2023-10-14 17:49:00 +08:00

206 lines
6.9 KiB
C

#include "types.h"
#include "arm11/drivers/lgyfb.h"
#include "arm11/drivers/interrupt.h"
#include "drivers/cache.h"
#include "drivers/corelink_dma-330.h"
#include "arm11/drivers/lcd.h"
#include "kevent.h"
static KHandle g_frameReadyEvent = 0;
// DMA330 docs don't tell you the recommended alignment so we assume it's bus width.
alignas(8) static u8 g_gbaFrameDmaProg[42] =
{
// All transfer settings for RGB8 at 360x240 to a 512x512 texture.
0xBC, 0x01, 0xE6, 0xC2, 0xB9, 0x00, // MOV CCR, SB15 SS64 SAF SP2 DB15 DS64 DAI DP2
0xBC, 0x00, 0x00, 0x10, 0x31, 0x10, // MOV SAR, 0x10311000
0xBC, 0x02, 0x00, 0x00, 0x20, 0x18, // MOV DAR, 0x18200000
0x35, 0x70, // FLUSHP 14
0x20, 0x1D, // LP 30
0x32, 0x70, // WFP 14, burst
0x22, 0x46, // LP 71
0x04, // LD
0x08, // ST
0x3C, 0x02, // LPEND
0x27, 0x70, // LDPB 14
0x08, // ST
0x56, 0x40, 0x0E, // ADDH DAR, 0xE40
0x38, 0x0E, // LPEND
0x13, // WMB
0x34, 0x00, // SEV 0
0x00 // END
};
static void gbaDmaIrqHandler(UNUSED u32 intSource)
{
DMA330_ackIrq(0);
DMA330_run(0, g_gbaFrameDmaProg);
// We can't match the GBA refreshrate exactly so keep the LCDs around 90%
// ahead of the GBA output which gives us a time window of around 1.6 ms to
// render the frame and hopefully reduces output lag as much as possible.
u32 vtotal;
if(REG_LCD_PDC0_VPOS > 414 - 41) vtotal = 415; // Slower than GBA.
else vtotal = 414; // Faster than GBA.
REG_LCD_PDC0_VTOTAL = vtotal;
signalEvent(g_frameReadyEvent, false);
}
static void patchDmaProg(const bool is240x160)
{
if(is240x160)
{
u8 *const prog = g_gbaFrameDmaProg;
// Adjust bursts. Needs to be 16 transfers for 240x160.
prog[2] = 0xF6;
prog[4] = 0xBD;
// Adjust outer loop count.
prog[21] = 20 - 1;
// Adjust inner loop count.
prog[25] = 44 - 1;
// Adjust gap skip.
*((u16*)&prog[34]) = 0x1980;
// Make sure the DMA controller can see the code.
flushDCacheRange(prog, sizeof(g_gbaFrameDmaProg));
}
// Else 360x240. Nothing to do.
}
/*
* Scale matrix limitations:
* First pattern bit must be 1 and last 0 (for V-scale) or it loses sync with the DS/GBA input.
* Vertical scaling is fucked with identity matrix.
*
* Matrix ranges:
* in[-3] -1024-1023 (0xFC00-0x03FF)
* in[-2] -4096-4095 (0xF000-0x0FFF)
* in[-1] -32768-32767 (0x8000-0x7FFF)
* in[0] -32768-32767 (0x8000-0x7FFF)
* in[1] -4096-4095 (0xF000-0x0FFF)
* in[2] -1024-1023 (0xFC00-0x03FF)
*
* Note: At scanline start the in FIFO is all filled with the first pixel.
* Note: The first column only allows 1 non-zero entry.
* Note: Bits 0-3 of each entry are ignored by the hardware.
* Note: 16384 (0x4000) is the maximum brightness of a pixel.
* The sum of all entries in a column should be 16384 or clipping will occur.
* Note: The window of (the 6) input pixels is post-increment.
* When the matching pattern bit is 0 it does not move forward.
*/
static void setScaleMatrix(LgyFbScaler *const scaler, const u32 len, const u32 patt,
const s16 *in, const u8 inBits, const u8 outBits)
{
scaler->len = len - 1;
scaler->patt = patt;
// Calculate the maximum values for input and output sub pixels.
s32 inMax = (0xFF00u>>inBits) & 0xFFu; // Input bits in upper part.
inMax = (inMax == 0 ? 1 : inMax);
s32 outMax = (1u<<outBits) - 1;
outMax = (outMax == 0 ? 1 : outMax);
vu32 *out = &scaler->matrix[0][0];
const vu32 *const outEnd = out + 6 * 8;
do
{
// Correct the color range using the scale matrix hardware.
// For example when converting RGB555 to RGB8 LgyFb lazily shifts the 5 bits up
// so 0b00011111 becomes 0b11111000. But for maximum pixel brightness on the
// input we also want the maximum on the output (0b11111000 --> 0b11111111).
// This will fix it and distribute the colors evenly across the output range.
// Also round up because the hardware will ignore the first 4 bits.
const s32 mEntry = *in++;
*out++ = mEntry * outMax / inMax + 8;
} while(out < outEnd);
}
KHandle LGYFB_init(/*const bool isTop,*/ const ScalerCfg *const cfg)
{
// TODO: Support TWL sized frames and using both LgyFb engines.
const bool is240x160 = cfg->w == 240 && cfg->h == 160;
patchDmaProg(is240x160);
if(DMA330_run(0, g_gbaFrameDmaProg)) return 0;
// Create KEvent for frame ready signal.
KHandle frameReadyEvent = createEvent(false);
g_frameReadyEvent = frameReadyEvent;
LgyFb *const lgyFb = getLgyFbRegs(true);
lgyFb->size = LGYFB_SIZE(cfg->w, cfg->h);
lgyFb->stat = LGYFB_IRQ_MASK;
lgyFb->irq = 0;
lgyFb->alpha = 0xFF;
// TODO: Can't we just always do color corrections on h? Output differs between the 2 when both are active.
if(is240x160)
{
setScaleMatrix(&lgyFb->h, cfg->hLen, cfg->hPatt, cfg->hMatrix, 5, 8);
}
else
{
setScaleMatrix(&lgyFb->v, cfg->vLen, cfg->vPatt, cfg->vMatrix, 5, 8);
setScaleMatrix(&lgyFb->h, cfg->hLen, cfg->hPatt, cfg->hMatrix, 0, 0);
}
// With RGB8 output solid red and blue are converted to 0xF8 and green to 0xFA.
// The green bias exists on the whole range of green colors.
// Some results:
// RGBA8: Same as RGB8 but with useless alpha component.
// RGB8: Observed best format. Invisible dithering and best color accuracy.
// RGB565: A little visible dithering. Good color accuracy.
// RGB5551: Lots of visible dithering. Good color accuracy (a little worse than 565).
u32 cnt = LGYFB_DMA_EN | LGYFB_OUT_SWIZZLE | LGYFB_OUT_FMT_8880 | LGYFB_HSCALE_EN | LGYFB_EN;
if(!is240x160) cnt |= LGYFB_VSCALE_EN;
lgyFb->cnt = cnt;
IRQ_registerIsr(IRQ_CDMA_EVENT0, 13, 0, gbaDmaIrqHandler);
return frameReadyEvent;
}
void LGYFB_deinit(/*const bool isTop*/ void)
{
// Disable LgyFb engine, acknowledge IRQs (if any), kill DMA channel and flush the FIFO.
LgyFb *const lgyFb = getLgyFbRegs(true);
lgyFb->cnt = 0;
// Acknowledge IRQs here. Nothing to do since none are enabled.
DMA330_kill(0);
lgyFb->flush = 0;
// Unregister isr and delete event (if any was created).
IRQ_unregisterIsr(IRQ_CDMA_EVENT0);
if(g_frameReadyEvent != 0)
deleteEvent(g_frameReadyEvent);
g_frameReadyEvent = 0;
}
void LGYFB_stop(/*const bool isTop*/ void)
{
// Disable LgyFb engine, acknowledge IRQs (if any), kill DMA channel and flush the FIFO.
LgyFb *const lgyFb = getLgyFbRegs(true);
lgyFb->cnt &= ~LGYFB_EN;
// Acknowledge IRQs here. Nothing to do since none are enabled.
DMA330_kill(0);
lgyFb->flush = 0;
// Clear event to prevent issues since we just disabled LgyFb.
clearEvent(g_frameReadyEvent);
}
void LGYFB_start(/*const bool isTop*/ void)
{
// Restart DMA and then LgyFb.
if(DMA330_run(0, g_gbaFrameDmaProg)) return;
getLgyFbRegs(true)->cnt |= LGYFB_EN;
}