lgdt330x.c

linux内核源码

		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
	}

	/* Keep track of the new frequency */
	/* FIXME this is the wrong way to do this...           */
	/* The tuner is shared with the video4linux analog API */
	state->current_frequency = param->frequency;

	lgdt330x_SwReset(state);
	return 0;
}

static int lgdt330x_get_frontend(struct dvb_frontend* fe,
				 struct dvb_frontend_parameters* param)
{
	struct lgdt330x_state *state = fe->demodulator_priv;
	param->frequency = state->current_frequency;
	return 0;
}

static int lgdt3302_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct lgdt330x_state* state = fe->demodulator_priv;
	u8 buf[3];

	*status = 0; /* Reset status result */

	/* AGC status register */
	i2c_read_demod_bytes(state, AGC_STATUS, buf, 1);
	dprintk("%s: AGC_STATUS = 0x%02x\n", __FUNCTION__, buf[0]);
	if ((buf[0] & 0x0c) == 0x8){
		/* Test signal does not exist flag */
		/* as well as the AGC lock flag.   */
		*status |= FE_HAS_SIGNAL;
	}

	/*
	 * You must set the Mask bits to 1 in the IRQ_MASK in order
	 * to see that status bit in the IRQ_STATUS register.
	 * This is done in SwReset();
	 */
	/* signal status */
	i2c_read_demod_bytes(state, TOP_CONTROL, buf, sizeof(buf));
	dprintk("%s: TOP_CONTROL = 0x%02x, IRO_MASK = 0x%02x, IRQ_STATUS = 0x%02x\n", __FUNCTION__, buf[0], buf[1], buf[2]);


	/* sync status */
	if ((buf[2] & 0x03) == 0x01) {
		*status |= FE_HAS_SYNC;
	}

	/* FEC error status */
	if ((buf[2] & 0x0c) == 0x08) {
		*status |= FE_HAS_LOCK;
		*status |= FE_HAS_VITERBI;
	}

	/* Carrier Recovery Lock Status Register */
	i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
	dprintk("%s: CARRIER_LOCK = 0x%02x\n", __FUNCTION__, buf[0]);
	switch (state->current_modulation) {
	case QAM_256:
	case QAM_64:
		/* Need to undestand why there are 3 lock levels here */
		if ((buf[0] & 0x07) == 0x07)
			*status |= FE_HAS_CARRIER;
		break;
	case VSB_8:
		if ((buf[0] & 0x80) == 0x80)
			*status |= FE_HAS_CARRIER;
		break;
	default:
		printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __FUNCTION__);
	}

	return 0;
}

static int lgdt3303_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct lgdt330x_state* state = fe->demodulator_priv;
	int err;
	u8 buf[3];

	*status = 0; /* Reset status result */

	/* lgdt3303 AGC status register */
	err = i2c_read_demod_bytes(state, 0x58, buf, 1);
	if (err < 0)
		return err;

	dprintk("%s: AGC_STATUS = 0x%02x\n", __FUNCTION__, buf[0]);
	if ((buf[0] & 0x21) == 0x01){
		/* Test input signal does not exist flag */
		/* as well as the AGC lock flag.   */
		*status |= FE_HAS_SIGNAL;
	}

	/* Carrier Recovery Lock Status Register */
	i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
	dprintk("%s: CARRIER_LOCK = 0x%02x\n", __FUNCTION__, buf[0]);
	switch (state->current_modulation) {
	case QAM_256:
	case QAM_64:
		/* Need to undestand why there are 3 lock levels here */
		if ((buf[0] & 0x07) == 0x07)
			*status |= FE_HAS_CARRIER;
		else
			break;
		i2c_read_demod_bytes(state, 0x8a, buf, 1);
		if ((buf[0] & 0x04) == 0x04)
			*status |= FE_HAS_SYNC;
		if ((buf[0] & 0x01) == 0x01)
			*status |= FE_HAS_LOCK;
		if ((buf[0] & 0x08) == 0x08)
			*status |= FE_HAS_VITERBI;
		break;
	case VSB_8:
		if ((buf[0] & 0x80) == 0x80)
			*status |= FE_HAS_CARRIER;
		else
			break;
		i2c_read_demod_bytes(state, 0x38, buf, 1);
		if ((buf[0] & 0x02) == 0x00)
			*status |= FE_HAS_SYNC;
		if ((buf[0] & 0x01) == 0x01) {
			*status |= FE_HAS_LOCK;
			*status |= FE_HAS_VITERBI;
		}
		break;
	default:
		printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __FUNCTION__);
	}
	return 0;
}

/* Calculate SNR estimation (scaled by 2^24)

   8-VSB SNR equations from LGDT3302 and LGDT3303 datasheets, QAM
   equations from LGDT3303 datasheet.  VSB is the same between the '02
   and '03, so maybe QAM is too?  Perhaps someone with a newer datasheet
   that has QAM information could verify?

   For 8-VSB: (two ways, take your pick)
   LGDT3302:
     SNR_EQ = 10 * log10(25 * 24^2 / EQ_MSE)
   LGDT3303:
     SNR_EQ = 10 * log10(25 * 32^2 / EQ_MSE)
   LGDT3302 & LGDT3303:
     SNR_PT = 10 * log10(25 * 32^2 / PT_MSE)  (we use this one)
   For 64-QAM:
     SNR    = 10 * log10( 688128   / MSEQAM)
   For 256-QAM:
     SNR    = 10 * log10( 696320   / MSEQAM)

   We re-write the snr equation as:
     SNR * 2^24 = 10*(c - intlog10(MSE))
   Where for 256-QAM, c = log10(696320) * 2^24, and so on. */

static u32 calculate_snr(u32 mse, u32 c)
{
	if (mse == 0) /* No signal */
		return 0;

	mse = intlog10(mse);
	if (mse > c) {
		/* Negative SNR, which is possible, but realisticly the
		demod will lose lock before the signal gets this bad.  The
		API only allows for unsigned values, so just return 0 */
		return 0;
	}
	return 10*(c - mse);
}

static int lgdt3302_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u8 buf[5];	/* read data buffer */
	u32 noise;	/* noise value */
	u32 c;		/* per-modulation SNR calculation constant */

	switch(state->current_modulation) {
	case VSB_8:
		i2c_read_demod_bytes(state, LGDT3302_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
		/* Use Equalizer Mean-Square Error Register */
		/* SNR for ranges from -15.61 to +41.58 */
		noise = ((buf[0] & 7) << 16) | (buf[1] << 8) | buf[2];
		c = 69765745; /* log10(25*24^2)*2^24 */
#else
		/* Use Phase Tracker Mean-Square Error Register */
		/* SNR for ranges from -13.11 to +44.08 */
		noise = ((buf[0] & 7<<3) << 13) | (buf[3] << 8) | buf[4];
		c = 73957994; /* log10(25*32^2)*2^24 */
#endif
		break;
	case QAM_64:
	case QAM_256:
		i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
		noise = ((buf[0] & 3) << 8) | buf[1];
		c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
		/* log10(688128)*2^24 and log10(696320)*2^24 */
		break;
	default:
		printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
		       __FUNCTION__);
		return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
	}

	state->snr = calculate_snr(noise, c);
	*snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */

	dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __FUNCTION__, noise,
		state->snr >> 24, (((state->snr>>8) & 0xffff) * 100) >> 16);

	return 0;
}

static int lgdt3303_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u8 buf[5];	/* read data buffer */
	u32 noise;	/* noise value */
	u32 c;		/* per-modulation SNR calculation constant */

	switch(state->current_modulation) {
	case VSB_8:
		i2c_read_demod_bytes(state, LGDT3303_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
		/* Use Equalizer Mean-Square Error Register */
		/* SNR for ranges from -16.12 to +44.08 */
		noise = ((buf[0] & 0x78) << 13) | (buf[1] << 8) | buf[2];
		c = 73957994; /* log10(25*32^2)*2^24 */
#else
		/* Use Phase Tracker Mean-Square Error Register */
		/* SNR for ranges from -13.11 to +44.08 */
		noise = ((buf[0] & 7) << 16) | (buf[3] << 8) | buf[4];
		c = 73957994; /* log10(25*32^2)*2^24 */
#endif
		break;
	case QAM_64:
	case QAM_256:
		i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
		noise = (buf[0] << 8) | buf[1];
		c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
		/* log10(688128)*2^24 and log10(696320)*2^24 */
		break;
	default:
		printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
		       __FUNCTION__);
		return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
	}

	state->snr = calculate_snr(noise, c);
	*snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */

	dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __FUNCTION__, noise,
		state->snr >> 24, (((state->snr >> 8) & 0xffff) * 100) >> 16);

	return 0;
}

static int lgdt330x_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
	/* Calculate Strength from SNR up to 35dB */
	/* Even though the SNR can go higher than 35dB, there is some comfort */
	/* factor in having a range of strong signals that can show at 100%   */
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u16 snr;
	int ret;

	ret = fe->ops.read_snr(fe, &snr);
	if (ret != 0)
		return ret;
	/* Rather than use the 8.8 value snr, use state->snr which is 8.24 */
	/* scale the range 0 - 35*2^24 into 0 - 65535 */
	if (state->snr >= 8960 * 0x10000)
		*strength = 0xffff;
	else
		*strength = state->snr / 8960;

	return 0;
}

static int lgdt330x_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fe_tune_settings)
{
	/* I have no idea about this - it may not be needed */
	fe_tune_settings->min_delay_ms = 500;
	fe_tune_settings->step_size = 0;
	fe_tune_settings->max_drift = 0;
	return 0;
}

static void lgdt330x_release(struct dvb_frontend* fe)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops lgdt3302_ops;
static struct dvb_frontend_ops lgdt3303_ops;

struct dvb_frontend* lgdt330x_attach(const struct lgdt330x_config* config,
				     struct i2c_adapter* i2c)
{
	struct lgdt330x_state* state = NULL;
	u8 buf[1];

	/* Allocate memory for the internal state */
	state = kzalloc(sizeof(struct lgdt330x_state), GFP_KERNEL);
	if (state == NULL)
		goto error;

	/* Setup the state */
	state->config = config;
	state->i2c = i2c;

	/* Create dvb_frontend */
	switch (config->demod_chip) {
	case LGDT3302:
		memcpy(&state->frontend.ops, &lgdt3302_ops, sizeof(struct dvb_frontend_ops));
		break;
	case LGDT3303:
		memcpy(&state->frontend.ops, &lgdt3303_ops, sizeof(struct dvb_frontend_ops));
		break;
	default:
		goto error;
	}
	state->frontend.demodulator_priv = state;

	/* Verify communication with demod chip */
	if (i2c_read_demod_bytes(state, 2, buf, 1))
		goto error;

	state->current_frequency = -1;
	state->current_modulation = -1;

	return &state->frontend;

error:
	kfree(state);
	dprintk("%s: ERROR\n",__FUNCTION__);
	return NULL;
}

static struct dvb_frontend_ops lgdt3302_ops = {
	.info = {
		.name= "LG Electronics LGDT3302 VSB/QAM Frontend",
		.type = FE_ATSC,
		.frequency_min= 54000000,
		.frequency_max= 858000000,
		.frequency_stepsize= 62500,
		.symbol_rate_min    = 5056941,	/* QAM 64 */
		.symbol_rate_max    = 10762000,	/* VSB 8  */
		.caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
	},
	.init                 = lgdt330x_init,
	.set_frontend         = lgdt330x_set_parameters,
	.get_frontend         = lgdt330x_get_frontend,
	.get_tune_settings    = lgdt330x_get_tune_settings,
	.read_status          = lgdt3302_read_status,
	.read_ber             = lgdt330x_read_ber,
	.read_signal_strength = lgdt330x_read_signal_strength,
	.read_snr             = lgdt3302_read_snr,
	.read_ucblocks        = lgdt330x_read_ucblocks,
	.release              = lgdt330x_release,
};

static struct dvb_frontend_ops lgdt3303_ops = {
	.info = {
		.name= "LG Electronics LGDT3303 VSB/QAM Frontend",
		.type = FE_ATSC,
		.frequency_min= 54000000,
		.frequency_max= 858000000,
		.frequency_stepsize= 62500,
		.symbol_rate_min    = 5056941,	/* QAM 64 */
		.symbol_rate_max    = 10762000,	/* VSB 8  */
		.caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
	},
	.init                 = lgdt330x_init,
	.set_frontend         = lgdt330x_set_parameters,
	.get_frontend         = lgdt330x_get_frontend,
	.get_tune_settings    = lgdt330x_get_tune_settings,
	.read_status          = lgdt3303_read_status,
	.read_ber             = lgdt330x_read_ber,
	.read_signal_strength = lgdt330x_read_signal_strength,
	.read_snr             = lgdt3303_read_snr,
	.read_ucblocks        = lgdt330x_read_ucblocks,
	.release              = lgdt330x_release,
};

MODULE_DESCRIPTION("LGDT330X (ATSC 8VSB & ITU-T J.83 AnnexB 64/256 QAM) Demodulator Driver");
MODULE_AUTHOR("Wilson Michaels");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(lgdt330x_attach);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */