Ability to read EDID

drivers/dv_display/dv_display.cpp

@@ -96,6 +96,10 @@ namespace pimoroni {
     return i2c.reg_read_uint8(I2C_ADDR, I2C_REG_GPIO_HI);
   }
 
+  void DVDisplay::get_edid(uint8_t* edid) {
+    i2c.read_bytes(I2C_ADDR, I2C_REG_EDID, edid, 128);
+  }
+
   void DVDisplay::write(uint32_t address, size_t len, const uint16_t colour)
   {
     uint32_t val = colour | ((uint32_t)colour << 16);
@@ -132,6 +136,20 @@ namespace pimoroni {
     write(pointToAddress(p), l, colour);
   }
 
+  void DVDisplay::write_pixel_span(const Point &p, uint l, uint16_t *data)
+  {
+    uint32_t offset = 0;
+    if (((uintptr_t)data & 0x2) != 0) {
+      uint32_t val = *data++;
+      ram.write(pointToAddress(p), &val, 2);
+      --l;
+      offset = 2;
+    }
+    if (l > 0) {
+      ram.write(pointToAddress(p) + offset, (uint32_t*)data, l << 1);
+    }
+  }
+
   void DVDisplay::read_pixel_span(const Point &p, uint l, uint16_t *data)
   {
     read(pointToAddress(p), l, data);

drivers/dv_display/dv_display.hpp

@@ -40,6 +40,7 @@ namespace pimoroni {
     static constexpr uint I2C_REG_START = 0xF9;
     static constexpr uint I2C_REG_GPIO = 0xC0;
     static constexpr uint I2C_REG_GPIO_HI = 0xC8;
+    static constexpr uint I2C_REG_EDID = 0xED;
     
     static constexpr uint32_t base_address = 0x10000;
     uint16_t width = 0;
@@ -96,6 +97,7 @@ namespace pimoroni {
       
       void write_pixel(const Point &p, uint16_t colour) override;
       void write_pixel_span(const Point &p, uint l, uint16_t colour) override;
+      void write_pixel_span(const Point &p, uint l, uint16_t *data);
       void read_pixel_span(const Point &p, uint l, uint16_t *data) override;
 
       void init();
@@ -107,6 +109,9 @@ namespace pimoroni {
       bool is_button_b_pressed() { return (get_driver_gpio() & 0x1) != 0x1; }
       bool is_button_c_pressed() { return (get_driver_gpio() & 0x2) != 0x2; }
 
+      // The supplied buffer must be at least 128 bytes long
+      void get_edid(uint8_t* edid);
+
     private:
       static constexpr int PIXEL_BUFFER_LEN_IN_WORDS = 16;
       uint32_t pixel_buffer[PIXEL_BUFFER_LEN_IN_WORDS];