From 86b3f07923ebbcff11950efc4d5b9a76f5b33710 Mon Sep 17 00:00:00 2001
From: barthess <barthess@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Mon, 2 Jan 2012 19:04:50 +0000
Subject: [PATCH] I2C. Reorganized locks.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3711 35acf78f-673a-0410-8e92-d51de3d6d3f4
---
 os/hal/platforms/STM32/i2c_lld.c | 10 ++++++++--
 os/hal/platforms/STM32/i2c_lld.h | 16 ++++------------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/os/hal/platforms/STM32/i2c_lld.c b/os/hal/platforms/STM32/i2c_lld.c
index 352d213f8..51e41d4fe 100644
--- a/os/hal/platforms/STM32/i2c_lld.c
+++ b/os/hal/platforms/STM32/i2c_lld.c
@@ -666,7 +666,9 @@ msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp,
   dmaStreamSetTransactionSize(i2cp->dmarx, rxbytes);
   dmaStreamSetMode(i2cp->dmarx, ((i2cp->dmamode) | STM32_DMA_CR_DIR_P2M));
 
-  i2c_lld_wait_bus_free(i2cp);
+  /* Wait until BUSY flag is reset.  */
+  while(i2cp->i2c->SR2 & I2C_SR2_BUSY)
+    ;
 
   /* wait stop bit from previous transaction*/
   while(i2cp->i2c->CR1 & I2C_CR1_STOP)
@@ -675,6 +677,7 @@ msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp,
   i2cp->i2c->CR2 |= I2C_CR2_ITERREN | I2C_CR2_ITEVTEN;
   i2cp->i2c->CR1 |= I2C_CR1_START | I2C_CR1_ACK;
 
+  chSysLock(); /* this lock will be released in high level part */
   i2c_lld_wait_s(i2cp, timeout, rdymsg);
 
   return rdymsg;
@@ -724,7 +727,9 @@ msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, uint8_t slave_addr,
   dmaStreamSetTransactionSize(i2cp->dmatx, txbytes);
   dmaStreamSetMode(i2cp->dmatx, ((i2cp->dmamode) | STM32_DMA_CR_DIR_M2P));
 
-  i2c_lld_wait_bus_free(i2cp);
+  /* Wait until BUSY flag is reset.  */
+  while(i2cp->i2c->SR2 & I2C_SR2_BUSY)
+    ;
 
   /* wait stop bit from previous transaction*/
   while(i2cp->i2c->CR1 & I2C_CR1_STOP)
@@ -733,6 +738,7 @@ msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, uint8_t slave_addr,
   i2cp->i2c->CR2 |= I2C_CR2_ITERREN | I2C_CR2_ITEVTEN;
   i2cp->i2c->CR1 |= I2C_CR1_START;
 
+  chSysLock(); /* this lock will be released in high level part */
   i2c_lld_wait_s(i2cp, timeout, rdymsg);
 
   return rdymsg;
diff --git a/os/hal/platforms/STM32/i2c_lld.h b/os/hal/platforms/STM32/i2c_lld.h
index 5a3757d88..f770be615 100644
--- a/os/hal/platforms/STM32/i2c_lld.h
+++ b/os/hal/platforms/STM32/i2c_lld.h
@@ -327,13 +327,6 @@ struct I2CDriver{
 /* Driver macros.                                                            */
 /*===========================================================================*/
 
-/**
- * Wait until BUSY flag is reset.
- */
-#define i2c_lld_wait_bus_free(i2cp) {                                       \
-  while(i2cp->i2c->SR2 & I2C_SR2_BUSY)                                      \
-    ;                                                                       \
-}
 /**
  * @brief   Waits for operation completion.
  * @details This function waits for the driver to complete the current
@@ -349,7 +342,6 @@ struct I2CDriver{
 #define i2c_lld_wait_s(i2cp, timeout, rdymsg) {                             \
   chDbgAssert((i2cp)->thread == NULL,                                       \
               "_i2c_wait(), #1", "already waiting");                        \
-  chSysLock(); /* this lock will be disarmed in high level part */          \
   (i2cp)->thread = chThdSelf();                                             \
   rdymsg = chSchGoSleepTimeoutS(THD_STATE_SUSPENDED, timeout);              \
 }
@@ -362,13 +354,13 @@ struct I2CDriver{
  * @notapi
  */
 #define i2c_lld_wakeup_isr(i2cp) {                                          \
+  chSysLockFromIsr();                                                       \
   if ((i2cp)->thread != NULL) {                                             \
     Thread *tp = (i2cp)->thread;                                            \
     (i2cp)->thread = NULL;                                                  \
-    chSysLockFromIsr();                                                     \
     chSchReadyI(tp);                                                        \
-    chSysUnlockFromIsr();                                                   \
   }                                                                         \
+  chSysUnlockFromIsr();                                                     \
 }
 
 /**
@@ -379,14 +371,14 @@ struct I2CDriver{
  * @notapi
  */
 #define i2c_lld_error_wakeup_isr(i2cp) {                                    \
+  chSysLockFromIsr();                                                       \
   if ((i2cp)->thread != NULL) {                                             \
     Thread *tp = (i2cp)->thread;                                            \
     (i2cp)->thread = NULL;                                                  \
-    chSysLockFromIsr();                                                     \
     tp->p_u.rdymsg = RDY_RESET;                                             \
     chSchReadyI(tp);                                                        \
-    chSysUnlockFromIsr();                                                   \
   }                                                                         \
+  chSysUnlockFromIsr();                                                     \
 }
 
 /**