| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2007 by Andree Buschmann |
| * |
| * 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. |
| * |
| ****************************************************************************/ |
| |
| .section .icode, "ax", %progbits |
| |
| /**************************************************************************** |
| * void lcd_write_data(const fb_data *addr, |
| * int pixelcount); |
| * |
| * Writes pixelcount pixels from src-pointer (lcd_framebuffer) to BCM dataport. |
| */ |
| .align 2 |
| .global lcd_write_data |
| .type lcd_write_data, %function |
| /* r0 = addr, must be aligned */ |
| lcd_write_data: /* r1 = pixel count, must be even */ |
| stmfd sp!, {r4-r5, lr} |
| mov lr, #0x30000000 /* LCD data port */ |
| |
| subs r1, r1, #16 |
| .loop16: |
| 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!, {r2-r5} |
| stmneia lr, {r2-r5} |
| tst r1, #4 |
| ldmneia r0!, {r2-r3} |
| stmneia lr, {r2-r3} |
| tst r1, #2 |
| ldrne r3, [r0], #4 |
| strne r3, [lr] |
| |
| ldmfd sp!, {r4-r5, pc} |
| |
| /**************************************************************************** |
| * extern void lcd_write_yuv420_lines(unsigned char const * const src[3], |
| * unsigned bcmaddr |
| * int width, |
| * int stride); |
| * |
| * Conversion from Motion JPEG and MPEG Y'PbPr to RGB is: |
| * |R| |1.164 0.000 1.596| |Y' - 16| |
| * |G| = |1.164 -0.391 -0.813| |Pb - 128| |
| * |B| |1.164 2.018 0.000| |Pr - 128| |
| * |
| * 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 |
| * |
| * Converts two lines from YUV to RGB565 and writes to BCM at once. First loop |
| * loads Cb/Cr, calculates the chroma offset and saves them to buffer. Within |
| * the second loop these chroma offset are reloaded from buffer. |
| * Within each loop two pixels are calculated and written to BCM. Before each |
| * loop the desired destination address is transmitted to BCM. |
| */ |
| .align 2 |
| .global lcd_write_yuv420_lines |
| .type lcd_write_yuv420_lines, %function |
| lcd_write_yuv420_lines: |
| /* r0 = src = yuv_src */ |
| /* r1 = dst = bcmaddr */ |
| /* r2 = width */ |
| /* r3 = 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, */ |
| bic r4, r4, #3 /* rounded up to multiples of 4 byte */ |
| sub sp, sp, r4 /* and allocate on stack */ |
| stmia sp, {r1-r4} /* bcmaddr, width, &ysrc[stride], stack_alloc */ |
| |
| mov r7, r2 /* r7 = loop count */ |
| add r8, sp, #16 /* chroma buffer */ |
| mov lr, #0x30000000 /* LCD data port */ |
| |
| /* The following writes dest address to BCM and waits for write ready */ |
| 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)) */ |
| tst r1, #0x2 |
| beq .busy_1 |
| |
| /* 1st loop start */ |
| 10: /* loop start */ |
| |
| 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 */ |
| |
| add r2, r1, r1, asl #1 /* r2 = Cr*51 + Cb*24 */ |
| add r2, r2, r2, asl #4 |
| add r2, r2, r0, asl #3 |
| add r2, r2, r0, asl #4 |
| |
| add r4, r1, r1, asl #2 /* r1 = Cr*101 */ |
| add r4, r4, r1, asl #5 |
| add r1, r4, r1, asl #6 |
| |
| add r1, r1, #256 /* r1 = rv = (r1 + 256) >> 9 */ |
| mov r1, r1, asr #9 |
| rsb r2, r2, #128 /* r2 = guv = (-r2 + 128) >> 8 */ |
| mov r2, r2, asr #8 |
| add r0, r0, #2 /* r0 = bu = (Cb*128 + 256) >> 9 */ |
| mov r0, r0, asr #2 |
| stmia r8!, {r0-r2} /* store r0, r1 and r2 to chroma buffer */ |
| |
| /* 1st loop, first pixel */ |
| 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 |
| |
| add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ |
| add r3, r2, r5, asr #7 /* r3 = g = (Y >> 8) + guv */ |
| add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ |
| |
| orr r5, r6, r4 /* check if clamping is needed... */ |
| orr r5, r5, r3, asr #1 /* ...at all */ |
| cmp r5, #31 |
| bls 15f /* -> no clamp */ |
| cmp r6, #31 /* clamp r */ |
| mvnhi r6, r6, asr #31 |
| andhi r6, r6, #31 |
| cmp r3, #63 /* clamp g */ |
| mvnhi r3, r3, asr #31 |
| andhi r3, r3, #63 |
| cmp r4, #31 /* clamp b */ |
| mvnhi r4, r4, asr #31 |
| andhi r4, r4, #31 |
| 15: /* no clamp */ |
| |
| /* calculate pixel_1 and save to r5 for later pixel packing */ |
| orr r4, r4, r3, lsl #5 /* pixel_1 = r<<11 | g<<5 | b */ |
| orr r5, r4, r6, lsl #11 /* r5 = pixel_1 */ |
| |
| /* 1st loop, second pixel */ |
| 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 |
| |
| add r6, r1, r4, asr #8 /* r6 = r = (Y >> 9) + rv */ |
| add r3, r2, r4, asr #7 /* r3 = g = (Y >> 8) + guv */ |
| add r4, r0, r4, asr #8 /* r4 = b = (Y >> 9) + bu */ |
| |
| orr r0, r6, r4 /* check if clamping is needed... */ |
| orr r0, r0, r3, asr #1 /* ...at all */ |
| cmp r0, #31 |
| bls 15f /* -> no clamp */ |
| cmp r6, #31 /* clamp r */ |
| mvnhi r6, r6, asr #31 |
| andhi r6, r6, #31 |
| cmp r3, #63 /* clamp g */ |
| mvnhi r3, r3, asr #31 |
| andhi r3, r3, #63 |
| cmp r4, #31 /* clamp b */ |
| mvnhi r4, r4, asr #31 |
| andhi r4, r4, #31 |
| 15: /* no clamp */ |
| |
| /* calculate pixel_2 and pack with pixel_1 before writing */ |
| 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, [lr] /* write packed pixels */ |
| |
| subs r7, r7, #2 /* check for loop end */ |
| bgt 10b /* back to beginning */ |
| /* 1st loop end */ |
| |
| /* Reload several registers for pointer rewinding for next loop */ |
| add r8, sp, #16 /* chroma buffer */ |
| ldmia sp, { r1, r7, r9} /* r1 = bcmaddr */ |
| /* r7 = loop count */ |
| /* r9 = &ysrc[stride] */ |
| |
| /* The following writes dest address to BCM and waits for write ready */ |
| 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: |
| ldrh r1, [r6] /* while (!(BCM_CONTROL & 0x2)) */ |
| tst r1, #0x2 |
| beq .busy_2 |
| |
| |
| /* 2nd loop start */ |
| 20: /* loop start */ |
| /* restore r0 (bu), r1 (rv) and r2 (guv) from chroma buffer */ |
| ldmia r8!, {r0-r2} |
| |
| /* 2nd loop, first pixel */ |
| 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 |
| |
| add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ |
| add r3, r2, r5, asr #7 /* r3 = g = (Y >> 8) + guv */ |
| add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ |
| |
| orr r5, r6, r4 /* check if clamping is needed... */ |
| orr r5, r5, r3, asr #1 /* ...at all */ |
| cmp r5, #31 |
| bls 15f /* -> no clamp */ |
| cmp r6, #31 /* clamp r */ |
| mvnhi r6, r6, asr #31 |
| andhi r6, r6, #31 |
| cmp r3, #63 /* clamp g */ |
| mvnhi r3, r3, asr #31 |
| andhi r3, r3, #63 |
| cmp r4, #31 /* clamp b */ |
| mvnhi r4, r4, asr #31 |
| andhi r4, r4, #31 |
| 15: /* no clamp */ |
| /* calculate pixel_1 and save to r5 for later pixel packing */ |
| orr r4, r4, r3, lsl #5 /* pixel_1 = r<<11 | g<<5 | b */ |
| orr r5, r4, r6, lsl #11 /* r5 = pixel_1 */ |
| |
| /* 2nd loop, second pixel */ |
| 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 |
| |
| add r6, r1, r4, asr #8 /* r6 = r = (Y >> 9) + rv */ |
| add r3, r2, r4, asr #7 /* r3 = g = (Y >> 8) + guv */ |
| add r4, r0, r4, asr #8 /* r4 = b = (Y >> 9) + bu */ |
| |
| orr r0, r6, r4 /* check if clamping is needed... */ |
| orr r0, r0, r3, asr #1 /* ...at all */ |
| cmp r0, #31 |
| bls 15f /* -> no clamp */ |
| cmp r6, #31 /* clamp r */ |
| mvnhi r6, r6, asr #31 |
| andhi r6, r6, #31 |
| cmp r3, #63 /* clamp g */ |
| mvnhi r3, r3, asr #31 |
| andhi r3, r3, #63 |
| cmp r4, #31 /* clamp b */ |
| mvnhi r4, r4, asr #31 |
| andhi r4, r4, #31 |
| 15: /* no clamp */ |
| |
| /* calculate pixel_2 and pack with pixel_1 before writing */ |
| 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, [lr] /* write packed pixels */ |
| |
| subs r7, r7, #2 /* check for loop end */ |
| bgt 20b /* back to beginning */ |
| /* 2nd loop end */ |
| |
| ldr r3, [sp, #12] |
| add sp, sp, r3 /* deallocate buffer */ |
| ldmfd sp!, { r4-r11, pc } /* restore registers */ |
| |
| .ltorg |
| .size lcd_write_yuv420_lines, .-lcd_write_yuv420_lines |