Code Cleanup

Patch by Gary Jennejohn, 04 Oct 2004:
- fix I2C on at91rm9200
- add support for Ricoh RS5C372A RTC

6 files changed, 415 insertions, 104 deletions

diff --git a/CHANGELOG b/CHANGELOG
index acc800e..db8cc8b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,10 @@
 Changes since U-Boot 1.1.1:
 ======================================================================
 
+* Patch by Gary Jennejohn, 04 Oct 2004:
+  - fix I2C on at91rm9200
+  - add support for Ricoh RS5C372A RTC
+
 * Patch by Gary Jennejohn, 01 Oct 2004:
   - add support for CMC PU2 board
   - add support for I2C on at91rm9200
diff --git a/board/cmc_pu2/memsetup.S b/board/cmc_pu2/memsetup.S
index 168cd6b..2d0e1d7 100644
--- a/board/cmc_pu2/memsetup.S
+++ b/board/cmc_pu2/memsetup.S
@@ -2,7 +2,7 @@
  * Memory Setup stuff - taken from blob memsetup.S
  *
  * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and
- *                     Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
+ *		       Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
  *
  * Modified for the at91rm9200dk board by
  * (C) Copyright 2004
@@ -18,7 +18,7 @@
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
@@ -92,36 +92,36 @@ _TEXT_BASE:
 .globl memsetup
 memsetup:
 	/* memory control configuration */
-	/* this isn't very elegant, but  what the heck */
-	ldr     r0, =SMRDATA
+	/* this isn't very elegant, but	 what the heck */
+	ldr	r0, =SMRDATA
 	ldr	r1, _TEXT_BASE
 	sub	r0, r0, r1
-	add     r2, r0, #80
+	add	r2, r0, #80
 0:
 	/* the address */
-	ldr     r1, [r0], #4
+	ldr	r1, [r0], #4
 	/* the value */
-	ldr     r3, [r0], #4
-	str     r3, [r1]
-	cmp     r2, r0
-	bne     0b
+	ldr	r3, [r0], #4
+	str	r3, [r1]
+	cmp	r2, r0
+	bne	0b
 	/* delay - this is all done by guess */
-	ldr 	r0, =0x00001000
+	ldr	r0, =0x00001000
 1:
-	subs    r0, r0, #1              
-	bhi     1b
-	ldr     r0, =SMRDATA1
+	subs	r0, r0, #1
+	bhi	1b
+	ldr	r0, =SMRDATA1
 	ldr	r1, _TEXT_BASE
 	sub	r0, r0, r1
-	add     r2, r0, #176
+	add	r2, r0, #176
 2:
 	/* the address */
-	ldr     r1, [r0], #4
+	ldr	r1, [r0], #4
 	/* the value */
-	ldr     r3, [r0], #4
-	str     r3, [r1]
-	cmp     r2, r0
-	bne     2b
+	ldr	r3, [r0], #4
+	str	r3, [r1]
+	cmp	r2, r0
+	bne	2b
 
 	/* everything is fine now */
 	mov	pc, lr
diff --git a/cpu/at91rm9200/i2c.c b/cpu/at91rm9200/i2c.c
index d5d6268..515792c 100644
--- a/cpu/at91rm9200/i2c.c
+++ b/cpu/at91rm9200/i2c.c
@@ -60,7 +60,6 @@ at91_xfer(unsigned char chip, unsigned int addr, int alen,
 	AT91PS_TWI twi = (AT91PS_TWI) AT91_TWI_BASE;
 	int length;
 	unsigned char *buf;
-
 	/* Set the TWI Master Mode Register */
 	twi->TWI_MMR = (chip << 16) | (alen << 8)
 		| ((rw == 1) ? AT91C_TWI_MREAD : 0);
@@ -126,13 +125,15 @@ int
 i2c_read(unsigned char chip, unsigned int addr, int alen,
 							unsigned char *buffer, int len)
 {
+#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 	/* we only allow one address byte */
 	if (alen > 1)
 		return 1;
-#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 	/* XXX assume an ATMEL AT24C16 */
 	if (alen == 1) {
+#if 0 /* EEPROM code already sets this correctly */
 		chip |= (addr >> 8) & 0xff;
+#endif
 		addr = addr & 0xff;
 	}
 #endif
@@ -146,22 +147,25 @@ i2c_write(unsigned char chip, unsigned int addr, int alen,
 	int i;
 	unsigned char *buf;
 
+#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 	/* we only allow one address byte */
 	if (alen > 1)
 		return 1;
-#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
 	/* XXX assume an ATMEL AT24C16 */
 	if (alen == 1) {
 		buf = buffer;
 		/* do single byte writes */
 		for (i = 0; i < len; i++) {
+#if 0 /* EEPROM code already sets this correctly */
 			chip |= (addr >> 8) & 0xff;
+#endif
 			addr = addr & 0xff;
 			if (at91_xfer(chip, addr, alen, buf++, 1, 0))
 				return 1;
+			addr++;
 		}
+		return 0;
 	}
-	return 0;
 #endif
 	return at91_xfer(chip, addr, alen, buffer, len, 0);
 }
diff --git a/include/at91rm9200_i2c.h b/include/at91rm9200_i2c.h
index cb13d9d..c2ec2f1 100644
--- a/include/at91rm9200_i2c.h
+++ b/include/at91rm9200_i2c.h
@@ -1,90 +1,90 @@
-// ----------------------------------------------------------------------------
-//          ATMEL Microcontroller Software Support  -  ROUSSET  -
-// ----------------------------------------------------------------------------
-//  The software is delivered "AS IS" without warranty or condition of any
-//  kind, either express, implied or statutory. This includes without
-//  limitation any warranty or condition with respect to merchantability or
-//  fitness for any particular purpose, or against the infringements of
-//  intellectual property rights of others.
-// ----------------------------------------------------------------------------
-// File Name           : at91rm9200_i2c.h
-// Object              : AT91RM9200 / TWI definitions
-// Generated           : AT91 SW Application Group  12/03/2002 (10:48:02)
-//
-// ----------------------------------------------------------------------------
+/* ---------------------------------------------------------------------------- */
+/*	    ATMEL Microcontroller Software Support  -  ROUSSET	-		*/
+/* ---------------------------------------------------------------------------- */
+/*  The software is delivered "AS IS" without warranty or condition of any	*/
+/*  kind, either express, implied or statutory. This includes without		*/
+/*  limitation any warranty or condition with respect to merchantability or	*/
+/*  fitness for any particular purpose, or against the infringements of		*/
+/*  intellectual property rights of others.					*/
+/* ---------------------------------------------------------------------------- */
+/* File Name	       : at91rm9200_i2c.h					*/
+/* Object	       : AT91RM9200 / TWI definitions				*/
+/* Generated	       : AT91 SW Application Group  12/03/2002 (10:48:02)	*/
+/*										*/
+/* ---------------------------------------------------------------------------- */
 
 #ifndef AT91RM9200_TWI_H
 #define AT91RM9200_TWI_H
 
-// *****************************************************************************
-//              SOFTWARE API DEFINITION  FOR Two-wire Interface
-// *****************************************************************************
+/* ******************************************************************************/
+/*		SOFTWARE API DEFINITION	 FOR Two-wire Interface			*/
+/* ******************************************************************************/
 #ifndef __ASSEMBLY__
 
 typedef struct _AT91S_TWI {
-	AT91_REG	 TWI_CR; 	// Control Register
-	AT91_REG	 TWI_MMR; 	// Master Mode Register
-	AT91_REG	 TWI_SMR; 	// Slave Mode Register
-	AT91_REG	 TWI_IADR; 	// Internal Address Register
-	AT91_REG	 TWI_CWGR; 	// Clock Waveform Generator Register
-	AT91_REG	 Reserved0[3]; 	//
-	AT91_REG	 TWI_SR; 	// Status Register
-	AT91_REG	 TWI_IER; 	// Interrupt Enable Register
-	AT91_REG	 TWI_IDR; 	// Interrupt Disable Register
-	AT91_REG	 TWI_IMR; 	// Interrupt Mask Register
-	AT91_REG	 TWI_RHR; 	// Receive Holding Register
-	AT91_REG	 TWI_THR; 	// Transmit Holding Register
-	AT91_REG	 Reserved1[50]; 	//
-	AT91_REG	 TWI_RPR; 	// Receive Pointer Register
-	AT91_REG	 TWI_RCR; 	// Receive Counter Register
-	AT91_REG	 TWI_TPR; 	// Transmit Pointer Register
-	AT91_REG	 TWI_TCR; 	// Transmit Counter Register
-	AT91_REG	 TWI_RNPR; 	// Receive Next Pointer Register
-	AT91_REG	 TWI_RNCR; 	// Receive Next Counter Register
-	AT91_REG	 TWI_TNPR; 	// Transmit Next Pointer Register
-	AT91_REG	 TWI_TNCR; 	// Transmit Next Counter Register
-	AT91_REG	 TWI_PTCR; 	// PDC Transfer Control Register
-	AT91_REG	 TWI_PTSR; 	// PDC Transfer Status Register
+	AT91_REG	 TWI_CR;	/* Control Register			*/
+	AT91_REG	 TWI_MMR;	/* Master Mode Register			*/
+	AT91_REG	 TWI_SMR;	/* Slave Mode Register			*/
+	AT91_REG	 TWI_IADR;	/* Internal Address Register		*/
+	AT91_REG	 TWI_CWGR;	/* Clock Waveform Generator Register	*/
+	AT91_REG	 Reserved0[3];
+	AT91_REG	 TWI_SR;	/* Status Register			*/
+	AT91_REG	 TWI_IER;	/* Interrupt Enable Register		*/
+	AT91_REG	 TWI_IDR;	/* Interrupt Disable Register		*/
+	AT91_REG	 TWI_IMR;	/* Interrupt Mask Register		*/
+	AT91_REG	 TWI_RHR;	/* Receive Holding Register		*/
+	AT91_REG	 TWI_THR;	/* Transmit Holding Register		*/
+	AT91_REG	 Reserved1[50];
+	AT91_REG	 TWI_RPR;	/* Receive Pointer Register		*/
+	AT91_REG	 TWI_RCR;	/* Receive Counter Register		*/
+	AT91_REG	 TWI_TPR;	/* Transmit Pointer Register		*/
+	AT91_REG	 TWI_TCR;	/* Transmit Counter Register		*/
+	AT91_REG	 TWI_RNPR;	/* Receive Next Pointer Register	*/
+	AT91_REG	 TWI_RNCR;	/* Receive Next Counter Register	*/
+	AT91_REG	 TWI_TNPR;	/* Transmit Next Pointer Register	*/
+	AT91_REG	 TWI_TNCR;	/* Transmit Next Counter Register	*/
+	AT91_REG	 TWI_PTCR;	/* PDC Transfer Control Register	*/
+	AT91_REG	 TWI_PTSR;	/* PDC Transfer Status Register		*/
 } AT91S_TWI, *AT91PS_TWI;
 
 #endif
 
-// -------- TWI_CR : (TWI Offset: 0x0) TWI Control Register --------
-#define AT91C_TWI_START       ( 0x1 <<  0) // (TWI) Send a START Condition
-#define AT91C_TWI_STOP        ( 0x1 <<  1) // (TWI) Send a STOP Condition
-#define AT91C_TWI_MSEN        ( 0x1 <<  2) // (TWI) TWI Master Transfer Enabled
-#define AT91C_TWI_MSDIS       ( 0x1 <<  3) // (TWI) TWI Master Transfer Disabled
-#define AT91C_TWI_SVEN        ( 0x1 <<  4) // (TWI) TWI Slave Transfer Enabled
-#define AT91C_TWI_SVDIS       ( 0x1 <<  5) // (TWI) TWI Slave Transfer Disabled
-#define AT91C_TWI_SWRST       ( 0x1 <<  7) // (TWI) Software Reset
-// -------- TWI_MMR : (TWI Offset: 0x4) TWI Master Mode Register --------
-#define AT91C_TWI_IADRSZ      ( 0x3 <<  8) // (TWI) Internal Device Address Size
-#define 	AT91C_TWI_IADRSZ_NO                   ( 0x0 <<  8) // (TWI) No internal device address
-#define 	AT91C_TWI_IADRSZ_1_BYTE               ( 0x1 <<  8) // (TWI) One-byte internal device address
-#define 	AT91C_TWI_IADRSZ_2_BYTE               ( 0x2 <<  8) // (TWI) Two-byte internal device address
-#define 	AT91C_TWI_IADRSZ_3_BYTE               ( 0x3 <<  8) // (TWI) Three-byte internal device address
-#define AT91C_TWI_MREAD       ( 0x1 << 12) // (TWI) Master Read Direction
-#define AT91C_TWI_DADR        ( 0x7F <<  6) // (TWI) Device Address
-// -------- TWI_SMR : (TWI Offset: 0x8) TWI Slave Mode Register --------
-#define AT91C_TWI_SADR        ( 0x7F << 16) // (TWI) Slave Device Address
-// -------- TWI_CWGR : (TWI Offset: 0x10) TWI Clock Waveform Generator Register --------
-#define AT91C_TWI_CLDIV       ( 0xFF <<  0) // (TWI) Clock Low Divider
-#define AT91C_TWI_CHDIV       ( 0xFF <<  8) // (TWI) Clock High Divider
-#define AT91C_TWI_CKDIV       ( 0x7 << 16) // (TWI) Clock Divider
-// -------- TWI_SR : (TWI Offset: 0x20) TWI Status Register --------
-#define AT91C_TWI_TXCOMP      ( 0x1 <<  0) // (TWI) Transmission Completed
-#define AT91C_TWI_RXRDY       ( 0x1 <<  1) // (TWI) Receive holding register ReaDY
-#define AT91C_TWI_TXRDY       ( 0x1 <<  2) // (TWI) Transmit holding register ReaDY
-#define AT91C_TWI_SVREAD      ( 0x1 <<  3) // (TWI) Slave Read
-#define AT91C_TWI_SVACC       ( 0x1 <<  4) // (TWI) Slave Access
-#define AT91C_TWI_GCACC       ( 0x1 <<  5) // (TWI) General Call Access
-#define AT91C_TWI_OVRE        ( 0x1 <<  6) // (TWI) Overrun Error
-#define AT91C_TWI_UNRE        ( 0x1 <<  7) // (TWI) Underrun Error
-#define AT91C_TWI_NACK        ( 0x1 <<  8) // (TWI) Not Acknowledged
-#define AT91C_TWI_ARBLST      ( 0x1 <<  9) // (TWI) Arbitration Lost
-// -------- TWI_IER : (TWI Offset: 0x24) TWI Interrupt Enable Register --------
-// -------- TWI_IDR : (TWI Offset: 0x28) TWI Interrupt Disable Register --------
-// -------- TWI_IMR : (TWI Offset: 0x2c) TWI Interrupt Mask Register --------
+/* -------- TWI_CR : (TWI Offset: 0x0) TWI Control Register --------		*/
+#define AT91C_TWI_START (0x1 <<	 0)	/* (TWI) Send a START Condition		*/
+#define AT91C_TWI_STOP	(0x1 <<	 1)	/* (TWI) Send a STOP Condition		*/
+#define AT91C_TWI_MSEN	(0x1 <<	 2)	/* (TWI) TWI Master Transfer Enabled	*/
+#define AT91C_TWI_MSDIS (0x1 <<	 3)	/* (TWI) TWI Master Transfer Disabled	*/
+#define AT91C_TWI_SVEN	(0x1 <<	 4)	/* (TWI) TWI Slave Transfer Enabled	*/
+#define AT91C_TWI_SVDIS (0x1 <<	 5)	/* (TWI) TWI Slave Transfer Disabled	*/
+#define AT91C_TWI_SWRST (0x1 <<	 7)	/* (TWI) Software Reset		*/
+/* -------- TWI_MMR : (TWI Offset: 0x4) TWI Master Mode Register --------	*/
+#define AT91C_TWI_IADRSZ      (0x3 <<  8) /* (TWI) Internal Device Address Size */
+#define	  AT91C_TWI_IADRSZ_NO	  (0x0 <<  8) /* (TWI) No internal device address	*/
+#define	  AT91C_TWI_IADRSZ_1_BYTE (0x1 <<  8) /* (TWI) One-byte internal device address */
+#define	  AT91C_TWI_IADRSZ_2_BYTE (0x2 <<  8) /* (TWI) Two-byte internal device address */
+#define	  AT91C_TWI_IADRSZ_3_BYTE (0x3 <<  8) /* (TWI) Three-byte internal device address */
+#define AT91C_TWI_MREAD (0x1 << 12)	/* (TWI) Master Read Direction		*/
+#define AT91C_TWI_DADR	(0x7F <<  6)	/* (TWI) Device Address			*/
+/* -------- TWI_SMR : (TWI Offset: 0x8) TWI Slave Mode Register --------	*/
+#define AT91C_TWI_SADR	(0x7F << 16)	/* (TWI) Slave Device Address		*/
+/* -------- TWI_CWGR : (TWI Offset: 0x10) TWI Clock Waveform Generator Register --------	*/
+#define AT91C_TWI_CLDIV	 (0xFF <<  0)	/* (TWI) Clock Low Divider		*/
+#define AT91C_TWI_CHDIV	 (0xFF <<  8)	/* (TWI) Clock High Divider		*/
+#define AT91C_TWI_CKDIV	 (0x7 << 16)	/* (TWI) Clock Divider			*/
+/* -------- TWI_SR : (TWI Offset: 0x20) TWI Status Register --------		*/
+#define AT91C_TWI_TXCOMP (0x1 <<  0)	/* (TWI) Transmission Completed		*/
+#define AT91C_TWI_RXRDY	 (0x1 <<  1)	/* (TWI) Receive holding register ReaDY */
+#define AT91C_TWI_TXRDY	 (0x1 <<  2)	/* (TWI) Transmit holding register ReaDY*/
+#define AT91C_TWI_SVREAD (0x1 <<  3)	/* (TWI) Slave Read			*/
+#define AT91C_TWI_SVACC	 (0x1 <<  4)	/* (TWI) Slave Access			*/
+#define AT91C_TWI_GCACC	 (0x1 <<  5)	/* (TWI) General Call Access		*/
+#define AT91C_TWI_OVRE	 (0x1 <<  6)	/* (TWI) Overrun Error			*/
+#define AT91C_TWI_UNRE	 (0x1 <<  7)	/* (TWI) Underrun Error			*/
+#define AT91C_TWI_NACK	 (0x1 <<  8)	/* (TWI) Not Acknowledged		*/
+#define AT91C_TWI_ARBLST (0x1 <<  9)	/* (TWI) Arbitration Lost		*/
+/* -------- TWI_IER : (TWI Offset: 0x24) TWI Interrupt Enable Register -------- */
+/* -------- TWI_IDR : (TWI Offset: 0x28) TWI Interrupt Disable Register ------- */
+/* -------- TWI_IMR : (TWI Offset: 0x2c) TWI Interrupt Mask Register --------	*/
 
 /*
     i2c Support for Atmel's AT91RM9200 Two-Wire Interface
@@ -120,7 +120,7 @@ typedef struct _AT91S_TWI {
 #endif
 #define AT91C_TWI_CLDIV3 ((AT91C_TWI_CLDIV2 + (4 - AT91C_TWI_CLDIV2 % 4)) >> 2)
 
-#define AT91C_EEPROM_I2C_ADDRESS        (0x50 << 16)
+#define AT91C_EEPROM_I2C_ADDRESS	(0x50 << 16)
 
-#endif
-#endif
+#endif	/* __ASSEMBLY__ */
+#endif	/* AT91RM9200_TWI_H */
diff --git a/rtc/Makefile b/rtc/Makefile
index 71fadea..4ceac76 100644
--- a/rtc/Makefile
+++ b/rtc/Makefile
@@ -31,7 +31,7 @@ OBJS	= date.o   \
 	  ds12887.o ds1302.o ds1306.o ds1307.o ds1337.o \
 	  ds1556.o ds164x.o ds174x.o \
 	  m41t11.o max6900.o m48t35ax.o mc146818.o mk48t59.o \
-	  mpc5xxx.o mpc8xx.o pcf8563.o s3c24x0_rtc.o
+	  mpc5xxx.o mpc8xx.o pcf8563.o s3c24x0_rtc.o rs5c372.o
 
 all:	$(LIB)
 
diff --git a/rtc/rs5c372.c b/rtc/rs5c372.c
new file mode 100644
index 0000000..0f8ec62
--- /dev/null
+++ b/rtc/rs5c372.c
@@ -0,0 +1,303 @@
+/*
+ * rs5c372.c
+ *
+ * Device driver for Ricoh's Real Time Controller RS5C372A.
+ *
+ * Copyright (C) 2004 Gary Jennejohn garyj@denx.de
+ *
+ * Based in part in ds1307.c -
+ * (C) Copyright 2001, 2002, 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ * Keith Outwater, keith_outwater@mvis.com`
+ * Steven Scholz, steven.scholz@imc-berlin.de
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+#if defined(CONFIG_RTC_RS5C372A) && (CONFIG_COMMANDS & CFG_CMD_DATE)
+/*
+ * Reads are always done starting with register 15, which requires some
+ * jumping-through-hoops to access the data correctly.
+ *
+ * Writes are always done starting with register 0.
+ */
+
+#define DEBUG 0
+
+#if DEBUG
+static unsigned int rtc_debug = DEBUG;
+#else
+#define rtc_debug 0	/* gcc will remove all the debug code for us */
+#endif
+
+#ifndef CFG_I2C_RTC_ADDR
+#define CFG_I2C_RTC_ADDR 0x32
+#endif
+
+#define RS5C372_RAM_SIZE 0x10
+#define RATE_32000HZ	0x80	/* Rate Select 32.000KHz */
+#define RATE_32768HZ	0x00	/* Rate Select 32.768KHz */
+
+#define STATUS_XPT  0x10    /* data invalid because voltage was 0 */
+
+#define USE_24HOUR_MODE 0x20
+#define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
+#define HOURS_AP(n)	(((n) >> 5) & 1)
+#define HOURS_12(n)	bcd2bin((n) & 0x1F)
+#define HOURS_24(n)	bcd2bin((n) & 0x3F)
+
+
+static uchar bin2bcd (unsigned int n);
+static unsigned bcd2bin (uchar c);
+
+static int setup_done = 0;
+
+static int
+rs5c372_readram(char *buf, int len)
+{
+	int ret;
+
+	ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, len);
+	if (ret != 0) {
+		printf("%s: failed to read\n", __FUNCTION__);
+		return ret;
+	}
+
+	if (buf[0] & STATUS_XPT)
+		printf("### Warning: RTC lost power\n");
+
+	return ret;
+}
+
+static void
+rs5c372_enable(void)
+{
+	unsigned char buf[RS5C372_RAM_SIZE + 1];
+	int ret;
+
+
+	/* note that this returns reg. 15 in buf[1] */
+	ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
+	if (ret != 0) {
+		printf("%s: failed\n", __FUNCTION__);
+		return;
+	}
+
+	buf[0] = 0;
+	/* we want to start writing at register 0 so we have to copy the */
+	/* register contents up one slot */
+	for (ret = 2; ret < 9; ret++)
+		buf[ret - 1] = buf[ret];
+	/* registers 0 to 6 (time values) are not touched */
+	buf[8] = RATE_32768HZ; /* reg. 7 */
+	buf[9] = 0; /* reg. 8 */
+	buf[10] = 0; /* reg. 9 */
+	buf[11] = 0; /* reg. 10 */
+	buf[12] = 0; /* reg. 11 */
+	buf[13] = 0; /* reg. 12 */
+	buf[14] = 0; /* reg. 13 */
+	buf[15] = 0; /* reg. 14 */
+	buf[16] = USE_24HOUR_MODE; /* reg. 15 */
+	ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
+	if (ret != 0) {
+		printf("%s: failed\n", __FUNCTION__);
+		return;
+	}
+	setup_done = 1;
+
+	return;
+}
+
+static void
+rs5c372_convert_to_time(struct rtc_time *dt, char *buf)
+{
+	/* buf[0] is register 15 */
+	dt->tm_sec = bcd2bin(buf[1]);
+	dt->tm_min = bcd2bin(buf[2]);
+
+	if (TWELVE_HOUR_MODE(buf[0])) {
+		dt->tm_hour = HOURS_12(buf[3]);
+		if (HOURS_AP(buf[3])) /* PM */
+			dt->tm_hour += 12;
+	} else /* 24-hour-mode */
+		dt->tm_hour = HOURS_24(buf[3]);
+
+	dt->tm_mday = bcd2bin(buf[5]);
+	dt->tm_mon = bcd2bin(buf[6]);
+	dt->tm_year = bcd2bin(buf[7]);
+	if (dt->tm_year >= 70)
+		dt->tm_year += 1900;
+	else
+		dt->tm_year += 2000;
+	/* 0 is Sunday */
+	dt->tm_wday = bcd2bin(buf[4] & 0x07);
+	dt->tm_yday = 0;
+	dt->tm_isdst= 0;
+
+	if(rtc_debug > 2) {
+		printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
+		printf("rs5c372_convert_to_time: mon  = %d\n", dt->tm_mon);
+		printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
+		printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
+		printf("rs5c372_convert_to_time: min  = %d\n", dt->tm_min);
+		printf("rs5c372_convert_to_time: sec  = %d\n", dt->tm_sec);
+	}
+}
+
+/*
+ * Get the current time from the RTC
+ */
+void
+rtc_get (struct rtc_time *tmp)
+{
+	unsigned char buf[RS5C372_RAM_SIZE];
+	int ret;
+
+	if (!setup_done)
+		rs5c372_enable();
+
+	if (!setup_done)
+		return;
+
+	memset(buf, 0, sizeof(buf));
+
+	/* note that this returns reg. 15 in buf[0] */
+	ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
+	if (ret != 0) {
+		printf("%s: failed\n", __FUNCTION__);
+		return;
+	}
+
+	rs5c372_convert_to_time(tmp, buf);
+
+	return;
+}
+
+/*
+ * Set the RTC
+ */
+void
+rtc_set (struct rtc_time *tmp)
+{
+	unsigned char buf[8], reg15;
+	int ret;
+
+	if (!setup_done)
+		rs5c372_enable();
+
+	if (!setup_done)
+		return;
+
+	if(rtc_debug > 2) {
+		printf("rtc_set: tm_year = %d\n", tmp->tm_year);
+		printf("rtc_set: tm_mon	 = %d\n", tmp->tm_mon);
+		printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
+		printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
+		printf("rtc_set: tm_min	 = %d\n", tmp->tm_min);
+		printf("rtc_set: tm_sec	 = %d\n", tmp->tm_sec);
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	/* only read register 15 */
+	ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 1);
+
+	if (ret == 0) {
+		/* need to save register 15 */
+		reg15 = buf[0];
+		buf[0] = 0;	/* register address on RS5C372 */
+		buf[1] = bin2bcd(tmp->tm_sec);
+		buf[2] = bin2bcd(tmp->tm_min);
+		/* need to handle 12 hour mode */
+		if (TWELVE_HOUR_MODE(reg15)) {
+			if (tmp->tm_hour >= 12) { /* PM */
+				/* 12 PM is a special case */
+				if (tmp->tm_hour == 12)
+					buf[3] = bin2bcd(tmp->tm_hour);
+				else
+					buf[3] = bin2bcd(tmp->tm_hour - 12);
+				buf[3] |= 0x20;
+			}
+		} else {
+			buf[3] = bin2bcd(tmp->tm_hour);
+		}
+
+		buf[4] = bin2bcd(tmp->tm_wday);
+		buf[5] = bin2bcd(tmp->tm_mday);
+		buf[6] = bin2bcd(tmp->tm_mon);
+		if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
+			printf("WARNING: year should be between 1970 and 2069!\n");
+		buf[7] = bin2bcd(tmp->tm_year % 100);
+
+		ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 8);
+		if (ret != 0)
+			printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
+	}
+
+	return;
+}
+
+/*
+ * Reset the RTC. We set the date back to 1970-01-01.
+ */
+void
+rtc_reset (void)
+{
+	struct rtc_time tmp;
+
+	if (!setup_done)
+		rs5c372_enable();
+
+	if (!setup_done)
+		return;
+
+	tmp.tm_year = 1970;
+	tmp.tm_mon = 1;
+	/* Jan. 1, 1970 was a Thursday */
+	tmp.tm_wday= 4;
+	tmp.tm_mday= 1;
+	tmp.tm_hour = 0;
+	tmp.tm_min = 0;
+	tmp.tm_sec = 0;
+
+	rtc_set(&tmp);
+
+	printf ("RTC:	%4d-%02d-%02d %2d:%02d:%02d UTC\n",
+		tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+		tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+	return;
+}
+
+static unsigned int
+bcd2bin (unsigned char n)
+{
+	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
+}
+
+static unsigned char
+bin2bcd (unsigned int n)
+{
+	return (((n / 10) << 4) | (n % 10));
+}
+#endif /* defined(CONFIG_RTC_RS5C372A) && (CONFIG_COMMANDS & CFG_CMD_DATE) */