From 8a38c7958bea1a4374bc74126414dde4b190c882 Mon Sep 17 00:00:00 2001
From: "Jakob.Meier" <meierj@irs.uni-stuttgart.de>
Date: Wed, 12 May 2021 10:22:23 +0200
Subject: [PATCH] spi mutex only blocked when gpio != NO_GPIO

---
 linux/gpio/LinuxLibgpioIF.cpp | 11 ++++++-----
 linux/spi/SpiComIF.cpp        | 11 +++++++----
 linux/spi/SpiComIF.h          |  5 +++++
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/linux/gpio/LinuxLibgpioIF.cpp b/linux/gpio/LinuxLibgpioIF.cpp
index b8151c6..3001b8a 100644
--- a/linux/gpio/LinuxLibgpioIF.cpp
+++ b/linux/gpio/LinuxLibgpioIF.cpp
@@ -82,7 +82,7 @@ ReturnValue_t LinuxLibgpioIF::configureRegularGpio(gpioId_t gpioId, GpiodRegular
     chipname = regularGpio->chipname;
     chip = gpiod_chip_open_by_name(chipname.c_str());
     if (!chip) {
-        sif::warning << "LinuxLibgpioIF::configureGpios: Failed to open chip "
+        sif::warning << "LinuxLibgpioIF::configureRegularGpio: Failed to open chip "
                 << chipname << ". Gpio ID: " << gpioId << std::endl;
         return RETURN_FAILED;
     }
@@ -90,9 +90,10 @@ ReturnValue_t LinuxLibgpioIF::configureRegularGpio(gpioId_t gpioId, GpiodRegular
     lineNum = regularGpio->lineNum;
     lineHandle = gpiod_chip_get_line(chip, lineNum);
     if (!lineHandle) {
-        sif::warning << "LinuxLibgpioIF::configureGpios: Failed to open line for GPIO" << std::endl;
-        sif::warning << "GPIO ID " << gpioId << "with line number " << lineNum <<
-                " and chipname " << chipname << std::endl;
+        sif::debug << "LinuxLibgpioIF::configureRegularGpio: Failed to open line " << std::endl;
+        sif::debug << "GPIO ID: " << gpioId << ", line number: " << lineNum <<
+                ", chipname: " << chipname << std::endl;
+        sif::debug << "Check if linux GPIO configuration has changed. " << std::endl;
         gpiod_chip_close(chip);
         return RETURN_FAILED;
     }
@@ -105,7 +106,7 @@ ReturnValue_t LinuxLibgpioIF::configureRegularGpio(gpioId_t gpioId, GpiodRegular
         result = gpiod_line_request_output(lineHandle, consumer.c_str(),
                 regularGpio->initValue);
         if (result < 0) {
-            sif::error << "LinuxLibgpioIF::configureGpios: Failed to request line " << lineNum <<
+            sif::error << "LinuxLibgpioIF::configureRegularGpio: Failed to request line " << lineNum <<
                     " from GPIO instance with ID: " << gpioId << std::endl;
             gpiod_line_release(lineHandle);
             return RETURN_FAILED;
diff --git a/linux/spi/SpiComIF.cpp b/linux/spi/SpiComIF.cpp
index d70f91a..2724ac4 100644
--- a/linux/spi/SpiComIF.cpp
+++ b/linux/spi/SpiComIF.cpp
@@ -178,11 +178,10 @@ ReturnValue_t SpiComIF::sendMessage(CookieIF *cookie, const uint8_t *sendData, s
     bool fullDuplex = spiCookie->isFullDuplex();
     gpioId_t gpioId = spiCookie->getChipSelectPin();
 
-    /* GPIO access is mutex protected */
-    MutexGuard(spiMutex, timeoutType, timeoutMs);
-
     /* Pull SPI CS low. For now, no support for active high given  */
     if(gpioId != gpio::NO_GPIO) {
+        /* GPIO access is mutex protected */
+        MutexGuard(spiMutex, timeoutType, timeoutMs);
         gpioComIF->pullLow(gpioId);
     }
 
@@ -263,8 +262,8 @@ ReturnValue_t SpiComIF::requestReceiveMessage(CookieIF *cookie, size_t requestLe
     }
 
     gpioId_t gpioId = spiCookie->getChipSelectPin();
-    MutexGuard(spiMutex, timeoutType, timeoutMs);
     if(gpioId != gpio::NO_GPIO) {
+        MutexGuard(spiMutex, timeoutType, timeoutMs);
         gpioComIF->pullLow(gpioId);
     }
 
@@ -302,6 +301,10 @@ ReturnValue_t SpiComIF::readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
     return HasReturnvaluesIF::RETURN_OK;
 }
 
+MutexIF* SpiComIF::getMutex() {
+    return spiMutex;
+}
+
 ReturnValue_t SpiComIF::getReadBuffer(address_t spiAddress, uint8_t** buffer) {
     if(buffer == nullptr) {
         return HasReturnvaluesIF::RETURN_FAILED;
diff --git a/linux/spi/SpiComIF.h b/linux/spi/SpiComIF.h
index 67f7923..9228994 100644
--- a/linux/spi/SpiComIF.h
+++ b/linux/spi/SpiComIF.h
@@ -39,6 +39,11 @@ public:
             size_t requestLen) override;
     ReturnValue_t readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
             size_t *size) override;
+    /**
+     * @brief   This function returns the mutex which can be used to protect the spi bus when
+     *          the chip select must be driven from outside of the com if.
+     */
+    MutexIF* getMutex();
 private:
 
     struct SpiInstance {
-- 
2.34.1