drivers/staging/rt2860/common/eeprom.c

/*
 *************************************************************************
 * Ralink Tech Inc.
 * 5F., No.36, Taiyuan St., Jhubei City,
 * Hsinchu County 302,
 * Taiwan, R.O.C.
 *
 * (c) Copyright 2002-2007, Ralink Technology, Inc.
 *
 * 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.             *
 *                                                                       *
 *************************************************************************

	Module Name:
	eeprom.c

	Abstract:

	Revision History:
	Who			When			What
	--------	----------		----------------------------------------------
	Name		Date			Modification logs
*/
#include "../rt_config.h"

// IRQL = PASSIVE_LEVEL
VOID RaiseClock(
    IN	PRTMP_ADAPTER	pAd,
    IN  UINT32 *x)
{
    *x = *x | EESK;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, *x);
    RTMPusecDelay(1);				// Max frequency = 1MHz in Spec. definition
}

// IRQL = PASSIVE_LEVEL
VOID LowerClock(
    IN	PRTMP_ADAPTER	pAd,
    IN  UINT32 *x)
{
    *x = *x & ~EESK;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, *x);
    RTMPusecDelay(1);
}

// IRQL = PASSIVE_LEVEL
USHORT ShiftInBits(
    IN	PRTMP_ADAPTER	pAd)
{
    UINT32		x,i;
	USHORT      data=0;

    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);

    x &= ~( EEDO | EEDI);

    for(i=0; i<16; i++)
    {
        data = data << 1;
        RaiseClock(pAd, &x);

        RTMP_IO_READ32(pAd, E2PROM_CSR, &x);

        x &= ~(EEDI);
        if(x & EEDO)
            data |= 1;

        LowerClock(pAd, &x);
    }

    return data;
}

// IRQL = PASSIVE_LEVEL
VOID ShiftOutBits(
    IN	PRTMP_ADAPTER	pAd,
    IN  USHORT data,
    IN  USHORT count)
{
    UINT32       x,mask;

    mask = 0x01 << (count - 1);
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);

    x &= ~(EEDO | EEDI);

    do
    {
        x &= ~EEDI;
        if(data & mask)		x |= EEDI;

        RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

        RaiseClock(pAd, &x);
        LowerClock(pAd, &x);

        mask = mask >> 1;
    } while(mask);

    x &= ~EEDI;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);
}

// IRQL = PASSIVE_LEVEL
VOID EEpromCleanup(
    IN	PRTMP_ADAPTER	pAd)
{
    UINT32 x;

    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);

    x &= ~(EECS | EEDI);
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

    RaiseClock(pAd, &x);
    LowerClock(pAd, &x);
}

VOID EWEN(
	IN	PRTMP_ADAPTER	pAd)
{
    UINT32	x;

    // reset bits and set EECS
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);
    x &= ~(EEDI | EEDO | EESK);
    x |= EECS;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

	// kick a pulse
	RaiseClock(pAd, &x);
	LowerClock(pAd, &x);

    // output the read_opcode and six pulse in that order
    ShiftOutBits(pAd, EEPROM_EWEN_OPCODE, 5);
    ShiftOutBits(pAd, 0, 6);

    EEpromCleanup(pAd);
}

VOID EWDS(
	IN	PRTMP_ADAPTER	pAd)
{
    UINT32	x;

    // reset bits and set EECS
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);
    x &= ~(EEDI | EEDO | EESK);
    x |= EECS;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

	// kick a pulse
	RaiseClock(pAd, &x);
	LowerClock(pAd, &x);

    // output the read_opcode and six pulse in that order
    ShiftOutBits(pAd, EEPROM_EWDS_OPCODE, 5);
    ShiftOutBits(pAd, 0, 6);

    EEpromCleanup(pAd);
}

// IRQL = PASSIVE_LEVEL
USHORT RTMP_EEPROM_READ16(
    IN	PRTMP_ADAPTER	pAd,
    IN  USHORT Offset)
{
    UINT32		x;
    USHORT		data;

    Offset /= 2;
    // reset bits and set EECS
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);
    x &= ~(EEDI | EEDO | EESK);
    x |= EECS;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

	// kick a pulse
	RaiseClock(pAd, &x);
	LowerClock(pAd, &x);

    // output the read_opcode and register number in that order
    ShiftOutBits(pAd, EEPROM_READ_OPCODE, 3);
    ShiftOutBits(pAd, Offset, pAd->EEPROMAddressNum);

    // Now read the data (16 bits) in from the selected EEPROM word
    data = ShiftInBits(pAd);

    EEpromCleanup(pAd);

    return data;
}	//ReadEEprom

VOID RTMP_EEPROM_WRITE16(
    IN	PRTMP_ADAPTER	pAd,
    IN  USHORT Offset,
    IN  USHORT Data)
{
    UINT32 x;

	Offset /= 2;

	EWEN(pAd);

    // reset bits and set EECS
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);
    x &= ~(EEDI | EEDO | EESK);
    x |= EECS;
    RTMP_IO_WRITE32(pAd, E2PROM_CSR, x);

	// kick a pulse
	RaiseClock(pAd, &x);
	LowerClock(pAd, &x);

    // output the read_opcode ,register number and data in that order
    ShiftOutBits(pAd, EEPROM_WRITE_OPCODE, 3);
    ShiftOutBits(pAd, Offset, pAd->EEPROMAddressNum);
	ShiftOutBits(pAd, Data, 16);		// 16-bit access

    // read DO status
    RTMP_IO_READ32(pAd, E2PROM_CSR, &x);

	EEpromCleanup(pAd);

	RTMPusecDelay(10000);	//delay for twp(MAX)=10ms

	EWDS(pAd);

    EEpromCleanup(pAd);
}