Merge branch 'wd'

1 files changed, 347 insertions, 0 deletions

diff --git a/board/gth2/ee_access.c b/board/gth2/ee_access.c
new file mode 100644
index 0000000..d4798c4
--- /dev/null
+++ b/board/gth2/ee_access.c
@@ -0,0 +1,347 @@
+/* Module for handling DALLAS DS2438, smart battery monitor
+   Chip can store up to 40 bytes of user data in EEPROM,
+   perform temp, voltage and current measurements.
+   Chip also contains a unique serial number.
+
+   Always read/write LSb first
+
+   For documentaion, see data sheet for DS2438, 2438.pdf
+
+   By Thomas.Lange@corelatus.com 001025
+
+   Copyright (C) 2000-2005 Corelatus AB */
+
+/* This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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 <asm/au1x00.h>
+#include <asm/io.h>
+#include "ee_dev.h"
+#include "ee_access.h"
+
+/* static int Debug = 1; */
+#undef E_DEBUG
+#define E_DEBUG(fmt,args...) /* */
+/* #define E_DEBUG(fmt,args...) printk("EEA:"fmt,##args); */
+
+/* We dont have kernel functions */
+#define printk printf
+#define KERN_DEBUG
+#define KERN_ERR
+#define EIO 1
+
+#ifndef TRUE
+#define TRUE 1
+#endif
+#ifndef FALSE
+#define FALSE 0
+#endif
+
+/* lookup table ripped from DS app note 17, understanding and using cyclic redundancy checks... */
+
+static u8 crc_lookup[256] = {
+	0,	94,	188,	226,	97,	63,	221,	131,
+	194,	156,	126,	32,	163,	253,	31,	65,
+	157,	195,	33,	127,	252,	162,	64,	30,
+	95,	1,	227,	189,	62,	96,	130,	220,
+	35,	125,	159,	193,	66,	28,	254,	160,
+	225,	191,	93,	3,	128,	222,	60,	98,
+	190,	224,	2,	92,	223,	129,	99,	61,
+	124,	34,	192,	158,	29,	67,	161,	255,
+	70,	24,	250,	164,	39,	121,	155,	197,
+	132,	218,	56,	102,	229,	187,	89,	7,
+	219,	133,	103,	57,	186,	228,	6,	88,
+	25,	71,	165,	251,	120,	38,	196,	154,
+	101,	59,	217,	135,	4,	90,	184,	230,
+	167,	249,	27,	69,	198,	152,	122,	36,
+	248,	166,	68,	26,	153,	199,	37,	123,
+	58,	100,	134,	216,	91,	5,	231,	185,
+	140,	210,	48,	110,	237,	179,	81,	15,
+	78,	16,	242,	172,	47,	113,	147,	205,
+	17,	79,	173,	243,	112,	46,	204,	146,
+	211,	141,	111,	49,	178,	236,	14,	80,
+	175,	241,	19,	77,	206,	144,	114,	44,
+	109,	51,	209,	143,	12,	82,	176,	238,
+	50,	108,	142,	208,	83,	13,	239,	177,
+	240,	174,	76,	18,	145,	207,	45,	115,
+	202,	148,	118,	40,	171,	245,	23,	73,
+	8,	86,	180,	234,	105,	55,	213,	139,
+	87,	9,	235,	181,	54,	104,	138,	212,
+	149,	203,	41,	119,	244,	170,	72,	22,
+	233,	183,	85,	11,	136,	214,	52,	106,
+	43,	117,	151,	201,	74,	20,	246,	168,
+	116,	42,	200,	150,	21,	75,	169,	247,
+	182,	232,	10,	84,	215,	137,	107,	53
+};
+
+static void
+write_gpio_data(int value ){
+	if(value){
+		/* Tristate */
+		gpio_tristate(GPIO_EEDQ);
+	}
+	else{
+		/* Drive 0 */
+		gpio_clear(GPIO_EEDQ);
+	}
+}
+
+static u8 make_new_crc( u8 Old_crc, u8 New_value ){
+	/* Compute a new checksum with new byte, using previous checksum as input
+	   See DS app note 17, understanding and using cyclic redundancy checks...
+	   Also see DS2438, page 11 */
+	return( crc_lookup[Old_crc ^ New_value ]);
+}
+
+int ee_crc_ok( u8 *Buffer, int Len, u8 Crc ){
+	/* Check if the checksum for this buffer is correct */
+	u8 Curr_crc=0;
+	int i;
+	u8 *Curr_byte = Buffer;
+
+	for(i=0;i<Len;i++){
+		Curr_crc = make_new_crc( Curr_crc, *Curr_byte);
+		Curr_byte++;
+	}
+	E_DEBUG("Calculated CRC = 0x%x, read = 0x%x\n", Curr_crc, Crc);
+
+	if(Curr_crc == Crc){
+		/* Good */
+		return(TRUE);
+	}
+	printk(KERN_ERR"EE checksum error, Calculated CRC = 0x%x, read = 0x%x\n", Curr_crc, Crc);
+	return(FALSE);
+}
+
+static void
+set_idle(void){
+	/* Send idle and keep start time
+	   Continous 1 is idle */
+	WRITE_PORT(1);
+}
+
+
+static int
+do_cpu_reset(void){
+	/* Release reset and verify that chip responds with presence pulse */
+	int Retries=0;
+	while(Retries<15){
+		udelay(RESET_LOW_TIME);
+
+		/* Send reset */
+		WRITE_PORT(0);
+		udelay(RESET_LOW_TIME);
+
+		/* Release reset */
+		WRITE_PORT(1);
+
+		/* Wait for EEPROM to drive output */
+		udelay(PRESENCE_TIMEOUT);
+		if(!READ_PORT){
+			/* Ok, EEPROM is driving a 0 */
+			E_DEBUG("Presence detected\n");
+			if(Retries){
+				E_DEBUG("Retries %d\n",Retries);
+			}
+			/* Make sure chip releases pin */
+			udelay(PRESENCE_LOW_TIME);
+			return 0;
+		}
+		Retries++;
+	}
+
+	printk(KERN_ERR"eeprom did not respond when releasing reset\n");
+
+	/* Make sure chip releases pin */
+	udelay(PRESENCE_LOW_TIME);
+
+	/* Set to idle again */
+	set_idle();
+
+	return(-EIO);
+}
+
+static u8
+read_cpu_byte(void){
+	/* Read a single byte from EEPROM
+	   Read LSb first */
+	int i;
+	int Value;
+	u8 Result=0;
+	u32 Flags;
+
+	E_DEBUG("Reading byte\n");
+
+	for(i=0;i<8;i++){
+		/* Small delay between pulses */
+		udelay(1);
+
+#ifdef __KERNEL__
+		/* Disable irq */
+		save_flags(Flags);
+		cli();
+#endif
+
+		/* Pull down pin short time to start read
+		   See page 26 in data sheet */
+
+		WRITE_PORT(0);
+		udelay(READ_LOW);
+		WRITE_PORT(1);
+
+		/* Wait for chip to drive pin */
+		udelay(READ_TIMEOUT);
+
+		Value = READ_PORT;
+		if(Value)
+			Value=1;
+
+#ifdef __KERNEL__
+		/* Enable irq */
+		restore_flags(Flags);
+#endif
+
+		/* Wait for chip to release pin */
+		udelay(TOTAL_READ_LOW-READ_TIMEOUT);
+
+		/* LSb first */
+		Result|=Value<<i;
+		/* E_DEBUG("Read %d\n",Value); */
+
+	}
+
+	E_DEBUG("Read byte 0x%x\n",Result);
+
+	return(Result);
+}
+
+static void
+write_cpu_byte(u8 Byte){
+	/* Write a single byte to EEPROM
+	   Write LSb first */
+	int i;
+	int Value;
+	u32 Flags;
+
+	E_DEBUG("Writing byte 0x%x\n",Byte);
+
+	for(i=0;i<8;i++){
+		/* Small delay between pulses */
+		udelay(1);
+		Value = Byte&1;
+
+#ifdef __KERNEL__
+		/* Disable irq */
+		save_flags(Flags);
+		cli();
+#endif
+
+		/* Pull down pin short time for a 1, long time for a 0
+		   See page 26 in data sheet */
+
+		WRITE_PORT(0);
+		if(Value){
+			/* Write a 1 */
+			udelay(WRITE_1_LOW);
+		}
+		else{
+			/* Write a 0 */
+			udelay(WRITE_0_LOW);
+		}
+
+		WRITE_PORT(1);
+
+#ifdef __KERNEL__
+		/* Enable irq */
+		restore_flags(Flags);
+#endif
+
+		if(Value)
+			/* Wait for chip to read the 1 */
+			udelay(TOTAL_WRITE_LOW-WRITE_1_LOW);
+
+		/* E_DEBUG("Wrote %d\n",Value); */
+		Byte>>=1;
+	}
+}
+
+int ee_do_cpu_command( u8 *Tx, int Tx_len, u8 *Rx, int Rx_len, int Send_skip ){
+	/* Execute this command string, including
+	   giving reset and setting to idle after command
+	   if Rx_len is set, we read out data from EEPROM */
+	int i;
+
+	E_DEBUG("Command, Tx_len %d, Rx_len %d\n", Tx_len, Rx_len );
+
+	if(do_cpu_reset()){
+		/* Failed! */
+		return(-EIO);
+	}
+
+	if(Send_skip)
+		/* Always send SKIP_ROM first to tell chip we are sending a command,
+		   except when we read out rom data for chip */
+		write_cpu_byte(SKIP_ROM);
+
+	/* Always have Tx data */
+	for(i=0;i<Tx_len;i++){
+		write_cpu_byte(Tx[i]);
+	}
+
+	if(Rx_len){
+		for(i=0;i<Rx_len;i++){
+			Rx[i]=read_cpu_byte();
+		}
+	}
+
+	set_idle();
+
+	E_DEBUG("Command done\n");
+
+	return(0);
+}
+
+int ee_init_cpu_data(void){
+	int i;
+	u8 Tx[10];
+
+	/* Leave it floting since altera is driving the same pin */
+	set_idle();
+
+	/* Copy all User EEPROM data to scratchpad */
+	for(i=0;i<USER_PAGES;i++){
+		Tx[0]=RECALL_MEMORY;
+		Tx[1]=EE_USER_PAGE_0+i;
+		if(ee_do_cpu_command(Tx,2,NULL,0,TRUE)) return(-EIO);
+	}
+
+	/* Make sure chip doesnt store measurements in NVRAM */
+	Tx[0]=WRITE_SCRATCHPAD;
+	Tx[1]=0; /* Page */
+	Tx[2]=9;
+	if(ee_do_cpu_command(Tx,3,NULL,0,TRUE)) return(-EIO);
+
+	Tx[0]=COPY_SCRATCHPAD;
+	if(ee_do_cpu_command(Tx,2,NULL,0,TRUE)) return(-EIO);
+
+	for(i=0;i<10;i++){
+		udelay(1000);
+	}
+
+	return(0);
+}