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Save a few registers in assembler routines for iPod 5Gs LCD driver and YUV conversion.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16840 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2008-03-27 07:46:04 +00:00
parent a3674c6bc0
commit 2364bc213c
1 changed files with 33 additions and 35 deletions
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68
firmware/target/arm/ipod/video/lcd-as-video.S
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@ -30,31 +30,30 @@
.type lcd_write_data, %function
/* r0 = addr, must be aligned */
lcd_write_data: /* r1 = pixel count, must be even */
stmfd sp!, {r4-r6}
mov r2, #0x30000000 /* LCD data port */
stmfd sp!, {r4-r5, lr}
mov lr, #0x30000000 /* LCD data port */
subs r1, r1, #16
.loop16:
ldmgeia r0!, {r3-r6}
stmgeia r2, {r3-r6}
ldmgeia r0!, {r3-r6}
stmgeia r2, {r3-r6}
ldmgeia r0!, {r2-r5}
stmgeia lr, {r2-r5}
ldmgeia r0!, {r2-r5}
stmgeia lr, {r2-r5}
subges r1, r1, #16
bge .loop16
/* no need to correct the count, we're just checking bits from now */
tst r1, #8
ldmneia r0!, {r3-r6}
stmneia r2, {r3-r6}
ldmneia r0!, {r2-r5}
stmneia lr, {r2-r5}
tst r1, #4
ldmneia r0!, {r3-r4}
stmneia r2, {r3-r4}
ldmneia r0!, {r2-r3}
stmneia lr, {r2-r3}
tst r1, #2
ldrne r3, [r0], #4
strne r3, [r2]
strne r3, [lr]
ldmfd sp!, {r4-r6}
bx lr
ldmfd sp!, {r4-r5, pc}
/****************************************************************************
* extern void lcd_write_yuv420_lines(unsigned char const * const src[3],
@ -86,11 +85,11 @@ lcd_write_yuv420_lines:
/* r1 = dst = bcmaddr */
/* r2 = width */
/* r3 = stride */
stmfd sp!, { r4-r12 } /* save non-scratch */
ldmia r0, { r10-r12 } /* r10 = yuv_src[0] = Y'_p */
/* r11 = yuv_src[1] = Cb_p */
/* r12 = yuv_src[2] = Cr_p */
add r3, r10, r3 /* r3 = &ysrc[stride] */
stmfd sp!, { r4-r11, lr } /* save non-scratch */
ldmia r0, { r9-r11 } /* r9 = yuv_src[0] = Y'_p */
/* r10 = yuv_src[1] = Cb_p */
/* r11 = yuv_src[2] = Cr_p */
add r3, r9, r3 /* r3 = &ysrc[stride] */
add r4, r2, r2, asr #1 /* chroma buffer lenght = width/2 *3 */
mov r4, r4, asl #2 /* use words for str/ldm possibility */
add r4, r4, #19 /* plus room for 4 additional words, */
@ -100,11 +99,11 @@ lcd_write_yuv420_lines:
mov r7, r2 /* r7 = loop count */
add r8, sp, #16 /* chroma buffer */
mov r9, #0x30000000 /* LCD data port */
mov lr, #0x30000000 /* LCD data port */
/* The following writes dest address to BCM and waits for write ready */
orr r2, r9, #0x00010000 /* r2 = BCM_WR_ADDR32 */
orr r6, r9, #0x00030000 /* r6 = BCM_CONTROL */
orr r2, lr, #0x00010000 /* r2 = BCM_WR_ADDR32 */
orr r6, lr, #0x00030000 /* r6 = BCM_CONTROL */
str r1, [r2] /* BCM_WR_ADDR32 = bcmaddr */
.busy_1:
ldrh r1, [r6] /* while (!(BCM_CONTROL & 0x2)) */
@ -114,8 +113,8 @@ lcd_write_yuv420_lines:
/* 1st loop start */
10: /* loop start */
ldrb r0, [r11], #1 /* r0 = *usrc++ = *Cb_p++ */
ldrb r1, [r12], #1 /* r1 = *vsrc++ = *Cr_p++ */
ldrb r0, [r10], #1 /* r0 = *usrc++ = *Cb_p++ */
ldrb r1, [r11], #1 /* r1 = *vsrc++ = *Cr_p++ */
sub r0, r0, #128 /* r0 = Cb-128 */
sub r1, r1, #128 /* r1 = Cr-128 */
@ -138,7 +137,7 @@ lcd_write_yuv420_lines:
stmia r8!, {r0-r2} /* store r0, r1 and r2 to chroma buffer */
/* 1st loop, first pixel */
ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */
ldrb r5, [r9], #1 /* r5 = *ysrc++ = *Y'_p++ */
sub r5, r5, #16 /* r5 = (Y'-16) * 74 */
add r3, r5, r5, asl #2
add r5, r3, r5, asl #5
@ -167,7 +166,7 @@ lcd_write_yuv420_lines:
orr r5, r4, r6, lsl #11 /* r5 = pixel_1 */
/* 1st loop, second pixel */
ldrb r4, [r10], #1 /* r4 = *ysrc++ = *Y'_p++ */
ldrb r4, [r9], #1 /* r4 = *ysrc++ = *Y'_p++ */
sub r4, r4, #16 /* r4 = (Y'-16) * 74 */
add r3, r4, r4, asl #2
add r4, r3, r4, asl #5
@ -195,7 +194,7 @@ lcd_write_yuv420_lines:
orr r4, r4, r3, lsl #5 /* pixel_2 = r<<11 | g<<5 | b */
orr r4, r4, r6, lsl #11 /* r4 = pixel_2 */
orr r4, r5, r4, lsl #16 /* r4 = pixel_2<<16 | pixel_1 */
str r4, [r9] /* write packed pixels */
str r4, [lr] /* write packed pixels */
subs r7, r7, #2 /* check for loop end */
bgt 10b /* back to beginning */
@ -203,13 +202,13 @@ lcd_write_yuv420_lines:
/* Reload several registers for pointer rewinding for next loop */
add r8, sp, #16 /* chroma buffer */
ldmia sp, { r1, r7, r10} /* r1 = bcmaddr */
ldmia sp, { r1, r7, r9} /* r1 = bcmaddr */
/* r7 = loop count */
/* r10 = &ysrc[stride] */
/* r9 = &ysrc[stride] */
/* The following writes dest address to BCM and waits for write ready */
orr r2, r9, #0x00010000 /* r2 = BCM_WR_ADDR32 */
orr r6, r9, #0x00030000 /* r6 = BCM_CONTROL */
orr r2, lr, #0x00010000 /* r2 = BCM_WR_ADDR32 */
orr r6, lr, #0x00030000 /* r6 = BCM_CONTROL */
add r1, r1, #640 /* dst += (LCD_WIDTH*2) */
str r1, [r2] /* BCM_WR_ADDR32 = dst */
.busy_2:
@ -224,7 +223,7 @@ lcd_write_yuv420_lines:
ldmia r8!, {r0-r2}
/* 2nd loop, first pixel */
ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */
ldrb r5, [r9], #1 /* r5 = *ysrc++ = *Y'_p++ */
sub r5, r5, #16 /* r5 = (Y'-16) * 74 */
add r3, r5, r5, asl #2
add r5, r3, r5, asl #5
@ -252,7 +251,7 @@ lcd_write_yuv420_lines:
orr r5, r4, r6, lsl #11 /* r5 = pixel_1 */
/* 2nd loop, second pixel */
ldrb r4, [r10], #1 /* r4 = *ysrc++ = *Y'_p++ */
ldrb r4, [r9], #1 /* r4 = *ysrc++ = *Y'_p++ */
sub r4, r4, #16 /* r4 = (Y'-16) * 74 */
add r3, r4, r4, asl #2
add r4, r3, r4, asl #5
@ -280,7 +279,7 @@ lcd_write_yuv420_lines:
orr r4, r4, r3, lsl #5 /* pixel_2 = r<<11 | g<<5 | b */
orr r4, r4, r6, lsl #11 /* r4 = pixel_2 */
orr r4, r5, r4, lsl #16 /* r4 = pixel_2<<16 | pixel_1 */
str r4, [r9] /* write packed pixels */
str r4, [lr] /* write packed pixels */
subs r7, r7, #2 /* check for loop end */
bgt 20b /* back to beginning */
@ -288,8 +287,7 @@ lcd_write_yuv420_lines:
ldr r3, [sp, #12]
add sp, sp, r3 /* deallocate buffer */
ldmfd sp!, { r4-r12 } /* restore registers */
bx lr
ldmfd sp!, { r4-r11, pc } /* restore registers */
.ltorg
.size lcd_write_yuv420_lines, .-lcd_write_yuv420_lines