Some DMA thoughts

src/PicoIris.cpp

@@ -8,6 +8,7 @@
 #include "hardware/timer.h"
 #include "hardware/clocks.h"
 #include "hardware/uart.h"
+#include "../../hardware_dma/include/hardware/dma.h"
 
 #include <ov2640/SCCB.hpp>
 #include <ov2640/camera.hpp>
@@ -32,6 +33,9 @@ int main()
 {
     stdio_init_all();
 
+    OV2640 left_cam = OV2640(left_eye_config);
+    left_cam.begin(DMA_IRQ_0);
+
     while (true) {
         printf("Hello, world!\n");
         sleep_ms(1000);

src/ov2640/camera.cpp

@@ -22,7 +22,6 @@ static uint16_t capture_pio_opcodes[] = {
     0b0010000000000000, // WAIT 0 GPIO 0 (mask in PCLK pin before use)
 };
 
-
 static struct pio_program cap_pio_program = {
     .instructions = capture_pio_opcodes,
     .length = sizeof capture_pio_opcodes / sizeof capture_pio_opcodes[0],
@@ -280,8 +279,7 @@ register_val_t OV2640_init[] = {
     {OV2640_REG0_ZMOH, 0x78},     // OUTH low bits
     {OV2640_REG0_ZMHH, 0x00},     // OUTW/H high bits
     {OV2640_REG0_R_DVP_SP, 0x02}, // Manual DVP PCLK setting
-    {OV2640_REG0_RESET, 0x00}
-};   // Go
+    {OV2640_REG0_RESET, 0x00}};   // Go
 // TODO: figure out how to set to JPEG and 260x260
 /*OV2640_qqvga[] =
     {// Configure OV2640 for QQVGA output
@@ -321,11 +319,17 @@ OV2640_yuv[] = {
     {OV2640_REG0_RESET, 0x00}
 }; // Go*/
 
-OV2640::OV2640(camera_config_t config) {
+uint8_t image_buf[3][13 * 1024];
+sm_dma_config_t gpios[48];
+
+OV2640::OV2640(camera_config_t config)
+{
     this->config = config;
+    this->fb = &image_buf;
 }
 
-int OV2640::begin() {
+int OV2640::begin(int dma_irq)
+{
     // Initialize peripherals for parallel+I2C camera:
 
     // XCLK generation (~20.83 MHz)
@@ -337,7 +341,7 @@ int OV2640::begin() {
     pwm_set_enabled(slice_num, true);
 
     // Init SCCB
-    this->sccb = SCCB(this->config.pin_sccb_sda,this->config.pin_sccb_scl);
+    this->sccb = SCCB(this->config.pin_sccb_sda, this->config.pin_sccb_scl);
     this->sccb.begin(this->config.sccb_ctrl);
 
     // ENABLE AND/OR RESET CAMERA --------------------------------------------
@@ -359,7 +363,8 @@ int OV2640::begin() {
     gpio_set_dir(this->config.pin_vsync, GPIO_IN);
     gpio_init(this->config.pin_href);
     gpio_set_dir(this->config.pin_href, GPIO_IN);
-    for (uint8_t i = 0; i < 8; i++) {
+    for (uint8_t i = 0; i < 8; i++)
+    {
         gpio_init(this->config.pin_data_base + i);
         gpio_set_dir(this->config.pin_data_base + i, GPIO_IN);
     }
@@ -376,8 +381,6 @@ int OV2640::begin() {
     uint offset = pio_add_program(pio2, &cap_pio_program);
     this->sm = pio_claim_unused_sm(pio2, true); // 0-3
 
-    // host->pins->data[0] is data bit 0. PIO code requires all 8 data be
-    // contiguous.
     pio_sm_set_consecutive_pindirs(pio2, this->sm, this->config.pin_data_base, 8, false);
 
     pio_sm_config c = pio_get_default_sm_config();
@@ -399,7 +402,7 @@ int OV2640::begin() {
     channel_config_set_transfer_data_size(&this->dma_config, DMA_SIZE_16);
     channel_config_set_read_increment(&this->dma_config, false);
     channel_config_set_write_increment(&this->dma_config, true);
-    channel_config_set_bswap(&this->dma_config, true); // TODO: bswap should be true or false? 
+    channel_config_set_bswap(&this->dma_config, true);
 
     // Set PIO RX as DMA trigger. Input shift register saturates at 16 bits
     // (1 pixel), configured in data size above and in PIO setup elsewhere.
@@ -413,35 +416,47 @@ int OV2640::begin() {
 
     // Set up end-of-DMA interrupt
     dma_channel_set_irq0_enabled(this->dma_channel, true);
-    // TODO: setup diffrent handlers for each cam???
-    irq_set_exclusive_handler(DMA_IRQ_0, iCap_dma_finish_irq);
-    irq_set_enabled(DMA_IRQ_0, true);
+    
+    //? setup diffrent handlers for each cam???
+    //? check with a button or smth if this fires all events or only one
+    //? cuz then I would be able to do dma_finish_irq_cam1, dma_finish_irq_cam2, dma_finish_irq_cam3
+    //? That would have hardcoded values for the buffers 
+    irq_set_exclusive_handler(dma_irq, dma_finish_irq);
+    irq_set_enabled(dma_irq, true);
 
     // SET UP VSYNC INTERRUPT ------------------------------------------------
-
+    //? This also could be redone with hardcoded values
     gpio_set_irq_enabled_with_callback(this->config.pin_vsync, GPIO_IRQ_EDGE_RISE, true,
-                                        &iCap_vsync_irq);
+                                       &vsync_irq);
 
     return 0;
 }
 
-// TODO: figure out how to get from where does IRQs originate from
-// TODO: how to transfer data?
-// TODO: what?
-// TODO: eep time
-// TODO: make a static array with something like a hashmap containing GPIO -> sm+dma_channel mappings
+
 // Pin interrupt on VSYNC calls this to start DMA transfer (unless suspended).
-static void iCap_vsync_irq(uint gpio, uint32_t events) {
+static void vsync_irq(uint gpio, uint32_t events)
+{
     pio_sm_clear_fifos(pio2, archptr->sm);
     dma_channel_start(archptr->dma_channel);
-  }
+}
 
-// TODO: make a static array with something like a hashmap containing GPIO -> sm+dma_channel mappings
-  static void iCap_dma_finish_irq() {
+static void dma_finish_irq()
+{
     // Channel MUST be reconfigured each time (to reset the dest address).
     dma_channel_set_write_addr(archptr->dma_channel,
-                               (uint8_t *)(capptr->getBuffer()), false);
+                               (uint8_t *)(image_buf), false);
     dma_hw->ints0 = 1u << archptr->dma_channel; // Clear IRQ
-  }
+}
+
+//! https://forums.raspberrypi.com/viewtopic.php?t=339299
+// TODO: change to switches and experiment with state machines, check if I can kinda reserve dma's so 0-3 would indicate state machines 0-3 
+/* Read the flags
+uint32_t flags = read_register(PIO0_BASE, PIO_IRQ_OFFSET)
+// Check the flags to determine which state machine made the request
+if (flags & 0b0001) { handle_sm_0(); }
+if (flags & 0b0010) { handle_sm_1(); }
+if (flags & 0b0100) { handle_sm_2(); }
+if (flags & 0b1000) { handle_sm_3(); }
+*/
 
 // TODO: add all of the specific controls like brightness and all of that scheiße

src/ov2640/camera.hpp

@@ -13,15 +13,22 @@ typedef struct {
     uint8_t sccb_ctrl;              /* Select i2c controller ctrl: 0 - i2c0, 1 - i2c1, 2 - pio0, 3 - pio1, 4 - pio2 */
 } camera_config_t;
 
+typedef struct {
+    uint sm;
+    uint dma_channel;
+} sm_dma_config_t;
+
+
 class OV2640 {
 public:
     OV2640(camera_config_t config);
     ~OV2640();
 
-    int begin();
+    int begin(int dma_irq);
 private:
     camera_config_t config;
     SCCB sccb;
+    uint8_t* (*fb)[3];
     uint sm;
     uint dma_channel;
     dma_channel_config dma_config;