From 29735aa7c43c0897faee20258318ff6152d25595 Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Fri, 5 Jan 2018 18:39:01 +0100
Subject: [PATCH] semaphore handling added to SPI interface

---
 examples/lsm303d/lsm303d_example.c |  9 ++++++---
 extras/lsm303d/lsm303d.c           | 12 ++++++++++++
 extras/lsm303d/lsm303d_platform.h  |  6 +++---
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/examples/lsm303d/lsm303d_example.c b/examples/lsm303d/lsm303d_example.c
index d4823d4..7ad44b2 100644
--- a/examples/lsm303d/lsm303d_example.c
+++ b/examples/lsm303d/lsm303d_example.c
@@ -177,11 +177,14 @@ void user_task_interrupt (void *pvParameters)
             // get the source of the interrupt that reset *INTx* signals
             #ifdef INT_DATA
             lsm303d_get_int_data_source    (sensor, &data_src);
-            #elif INT_THRESH
+            #endif
+            #ifdef INT_THRESH
             lsm303d_get_int_m_thresh_source(sensor, &thresh_src);
-            #elif INT_EVENT
+            #endif
+            #ifdef INT_EVENT
             lsm303d_get_int_event_source   (sensor, &event_src, lsm303d_int_event1_gen);
-            #elif INT_CLICK
+            #endif
+            #ifdef INT_CLICK
             lsm303d_get_int_click_source   (sensor, &click_src);
             #endif
 
diff --git a/extras/lsm303d/lsm303d.c b/extras/lsm303d/lsm303d.c
index be54e0d..3a7297f 100644
--- a/extras/lsm303d/lsm303d.c
+++ b/extras/lsm303d/lsm303d.c
@@ -397,6 +397,8 @@ lsm303d_sensor_t* lsm303d_init_sensor (uint8_t bus, uint8_t addr, uint8_t cs)
         free (dev);
         return NULL;
     }
+    if (!addr) 
+        spi_semaphore_init(dev);
         
     // check availability of the sensor
     if (!lsm303d_is_available (dev))
@@ -1554,6 +1556,8 @@ static bool lsm303d_spi_read(lsm303d_sensor_t* dev, uint8_t reg, uint8_t *data,
 
     uint8_t addr = (reg & 0x3f) | LSM303D_SPI_READ_FLAG | LSM303D_SPI_AUTO_INC_FLAG;
     
+    spi_semaphore_take (dev);
+
     static uint8_t mosi[LSM303D_SPI_BUF_SIZE];
     static uint8_t miso[LSM303D_SPI_BUF_SIZE];
 
@@ -1564,6 +1568,7 @@ static bool lsm303d_spi_read(lsm303d_sensor_t* dev, uint8_t reg, uint8_t *data,
     
     if (!spi_transfer_pf (dev->bus, dev->cs, mosi, miso, len+1))
     {
+        spi_semaphore_give (dev);
         error_dev ("Could not read data from SPI", __FUNCTION__, dev);
         dev->error_code |= LSM303D_SPI_READ_FAILED;
         return false;
@@ -1573,6 +1578,8 @@ static bool lsm303d_spi_read(lsm303d_sensor_t* dev, uint8_t reg, uint8_t *data,
     for (int i=0; i < len; i++)
       data[i] = miso[i+1];
 
+    spi_semaphore_give (dev);
+
     #ifdef LSM303D_DEBUG_LEVEL_2
     printf("LSM303D %s: read the following bytes from reg %02x: ", __FUNCTION__, reg);
     for (int i=0; i < len; i++)
@@ -1602,6 +1609,8 @@ static bool lsm303d_spi_write(lsm303d_sensor_t* dev, uint8_t reg, uint8_t *data,
         return false;
     }
 
+    spi_semaphore_take (dev);
+
     reg &= 0x7f;
 
     // first byte in output is the register address
@@ -1620,11 +1629,14 @@ static bool lsm303d_spi_write(lsm303d_sensor_t* dev, uint8_t reg, uint8_t *data,
 
     if (!spi_transfer_pf (dev->bus, dev->cs, mosi, NULL, len+1))
     {
+        spi_semaphore_give (dev);
         error_dev ("Could not write data to SPI.", __FUNCTION__, dev);
         dev->error_code |= LSM303D_SPI_WRITE_FAILED;
         return false;
     }
 
+    spi_semaphore_give (dev);
+
     return true;
 }
 
diff --git a/extras/lsm303d/lsm303d_platform.h b/extras/lsm303d/lsm303d_platform.h
index ba3eb71..f697212 100644
--- a/extras/lsm303d/lsm303d_platform.h
+++ b/extras/lsm303d/lsm303d_platform.h
@@ -69,9 +69,9 @@
 
 // platform specific definitions
 
-#define spi_semaphore_init()
-#define spi_semaphore_take()
-#define spi_semaphore_give()
+#define spi_semaphore_init(d)
+#define spi_semaphore_take(d)
+#define spi_semaphore_give(d)
 
 // platform specific SPI functions