IRQ-based SPI works. Don't try to do multiple transactions without waiting for results first. In fact, don't try to do

an I2C transaction while an SPI transaction is pending.

2 files changed, 18 insertions, 13 deletions

diff --git a/firmware/microblaze/lib/spi.c b/firmware/microblaze/lib/spi.c
index 33fcce05f..2a41a1bfa 100644
--- a/firmware/microblaze/lib/spi.c
+++ b/firmware/microblaze/lib/spi.c
@@ -22,6 +22,8 @@
 
 void (*volatile spi_callback)(void); //SPI callback when xfer complete.
 
+static void spi_irq_handler(unsigned irq);
+
 void
 spi_init(void) 
 {
@@ -68,8 +70,10 @@ void spi_register_callback(void (*volatile callback)(void)) {
   spi_callback = callback;
 }
 
-void spi_irq_handler(void) {
-  printf("SPI IRQ handler\n");
+static void spi_irq_handler(unsigned irq) {
+//  printf("SPI IRQ handler\n");
+//  uint32_t wat = spi_regs->ctrl; //read a register just to clear the interrupt
+  //spi_regs->ctrl &= ~SPI_CTRL_IE;
   if(spi_callback) spi_callback(); //we could just use the PIC to register the user's callback, but this provides the ability to do other things later
 }
 
@@ -80,9 +84,12 @@ uint32_t spi_get_data(void) {
 bool 
 spi_async_transact(int slave, uint32_t data, int length, uint32_t flags, void (*volatile callback)(void)) {
   flags &= (SPI_CTRL_TXNEG | SPI_CTRL_RXNEG);
-  int ctrl = SPI_CTRL_ASS | (SPI_CTRL_CHAR_LEN_MASK & length) | flags;
+  int ctrl = SPI_CTRL_ASS | SPI_CTRL_IE | (SPI_CTRL_CHAR_LEN_MASK & length) | flags;
 
-  if(spi_regs->ctrl & SPI_CTRL_GO_BSY) return false; //we don't wait on busy, we just return failure.
+  if(spi_regs->ctrl & SPI_CTRL_GO_BSY) {
+    printf("Async SPI busy!\n");
+    return false; //we don't wait on busy, we just return failure. we count on the host to not set up another transaction before the last one finishes.
+  }
 
   // Tell it which SPI slave device to access
   spi_regs->ss = slave & 0xffff;
@@ -90,14 +97,12 @@ spi_async_transact(int slave, uint32_t data, int length, uint32_t flags, void (*
   // Data we will send
   spi_regs->txrx0 = data;
 
+  spi_register_callback(callback);
+  pic_register_handler(IRQ_SPI, spi_irq_handler);
+
   // Run it -- write once and rewrite with GO set
   spi_regs->ctrl = ctrl;
   spi_regs->ctrl = ctrl | SPI_CTRL_GO_BSY;
 
-  spi_regs->ctrl |= SPI_CTRL_IE; //we do these here so that we don't have to start the PIC before the SPI sets up the clocks on startup
-  pic_register_handler(IRQ_SPI, spi_irq_handler);
-
-  spi_register_callback(callback);
-
   return true;
 }
diff --git a/firmware/microblaze/lib/spi.h b/firmware/microblaze/lib/spi.h
index 18699f21a..54618cedd 100644
--- a/firmware/microblaze/lib/spi.h
+++ b/firmware/microblaze/lib/spi.h
@@ -48,13 +48,13 @@ void spi_wait(void);
 uint32_t
 spi_transact(bool readback, int slave, uint32_t data, int length, uint32_t flags);
 
-bool 
-spi_async_transact(int slave, uint32_t data, int length, uint32_t flags, void (*volatile callback)(void));
-
 uint32_t spi_get_data(void);
-void spi_irq_handler(void);
+//static void spi_irq_handler(unsigned irq);
 void spi_register_callback(void (*volatile callback)(void));
 
+bool 
+spi_async_transact(int slave, uint32_t data, int length, uint32_t flags, void (*volatile callback)(void));
+
 // ----------------------------------------------------------------
 // Routines that manipulate the FLASH SPI BUS
 // ----------------------------------------------------------------