1. 根目录:
2. drivers
3. staging
4. sbe-2t3e3
5. exar7300.c

/*
 * SBE 2T3E3 synchronous serial card driver for Linux
 *
 * Copyright (C) 2009-2010 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * 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 code is based on a driver written by SBE Inc.
 */

#include "2t3e3.h"
#include "ctrl.h"

void exar7300_init(struct channel *sc)
{
	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG1, 0);

	/* enable line decodeer and encoder */
	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG2, 0);
	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG3, 0);
	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG4,
		       SBE_2T3E3_LIU_VAL_T3_MODE_SELECT |
		       SBE_2T3E3_LIU_VAL_LOOPBACK_OFF);
}

void exar7300_set_loopback(struct channel *sc, u32 mode)
{
	u32 val;

	switch (mode) {
	case SBE_2T3E3_LIU_VAL_LOOPBACK_OFF:
	case SBE_2T3E3_LIU_VAL_LOOPBACK_REMOTE:
	case SBE_2T3E3_LIU_VAL_LOOPBACK_ANALOG:
	case SBE_2T3E3_LIU_VAL_LOOPBACK_DIGITAL:
		break;
	default:
		return;
	}

	val = exar7300_read(sc, SBE_2T3E3_LIU_REG_REG4);
	val &= ~(SBE_2T3E3_LIU_VAL_LOCAL_LOOPBACK | SBE_2T3E3_LIU_VAL_REMOTE_LOOPBACK);
	val |= mode;
	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG4, val);

#if 0
	/* TODO - is it necessary? idea from 2T3E3_HW_Test_code */
	switch (mode) {
	case SBE_2T3E3_LIU_VAL_LOOPBACK_OFF:
		break;
	case SBE_2T3E3_LIU_VAL_LOOPBACK_REMOTE:
		exar7300_receive_equalization_onoff(sc, SBE_2T3E3_ON);
		break;
	case SBE_2T3E3_LIU_VAL_LOOPBACK_ANALOG:
		exar7300_receive_equalization_onoff(sc, SBE_2T3E3_OFF);
		break;
	case SBE_2T3E3_LIU_VAL_LOOPBACK_DIGITAL:
		exar7300_receive_equalization_onoff(sc, SBE_2T3E3_ON);
		break;
	}
#endif
}

void exar7300_set_frame_type(struct channel *sc, u32 type)
{
	u32 val;

	switch (type) {
	case SBE_2T3E3_FRAME_TYPE_T3_CBIT:
	case SBE_2T3E3_FRAME_TYPE_T3_M13:
	case SBE_2T3E3_FRAME_TYPE_E3_G751:
	case SBE_2T3E3_FRAME_TYPE_E3_G832:
		break;
	default:
		return;
	}

	val = exar7300_read(sc, SBE_2T3E3_LIU_REG_REG4);
	val &= ~(SBE_2T3E3_LIU_VAL_T3_MODE_SELECT |
		 SBE_2T3E3_LIU_VAL_E3_MODE_SELECT);

	switch (type) {
	case SBE_2T3E3_FRAME_TYPE_T3_CBIT:
	case SBE_2T3E3_FRAME_TYPE_T3_M13:
		val |= SBE_2T3E3_LIU_VAL_T3_MODE_SELECT;
		break;
	case SBE_2T3E3_FRAME_TYPE_E3_G751:
	case SBE_2T3E3_FRAME_TYPE_E3_G832:
		val |= SBE_2T3E3_LIU_VAL_E3_MODE_SELECT;
		break;
	default:
		return;
	}

	exar7300_write(sc, SBE_2T3E3_LIU_REG_REG4, val);
}


void exar7300_transmit_all_ones_onoff(struct channel *sc, u32 mode)
{
	if (sc->p.transmit_all_ones == mode)
		return;

	switch (mode) {
	case SBE_2T3E3_ON:
		exar7300_set_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				 SBE_2T3E3_LIU_VAL_TRANSMIT_ALL_ONES);
		break;
	case SBE_2T3E3_OFF:
		exar7300_clear_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				   SBE_2T3E3_LIU_VAL_TRANSMIT_ALL_ONES);
		break;
	default:
		return;
	}

	sc->p.transmit_all_ones = mode;
}

void exar7300_receive_equalization_onoff(struct channel *sc, u32 mode)
{
	if (sc->p.receive_equalization == mode)
		return;

	switch (mode) {
	case SBE_2T3E3_OFF:
		exar7300_set_bit(sc, SBE_2T3E3_LIU_REG_REG2,
				 SBE_2T3E3_LIU_VAL_RECEIVE_EQUALIZATION_DISABLE);
		break;
	case SBE_2T3E3_ON:
		exar7300_clear_bit(sc, SBE_2T3E3_LIU_REG_REG2,
				   SBE_2T3E3_LIU_VAL_RECEIVE_EQUALIZATION_DISABLE);
		break;
	default:
		return;
	}

	sc->p.receive_equalization = mode;
}

void exar7300_line_build_out_onoff(struct channel *sc, u32 mode)
{
	if (sc->p.line_build_out == mode)
		return;

	switch (mode) {
	case SBE_2T3E3_OFF:
		exar7300_set_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				 SBE_2T3E3_LIU_VAL_TRANSMIT_LEVEL_SELECT);
		exar7300_receive_equalization_onoff(sc, SBE_2T3E3_OFF);
		break;
	case SBE_2T3E3_ON:
		exar7300_clear_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				   SBE_2T3E3_LIU_VAL_TRANSMIT_LEVEL_SELECT);
		exar7300_receive_equalization_onoff(sc, SBE_2T3E3_ON);
		break;
	default:
		return;
	}

	sc->p.line_build_out = mode;
}

/* TODO - what about encoder in raw mode??? disable it too? */
void exar7300_unipolar_onoff(struct channel *sc, u32 mode)
{
	switch (mode) {
	case SBE_2T3E3_OFF:
		exar7300_clear_bit(sc, SBE_2T3E3_LIU_REG_REG3,
				   SBE_2T3E3_LIU_VAL_DECODER_DISABLE);
		exar7300_clear_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				   SBE_2T3E3_LIU_VAL_TRANSMIT_BINARY_DATA);
		break;
	case SBE_2T3E3_ON:
		exar7300_set_bit(sc, SBE_2T3E3_LIU_REG_REG3,
				 SBE_2T3E3_LIU_VAL_DECODER_DISABLE);
		exar7300_set_bit(sc, SBE_2T3E3_LIU_REG_REG1,
				 SBE_2T3E3_LIU_VAL_TRANSMIT_BINARY_DATA);
		break;
	}
}