From 4af2a9a9cc72506e26a47c8bc7cb77b996bf783d Mon Sep 17 00:00:00 2001
From: Gustavo Jose de Sousa <gustavo.sousa@intel.com>
Date: Wed, 19 Aug 2015 12:36:45 -0300
Subject: [PATCH] AP_HAL_Linux: SPI: adapt to the new signature of
 transaction()

---
 libraries/AP_HAL_Linux/SPIDriver.cpp | 22 +++++++++++++++++-----
 libraries/AP_HAL_Linux/SPIDriver.h   |  4 ++--
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/libraries/AP_HAL_Linux/SPIDriver.cpp b/libraries/AP_HAL_Linux/SPIDriver.cpp
index c33ddaf4ca..8cc8cce010 100644
--- a/libraries/AP_HAL_Linux/SPIDriver.cpp
+++ b/libraries/AP_HAL_Linux/SPIDriver.cpp
@@ -90,9 +90,9 @@ AP_HAL::Semaphore* LinuxSPIDeviceDriver::get_semaphore()
     return LinuxSPIDeviceManager::get_semaphore(_bus);
 }
 
-void LinuxSPIDeviceDriver::transaction(const uint8_t *tx, uint8_t *rx, uint16_t len)
+bool LinuxSPIDeviceDriver::transaction(const uint8_t *tx, uint8_t *rx, uint16_t len)
 {
-    LinuxSPIDeviceManager::transaction(*this, tx, rx, len);
+    return LinuxSPIDeviceManager::transaction(*this, tx, rx, len);
 }
 
 void LinuxSPIDeviceDriver::set_bus_speed(enum bus_speed speed)
@@ -210,11 +210,16 @@ void LinuxSPIDeviceManager::cs_release(enum AP_HAL::SPIDevice type)
     }
 }
 
-void LinuxSPIDeviceManager::transaction(LinuxSPIDeviceDriver &driver, const uint8_t *tx, uint8_t *rx, uint16_t len)
+bool LinuxSPIDeviceManager::transaction(LinuxSPIDeviceDriver &driver, const uint8_t *tx, uint8_t *rx, uint16_t len)
 {
+    int r;
     // we set the mode before we assert the CS line so that the bus is
     // in the correct idle state before the chip is selected
-    ioctl(driver._fd, SPI_IOC_WR_MODE, &driver._mode);
+    r = ioctl(driver._fd, SPI_IOC_WR_MODE, &driver._mode);
+    if (r == -1) {
+        hal.console->printf("SPI: error on setting mode\n");
+        return false;
+    }
 
     cs_assert(driver._type);
     struct spi_ioc_transfer spi[1];
@@ -232,8 +237,15 @@ void LinuxSPIDeviceManager::transaction(LinuxSPIDeviceDriver &driver, const uint
         memset(rx, 0, len);
     }
 
-    ioctl(driver._fd, SPI_IOC_MESSAGE(1), &spi);
+    r = ioctl(driver._fd, SPI_IOC_MESSAGE(1), &spi);
     cs_release(driver._type);
+
+    if (r == -1) {
+        hal.console->printf("SPI: error on doing transaction\n");
+        return false;
+    }
+
+    return true;
 }
 
 /*
diff --git a/libraries/AP_HAL_Linux/SPIDriver.h b/libraries/AP_HAL_Linux/SPIDriver.h
index 445f029038..cb48ef88b4 100644
--- a/libraries/AP_HAL_Linux/SPIDriver.h
+++ b/libraries/AP_HAL_Linux/SPIDriver.h
@@ -21,7 +21,7 @@ public:
     LinuxSPIDeviceDriver(uint16_t bus, uint16_t subdev, enum AP_HAL::SPIDevice type, uint8_t mode, uint8_t bitsPerWord, int16_t cs_pin, uint32_t lowspeed, uint32_t highspeed);
     void init();
     AP_HAL::Semaphore *get_semaphore();
-    void transaction(const uint8_t *tx, uint8_t *rx, uint16_t len);
+    bool transaction(const uint8_t *tx, uint8_t *rx, uint16_t len);
 
     void cs_assert();
     void cs_release();
@@ -55,7 +55,7 @@ public:
 
     static void cs_assert(enum AP_HAL::SPIDevice type);
     static void cs_release(enum AP_HAL::SPIDevice type);
-    static void transaction(LinuxSPIDeviceDriver &driver, const uint8_t *tx, uint8_t *rx, uint16_t len);
+    static bool transaction(LinuxSPIDeviceDriver &driver, const uint8_t *tx, uint8_t *rx, uint16_t len);
 
 private:
     static LinuxSPIDeviceDriver _device[];