sk98lin: resurrect driver

This reverts commit e1abecc48938fbe1966ea6e78267fc673fa59295.

The driver works on some hardware that skge doesn't handle yet.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/sk98lin/sklm80.c b/drivers/net/sk98lin/sklm80.c
new file mode 100644
index 0000000..a204f5b
--- /dev/null
+++ b/drivers/net/sk98lin/sklm80.c
@@ -0,0 +1,141 @@
+/******************************************************************************
+ *
+ * Name:	sklm80.c
+ * Project:	Gigabit Ethernet Adapters, TWSI-Module
+ * Version:	$Revision: 1.22 $
+ * Date:	$Date: 2003/10/20 09:08:21 $
+ * Purpose:	Functions to access Voltage and Temperature Sensor (LM80)
+ *
+ ******************************************************************************/
+
+/******************************************************************************
+ *
+ *	(C)Copyright 1998-2002 SysKonnect.
+ *	(C)Copyright 2002-2003 Marvell.
+ *
+ *	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.
+ *
+ *	The information in this file is provided "AS IS" without warranty.
+ *
+ ******************************************************************************/
+
+/*
+	LM80 functions
+*/
+#if (defined(DEBUG) || ((!defined(LINT)) && (!defined(SK_SLIM))))
+static const char SysKonnectFileId[] =
+	"@(#) $Id: sklm80.c,v 1.22 2003/10/20 09:08:21 rschmidt Exp $ (C) Marvell. ";
+#endif
+
+#include "h/skdrv1st.h"		/* Driver Specific Definitions */
+#include "h/lm80.h"
+#include "h/skdrv2nd.h"		/* Adapter Control- and Driver specific Def. */
+
+#define	BREAK_OR_WAIT(pAC,IoC,Event)	break
+
+/*
+ * read a sensors value (LM80 specific)
+ *
+ * This function reads a sensors value from the I2C sensor chip LM80.
+ * The sensor is defined by its index into the sensors database in the struct
+ * pAC points to.
+ *
+ * Returns	1 if the read is completed
+ *		0 if the read must be continued (I2C Bus still allocated)
+ */
+int SkLm80ReadSensor(
+SK_AC		*pAC,	/* Adapter Context */
+SK_IOC		IoC,	/* I/O Context needed in level 1 and 2 */
+SK_SENSOR	*pSen)	/* Sensor to be read */
+{
+	SK_I32		Value;
+
+	switch (pSen->SenState) {
+	case SK_SEN_IDLE:
+		/* Send address to ADDR register */
+		SK_I2C_CTL(IoC, I2C_READ, pSen->SenDev, I2C_025K_DEV, pSen->SenReg, 0);
+
+		pSen->SenState = SK_SEN_VALUE ;
+		BREAK_OR_WAIT(pAC, IoC, I2C_READ);
+	
+	case SK_SEN_VALUE:
+		/* Read value from data register */
+		SK_IN32(IoC, B2_I2C_DATA, ((SK_U32 *)&Value));
+		
+		Value &= 0xff; /* only least significant byte is valid */
+
+		/* Do NOT check the Value against the thresholds */
+		/* Checking is done in the calling instance */
+
+		if (pSen->SenType == SK_SEN_VOLT) {
+			/* Voltage sensor */
+			pSen->SenValue = Value * SK_LM80_VT_LSB;
+			pSen->SenState = SK_SEN_IDLE ;
+			return(1);
+		}
+
+		if (pSen->SenType == SK_SEN_FAN) {
+			if (Value != 0 && Value != 0xff) {
+				/* Fan speed counter */
+				pSen->SenValue = SK_LM80_FAN_FAKTOR/Value;
+			}
+			else {
+				/* Indicate Fan error */
+				pSen->SenValue = 0;
+			}
+			pSen->SenState = SK_SEN_IDLE ;
+			return(1);
+		}
+
+		/* First: correct the value: it might be negative */
+		if ((Value & 0x80) != 0) {
+			/* Value is negative */
+			Value = Value - 256;
+		}
+
+		/* We have a temperature sensor and need to get the signed extension.
+		 * For now we get the extension from the last reading, so in the normal
+		 * case we won't see flickering temperatures.
+		 */
+		pSen->SenValue = (Value * SK_LM80_TEMP_LSB) +
+			(pSen->SenValue % SK_LM80_TEMP_LSB);
+
+		/* Send address to ADDR register */
+		SK_I2C_CTL(IoC, I2C_READ, pSen->SenDev, I2C_025K_DEV, LM80_TEMP_CTRL, 0);
+
+		pSen->SenState = SK_SEN_VALEXT ;
+		BREAK_OR_WAIT(pAC, IoC, I2C_READ);
+	
+	case SK_SEN_VALEXT:
+		/* Read value from data register */
+		SK_IN32(IoC, B2_I2C_DATA, ((SK_U32 *)&Value));
+		Value &= LM80_TEMP_LSB_9; /* only bit 7 is valid */
+
+		/* cut the LSB bit */
+		pSen->SenValue = ((pSen->SenValue / SK_LM80_TEMP_LSB) *
+			SK_LM80_TEMP_LSB);
+
+		if (pSen->SenValue < 0) {
+			/* Value negative: The bit value must be subtracted */
+			pSen->SenValue -= ((Value >> 7) * SK_LM80_TEMPEXT_LSB);
+		}
+		else {
+			/* Value positive: The bit value must be added */
+			pSen->SenValue += ((Value >> 7) * SK_LM80_TEMPEXT_LSB);
+		}
+
+		pSen->SenState = SK_SEN_IDLE ;
+		return(1);
+	
+	default:
+		SK_ERR_LOG(pAC, SK_ERRCL_SW, SKERR_I2C_E007, SKERR_I2C_E007MSG);
+		return(1);
+	}
+
+	/* Not completed */
+	return(0);
+}
+