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https://github.com/adafruit/Adafruit-GFX-Library.git
synced 2024-10-03 18:18:46 -04:00
Change DMA polling behavior.
This commit is contained in:
Phillip Burgess
parent
860cd24319
commit
555c82160a
@ -57,35 +57,11 @@
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#include <malloc.h> // memalign() function
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// DMA transfer-in-progress indicator and callback
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static volatile boolean dma_busy = false;
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static volatile Adafruit_SPITFT *spitft = NULL;
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static volatile boolean dma_busy = false;
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static void dma_callback(Adafruit_ZeroDMA *dma) {
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// If spitft pointer is set, deselect TFT and end the SPI transaction
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// here in the callback rather than at end of drawing function. Avoids
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// a (possibly unnecessary) function call at the start of every graphics
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// operation. Can't do this in SPI_BEGIN_TRANSACTION because other code
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// outside the library (e.g. SD card reading) may be waiting on the
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// GFX SPI transaction to end first.
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if(spitft) {
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((Adafruit_SPITFT *)spitft)->endWrite();
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spitft = NULL;
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}
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dma_busy = false;
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}
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/**************************************************************************/
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/*!
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@brief Poll whether a previous DMA operation is still in-progress.
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@return true if SPITFT DMA operation in progress, false if available.
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*/
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/**************************************************************************/
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boolean Adafruit_SPITFT::DMA_busy(void) {
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return dma_busy;
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}
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#define DMA_WAIT while(dma_busy); ///< Wait for dma busy flag to clear
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#else
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#define DMA_WAIT ///< Do nothing; DMA not used
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#endif // USE_SPI_DMA
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/**************************************************************************/
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@ -431,7 +407,6 @@ void Adafruit_SPITFT::spiWrite(uint8_t b) {
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*/
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/**************************************************************************/
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void inline Adafruit_SPITFT::startWrite(void){
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DMA_WAIT; // Wait for any prior SPI DMA to complete
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SPI_BEGIN_TRANSACTION();
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SPI_CS_LOW();
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}
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@ -442,19 +417,8 @@ void inline Adafruit_SPITFT::startWrite(void){
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*/
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/**************************************************************************/
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void inline Adafruit_SPITFT::endWrite(void){
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#ifdef USE_SPI_DMA
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// SPI DMA enabled: wait for DMA completion and end transaction ONLY if
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// spitft is NULL. Otherwise, calling function can proceed and
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// equivalent code in DMA callback is used.
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if(!spitft) {
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DMA_WAIT; // Wait for DMA operation to complete
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SPI_CS_HIGH();
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SPI_END_TRANSACTION();
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}
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#else
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SPI_CS_HIGH();
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SPI_END_TRANSACTION();
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#endif
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}
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/**************************************************************************/
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@ -511,7 +475,7 @@ void Adafruit_SPITFT::writePixels(uint16_t *colors, uint32_t len) {
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descriptor[pixelBufIdx].BTCNT.reg = count * 2;
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descriptor[pixelBufIdx].DESCADDR.reg = 0;
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DMA_WAIT; // NOW wait for prior DMA to complete
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while(dma_busy); // wait for prior line to complete
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// Move new descriptor into place...
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memcpy(dptr, &descriptor[pixelBufIdx], sizeof(DmacDescriptor));
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@ -523,11 +487,7 @@ void Adafruit_SPITFT::writePixels(uint16_t *colors, uint32_t len) {
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}
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lastFillColor = 0x0000; // pixelBuf has been sullied
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lastFillLen = 0;
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// Return immediately -- other code runs with last DMA transfer in
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// background. startWrite() will wait for the transfer to complete
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// before issuing any more commands. User code MUST poll
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// display.DMA_busy() before attempting anything else on the same
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// SPI bus (e.g. SD card access).
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while(dma_busy); // Wait for last line to complete
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#else
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SPI_WRITE_PIXELS((uint8_t*)colors , len * 2);
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#endif
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@ -599,14 +559,14 @@ void Adafruit_SPITFT::writeColor(uint16_t color, uint32_t len) {
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}
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}
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memcpy(dptr, &descriptor[0], sizeof(DmacDescriptor));
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dma_busy = true; // ANY function using SPI must poll busy flag!
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spitft = this; // Save pointer to Adafruit_SPITFT type for callback
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dma_busy = true;
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dma.startJob(); // Trigger SPI DMA transfer
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// Return immediately -- other code runs with DMA transfer in
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// background. startWrite() will wait for the transfer to complete
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// before issuing any more commands. User code MUST poll
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// display.DMA_busy() before attempting anything else on the same
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// SPI bus (e.g. SD card access).
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while(dma_busy); // Wait for completion
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// Unfortunately the wait is necessary. An earlier version returned
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// immediately and checked dma_busy on startWrite() instead, but it
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// turns out to be MUCH slower on many graphics operations (as when
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// drawing lines, pixel-by-pixel), perhaps because it's a volatile
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// type.
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#else // Non-DMA
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@ -658,7 +618,6 @@ void Adafruit_SPITFT::writeColor(uint16_t color, uint32_t len) {
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/**************************************************************************/
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void Adafruit_SPITFT::writePixel(int16_t x, int16_t y, uint16_t color) {
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if((x < 0) ||(x >= _width) || (y < 0) || (y >= _height)) return;
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DMA_WAIT;
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setAddrWindow(x,y,1,1);
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writePixel(color);
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}
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@ -693,7 +652,6 @@ void Adafruit_SPITFT::writeFillRect(int16_t x, int16_t y, int16_t w, int16_t h,
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if(y2 >= _height) h = _height - y;
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int32_t len = (int32_t)w * h;
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DMA_WAIT;
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setAddrWindow(x, y, w, h);
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writeColor(color, len);
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}
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@ -848,7 +806,7 @@ void Adafruit_SPITFT::drawRGBBitmap(int16_t x, int16_t y,
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if(y2 >= _height) h = _height - y; // Clip bottom
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pcolors += by1 * saveW + bx1; // Offset bitmap ptr to clipped top-left
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startWrite(); // Includes a DMA_WAIT
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startWrite();
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setAddrWindow(x, y, w, h); // Clipped area
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while(h--) { // For each (clipped) scanline...
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writePixels(pcolors, w); // Push one (clipped) row
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@ -15,8 +15,6 @@
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#define USE_FAST_PINIO ///< If set, use PORT access instead of digitalWrite()
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//#define USE_SPI_DMA ///< If set, use SPI DMA if available
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// If DMA is enabled, Arduino sketch MUST #include <Adafruit_ZeroDMA.h>
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// Sketches MUST poll tft.DMA_busy() before doing other things that work
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// on the SPI bus (e.g. accessing SD card).
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// Estimated RAM usage:
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// 4 bytes/pixel on display major axis + 8 bytes/pixel on minor axis,
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// e.g. 320x240 pixels = 320 * 4 + 240 * 8 = 3,200 bytes.
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@ -105,9 +103,6 @@ class Adafruit_SPITFT : public Adafruit_GFX {
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void writeCommand(uint8_t cmd);
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void spiWrite(uint8_t v);
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uint8_t spiRead(void);
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#ifdef USE_SPI_DMA
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boolean DMA_busy(void);
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#endif
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protected:
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SPIClass *_spi; ///< The SPI device we want to use (set in constructor)
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