r7, r7, asl #2 @
+ add r12, r12, r12, asl #4 @
+ add r7, r12, r7, asl #6 @
+ @ compute R, G, and B
+ add r3, r8, r7 @ r3 = b' = Y + bu
+ add r11, r9, r7, asl #1 @ r11 = r' = Y*2 + rv
+ rsb r7, r10, r7 @ r7 = g' = Y + guv
+ @
+ sub r12, r3, r3, lsr #5 @ r3 = 31/32*b + b/256
+ add r3, r12, r3, lsr #8 @
+ @
+ sub r12, r11, r11, lsr #5 @ r11 = 31/32*r + r/256
+ add r11, r12, r11, lsr #8 @
+ @
+ sub r12, r7, r7, lsr #6 @ r7 = 63/64*g + g/256
+ add r7, r12, r7, lsr #8 @
+ @
+ add r12, r14, #0x300 @
+ @
+ add r3, r3, r12 @ b = r3 + delta
+ add r11, r11, r12, lsl #1 @ r = r11 + delta*2
+ add r7, r7, r12, lsr #1 @ g = r7 + delta/2
+ @
+ orr r12, r3, r11, asr #1 @ check if clamping is needed...
+ orr r12, r12, r7 @ ...at all
+ movs r12, r12, asr #15 @
+ beq 15f @ no clamp @
+ movs r12, r3, asr #15 @ clamp b
+ mvnne r3, r12, lsr #15 @
+ andne r3, r3, #0x7c00 @ mask b only if clamped
+ movs r12, r11, asr #16 @ clamp r
+ mvnne r11, r12, lsr #16 @
+ movs r12, r7, asr #15 @ clamp g
+ mvnne r7, r12, lsr #15 @
+15: @ no clamp @
+ @
+ and r11, r11, #0xf800 @ pack pixel
+ and r7, r7, #0x7e00 @ r3 = pixel = (r & 0xf800) |
+ orr r11, r11, r7, lsr #4 @ ((g & 0x7e00) >> 4) |
+ orr r3, r11, r3, lsr #10 @ (b >> 10)
+ @
+ mov r11, #LCD2_DATA_MASK @ store pixel
+ orr r7, r11, r3, lsr #8 @
+ orr r11, r11, r3 @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r7, [r0] @
+20: @
+ ldr r3, [r0] @
+ tst r3, #LCD2_BUSY_MASK @
+ bne 20b @
+ str r11, [r0] @
+ @
+ subs r1, r1, #2 @ subtract block from width
+ bgt 10b @ loop line @
+ @
+ ldmfd sp!, { r4-r12, pc } @ restore registers and return
+ .ltorg @ dump constant pool
+ .size lcd_write_yuv420_lines_odither, .-lcd_write_yuv420_lines_odither