flatten out SPI driver for MCP2515.

include/spi/spidev.h

@@ -132,6 +132,10 @@
      */
     #define SPI_IOC_WR_MAX_SPEED_HZ IOW(SPI_IOC_MAGIC, 4, sizeof(uint32_t))
 
+    /** Get an object pointer for the SPI device
+     */
+    #define SPI_IOC_GET_OBJECT_REFERENCE IOR(SPI_IOC_MAGIC, 5, sizeof(void*))
+
 #else
     #error SPI drivers not supported on this OS
 #endif

src/freertos_drivers/common/MCP2515Can.cxx

@@ -97,8 +97,11 @@ const MCP2515Can::BitModify MCP2515Can::tx1TransmitEnable(CANINTE, TX0I << 1,
  */
 void MCP2515Can::init(const char *spi_name, uint32_t freq, uint32_t baud)
 {
-    spi = ::open(spi_name, O_RDWR);
-    HASSERT(spi >= 0);
+    spiFd = ::open(spi_name, O_RDWR);
+    HASSERT(spiFd >= 0);
+
+    ::ioctl(spiFd, SPI_IOC_GET_OBJECT_REFERENCE, &spi);
+    HASSERT(spi);
 
     /* configure SPI bus settings */
     uint8_t spi_mode = SPI_MODE_0;
@@ -108,9 +111,9 @@ void MCP2515Can::init(const char *spi_name, uint32_t freq, uint32_t baud)
     {
         spi_max_speed_hz = SPI_MAX_SPEED_HZ;
     }
-    ::ioctl(spi, SPI_IOC_WR_MODE, &spi_mode);
-    ::ioctl(spi, SPI_IOC_WR_BITS_PER_WORD, &spi_bpw);
-    ::ioctl(spi, SPI_IOC_WR_MAX_SPEED_HZ, &spi_max_speed_hz);
+    ::ioctl(spiFd, SPI_IOC_WR_MODE, &spi_mode);
+    ::ioctl(spiFd, SPI_IOC_WR_BITS_PER_WORD, &spi_bpw);
+    ::ioctl(spiFd, SPI_IOC_WR_MAX_SPEED_HZ, &spi_max_speed_hz);
 
     /* reset device */
     reset();
@@ -247,10 +250,11 @@ void MCP2515Can::tx_msg_locked()
             }
             ++count;
 
-            HASSERT(count <= ARRAYSIZE(xfer_));
+            //HASSERT(count <= ARRAYSIZE(xfer_));
 
             // tranfer the messages
-            ::ioctl(spi, SPI_IOC_MESSAGE(count), xfer_);
+            //::ioctl(spiFd, SPI_IOC_MESSAGE(count), xfer_);
+            SPI::transfer_messages(spi, xfer_, count);
         }
         else
         {
@@ -310,7 +314,7 @@ void *MCP2515Can::entry()
             xfer[1].rx_buf = (unsigned long)regs;
             xfer[1].len = sizeof(regs);
             xfer[1].cs_change = 1;
-            ::ioctl(spi, SPI_IOC_MESSAGE(2), xfer);
+            ::ioctl(spiFd, SPI_IOC_MESSAGE(2), xfer);
             lock_.unlock();
             continue;
         }
@@ -375,7 +379,7 @@ void *MCP2515Can::entry()
             {
                 /* receive interrupt active */
                 new (&rx_buf) BufferRead(xfer_ + count, 0);
-                count += rx_buf.xfer_count();
+                ++count;
                 receive = true;
             }
 
@@ -430,7 +434,7 @@ void *MCP2515Can::entry()
                         txBuf->consume(1);
                         portEXIT_CRITICAL();
 
-                        count += tx_buf.xfer_count();
+                        ++count;;
                         txPending |= (0x1 << index);
 
                         /* request to send at lowest priority */
@@ -456,7 +460,7 @@ void *MCP2515Can::entry()
                 }
             }
 
-            HASSERT(count <= ARRAYSIZE(xfer_));
+            //HASSERT(count <= ARRAYSIZE(xfer_));
 
             // tranfer the messages
             if (count == 0)
@@ -465,7 +469,7 @@ void *MCP2515Can::entry()
             }
             else
             {
-                ::ioctl(spi, SPI_IOC_MESSAGE(count), xfer_);
+                SPI::transfer_messages(spi, xfer_, count);
             }
 
             if (receive)

src/freertos_drivers/common/MCP2515Can.hxx

@@ -67,7 +67,8 @@ public:
         , gpoData(0x0)
         , gpiData(0x7)
         , ioPending(false)
-        , spi(-1)
+        , spiFd(-1)
+        , spi(nullptr)
         , sem()
     {
     }
@@ -652,7 +653,7 @@ private:
     void reset()
     {
         uint8_t reset = RESET;
-        ::write(spi, &reset, 1);
+        ::write(spiFd, &reset, 1);
     }
 
     /** Read from a SPI register.
@@ -671,7 +672,8 @@ private:
         xfer[1].rx_buf = (unsigned long)rd_data;
         xfer[1].len = sizeof(rd_data);
         xfer[1].cs_change = 1;
-        ::ioctl(spi, SPI_IOC_MESSAGE(2), xfer);
+
+        SPI::transfer_messages(spi, xfer, 2);
 
         return rd_data[0];
     }
@@ -692,7 +694,7 @@ private:
         xfer[1].rx_buf = (unsigned long)buffer;
         xfer[1].len = 13;
         xfer[1].cs_change = 1;
-        ::ioctl(spi, SPI_IOC_MESSAGE(2), xfer);
+        ::ioctl(spiFd, SPI_IOC_MESSAGE(2), xfer);
     }
 
     /** Write to a SPI register.
@@ -702,8 +704,15 @@ private:
     __attribute__((optimize("-O3")))
     void register_write(Registers address, uint8_t data)
     {
+        spi_ioc_transfer xfer[1];
+        memset(xfer, 0, sizeof(xfer));
         uint8_t payload[] = {WRITE, address, data};
-        ::write(spi, payload, sizeof(payload));
+
+        xfer[0].tx_buf = (unsigned long)payload;
+        xfer[0].len = sizeof(payload);
+        xfer[0].cs_change = 1;
+
+        SPI::transfer_messages(spi, xfer, 1);
     }
 
     /** Write to a TX buffer.
@@ -722,7 +731,7 @@ private:
         xfer[1].tx_buf = (unsigned long)buffer;
         xfer[1].len = 13;
         xfer[1].cs_change = 1;
-        ::ioctl(spi, SPI_IOC_MESSAGE(2), xfer);
+        ::ioctl(spiFd, SPI_IOC_MESSAGE(2), xfer);
     }
 
     /** Bit modify to a SPI register.
@@ -733,7 +742,7 @@ private:
     void bit_modify(Registers address, uint8_t data, uint8_t mask)
     {
         uint8_t payload[] = {BIT_MODIFY, address, mask, data};
-        ::write(spi, payload, sizeof(payload));
+        ::write(spiFd, payload, sizeof(payload));
     }
 
     /** Request a transmit buffer to send.
@@ -743,7 +752,7 @@ private:
     void request_to_send(int index)
     {
         uint8_t rts = RTS | (0x01 << index);
-        ::write(spi, &rts, 1);
+        ::write(spiFd, &rts, 1);
     }
 
     /** Request that the GPIO cache be refreshed.
@@ -762,7 +771,9 @@ private:
     unsigned gpiData   : 3; /**< local copy of the I/O expansion input data */
     unsigned ioPending : 1; /**< true if an I/O update is pending */
 
-    int spi; /**< SPI bus that accesses MCP2515 */
+    int spiFd; /**< SPI bus that accesses MCP2515 */
+    SPI *spi; /**< pointer to a SPI object instance */
+
     OSSem sem; /**< semaphore for posting events */
 #if MCP2515_DEBUG
     volatile uint8_t regs[128]; /**< debug copy of MCP2515 registers */

src/freertos_drivers/common/SPI.cxx

@@ -32,7 +32,6 @@
  */
 
 #include <cstdint>
-#include <unistd.h>
 #include <fcntl.h>
 #include "Devtab.hxx"
 #include "SPI.hxx"
@@ -136,6 +135,12 @@ int SPI::ioctl(File *file, unsigned long int key, unsigned long data)
     {
         default:
             return -EINVAL;
+        case SPI_IOC_GET_OBJECT_REFERENCE:
+        {
+            SPI **self = (SPI**)data;
+            *self = this;
+            return 0;
+        }
         case SPI_IOC_RD_MODE:
         {
             uint8_t *m = (uint8_t*)data;
@@ -196,46 +201,3 @@ int SPI::ioctl(File *file, unsigned long int key, unsigned long data)
     return result;
 }
 
-/** Conduct multiple message transfers with one stop at the end.
- * @param msgs array of messages to transfer
- * @param num number of messages to transfer
- * @return total number of bytes transfered, -errno upon failure
- */
-__attribute__((optimize("-O3")))
-int SPI::transfer_messages(struct spi_ioc_transfer *msgs, int num)
-{
-    HASSERT(num > 0);
-
-    int count = 0;
-    int result;
-
-    lock_.lock();
-    bus_lock();
-    for (int i = 0; i < num; ++i, ++msgs)
-    {
-        count += msgs->len;
-        csAssert();
-        result = transfer(msgs);
-        if (result < 0)
-        {
-            /* something bad happened, reset the bus and bail */
-            csDeassert();
-            bus_unlock();
-            lock_.unlock();
-            return result;
-        }
-        if (msgs->cs_change)
-        {
-            if (msgs->delay_usec)
-            {
-                usleep(msgs->delay_usec);
-            }
-            csDeassert();
-        }
-    }
-    bus_unlock();
-    lock_.unlock();
-
-    return count;
-}
-

src/freertos_drivers/common/SPI.hxx

@@ -34,7 +34,7 @@
 #ifndef _FREERTOS_DRIVERS_COMMON_SPI_HXX_
 #define _FREERTOS_DRIVERS_COMMON_SPI_HXX_
 
-
+#include <unistd.h>
 
 #include "BlockOrWakeUp.hxx"
 #include "SimpleLog.hxx"
@@ -54,6 +54,18 @@ public:
     /** Function point for the chip select assert and deassert methods */
     typedef void (*ChipSelectMethod)();
 
+    /** Conduct multiple message transfers with one stop at the end.
+     * @param self pointer to a SPI object instance
+     * @param msgs array of messages to transfer
+     * @param num number of messages to transfer
+     * @return total number of bytes transfered, -errno upon failure
+     */
+    static int transfer_messages(SPI *self,
+                                 struct spi_ioc_transfer *msgs, int num)
+    {
+        return self->transfer_messages(msgs, num);
+    }
+
 protected:
     /** Constructor
      * @param name device name in file system
@@ -113,7 +125,43 @@ protected:
      * @param num number of messages to transfer
      * @return total number of bytes transfered, -errno upon failure
      */
-    virtual int transfer_messages(struct spi_ioc_transfer *msgs, int num);
+    __attribute__((optimize("-O3")))
+    int transfer_messages(struct spi_ioc_transfer *msgs, int num)
+    {
+        //HASSERT(num > 0);
+
+        int count = 0;
+        int result;
+
+        //lock_.lock();
+        //bus_lock();
+        for (int i = 0; i < num; ++i, ++msgs)
+        {
+            count += msgs->len;
+            csAssert();
+            result = transfer(msgs);
+            if (result < 0)
+            {
+                /* something bad happened, reset the bus and bail */
+                csDeassert();
+                //bus_unlock();
+                //lock_.unlock();
+                return result;
+            }
+            if (msgs->cs_change)
+            {
+                //if (msgs->delay_usec)
+                {
+                    //usleep(msgs->delay_usec);
+                }
+                csDeassert();
+            }
+        }
+        //bus_unlock();
+        //lock_.unlock();
+
+        return count;
+    }
 
     /** Update the configuration of the bus.
      * @return >= 0 upon success, -errno upon failure