From 1c9c40543009ecd95b56362e6564d26a2755b92a Mon Sep 17 00:00:00 2001
From: gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Sun, 10 Oct 2010 16:28:34 +0000
Subject: [PATCH] Fixed bug 3084764. More enhancements to the SPI driver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2244 35acf78f-673a-0410-8e92-d51de3d6d3f4
---
 os/hal/include/spi.h       | 15 ++++++++-
 os/hal/src/spi.c           | 65 +++++++++++++++++++++++++++++++++++++-
 os/hal/templates/spi_lld.h |  6 ++++
 readme.txt                 |  2 ++
 4 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/os/hal/include/spi.h b/os/hal/include/spi.h
index b09e33089..e6fbe7c90 100644
--- a/os/hal/include/spi.h
+++ b/os/hal/include/spi.h
@@ -39,7 +39,16 @@
 /*===========================================================================*/
 
 /**
- * @brief   Enables the mutual exclusion APIs on the SPI bus.
+ * @brief   Enables the @p spiWait() API.
+ * @note    Disabling this option saves both code and data space.
+ */
+#if !defined(SPI_USE_WAIT) || defined(__DOXYGEN__)
+#define SPI_USE_WAIT                TRUE
+#endif
+
+/**
+ * @brief   Enables the @p spiAcquireBus() and @p spiReleaseBus() APIs.
+ * @note    Disabling this option saves both code and data space.
  */
 #if !defined(SPI_USE_MUTUAL_EXCLUSION) || defined(__DOXYGEN__)
 #define SPI_USE_MUTUAL_EXCLUSION    TRUE
@@ -218,6 +227,10 @@ extern "C" {
   void spiExchange(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf);
   void spiSend(SPIDriver *spip, size_t n, const void *txbuf);
   void spiReceive(SPIDriver *spip, size_t n, void *rxbuf);
+#if SPI_USE_WAIT
+  void _spi_wakeup(SPIDriver *spip, mag_t msg);
+  msg_t spiWait(SPIDriver *spip);
+#endif /* SPI_USE_WAIT */
 #if SPI_USE_MUTUAL_EXCLUSION
   void spiAcquireBus(SPIDriver *spip);
   void spiReleaseBus(SPIDriver *spip);
diff --git a/os/hal/src/spi.c b/os/hal/src/spi.c
index cd5857aa9..75589c736 100644
--- a/os/hal/src/spi.c
+++ b/os/hal/src/spi.c
@@ -66,11 +66,16 @@ void spiInit(void) {
 void spiObjectInit(SPIDriver *spip) {
 
   spip->spd_state = SPI_STOP;
+#if SPI_USE_WAIT
+  spip->spd_thread = NULL;
+#endif /* SPI_USE_WAIT */
+#if SPI_USE_MUTUAL_EXCLUSION
 #if CH_USE_MUTEXES
   chMtxInit(&spip->spd_mutex);
-#elif CH_USE_SEMAPHORES
+#else
   chSemInit(&spip->spd_semaphore, 1);
 #endif
+#endif /* SPI_USE_MUTUAL_EXCLUSION */
   spip->spd_config = NULL;
 }
 
@@ -296,6 +301,64 @@ void spiReceive(SPIDriver *spip, size_t n, void *rxbuf) {
   chSysUnlock();
 }
 
+#if SPI_USE_WAIT || defined(__DOXYGEN__)
+/**
+ * @brief   Awakens the thread waiting for operation completion, if any.
+ *
+ * @param[in] spip      pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void _spi_wakeup(SPIDriver *spip) {
+
+  if (spip->spd_thread != NULL) {
+    Thread *tp = spip->spd_thread;
+    spip->spd_thread = NULL;
+    tp->p_u.rdymsg = RDY_RESET;
+    chSchReadyI(tp);
+  }
+}
+
+/**
+ * @brief   Wait for operation completion.
+ * @details This function waits for the driver to complete the current
+ *          operation, if an operation is not running when the function is
+ *          invoked then it immediately returns.
+ * @note    No more than one thread can wait on a SPI driver using
+ *          this function.
+ *
+ * @param[in] spip      pointer to the @p SPIDriver object
+ * @return              The wait status.
+ * @retval RDY_OK       There was not operation running when the function
+ *                      has been invoked.
+ * @retval RDY_RESET    The operation completed.
+ */
+msg_t spiWait(SPIDriver *spip) {
+  msg_t msg;
+
+  chDbgCheck(spip != NULL, "spiWait");
+
+  chSysLock();
+  chDbgAssert((spip->spd_state == SPI_READY) ||
+              (spip->spd_state == SPI_SELECTED) ||
+              (spip->spd_state == SPI_ACTIVE) ||
+              (spip->spd_state == SPI_SYNC),
+              "spiUnselect(), #1",
+              "invalid state");
+  chDbgAssert(spip->spd_thread == NULL, "spiWait(), #3", "already waiting");
+  if ((spip->spd_state == SPI_ACTIVE) || (spip->spd_state == SPI_SYNC)) {
+    spip->spd_thread = chThdSelf();
+    chSchGoSleepS(spip->spd_thread, THD_STATE_SUSPENDED);
+    msg = chThdSelf()->p_u.rdymsg;
+  }
+  else
+    msg = RDY_OK;
+  chSysUnlock();
+  return msg;
+}
+
+#endif /* SPI_USE_WAIT */
+
 #if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
 /**
  * @brief   Gains exclusive access to the SPI bus.
diff --git a/os/hal/templates/spi_lld.h b/os/hal/templates/spi_lld.h
index 152784701..2aa63b455 100644
--- a/os/hal/templates/spi_lld.h
+++ b/os/hal/templates/spi_lld.h
@@ -77,6 +77,12 @@ typedef struct {
    * @brief Driver state.
    */
   spistate_t            spd_state;
+#if SPI_USE_WAIT || defined(__DOXYGEN__)
+  /**
+   * @brief Waiting thread.
+   */
+  Thread                *spd_thread;
+#endif /* SPI_USE_WAIT */
 #if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
 #if CH_USE_MUTEXES || defined(__DOXYGEN__)
   /**
diff --git a/readme.txt b/readme.txt
index 5fcc39c0d..b5304e069 100644
--- a/readme.txt
+++ b/readme.txt
@@ -63,6 +63,8 @@
 *****************************************************************************
 
 *** 2.1.2 ***
+- FIX: Fixed non functioning option SPI_USE_MUTUAL_EXCLUSION=FALSE (bug
+  3084764)(backported to 2.0.6).
 - FIX: Fixed wrong macro check in STM32 serial support (bug 3078891)(backported
   to 2.0.6).
 - FIX: Fixed non functioning option CH_USE_NESTED_LOCKS (bug 3075544)