modified busy waiting loops (new function: waitfor(us, condition) to only wait for a certain time until the expected condition comes true, otherwise just return without the job done

BaS_gcc/include/bas_types.h

@@ -0,0 +1,19 @@
+/*
+ * bas_types.h
+ *
+ *  Created on: 17.11.2012
+ *      Author: mfro
+ */
+
+#ifndef BAS_TYPES_H_
+#define BAS_TYPES_H_
+
+#ifndef _CPLUSPLUS_
+typedef int bool;
+#define TRUE	1
+#define FALSE	0
+#endif /* _CPLUSPLUS_ */
+
+
+
+#endif /* BAS_TYPES_H_ */

BaS_gcc/sources/BaS.c

@@ -9,6 +9,7 @@
 #include "startcf.h"
 #include "cache.h"
 #include "bas_printf.h"
+#include "bas_types.h"
 
 /* imported routines */
 extern int mmu_init();
@@ -18,7 +19,8 @@ extern void sd_card_idle();
 extern int sd_card_init();
 
 /* wait...() routines moved to sysinit.c */
-extern void wait(uint32_t us);
+extern inline void wait(uint32_t us);
+extern inline bool waitfor(uint32_t us,int (*condition)(void));
 
 /* Symbols from the linker script */
 extern uint8_t _STRAM_END[];
@@ -32,10 +34,27 @@ extern uint8_t _EMUTOS[];
 extern uint8_t _EMUTOS_SIZE[];
 #define EMUTOS_SIZE ((uint32_t)_EMUTOS_SIZE) /* size of EmuTOS, in bytes */
 
+static inline bool pic_txready(void)
+{
+	if (MCF_PSC3_PSCSR & MCF_PSC_PSCSR_TXRDY)
+		return TRUE;
+
+	return FALSE;
+}
+
+static inline bool pic_rxready(void)
+{
+	if (MCF_PSC3_PSCSR & MCF_PSC_PSCSR_RXRDY)
+		return TRUE;
+
+	return FALSE;
+}
+
 void write_pic_byte(uint8_t value)
 {
-    /* Wait until the tramsmitter is ready */
-    while (!(MCF_PSC3_PSCSR & MCF_PSC_PSCSR_TXRDY)); 
+    /* Wait until the tramsmitter is ready or 1000us are passed */
+	waitfor(1000, pic_txready);
+    //while (!(MCF_PSC3_PSCSR & MCF_PSC_PSCSR_TXRDY));
 
     /* Transmit the byte */
     //MCF_PSC3_PSCTB_8BIT = value; // This define is actually 32-bit
@@ -44,8 +63,8 @@ void write_pic_byte(uint8_t value)
 
 uint8_t read_pic_byte(void)
 {
-    /* Wait until a byte has been received */
-    while (!(MCF_PSC3_PSCSR & MCF_PSC_PSCSR_RXRDY)); 
+    /* Wait until a byte has been received or 1000us are passed */
+	waitfor(1000, pic_rxready);
 
     /* Return the received byte */
     //return MCF_PSC3_PSCRB_8BIT; // This define is actually 32-bit

BaS_gcc/sources/sysinit.c

@@ -11,6 +11,7 @@
 #include "cache.h"
 #include "sysinit.h"
 #include "bas_printf.h"
+#include "bas_types.h"
 
 extern void xprintf_before_copy(const char *fmt, ...);
 #define xprintf	 xprintf_before_copy
@@ -25,14 +26,28 @@ extern volatile long _VRAM;	/* start address of video ram from linker script */
  * wait for the specified number of us on slice timer 0. Replaces the original routines that had
  * the number of useconds to wait for hardcoded in their name.
  */
-void wait(uint32_t us)
+inline void wait(uint32_t us)
 {
 	uint32_t target = MCF_SLT_SCNT(0) - (us * 132);
 
 	while (MCF_SLT_SCNT(0) > target);
 }
 
+/*
+ * the same as above, with a checker function which gets called while
+ * busy waiting and allows for an early return if it returns true
+ */
+inline bool waitfor(uint32_t us, int (*condition)(void))
+{
+	uint32_t target = MCF_SLT_SCNT(0) - (us * 132);
 
+	do
+	{
+		if ((*condition)())
+			return TRUE;
+	} while (MCF_SLT_SCNT(0) > target);
+	return FALSE;
+}
 /*
  * init SLICE TIMER 0 
  * all  = 32.538 sec = 30.736mHz
@@ -472,12 +487,25 @@ void test_upd720101(void)
 	xprintf("finished\r\n");
 }
 
+static bool i2c_transfer_finished(void)
+{
+	if (MCF_I2C_I2SR & MCF_I2C_I2SR_IIF)
+		return TRUE;
+
+	return FALSE;
+}
+
 static void wait_i2c_transfer_finished(void)
 {
-	while (!(MCF_I2C_I2SR & MCF_I2C_I2SR_IIF));	/* wait until interrupt bit has been set */
+	waitfor(100000, i2c_transfer_finished);		/* wait until interrupt bit has been set */
 	MCF_I2C_I2SR &= ~MCF_I2C_I2SR_IIF; 			/* clear interrupt bit (byte transfer finished */
 }
 
+static bool i2c_bus_free(void)
+{
+	return (MCF_I2C_I2SR & MCF_I2C_I2SR_IBB);
+}
+
 /*
  * TFP410 (DVI) on
  */
@@ -544,7 +572,7 @@ void dvi_on(void) {
 		MCF_I2C_I2CR = 0x0; // stop
 		MCF_I2C_I2SR = 0x0; // clear sr
 
-		while ((MCF_I2C_I2SR & MCF_I2C_I2SR_IBB));	/* wait for bus free */
+		waitfor(10000, i2c_bus_free);
 
 		MCF_I2C_I2CR = 0xb0; // on tx master
 		MCF_I2C_I2DR = 0x7A;
@@ -566,7 +594,7 @@ void dvi_on(void) {
 		dummyByte = MCF_I2C_I2DR; // dummy read
 		MCF_I2C_I2SR = 0x0; // clear sr
 
-		while ((MCF_I2C_I2SR & MCF_I2C_I2SR_IBB)); /* wait until bus free */
+		waitfor(10000, i2c_bus_free);
 
 		MCF_I2C_I2CR = 0xb0;
 		MCF_I2C_I2DR = 0x7A;