/******************************************************************************
 * rtl871x_eeprom.c
 *
 * Copyright(c) 2007 - 2010 Realtek Corporation. All rights reserved.
 * Linux device driver for RTL8192SU
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * Modifications for inclusion into the Linux staging tree are
 * Copyright(c) 2010 Larry Finger. All rights reserved.
 *
 * Contact information:
 * WLAN FAE <wlanfae@realtek.com>
 * Larry Finger <Larry.Finger@lwfinger.net>
 *
 ******************************************************************************/

#define _RTL871X_EEPROM_C_

#include "osdep_service.h"
#include "drv_types.h"

static void up_clk(struct _adapter *padapter, u16 *x)
{
        *x = *x | _EESK;
        r8712_write8(padapter, EE_9346CR, (u8)*x);
        udelay(CLOCK_RATE);
}

static void down_clk(struct _adapter *padapter, u16 *x)
{
        *x = *x & ~_EESK;
        r8712_write8(padapter, EE_9346CR, (u8)*x);
        udelay(CLOCK_RATE);
}

static void shift_out_bits(struct _adapter *padapter, u16 data, u16 count)
{
        u16 x, mask;

        if (padapter->bSurpriseRemoved)
                goto out;
        mask = 0x01 << (count - 1);
        x = r8712_read8(padapter, EE_9346CR);
        x &= ~(_EEDO | _EEDI);
        do {
                x &= ~_EEDI;
                if (data & mask)
                        x |= _EEDI;
                if (padapter->bSurpriseRemoved)
                        goto out;
                r8712_write8(padapter, EE_9346CR, (u8)x);
                udelay(CLOCK_RATE);
                up_clk(padapter, &x);
                down_clk(padapter, &x);
                mask >>= 1;
        } while (mask);
        if (padapter->bSurpriseRemoved)
                goto out;
        x &= ~_EEDI;
        r8712_write8(padapter, EE_9346CR, (u8)x);
out:;
}

static u16 shift_in_bits(struct _adapter *padapter)
{
        u16 x, d = 0, i;

        if (padapter->bSurpriseRemoved)
                goto out;
        x = r8712_read8(padapter, EE_9346CR);
        x &= ~(_EEDO | _EEDI);
        d = 0;
        for (i = 0; i < 16; i++) {
                d <<= 1;
                up_clk(padapter, &x);
                if (padapter->bSurpriseRemoved)
                        goto out;
                x = r8712_read8(padapter, EE_9346CR);
                x &= ~(_EEDI);
                if (x & _EEDO)
                        d |= 1;
                down_clk(padapter, &x);
        }
out:
        return d;
}

static void standby(struct _adapter *padapter)
{
        u8   x;

        x = r8712_read8(padapter, EE_9346CR);
        x &= ~(_EECS | _EESK);
        r8712_write8(padapter, EE_9346CR, x);
        udelay(CLOCK_RATE);
        x |= _EECS;
        r8712_write8(padapter, EE_9346CR, x);
        udelay(CLOCK_RATE);
}

static u16 wait_eeprom_cmd_done(struct _adapter *padapter)
{
        u8      x;
        u16     i;

        standby(padapter);
        for (i = 0; i < 200; i++) {
                x = r8712_read8(padapter, EE_9346CR);
                if (x & _EEDO)
                        return true;
                udelay(CLOCK_RATE);
        }
        return false;
}

static void eeprom_clean(struct _adapter *padapter)
{
        u16 x;

        if (padapter->bSurpriseRemoved)
                return;
        x = r8712_read8(padapter, EE_9346CR);
        if (padapter->bSurpriseRemoved)
                return;
        x &= ~(_EECS | _EEDI);
        r8712_write8(padapter, EE_9346CR, (u8)x);
        if (padapter->bSurpriseRemoved)
                return;
        up_clk(padapter, &x);
        if (padapter->bSurpriseRemoved)
                return;
        down_clk(padapter, &x);
}

void r8712_eeprom_write16(struct _adapter *padapter, u16 reg, u16 data)
{
        u8 x;
        u8 tmp8_ori, tmp8_new, tmp8_clk_ori, tmp8_clk_new;

        tmp8_ori = r8712_read8(padapter, 0x102502f1);
        tmp8_new = tmp8_ori & 0xf7;
        if (tmp8_ori != tmp8_new)
                r8712_write8(padapter, 0x102502f1, tmp8_new);
        tmp8_clk_ori = r8712_read8(padapter, 0x10250003);
        tmp8_clk_new = tmp8_clk_ori | 0x20;
        if (tmp8_clk_new != tmp8_clk_ori)
                r8712_write8(padapter, 0x10250003, tmp8_clk_new);
        x = r8712_read8(padapter, EE_9346CR);
        x &= ~(_EEDI | _EEDO | _EESK | _EEM0);
        x |= _EEM1 | _EECS;
        r8712_write8(padapter, EE_9346CR, x);
        shift_out_bits(padapter, EEPROM_EWEN_OPCODE, 5);
        if (padapter->EepromAddressSize == 8)   /*CF+ and SDIO*/
                shift_out_bits(padapter, 0, 6);
        else    /* USB */
                shift_out_bits(padapter, 0, 4);
        standby(padapter);
        /* Erase this particular word.  Write the erase opcode and register
         * number in that order. The opcode is 3bits in length; reg is 6
         * bits long.
         */
        standby(padapter);
        /* write the new word to the EEPROM
         * send the write opcode the EEPORM
         */
        shift_out_bits(padapter, EEPROM_WRITE_OPCODE, 3);
        /* select which word in the EEPROM that we are writing to. */
        shift_out_bits(padapter, reg, padapter->EepromAddressSize);
        /* write the data to the selected EEPROM word. */
        shift_out_bits(padapter, data, 16);
        if (wait_eeprom_cmd_done(padapter)) {
                standby(padapter);
                shift_out_bits(padapter, EEPROM_EWDS_OPCODE, 5);
                shift_out_bits(padapter, reg, 4);
                eeprom_clean(padapter);
        }
        if (tmp8_clk_new != tmp8_clk_ori)
                r8712_write8(padapter, 0x10250003, tmp8_clk_ori);
        if (tmp8_new != tmp8_ori)
                r8712_write8(padapter, 0x102502f1, tmp8_ori);
}

u16 r8712_eeprom_read16(struct _adapter *padapter, u16 reg) /*ReadEEprom*/
{
        u16 x;
        u16 data = 0;
        u8 tmp8_ori, tmp8_new, tmp8_clk_ori, tmp8_clk_new;

        tmp8_ori = r8712_read8(padapter, 0x102502f1);
        tmp8_new = tmp8_ori & 0xf7;
        if (tmp8_ori != tmp8_new)
                r8712_write8(padapter, 0x102502f1, tmp8_new);
        tmp8_clk_ori = r8712_read8(padapter, 0x10250003);
        tmp8_clk_new = tmp8_clk_ori | 0x20;
        if (tmp8_clk_new != tmp8_clk_ori)
                r8712_write8(padapter, 0x10250003, tmp8_clk_new);
        if (padapter->bSurpriseRemoved)
                goto out;
        /* select EEPROM, reset bits, set _EECS */
        x = r8712_read8(padapter, EE_9346CR);
        if (padapter->bSurpriseRemoved)
                goto out;
        x &= ~(_EEDI | _EEDO | _EESK | _EEM0);
        x |= _EEM1 | _EECS;
        r8712_write8(padapter, EE_9346CR, (unsigned char)x);
        /* write the read opcode and register number in that order
         * The opcode is 3bits in length, reg is 6 bits long
         */
        shift_out_bits(padapter, EEPROM_READ_OPCODE, 3);
        shift_out_bits(padapter, reg, padapter->EepromAddressSize);
        /* Now read the data (16 bits) in from the selected EEPROM word */
        data = shift_in_bits(padapter);
        eeprom_clean(padapter);
out:
        if (tmp8_clk_new != tmp8_clk_ori)
                r8712_write8(padapter, 0x10250003, tmp8_clk_ori);
        if (tmp8_new != tmp8_ori)
                r8712_write8(padapter, 0x102502f1, tmp8_ori);
        return data;
}