sam3n spi: fix interrupt enable/disable logic. Interrupt is enabled only when

there are data to send and turned off when interrupt handler find an empty
fifo.  To test in depth.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4441 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/cpu/cortex-m3/drv/ser_sam3.c b/bertos/cpu/cortex-m3/drv/ser_sam3.c
index 6222ece5e9180fc3bd912b1473f929a9932445e0..ac9021270f7c6ea2686e79abb69a7dfb0f6661bc 100644 (file)
--- a/bertos/cpu/cortex-m3/drv/ser_sam3.c
+++ b/bertos/cpu/cortex-m3/drv/ser_sam3.c
@@ -35,6 +35,7 @@
  *
  *
  * \author Daniele Basile <asterix@develer.com>
+ * \author Stefano Fedrigo <aleph@develer.com>
  */
 
 #include "hw/hw_ser.h"  /* Required for bus macros overrides */
@@ -188,7 +189,7 @@
                        /* PIO is peripheral A */ \
                        PIOA_ABCDSR1 &= ~(BV(SPI0_SPCK) | BV(SPI0_MOSI) | BV(SPI0_MISO)); \
                        PIOA_ABCDSR2 &= ~(BV(SPI0_SPCK) | BV(SPI0_MOSI) | BV(SPI0_MISO)); \
-                       /* Peripheral B for chip select for display */ \
+                       /* Peripheral B for chip select for display (FIXME: move away from driver) */ \
                        PIOA_ABCDSR1 |= BV(30); \
                        PIOA_ABCDSR2 &= ~BV(30); \
                } while (0)
@@ -548,9 +549,6 @@ static void spi0_init(UNUSED_ARG(struct SerialHardware *, _hw), UNUSED_ARG(struc
        sysirq_setHandler(INT_SPI0, spi0_irq_handler);
        PMC_PCER = BV(SPI0_ID);
 
-       /* Enable interrupt on tx buffer empty */
-       SPI0_IER = BV(SPI_TXEMPTY);
-
        /* Enable SPI */
        SPI0_CR = BV(SPI_SPIEN);
 
@@ -580,6 +578,8 @@ static void spi0_starttx(struct SerialHardware *_hw)
        {
                hw->sending = true;
                SPI0_TDR = fifo_pop(&ser_handles[SER_SPI0]->txfifo);
+               /* Enable interrupt on tx buffer empty */
+               SPI0_IER = BV(SPI_TXEMPTY);
        }
 
        IRQ_RESTORE(flags);
@@ -622,9 +622,6 @@ static void spi1_init(UNUSED_ARG(struct SerialHardware *, _hw), UNUSED_ARG(struc
        sysirq_setHandler(INT_SPI1, spi1_irq_dispatcher);
        PMC_PCER = BV(SPI1_ID);
 
-       /* Enable interrupt on tx buffer empty */
-       SPI1_IER = BV(SPI_TXEMPTY);
-
        /* Enable SPI */
        SPI1_CR = BV(SPI_SPIEN);
 
@@ -654,6 +651,8 @@ static void spi1_starttx(struct SerialHardware *_hw)
        {
                hw->sending = true;
                SPI1_TDR = fifo_pop(&ser_handles[SER_SPI1]->txfifo);
+               /* Enable interrupt on tx buffer empty */
+               SPI1_IER = BV(SPI_TXEMPTY);
        }
 
        IRQ_RESTORE(flags);
@@ -935,7 +934,11 @@ static DECLARE_ISR(spi0_irq_handler)
        if (!fifo_isempty(&ser_handles[SER_SPI0]->txfifo))
                SPI0_TDR = fifo_pop(&ser_handles[SER_SPI0]->txfifo);
        else
+       {
                UARTDescs[SER_SPI0].sending = false;
+               /* Disable interrupt on tx buffer empty */
+               SPI0_IDR = BV(SPI_TXEMPTY);
+       }
 
        SER_INT_ACK;
 
@@ -965,7 +968,11 @@ static DECLARE_ISR(spi1_irq_handler)
        if (!fifo_isempty(&ser_handles[SER_SPI1]->txfifo))
                SPI1_TDR = fifo_pop(&ser_handles[SER_SPI1]->txfifo);
        else
+       {
                UARTDescs[SER_SPI1].sending = false;
+               /* Disable interrupt on tx buffer empty */
+               SPI1_IDR = BV(SPI_TXEMPTY);
+       }
 
        SER_INT_ACK;