verify more assumptions in i2c

add selftest to I2c and readback Dino configuration to verify it was
actually set

Signed-off-by: Niklas Eiling <niklas.eiling@eonerc.rwth-aachen.de>

fpga/include/villas/fpga/ips/i2c.hpp

@@ -43,9 +43,10 @@ public:
 
   class Switch {
   public:
-    Switch(I2c *i2c, uint8_t address)
-        : i2c(i2c), address(address), channel(0), readOnce(false),
-          switchLock(){};
+    Switch(I2c *i2c, uint8_t address,
+           Logger logger = villas::logging.get("i2c"))
+        : i2c(i2c), address(address), channel(0), readOnce(false), switchLock(),
+          logger(logger){};
     Switch(const Switch &other) = delete;
     Switch &operator=(const Switch &other) = delete;
     void setChannel(uint8_t channel);
@@ -57,6 +58,7 @@ public:
     uint8_t getChannel();
     void setAddress(uint8_t address) { this->address = address; }
     uint8_t getAddress() { return address; }
+    bool selfTest();
 
   private:
     I2c *i2c;
@@ -64,10 +66,11 @@ public:
     uint8_t channel;
     bool readOnce;
     std::mutex switchLock;
+    Logger logger;
   };
   Switch &getSwitch(uint8_t address = I2C_SWTICH_ADDR) {
     if (switchInstance == nullptr) {
-      switchInstance = std::make_unique<Switch>(this, address);
+      switchInstance = std::make_unique<Switch>(this, address, logger);
     } else {
       switchInstance->setAddress(address);
     }

fpga/lib/ips/dino.cpp

@@ -87,6 +87,12 @@ void DinoAdc::configureHardware() {
   IoextPorts ioext = {.raw = 0};
   ioext.fields.sat_detect = true;
   setIoextDir(ioext);
+  auto readback = getIoextDir();
+  if (readback.raw != ioext.raw) {
+    logger->error("Ioext direction register readback incorrect: {:#x} != {:#x}",
+                  readback.raw, ioext.raw);
+    throw RuntimeError("Failed to set IOEXT direction register");
+  }
   ioext.raw = 0;
   ioext.fields.data_dir = true;
   ioext.fields.status_led = true;
@@ -95,6 +101,12 @@ void DinoAdc::configureHardware() {
   setIoextOut(ioext);
   ioext.fields.n_we = false;
   setIoextOut(ioext);
+  readback = getIoextOut();
+  if (readback.raw != ioext.raw) {
+    logger->error("Ioext output register readback incorrect: {:#x} != {:#x}",
+                  readback.raw, ioext.raw);
+    throw RuntimeError("Failed to set IOEXT output register");
+  }
   i2cdev->getSwitch().unlockChannel();
 }
 
@@ -109,10 +121,24 @@ void DinoDac::configureHardware() {
   i2cdev->getSwitch().setAndLockChannel(i2c_channel);
   IoextPorts ioext = {.raw = 0};
   setIoextDir(ioext);
+  auto readback = getIoextDir();
+  if (readback.raw != ioext.raw) {
+    logger->error("Ioext direction register readback incorrect: {:#x} != {:#x}",
+                  readback.raw, ioext.raw);
+    throw RuntimeError("Failed to set IOEXT direction register");
+  }
   ioext.fields.status_led = true;
+  // Default gain is 1. Although not really necessary, let's be explicit here
+  ioext.fields.gain_lsb = 0x00 & 0x1;
+  ioext.fields.gain_msb = 0x00 & 0x2;
   setIoextOut(ioext);
+  readback = getIoextOut();
+  if (readback.raw != ioext.raw) {
+    logger->error("Ioext output register readback incorrect: {:#x} != {:#x}",
+                  readback.raw, ioext.raw);
+    throw RuntimeError("Failed to set IOEXT output register");
+  }
   i2cdev->getSwitch().unlockChannel();
-  setGain(GAIN_1);
 }
 
 void DinoDac::setGain(Gain gain) {

fpga/lib/ips/i2c.cpp

@@ -12,6 +12,7 @@
 
 #include <villas/fpga/ips/i2c.hpp>
 #include <villas/fpga/ips/intc.hpp>
+#include <villas/log.hpp>
 
 using namespace villas::fpga::ip;
 
@@ -220,7 +221,7 @@ void I2c::Switch::setChannel(uint8_t channel) {
 }
 
 uint8_t I2c::Switch::getChannel() {
-  std::vector<u8> data(1);
+  std::vector<u8> data;
   int retries = 10;
   do {
     i2c->read(address, data, 1);
@@ -242,6 +243,26 @@ uint8_t I2c::Switch::getChannel() {
   return channel;
 }
 
+bool I2c::Switch::selfTest() {
+  uint8_t readback;
+  logger->debug("I2c::Switch self test. Testing {} channels of device {:#x}",
+                sizeof(CHANNEL_MAP) / sizeof(CHANNEL_MAP[0]), address);
+  for (size_t i = 0; i < sizeof(CHANNEL_MAP) / sizeof(CHANNEL_MAP[0]); ++i) {
+    logger->debug("Setting switch to channel {}, data byte {:#x}", i,
+                  CHANNEL_MAP[i]);
+    setAndLockChannel(i);
+    try {
+      readback = getChannel();
+      logger->debug("Readback channel: {}", readback);
+    } catch (const RuntimeError &e) {
+      logger->debug("Encoutered error on readback: {}", e.what());
+      return false;
+    }
+    unlockChannel();
+  }
+  return true;
+}
+
 void I2cFactory::parse(Core &ip, json_t *cfg) {
   NodeFactory::parse(ip, cfg);