* Patch by Seb James, 30 Jun 2003:

Improve documentation of I2C configuration in README

* Fix problems with previous log buffer "fixes"

* Fix minor help text issues

* "log append" did not append a newline

CHANGELOG

@@ -1,3 +1,16 @@
+======================================================================
+Changes for U-Boot 0.4.2:
+======================================================================
+
+* Patch by Seb James, 30 Jun 2003:
+  Improve documentation of I2C configuration in README
+
+* Fix problems with previous log buffer "fixes"
+
+* Fix minor help text issues
+
+* "log append" did not append a newline
+
 ======================================================================
 Changes for U-Boot 0.4.1:
 ======================================================================

README

@@ -653,6 +653,9 @@ The following options need to be configured:
 		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
 		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
 
+		Note that if the RTC uses I2C, then the I2C interface
+		must also be configured. See I2C Support, below.
+
 - Timestamp Support:
 
 		When CONFIG_TIMESTAMP is selected, the timestamp
@@ -904,29 +907,48 @@ The following options need to be configured:
 
 - I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
 
-		Enables I2C serial bus commands.  If this is selected,
+		These enable I2C serial bus commands. Defining either of
-		either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
+		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 
-		to include the appropriate I2C driver.
+		include the appropriate I2C driver for the selected cpu. 
 
-		See also: common/cmd_i2c.c for a description of the
+		This will allow you to use i2c commands at the u-boot 
+		command line (as long as you set CFG_CMD_I2C in 
+		CONFIG_COMMANDS) and communicate with i2c based realtime
+		clock chips. See common/cmd_i2c.c for a description of the
 		command line interface.
 
+		CONFIG_HARD_I2C	selects the CPM hardware driver for I2C. 
 
-		CONFIG_HARD_I2C
+		CONFIG_SOFT_I2C configures u-boot to use a software (aka 
+		bit-banging) driver instead of CPM or similar hardware
+		support for I2C.
 
-		Selects the CPM hardware driver for I2C.
+		There are several other quantities that must also be 
+		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
 
-		CONFIG_SOFT_I2C
+		In both cases you will need to define CFG_I2C_SPEED
+		to be the frequency (in Hz) at which you wish your i2c bus 
+		to run and CFG_I2C_SLAVE to be the address of this node (ie 
+		the cpu's i2c node address). 
 		
-		Use software (aka bit-banging) driver instead of CPM
+		Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
-		or similar hardware support for I2C.  This is configured
+		sets the cpu up as a master node and so its address should
-		via the following defines.
+		therefore be cleared to 0 (See, eg, MPC823e User's Manual
+		p.16-473). So, set CFG_I2C_SLAVE to 0.  
+
+		That's all that's required for CONFIG_HARD_I2C. 
+
+		If you use the software i2c interface (CONFIG_SOFT_I2C)
+		then the following macros need to be defined (examples are
+		from include/configs/lwmon.h):
 
 		I2C_INIT
 
-		(Optional). Any commands necessary to enable I2C
+		(Optional). Any commands necessary to enable the I2C
 		controller or configure ports.
 
+		eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |=  PB_SCL)
+
 		I2C_PORT
 
 		(Only for MPC8260 CPU). The I/O port to use (the code
@@ -939,32 +961,49 @@ The following options need to be configured:
 		(driven).  If the data line is open collector, this
 		define can be null.
 
+		eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |=  PB_SDA)
+
 		I2C_TRISTATE
 
 		The code necessary to make the I2C data line tri-stated
 		(inactive).  If the data line is open collector, this
 		define can be null.
 
+		eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
+
 		I2C_READ
 
 		Code that returns TRUE if the I2C data line is high,
 		FALSE if it is low.
 
+		eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
+
 		I2C_SDA(bit)
 
 		If <bit> is TRUE, sets the I2C data line high. If it
 		is FALSE, it clears it (low).
 
+		eg: #define I2C_SDA(bit) \
+		         if(bit) immr->im_cpm.cp_pbdat |=  PB_SDA; \
+		         else    immr->im_cpm.cp_pbdat &= ~PB_SDA
+
 		I2C_SCL(bit)
 
 		If <bit> is TRUE, sets the I2C clock line high. If it
 		is FALSE, it clears it (low).
 
+		eg: #define I2C_SCL(bit) \
+		         if(bit) immr->im_cpm.cp_pbdat |=  PB_SCL; \
+		         else    immr->im_cpm.cp_pbdat &= ~PB_SCL 
+
 		I2C_DELAY
 
 		This delay is invoked four times per clock cycle so this
 		controls the rate of data transfer.  The data rate thus
-		is 1 / (I2C_DELAY * 4).
+		is 1 / (I2C_DELAY * 4). Often defined to be something
+		like: 
+		
+		#define I2C_DELAY  udelay(2)
 
 		CFG_I2C_INIT_BOARD
 

common/cmd_bmp.c

@@ -1,6 +1,6 @@
 /*
  * (C) Copyright 2002
- * Dtlev Zundel, DENX Software Engineering, dzu@denx.de.
+ * Detlev Zundel, DENX Software Engineering, dzu@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
  * project.

common/cmd_log.c

@@ -74,22 +74,26 @@ static unsigned long *ext_logged_chars;
 void logbuff_init_ptrs (void)
 {
 	DECLARE_GLOBAL_DATA_PTR;
+	unsigned long *ext_tag;
 	char *s;
 
 	log_buf = (unsigned char *)(gd->bd->bi_memsize-LOGBUFF_LEN);
+	ext_tag = (unsigned long *)(log_buf)-4;
  	ext_log_start = (unsigned long *)(log_buf)-3;
 	ext_log_size = (unsigned long *)(log_buf)-2;
 	ext_logged_chars = (unsigned long *)(log_buf)-1;
 #ifdef CONFIG_POST
 	/* The post routines have setup the word so we can simply test it */
- 	if (post_word_load () & POST_POWERON) {
+ 	if ((post_word_load () & 0xffff) == POST_POWERON) {
  		logged_chars = log_size = log_start = 0;
+		*ext_tag = LOGBUFF_MAGIC;
  	}
 #else
 	/* No post routines, so we do our own checking                    */
  	if (post_word_load () != LOGBUFF_MAGIC) {
  		logged_chars = log_size = log_start = 0;
 		post_word_store (LOGBUFF_MAGIC);
+		*ext_tag = LOGBUFF_MAGIC;
  	}
 #endif
 	/* Initialize default loglevel if present */
@@ -162,12 +166,8 @@ int do_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 	if (strcmp(argv[1],"append") == 0) {
 		/* Log concatenation of all arguments separated by spaces */
 		for (i=2; i<argc; i++) {
-			if (i<argc-1) {
 			logbuff_printk (argv[i]);
-				logbuff_putc (' ');
+			logbuff_putc ((i<argc-1) ? ' ' : '\n');
-			} else {
-				logbuff_puts (argv[i]);
-			}
 		}
 		return 0;
 	}
@@ -205,7 +205,7 @@ int do_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 cmd_tbl_t U_BOOT_CMD(LOG) = MK_CMD_ENTRY(
 	"log",     255,	1,	do_log,
 	"log     - manipulate logbuffer\n",
-	"log info   - show pointer details\n"
+	"info   - show pointer details\n"
 	"log reset  - clear contents\n"
 	"log show   - show contents\n"
 	"log append <msg> - append <msg> to the logbuffer\n"

include/version.h

@@ -24,6 +24,6 @@
 #ifndef	__VERSION_H__
 #define	__VERSION_H__
 
-#define	U_BOOT_VERSION	"U-Boot 0.4.1"
+#define	U_BOOT_VERSION	"U-Boot 0.4.2"
 
 #endif	/* __VERSION_H__ */