From 3f83d40ec83f455d3f4490387daa7e2dde8e936a Mon Sep 17 00:00:00 2001
From: Jan-Henrik Bruhn <hi@jhbruhn.de>
Date: Sat, 18 Apr 2020 17:37:08 +0200
Subject: [PATCH] Add draft of AD57X4 driver

---
 midi2cv/drivers/ad57x4.cc   | 64 +++++++++++++++++++++++++++++++++++++
 midi2cv/drivers/ad57x4.h    | 33 +++++++++++++++++++
 midi2cv/drivers/spi_mode.cc | 20 +++++++++++-
 midi2cv/midi2cv.cc          |  2 ++
 4 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 midi2cv/drivers/ad57x4.cc
 create mode 100644 midi2cv/drivers/ad57x4.h

diff --git a/midi2cv/drivers/ad57x4.cc b/midi2cv/drivers/ad57x4.cc
new file mode 100644
index 0000000..42868e0
--- /dev/null
+++ b/midi2cv/drivers/ad57x4.cc
@@ -0,0 +1,64 @@
+#include "ad57x4.h"
+#include "peripherals.h"
+#include "spi_mode.h"
+#include "stm32f3xx_hal_gpio.h"
+#include <stm32f3xx_hal.h>
+
+static const uint32_t kPinEnable = GPIO_PIN_5;
+
+void AD57X4::Init()
+{
+  GPIO_InitTypeDef init;
+  init.Pin = kPinEnable;
+  init.Mode = GPIO_MODE_OUTPUT_PP;
+  init.Pull = GPIO_NOPULL;
+  init.Speed = GPIO_SPEED_FREQ_HIGH;
+  HAL_GPIO_Init(GPIOB, &init);
+
+  HAL_GPIO_WritePin(GPIOB, kPinEnable, GPIO_PIN_SET);
+}
+
+void AD57X4::EnableAndSetRange(uint8_t dac, VoltageRange range, bool bipolar)
+{
+  if (!(this->dacPower & (1 << dac))) {
+    // power on dac
+    this->dacPower |= 1 << dac;
+    this->Write(REGISTER_POWER_CONTROL, 0, this->dacPower);
+  }
+  if (this->dacRange[dac] != range) {
+    this->Write(REGISTER_OUTPUT_RANGE, dac, range + (bipolar ? 3 : 0));
+    this->dacRange[dac] = range;
+  }
+}
+
+void AD57X4::WriteDacUnipolar(uint8_t dac, VoltageRange range, uint16_t value)
+{
+  EnableAndSetRange(dac, range, false);
+  this->Write(REGISTER_DAC, dac, value);
+}
+
+void AD57X4::WriteDacBipolar(uint8_t dac, VoltageRange range, int16_t value)
+{
+  uint16_t twosComplement = value;
+  if (value < 0) {
+    twosComplement = ~(-value) + 1;
+  }
+
+  EnableAndSetRange(dac, range, true);
+  this->Write(REGISTER_DAC, dac, twosComplement);
+}
+
+void AD57X4::Write(Register reg, uint8_t address, uint16_t data)
+{
+  uint8_t first = address; // select address
+  first |= reg << 3;       // select register
+  first |= 0 << 7;         // write command
+  first |= 0 << 6;         // always 0
+
+  InitSPI(SPI_MODE_DAC1);
+
+  HAL_GPIO_WritePin(GPIOB, kPinEnable, GPIO_PIN_RESET);
+  HAL_SPI_Transmit(&hspi2, &first, 1, HAL_MAX_DELAY); // write data
+  HAL_SPI_Transmit(&hspi2, reinterpret_cast<uint8_t*>(&data), 2, HAL_MAX_DELAY);
+  HAL_GPIO_WritePin(GPIOB, kPinEnable, GPIO_PIN_SET);
+}
diff --git a/midi2cv/drivers/ad57x4.h b/midi2cv/drivers/ad57x4.h
new file mode 100644
index 0000000..121b065
--- /dev/null
+++ b/midi2cv/drivers/ad57x4.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include "stmlib/stmlib.h"
+
+enum VoltageRange {
+  VOLTAGE_RANGE_FIVE_VOLTS = 0,
+  VOLTAGE_RANGE_TEN_VOLTS = 1,
+  VOLTAGE_RANGE_TEN_EIGHT_VOLTS = 2
+};
+
+enum Register {
+  REGISTER_DAC = 0,
+  REGISTER_OUTPUT_RANGE = 1,
+  REGISTER_CONTROL = 2,
+  REGISTER_POWER_CONTROL = 3
+};
+
+class AD57X4 {
+  public:
+  AD57X4() {};
+
+  void Init();
+
+  void WriteDacBipolar(uint8_t dac, VoltageRange range, int16_t value);
+  void WriteDacUnipolar(uint8_t dac, VoltageRange range, uint16_t value);
+
+  private:
+  uint8_t dacPower = 0;
+  VoltageRange dacRange[4];
+  void EnableAndSetRange(uint8_t dac, VoltageRange range, bool bipolar);
+  void Write(Register reg, uint8_t address, uint16_t data);
+  DISALLOW_COPY_AND_ASSIGN(AD57X4);
+};
diff --git a/midi2cv/drivers/spi_mode.cc b/midi2cv/drivers/spi_mode.cc
index 8bf3008..1b228fb 100644
--- a/midi2cv/drivers/spi_mode.cc
+++ b/midi2cv/drivers/spi_mode.cc
@@ -6,6 +6,7 @@
 SPIMode currentMode = SPI_MODE_UNINITIALIZED;
 
 void InitSPIDisplay(void);
+void InitSPIAD5754(void);
 
 void InitSPI(SPIMode mode)
 {
@@ -26,8 +27,10 @@ void InitSPI(SPIMode mode)
     case SPI_MODE_DISPLAY:
       InitSPIDisplay();
       break;
-    case SPI_MODE_DAC0:
     case SPI_MODE_DAC1:
+      InitSPIAD5754();
+      break;
+    case SPI_MODE_DAC0:
     case SPI_MODE_USB:
     case SPI_MODE_UNINITIALIZED:
 
@@ -37,6 +40,21 @@ void InitSPI(SPIMode mode)
   }
 }
 
+void InitSPIAD5754(void)
+{ // the same as the display(?)
+  hspi2.Init.Direction = SPI_DIRECTION_2LINES;
+  hspi2.Init.Mode = SPI_MODE_MASTER;
+  hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
+  hspi2.Init.CLKPolarity = SPI_POLARITY_LOW;
+  hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
+  hspi2.Init.NSS = SPI_NSS_SOFT;
+  hspi2.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
+  hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
+  hspi2.Init.CRCPolynomial = 7;
+  hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
+  HAL_SPI_Init(&hspi2);
+}
+
 void InitSPIDisplay(void)
 {
   hspi2.Init.Direction = SPI_DIRECTION_2LINES;
diff --git a/midi2cv/midi2cv.cc b/midi2cv/midi2cv.cc
index 99d1c70..83a4d9a 100644
--- a/midi2cv/midi2cv.cc
+++ b/midi2cv/midi2cv.cc
@@ -4,6 +4,7 @@
 #include "drivers/display.h"
 #include "drivers/encoder.h"
 #include "drivers/peripherals.h"
+#include "drivers/ad57x4.h"
 #include "menu/menu.h"
 #include "menu/menu_items.h"
 #include "part.h"
@@ -30,6 +31,7 @@ extern "C" void __cxa_pure_virtual()
 using namespace stmlib;
 
 Display display;
+AD57X4 dac1;
 Encoder encoder;
 
 Settings settings;