From 16759c4dd55abecc6f51539ba00dffcffc1e29d0 Mon Sep 17 00:00:00 2001
From: Klaus K Wilting <Klaus.K.Wilting@deutschebahn.com>
Date: Sat, 27 Oct 2018 13:51:59 +0200
Subject: [PATCH] SPI code added (experimental)

---
 include/spisend.h | 25 ++++++++++++++++++++++++
 src/spisend.cpp   | 50 ++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/include/spisend.h b/include/spisend.h
index 750a3c20..70cc4437 100644
--- a/include/spisend.h
+++ b/include/spisend.h
@@ -1,9 +1,34 @@
 #ifndef _SPISEND_H
 #define _SPISEND_H
 
+#include "globals.h"
+#include "spi.h"
+
 extern TaskHandle_t SpiTask;
 extern QueueHandle_t SPISendQueue;
 
+/*
+ * Process data in SPI send queue
+ */
 void spi_loop(void *pvParameters);
 
+/*
+* initialize local SPI wire interface
+*/
+void hal_spi_init();
+
+/*
+ * Perform SPI write transaction on local SPI wire interface
+ *   - write the command byte 'cmd'
+ *   - write 'len' bytes out of 'buf'
+ */
+void hal_spi_write(uint8_t cmd, const uint8_t* buf, int len);
+
+/*
+ * Perform SPI read transaction on local SPI wire interface
+ *   - read the command byte 'cmd'
+ *   - read 'len' bytes into 'buf'
+ */
+void hal_spi_read(uint8_t cmd, uint8_t* buf, int len);
+
 #endif
\ No newline at end of file
diff --git a/src/spisend.cpp b/src/spisend.cpp
index 57da9287..c778a887 100644
--- a/src/spisend.cpp
+++ b/src/spisend.cpp
@@ -1,6 +1,6 @@
 #ifdef HAS_SPI
 
-#include "globals.h"
+#include "spisend.h"
 
 // Local logging tag
 static const char TAG[] = "main";
@@ -13,18 +13,62 @@ TaskHandle_t SpiTask;
 // SPI feed Task
 void spi_loop(void *pvParameters) {
 
+  uint8_t buf[32];
+
   configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check
 
   while (1) {
+    // check if data to send on SPI interface
     if (xQueueReceive(SPISendQueue, &SendBuffer, (TickType_t)0) == pdTRUE) {
+      hal_spi_write(SendBuffer.MessagePort, SendBuffer.Message,
+                    SendBuffer.MessageSize);
       ESP_LOGI(TAG, "%d bytes sent to SPI", SendBuffer.MessageSize);
     }
-    vTaskDelay(2 / portTICK_PERIOD_MS); // yield to CPU
 
-  } // end of infinite loop
+    // check if command is received on SPI command port, then call interpreter
+    hal_spi_read(RCMDPORT, buf, 32);
+    if (buf[0])
+      rcommand(buf, sizeof(buf));
+
+    vTaskDelay(2 / portTICK_PERIOD_MS); // yield to CPU
+  }                                     // end of infinite loop
 
   vTaskDelete(NULL); // shoud never be reached
 
 } // spi_loop()
 
+// SPI hardware abstraction layer
+
+void hal_spi_init() { SPI.begin(SCK, MISO, MOSI, SS); }
+
+void hal_spi_trx(u1_t cmd, u1_t *buf, int len, u1_t is_read) {
+
+  u1_t nss = SS;
+  SPISettings settings(1E6, MSBFIRST, SPI_MODE0);
+  SPI.beginTransaction(settings);
+
+  digitalWrite(nss, 0);
+
+  SPI.transfer(cmd);
+
+  for (u1_t i = 0; i < len; i++) {
+    u1_t *p = buf + i;
+    u1_t data = is_read ? 0x00 : *p;
+    data = SPI.transfer(data);
+    if (is_read)
+      *p = data;
+  }
+
+  digitalWrite(nss, 1);
+  SPI.endTransaction();
+}
+
+void hal_spi_write(u1_t cmd, const u1_t *buf, int len) {
+  hal_spi_trx(cmd, (u1_t *)buf, len, 0);
+}
+
+void hal_spi_read(u1_t cmd, u1_t *buf, int len) {
+  hal_spi_trx(cmd, buf, len, 1);
+}
+
 #endif // HAS_SPI
\ No newline at end of file