2007-11-20 Till Straumann <strauman@slac.stanford.edu>

	* libchip/rtc/ds1375.c, libchip/rtc/ds1375-rtc.h:
	Avoid using 'stdio' before the system is up and fully
	initialized.

2 files changed, 27 insertions, 3 deletions

diff --git a/c/src/libchip/rtc/ds1375-rtc.h b/c/src/libchip/rtc/ds1375-rtc.h
index d1d68a96ac..99100b8b07 100644
--- a/c/src/libchip/rtc/ds1375-rtc.h
+++ b/c/src/libchip/rtc/ds1375-rtc.h
@@ -71,6 +71,13 @@ rtc_ds1375_set_register( uint32_t port, uint8_t reg, uint32_t value );
  * BSP must supply string constant argument 'i2cname' which matches
  * the registered device name of the raw i2c device (created with mknod).
  * E.g., "/dev/i2c.ds1375-raw"
+ *
+ * NOTE: The i2c bus driver must already be up and 'i2cname' already
+ *       be available when this ENTRY is registered or initialized.
+ *
+ *       If you want to allow applications to add the RTC driver to
+ *       the configuration table then the i2c subsystem must be
+ *       initialized by the BSP from the predriver_hook.
  */
 #define DS1375_RTC_TBL_ENTRY(i2cname) \
 {                                              	      \
diff --git a/c/src/libchip/rtc/ds1375.c b/c/src/libchip/rtc/ds1375.c
index 3afd966946..5859190d50 100644
--- a/c/src/libchip/rtc/ds1375.c
+++ b/c/src/libchip/rtc/ds1375.c
@@ -54,6 +54,7 @@
 #include <libchip/ds1375-rtc.h>
 
 #include <sys/fcntl.h>
+#include <sys/errno.h>
 #include <stdio.h>
 #include <inttypes.h>
 
@@ -61,6 +62,22 @@
 #define STATIC static
 #undef  DEBUG
 
+/* The RTC driver routines are possibly called during
+ * system initialization -- that would be prior to opening
+ * the console. At this point it is not safe to use stdio
+ * (printf, perror etc.).
+ * Our file descriptors may even be 0..2
+ */
+#define STDIOSAFE(fmt,args...)	    	\
+	do {                                \
+		if ( _System_state_Is_up( _System_state_Get() ) ) { \
+			fprintf(stderr,fmt,args);   \
+		} else {                        \
+			printk(fmt,args);           \
+		}                               \
+	} while (0)
+ 
+
 STATIC uint8_t ds1375_bcd2bin(uint8_t x)
 {
 uint8_t h = x & 0xf0;
@@ -399,19 +416,19 @@ rtc_ds1375_device_probe( int minor )
 int fd;
 
 	if ( ( fd = getfd( minor ) ) < 0 ) {
-		perror("ds1375_probe (open)");
+		STDIOSAFE( "ds1375_probe (open): %s\n", strerror( errno ) );
 		return FALSE;
 	}
 
 	/* Try to set file pointer */
 	if ( 0 != wr_bytes( fd, DS1375_SEC_REG, 0, 0 ) ) {
-		perror( "ds1375_probe (wr_bytes)" );
+		STDIOSAFE( "ds1375_probe (wr_bytes): %s\n", strerror( errno ) );
 		close( fd );
 		return FALSE;
 	}
 
 	if ( close( fd ) ) {
-		perror( "ds1375_probe (close)" );
+		STDIOSAFE( "ds1375_probe (close): %s\n", strerror( errno ) );
 		return FALSE;
 	}