or51132.c

linux内核源码

	int clock_mode;

	/* Upload new firmware only if we need a different one */
	if (modulation_fw_class(state->current_modulation) !=
	    modulation_fw_class(param->u.vsb.modulation)) {
		switch(modulation_fw_class(param->u.vsb.modulation)) {
		case MOD_FWCLASS_VSB:
			dprintk("set_parameters VSB MODE\n");
			fwname = OR51132_VSB_FIRMWARE;

			/* Set non-punctured clock for VSB */
			clock_mode = 0;
			break;
		case MOD_FWCLASS_QAM:
			dprintk("set_parameters QAM MODE\n");
			fwname = OR51132_QAM_FIRMWARE;

			/* Set punctured clock for QAM */
			clock_mode = 1;
			break;
		default:
			printk("or51132: Modulation type(%d) UNSUPPORTED\n",
			       param->u.vsb.modulation);
			return -1;
		}
		printk("or51132: Waiting for firmware upload(%s)...\n",
		       fwname);
		ret = request_firmware(&fw, fwname, &state->i2c->dev);
		if (ret) {
			printk(KERN_WARNING "or51132: No firmware up"
			       "loaded(timeout or file not found?)\n");
			return ret;
		}
		ret = or51132_load_firmware(fe, fw);
		release_firmware(fw);
		if (ret) {
			printk(KERN_WARNING "or51132: Writing firmware to "
			       "device failed!\n");
			return ret;
		}
		printk("or51132: Firmware upload complete.\n");
		state->config->set_ts_params(fe, clock_mode);
	}
	/* Change only if we are actually changing the modulation */
	if (state->current_modulation != param->u.vsb.modulation) {
		state->current_modulation = param->u.vsb.modulation;
		or51132_setmode(fe);
	}

	if (fe->ops.tuner_ops.set_params) {
		fe->ops.tuner_ops.set_params(fe, param);
		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
	}

	/* Set to current mode */
	or51132_setmode(fe);

	/* Update current frequency */
	state->current_frequency = param->frequency;
	return 0;
}

static int or51132_get_parameters(struct dvb_frontend* fe,
				  struct dvb_frontend_parameters *param)
{
	struct or51132_state* state = fe->demodulator_priv;
	int status;
	int retry = 1;

start:
	/* Receiver Status */
	if ((status = or51132_readreg(state, 0x00)) < 0) {
		printk(KERN_WARNING "or51132: get_parameters: error reading receiver status\n");
		return -EREMOTEIO;
	}
	switch(status&0xff) {
		case 0x06: param->u.vsb.modulation = VSB_8; break;
		case 0x43: param->u.vsb.modulation = QAM_64; break;
		case 0x45: param->u.vsb.modulation = QAM_256; break;
		default:
			if (retry--) goto start;
			printk(KERN_WARNING "or51132: unknown status 0x%02x\n",
			       status&0xff);
			return -EREMOTEIO;
	}

	/* FIXME: Read frequency from frontend, take AFC into account */
	param->frequency = state->current_frequency;

	/* FIXME: How to read inversion setting? Receiver 6 register? */
	param->inversion = INVERSION_AUTO;

	return 0;
}

static int or51132_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct or51132_state* state = fe->demodulator_priv;
	int reg;

	/* Receiver Status */
	if ((reg = or51132_readreg(state, 0x00)) < 0) {
		printk(KERN_WARNING "or51132: read_status: error reading receiver status: %d\n", reg);
		*status = 0;
		return -EREMOTEIO;
	}
	dprintk("%s: read_status %04x\n", __FUNCTION__, reg);

	if (reg & 0x0100) /* Receiver Lock */
		*status = FE_HAS_SIGNAL|FE_HAS_CARRIER|FE_HAS_VITERBI|
			  FE_HAS_SYNC|FE_HAS_LOCK;
	else
		*status = 0;
	return 0;
}

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

   8-VSB SNR and QAM equations from Oren datasheets

   For 8-VSB:
     SNR[dB] = 10 * log10(897152044.8282 / MSE^2 ) - K

     Where K = 0 if NTSC rejection filter is OFF; and
	   K = 3 if NTSC rejection filter is ON

   For QAM64:
     SNR[dB] = 10 * log10(897152044.8282 / MSE^2 )

   For QAM256:
     SNR[dB] = 10 * log10(907832426.314266  / MSE^2 )

   We re-write the snr equation as:
     SNR * 2^24 = 10*(c - 2*intlog10(MSE))
   Where for QAM256, c = log10(907832426.314266) * 2^24
   and for 8-VSB and QAM64, c = log10(897152044.8282) * 2^24 */

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

	mse = 2*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 or51132_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct or51132_state* state = fe->demodulator_priv;
	int noise, reg;
	u32 c, usK = 0;
	int retry = 1;

start:
	/* SNR after Equalizer */
	noise = or51132_readreg(state, 0x02);
	if (noise < 0) {
		printk(KERN_WARNING "or51132: read_snr: error reading equalizer\n");
		return -EREMOTEIO;
	}
	dprintk("read_snr noise (%d)\n", noise);

	/* Read status, contains modulation type for QAM_AUTO and
	   NTSC filter for VSB */
	reg = or51132_readreg(state, 0x00);
	if (reg < 0) {
		printk(KERN_WARNING "or51132: read_snr: error reading receiver status\n");
		return -EREMOTEIO;
	}

	switch (reg&0xff) {
	case 0x06:
		if (reg & 0x1000) usK = 3 << 24;
		/* Fall through to QAM64 case */
	case 0x43:
		c = 150204167;
		break;
	case 0x45:
		c = 150290396;
		break;
	default:
		printk(KERN_WARNING "or51132: unknown status 0x%02x\n", reg&0xff);
		if (retry--) goto start;
		return -EREMOTEIO;
	}
	dprintk("%s: modulation %02x, NTSC rej O%s\n", __FUNCTION__,
		reg&0xff, reg&0x1000?"n":"ff");

	/* Calculate SNR using noise, c, and NTSC rejection correction */
	state->snr = calculate_snr(noise, c) - usK;
	*snr = (state->snr) >> 16;

	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 or51132_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 or51132_state* state = (struct or51132_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 or51132_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fe_tune_settings)
{
	fe_tune_settings->min_delay_ms = 500;
	fe_tune_settings->step_size = 0;
	fe_tune_settings->max_drift = 0;

	return 0;
}

static void or51132_release(struct dvb_frontend* fe)
{
	struct or51132_state* state = fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops or51132_ops;

struct dvb_frontend* or51132_attach(const struct or51132_config* config,
				    struct i2c_adapter* i2c)
{
	struct or51132_state* state = NULL;

	/* Allocate memory for the internal state */
	state = kmalloc(sizeof(struct or51132_state), GFP_KERNEL);
	if (state == NULL)
		goto error;

	/* Setup the state */
	state->config = config;
	state->i2c = i2c;
	state->current_frequency = -1;
	state->current_modulation = -1;

	/* Create dvb_frontend */
	memcpy(&state->frontend.ops, &or51132_ops, sizeof(struct dvb_frontend_ops));
	state->frontend.demodulator_priv = state;
	return &state->frontend;

error:
	kfree(state);
	return NULL;
}

static struct dvb_frontend_ops or51132_ops = {

	.info = {
		.name			= "Oren OR51132 VSB/QAM Frontend",
		.type			= FE_ATSC,
		.frequency_min		= 44000000,
		.frequency_max		= 958000000,
		.frequency_stepsize	= 166666,
		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
			FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
			FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_QAM_AUTO |
			FE_CAN_8VSB
	},

	.release = or51132_release,

	.init = or51132_init,
	.sleep = or51132_sleep,

	.set_frontend = or51132_set_parameters,
	.get_frontend = or51132_get_parameters,
	.get_tune_settings = or51132_get_tune_settings,

	.read_status = or51132_read_status,
	.read_ber = or51132_read_ber,
	.read_signal_strength = or51132_read_signal_strength,
	.read_snr = or51132_read_snr,
	.read_ucblocks = or51132_read_ucblocks,
};

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");

MODULE_DESCRIPTION("OR51132 ATSC [pcHDTV HD-3000] (8VSB & ITU J83 AnnexB FEC QAM64/256) Demodulator Driver");
MODULE_AUTHOR("Kirk Lapray");
MODULE_AUTHOR("Trent Piepho");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(or51132_attach);

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