Lock SPI bus while in use by InkHUD (#6719)

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/graphics/niche/Drivers/EInk/LCMEN2R13EFC1.cpp

@@ -1,9 +1,11 @@
-#include "./LCMEN2R13EFC1.h"
-
 #ifdef MESHTASTIC_INCLUDE_NICHE_GRAPHICS
 
+#include "./LCMEN2R13EFC1.h"
+
 #include <assert.h>
 
+#include "SPILock.h"
+
 using namespace NicheGraphics::Drivers;
 
 // Look up table: fast refresh, common electrode
@@ -150,6 +152,9 @@ void LCMEN213EFC1::reset()
 
 void LCMEN213EFC1::sendCommand(const uint8_t command)
 {
+    // Take firmware's SPI lock
+    spiLock->lock();
+
     spi->beginTransaction(spiSettings);
     digitalWrite(pin_dc, LOW); // DC pin low indicates command
     digitalWrite(pin_cs, LOW);
@@ -157,6 +162,8 @@ void LCMEN213EFC1::sendCommand(const uint8_t command)
     digitalWrite(pin_cs, HIGH);
     digitalWrite(pin_dc, HIGH);
     spi->endTransaction();
+
+    spiLock->unlock();
 }
 
 void LCMEN213EFC1::sendData(uint8_t data)
@@ -166,6 +173,9 @@ void LCMEN213EFC1::sendData(uint8_t data)
 
 void LCMEN213EFC1::sendData(const uint8_t *data, uint32_t size)
 {
+    // Take firmware's SPI lock
+    spiLock->lock();
+
     spi->beginTransaction(spiSettings);
     digitalWrite(pin_dc, HIGH); // DC pin HIGH indicates data, instead of command
     digitalWrite(pin_cs, LOW);
@@ -183,6 +193,8 @@ void LCMEN213EFC1::sendData(const uint8_t *data, uint32_t size)
     digitalWrite(pin_cs, HIGH);
     digitalWrite(pin_dc, HIGH);
     spi->endTransaction();
+
+    spiLock->unlock();
 }
 
 void LCMEN213EFC1::configFull()

src/graphics/niche/Drivers/EInk/SSD16XX.cpp

@@ -1,6 +1,9 @@
+#ifdef MESHTASTIC_INCLUDE_NICHE_GRAPHICS
+
 #include "./SSD16XX.h"
 
-#ifdef MESHTASTIC_INCLUDE_NICHE_GRAPHICS
+#include "SPILock.h"
+
 using namespace NicheGraphics::Drivers;
 
 SSD16XX::SSD16XX(uint16_t width, uint16_t height, UpdateTypes supported, uint8_t bufferOffsetX)
@@ -82,6 +85,9 @@ void SSD16XX::sendCommand(const uint8_t command)
     if (failed)
         return;
 
+    // Take firmware's SPI lock
+    spiLock->lock();
+
     spi->beginTransaction(spiSettings);
     digitalWrite(pin_dc, LOW); // DC pin low indicates command
     digitalWrite(pin_cs, LOW);
@@ -89,6 +95,8 @@ void SSD16XX::sendCommand(const uint8_t command)
     digitalWrite(pin_cs, HIGH);
     digitalWrite(pin_dc, HIGH);
     spi->endTransaction();
+
+    spiLock->unlock();
 }
 
 void SSD16XX::sendData(uint8_t data)
@@ -103,6 +111,9 @@ void SSD16XX::sendData(const uint8_t *data, uint32_t size)
     if (failed)
         return;
 
+    // Take firmware's SPI lock
+    spiLock->lock();
+
     spi->beginTransaction(spiSettings);
     digitalWrite(pin_dc, HIGH); // DC pin HIGH indicates data, instead of command
     digitalWrite(pin_cs, LOW);
@@ -119,6 +130,8 @@ void SSD16XX::sendData(const uint8_t *data, uint32_t size)
     digitalWrite(pin_cs, HIGH);
     digitalWrite(pin_dc, HIGH);
     spi->endTransaction();
+
+    spiLock->unlock();
 }
 
 void SSD16XX::configFullscreen()

src/graphics/niche/FlashData.h

@@ -13,6 +13,7 @@ Avoid bloating everyone's protobuf code for our one-off UI implementations
 
 #include "configuration.h"
 
+#include "SPILock.h"
 #include "SafeFile.h"
 
 namespace NicheGraphics
@@ -46,6 +47,9 @@ template <typename T> class FlashData
   public:
     static bool load(T *data, const char *label)
     {
+        // Take firmware's SPI lock
+        concurrency::LockGuard guard(spiLock);
+
         // Set false if we run into issues
         bool okay = true;
 
@@ -103,14 +107,18 @@ template <typename T> class FlashData
         return okay;
     }
 
-    // Save module's custom data (settings?) to flash. Does use protobufs
+    // Save module's custom data (settings?) to flash. Doesn't use protobufs
+    // Takes the firmware's SPI lock, in case the files are stored on SD card
+    // Need to lock and unlock around specific FS methods, as the SafeFile class takes the lock for itself internally.
     static void save(T *data, const char *label)
     {
         // Get a filename based on the label
         std::string filename = getFilename(label);
 
 #ifdef FSCom
+        spiLock->lock();
         FSCom.mkdir("/NicheGraphics");
+        spiLock->unlock();
 
         auto f = SafeFile(filename.c_str(), true); // "true": full atomic. Write new data to temp file, then rename.
 
@@ -119,10 +127,10 @@ template <typename T> class FlashData
         // Calculate a hash of the data
         uint32_t hash = getHash(data);
 
+        spiLock->lock();
         f.write((uint8_t *)data, sizeof(T));     // Write the actual data
         f.write((uint8_t *)&hash, sizeof(hash)); // Append the hash
-
+        spiLock->unlock();
-        // f.flush();
 
         bool writeSucceeded = f.close();
 
@@ -139,6 +147,9 @@ template <typename T> class FlashData
 inline void clearFlashData()
 {
 
+    // Take firmware's SPI lock, in case the files are stored on SD card
+    concurrency::LockGuard guard(spiLock);
+
 #ifdef FSCom
     File dir = FSCom.open("/NicheGraphics"); // Open the directory
     File file = dir.openNextFile();          // Attempt to open the first file in the directory

src/graphics/niche/InkHUD/MessageStore.cpp

@@ -22,6 +22,8 @@ InkHUD::MessageStore::MessageStore(std::string label)
 }
 
 // Write the contents of the MessageStore::messages object to flash
+// Takes the firmware's SPI lock during FS operations. Implemented for consistency, but only relevant when using SD card.
+// Need to lock and unlock around specific FS methods, as the SafeFile class takes the lock for itself internally
 void InkHUD::MessageStore::saveToFlash()
 {
     assert(!filename.empty());
@@ -29,7 +31,9 @@ void InkHUD::MessageStore::saveToFlash()
 #ifdef FSCom
     // Make the directory, if doesn't already exist
     // This is the same directory accessed by NicheGraphics::FlashData
+    spiLock->lock();
     FSCom.mkdir("/NicheGraphics");
+    spiLock->unlock();
 
     // Open or create the file
     // No "full atomic": don't save then rename
@@ -37,6 +41,9 @@ void InkHUD::MessageStore::saveToFlash()
 
     LOG_INFO("Saving messages in %s", filename.c_str());
 
+    // Take firmware's SPI Lock while writing
+    spiLock->lock();
+
     // 1st byte: how many messages will be written to store
     f.write(messages.size());
 
@@ -51,6 +58,9 @@ void InkHUD::MessageStore::saveToFlash()
         LOG_DEBUG("Wrote message %u, length %u, text \"%s\"", (uint32_t)i, min(MAX_MESSAGE_SIZE, m.text.size()), m.text.c_str());
     }
 
+    // Release firmware's SPI lock, because SafeFile::close needs it
+    spiLock->unlock();
+
     bool writeSucceeded = f.close();
 
     if (!writeSucceeded) {
@@ -63,6 +73,7 @@ void InkHUD::MessageStore::saveToFlash()
 
 // Attempt to load the previous contents of the MessageStore:message deque from flash.
 // Filename is controlled by the "label" parameter
+// Takes the firmware's SPI lock during FS operations. Implemented for consistency, but only relevant when using SD card.
 void InkHUD::MessageStore::loadFromFlash()
 {
     // Hopefully redundant. Initial intention is to only load / save once per boot.
@@ -70,6 +81,9 @@ void InkHUD::MessageStore::loadFromFlash()
 
 #ifdef FSCom
 
+    // Take the firmware's SPI Lock, in case filesystem is on SD card
+    concurrency::LockGuard guard(spiLock);
+
     // Check that the file *does* actually exist
     if (!FSCom.exists(filename.c_str())) {
         LOG_WARN("'%s' not found. Using default values", filename.c_str());