162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later
262306a36Sopenharmony_ci/*
362306a36Sopenharmony_ci * NXP TDA18218HN silicon tuner driver
462306a36Sopenharmony_ci *
562306a36Sopenharmony_ci * Copyright (C) 2010 Antti Palosaari <crope@iki.fi>
662306a36Sopenharmony_ci */
762306a36Sopenharmony_ci
862306a36Sopenharmony_ci#include "tda18218_priv.h"
962306a36Sopenharmony_ci
1062306a36Sopenharmony_ci/* Max transfer size done by I2C transfer functions */
1162306a36Sopenharmony_ci#define MAX_XFER_SIZE  64
1262306a36Sopenharmony_ci
1362306a36Sopenharmony_ci/* write multiple registers */
1462306a36Sopenharmony_cistatic int tda18218_wr_regs(struct tda18218_priv *priv, u8 reg, u8 *val, u8 len)
1562306a36Sopenharmony_ci{
1662306a36Sopenharmony_ci	int ret = 0, len2, remaining;
1762306a36Sopenharmony_ci	u8 buf[MAX_XFER_SIZE];
1862306a36Sopenharmony_ci	struct i2c_msg msg[1] = {
1962306a36Sopenharmony_ci		{
2062306a36Sopenharmony_ci			.addr = priv->cfg->i2c_address,
2162306a36Sopenharmony_ci			.flags = 0,
2262306a36Sopenharmony_ci			.buf = buf,
2362306a36Sopenharmony_ci		}
2462306a36Sopenharmony_ci	};
2562306a36Sopenharmony_ci
2662306a36Sopenharmony_ci	if (1 + len > sizeof(buf)) {
2762306a36Sopenharmony_ci		dev_warn(&priv->i2c->dev,
2862306a36Sopenharmony_ci			 "%s: i2c wr reg=%04x: len=%d is too big!\n",
2962306a36Sopenharmony_ci			 KBUILD_MODNAME, reg, len);
3062306a36Sopenharmony_ci		return -EINVAL;
3162306a36Sopenharmony_ci	}
3262306a36Sopenharmony_ci
3362306a36Sopenharmony_ci	for (remaining = len; remaining > 0;
3462306a36Sopenharmony_ci			remaining -= (priv->cfg->i2c_wr_max - 1)) {
3562306a36Sopenharmony_ci		len2 = remaining;
3662306a36Sopenharmony_ci		if (len2 > (priv->cfg->i2c_wr_max - 1))
3762306a36Sopenharmony_ci			len2 = (priv->cfg->i2c_wr_max - 1);
3862306a36Sopenharmony_ci
3962306a36Sopenharmony_ci		msg[0].len = 1 + len2;
4062306a36Sopenharmony_ci		buf[0] = reg + len - remaining;
4162306a36Sopenharmony_ci		memcpy(&buf[1], &val[len - remaining], len2);
4262306a36Sopenharmony_ci
4362306a36Sopenharmony_ci		ret = i2c_transfer(priv->i2c, msg, 1);
4462306a36Sopenharmony_ci		if (ret != 1)
4562306a36Sopenharmony_ci			break;
4662306a36Sopenharmony_ci	}
4762306a36Sopenharmony_ci
4862306a36Sopenharmony_ci	if (ret == 1) {
4962306a36Sopenharmony_ci		ret = 0;
5062306a36Sopenharmony_ci	} else {
5162306a36Sopenharmony_ci		dev_warn(&priv->i2c->dev, "%s: i2c wr failed=%d reg=%02x " \
5262306a36Sopenharmony_ci				"len=%d\n", KBUILD_MODNAME, ret, reg, len);
5362306a36Sopenharmony_ci		ret = -EREMOTEIO;
5462306a36Sopenharmony_ci	}
5562306a36Sopenharmony_ci
5662306a36Sopenharmony_ci	return ret;
5762306a36Sopenharmony_ci}
5862306a36Sopenharmony_ci
5962306a36Sopenharmony_ci/* read multiple registers */
6062306a36Sopenharmony_cistatic int tda18218_rd_regs(struct tda18218_priv *priv, u8 reg, u8 *val, u8 len)
6162306a36Sopenharmony_ci{
6262306a36Sopenharmony_ci	int ret;
6362306a36Sopenharmony_ci	u8 buf[MAX_XFER_SIZE]; /* we must start read always from reg 0x00 */
6462306a36Sopenharmony_ci	struct i2c_msg msg[2] = {
6562306a36Sopenharmony_ci		{
6662306a36Sopenharmony_ci			.addr = priv->cfg->i2c_address,
6762306a36Sopenharmony_ci			.flags = 0,
6862306a36Sopenharmony_ci			.len = 1,
6962306a36Sopenharmony_ci			.buf = "\x00",
7062306a36Sopenharmony_ci		}, {
7162306a36Sopenharmony_ci			.addr = priv->cfg->i2c_address,
7262306a36Sopenharmony_ci			.flags = I2C_M_RD,
7362306a36Sopenharmony_ci			.len = reg + len,
7462306a36Sopenharmony_ci			.buf = buf,
7562306a36Sopenharmony_ci		}
7662306a36Sopenharmony_ci	};
7762306a36Sopenharmony_ci
7862306a36Sopenharmony_ci	if (reg + len > sizeof(buf)) {
7962306a36Sopenharmony_ci		dev_warn(&priv->i2c->dev,
8062306a36Sopenharmony_ci			 "%s: i2c wr reg=%04x: len=%d is too big!\n",
8162306a36Sopenharmony_ci			 KBUILD_MODNAME, reg, len);
8262306a36Sopenharmony_ci		return -EINVAL;
8362306a36Sopenharmony_ci	}
8462306a36Sopenharmony_ci
8562306a36Sopenharmony_ci	ret = i2c_transfer(priv->i2c, msg, 2);
8662306a36Sopenharmony_ci	if (ret == 2) {
8762306a36Sopenharmony_ci		memcpy(val, &buf[reg], len);
8862306a36Sopenharmony_ci		ret = 0;
8962306a36Sopenharmony_ci	} else {
9062306a36Sopenharmony_ci		dev_warn(&priv->i2c->dev, "%s: i2c rd failed=%d reg=%02x " \
9162306a36Sopenharmony_ci				"len=%d\n", KBUILD_MODNAME, ret, reg, len);
9262306a36Sopenharmony_ci		ret = -EREMOTEIO;
9362306a36Sopenharmony_ci	}
9462306a36Sopenharmony_ci
9562306a36Sopenharmony_ci	return ret;
9662306a36Sopenharmony_ci}
9762306a36Sopenharmony_ci
9862306a36Sopenharmony_ci/* write single register */
9962306a36Sopenharmony_cistatic int tda18218_wr_reg(struct tda18218_priv *priv, u8 reg, u8 val)
10062306a36Sopenharmony_ci{
10162306a36Sopenharmony_ci	return tda18218_wr_regs(priv, reg, &val, 1);
10262306a36Sopenharmony_ci}
10362306a36Sopenharmony_ci
10462306a36Sopenharmony_ci/* read single register */
10562306a36Sopenharmony_ci
10662306a36Sopenharmony_cistatic int tda18218_rd_reg(struct tda18218_priv *priv, u8 reg, u8 *val)
10762306a36Sopenharmony_ci{
10862306a36Sopenharmony_ci	return tda18218_rd_regs(priv, reg, val, 1);
10962306a36Sopenharmony_ci}
11062306a36Sopenharmony_ci
11162306a36Sopenharmony_cistatic int tda18218_set_params(struct dvb_frontend *fe)
11262306a36Sopenharmony_ci{
11362306a36Sopenharmony_ci	struct tda18218_priv *priv = fe->tuner_priv;
11462306a36Sopenharmony_ci	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
11562306a36Sopenharmony_ci	u32 bw = c->bandwidth_hz;
11662306a36Sopenharmony_ci	int ret;
11762306a36Sopenharmony_ci	u8 buf[3], i, BP_Filter, LP_Fc;
11862306a36Sopenharmony_ci	u32 LO_Frac;
11962306a36Sopenharmony_ci	/* TODO: find out correct AGC algorithm */
12062306a36Sopenharmony_ci	u8 agc[][2] = {
12162306a36Sopenharmony_ci		{ R20_AGC11, 0x60 },
12262306a36Sopenharmony_ci		{ R23_AGC21, 0x02 },
12362306a36Sopenharmony_ci		{ R20_AGC11, 0xa0 },
12462306a36Sopenharmony_ci		{ R23_AGC21, 0x09 },
12562306a36Sopenharmony_ci		{ R20_AGC11, 0xe0 },
12662306a36Sopenharmony_ci		{ R23_AGC21, 0x0c },
12762306a36Sopenharmony_ci		{ R20_AGC11, 0x40 },
12862306a36Sopenharmony_ci		{ R23_AGC21, 0x01 },
12962306a36Sopenharmony_ci		{ R20_AGC11, 0x80 },
13062306a36Sopenharmony_ci		{ R23_AGC21, 0x08 },
13162306a36Sopenharmony_ci		{ R20_AGC11, 0xc0 },
13262306a36Sopenharmony_ci		{ R23_AGC21, 0x0b },
13362306a36Sopenharmony_ci		{ R24_AGC22, 0x1c },
13462306a36Sopenharmony_ci		{ R24_AGC22, 0x0c },
13562306a36Sopenharmony_ci	};
13662306a36Sopenharmony_ci
13762306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
13862306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */
13962306a36Sopenharmony_ci
14062306a36Sopenharmony_ci	/* low-pass filter cut-off frequency */
14162306a36Sopenharmony_ci	if (bw <= 6000000) {
14262306a36Sopenharmony_ci		LP_Fc = 0;
14362306a36Sopenharmony_ci		priv->if_frequency = 3000000;
14462306a36Sopenharmony_ci	} else if (bw <= 7000000) {
14562306a36Sopenharmony_ci		LP_Fc = 1;
14662306a36Sopenharmony_ci		priv->if_frequency = 3500000;
14762306a36Sopenharmony_ci	} else {
14862306a36Sopenharmony_ci		LP_Fc = 2;
14962306a36Sopenharmony_ci		priv->if_frequency = 4000000;
15062306a36Sopenharmony_ci	}
15162306a36Sopenharmony_ci
15262306a36Sopenharmony_ci	LO_Frac = c->frequency + priv->if_frequency;
15362306a36Sopenharmony_ci
15462306a36Sopenharmony_ci	/* band-pass filter */
15562306a36Sopenharmony_ci	if (LO_Frac < 188000000)
15662306a36Sopenharmony_ci		BP_Filter = 3;
15762306a36Sopenharmony_ci	else if (LO_Frac < 253000000)
15862306a36Sopenharmony_ci		BP_Filter = 4;
15962306a36Sopenharmony_ci	else if (LO_Frac < 343000000)
16062306a36Sopenharmony_ci		BP_Filter = 5;
16162306a36Sopenharmony_ci	else
16262306a36Sopenharmony_ci		BP_Filter = 6;
16362306a36Sopenharmony_ci
16462306a36Sopenharmony_ci	buf[0] = (priv->regs[R1A_IF1] & ~7) | BP_Filter; /* BP_Filter */
16562306a36Sopenharmony_ci	buf[1] = (priv->regs[R1B_IF2] & ~3) | LP_Fc; /* LP_Fc */
16662306a36Sopenharmony_ci	buf[2] = priv->regs[R1C_AGC2B];
16762306a36Sopenharmony_ci	ret = tda18218_wr_regs(priv, R1A_IF1, buf, 3);
16862306a36Sopenharmony_ci	if (ret)
16962306a36Sopenharmony_ci		goto error;
17062306a36Sopenharmony_ci
17162306a36Sopenharmony_ci	buf[0] = (LO_Frac / 1000) >> 12; /* LO_Frac_0 */
17262306a36Sopenharmony_ci	buf[1] = (LO_Frac / 1000) >> 4; /* LO_Frac_1 */
17362306a36Sopenharmony_ci	buf[2] = (LO_Frac / 1000) << 4 |
17462306a36Sopenharmony_ci		(priv->regs[R0C_MD5] & 0x0f); /* LO_Frac_2 */
17562306a36Sopenharmony_ci	ret = tda18218_wr_regs(priv, R0A_MD3, buf, 3);
17662306a36Sopenharmony_ci	if (ret)
17762306a36Sopenharmony_ci		goto error;
17862306a36Sopenharmony_ci
17962306a36Sopenharmony_ci	buf[0] = priv->regs[R0F_MD8] | (1 << 6); /* Freq_prog_Start */
18062306a36Sopenharmony_ci	ret = tda18218_wr_regs(priv, R0F_MD8, buf, 1);
18162306a36Sopenharmony_ci	if (ret)
18262306a36Sopenharmony_ci		goto error;
18362306a36Sopenharmony_ci
18462306a36Sopenharmony_ci	buf[0] = priv->regs[R0F_MD8] & ~(1 << 6); /* Freq_prog_Start */
18562306a36Sopenharmony_ci	ret = tda18218_wr_regs(priv, R0F_MD8, buf, 1);
18662306a36Sopenharmony_ci	if (ret)
18762306a36Sopenharmony_ci		goto error;
18862306a36Sopenharmony_ci
18962306a36Sopenharmony_ci	/* trigger AGC */
19062306a36Sopenharmony_ci	for (i = 0; i < ARRAY_SIZE(agc); i++) {
19162306a36Sopenharmony_ci		ret = tda18218_wr_reg(priv, agc[i][0], agc[i][1]);
19262306a36Sopenharmony_ci		if (ret)
19362306a36Sopenharmony_ci			goto error;
19462306a36Sopenharmony_ci	}
19562306a36Sopenharmony_ci
19662306a36Sopenharmony_cierror:
19762306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
19862306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
19962306a36Sopenharmony_ci
20062306a36Sopenharmony_ci	if (ret)
20162306a36Sopenharmony_ci		dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
20262306a36Sopenharmony_ci
20362306a36Sopenharmony_ci	return ret;
20462306a36Sopenharmony_ci}
20562306a36Sopenharmony_ci
20662306a36Sopenharmony_cistatic int tda18218_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
20762306a36Sopenharmony_ci{
20862306a36Sopenharmony_ci	struct tda18218_priv *priv = fe->tuner_priv;
20962306a36Sopenharmony_ci	*frequency = priv->if_frequency;
21062306a36Sopenharmony_ci	dev_dbg(&priv->i2c->dev, "%s: if_frequency=%d\n", __func__, *frequency);
21162306a36Sopenharmony_ci	return 0;
21262306a36Sopenharmony_ci}
21362306a36Sopenharmony_ci
21462306a36Sopenharmony_cistatic int tda18218_sleep(struct dvb_frontend *fe)
21562306a36Sopenharmony_ci{
21662306a36Sopenharmony_ci	struct tda18218_priv *priv = fe->tuner_priv;
21762306a36Sopenharmony_ci	int ret;
21862306a36Sopenharmony_ci
21962306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
22062306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */
22162306a36Sopenharmony_ci
22262306a36Sopenharmony_ci	/* standby */
22362306a36Sopenharmony_ci	ret = tda18218_wr_reg(priv, R17_PD1, priv->regs[R17_PD1] | (1 << 0));
22462306a36Sopenharmony_ci
22562306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
22662306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
22762306a36Sopenharmony_ci
22862306a36Sopenharmony_ci	if (ret)
22962306a36Sopenharmony_ci		dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
23062306a36Sopenharmony_ci
23162306a36Sopenharmony_ci	return ret;
23262306a36Sopenharmony_ci}
23362306a36Sopenharmony_ci
23462306a36Sopenharmony_cistatic int tda18218_init(struct dvb_frontend *fe)
23562306a36Sopenharmony_ci{
23662306a36Sopenharmony_ci	struct tda18218_priv *priv = fe->tuner_priv;
23762306a36Sopenharmony_ci	int ret;
23862306a36Sopenharmony_ci
23962306a36Sopenharmony_ci	/* TODO: calibrations */
24062306a36Sopenharmony_ci
24162306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
24262306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */
24362306a36Sopenharmony_ci
24462306a36Sopenharmony_ci	ret = tda18218_wr_regs(priv, R00_ID, priv->regs, TDA18218_NUM_REGS);
24562306a36Sopenharmony_ci
24662306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
24762306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
24862306a36Sopenharmony_ci
24962306a36Sopenharmony_ci	if (ret)
25062306a36Sopenharmony_ci		dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
25162306a36Sopenharmony_ci
25262306a36Sopenharmony_ci	return ret;
25362306a36Sopenharmony_ci}
25462306a36Sopenharmony_ci
25562306a36Sopenharmony_cistatic void tda18218_release(struct dvb_frontend *fe)
25662306a36Sopenharmony_ci{
25762306a36Sopenharmony_ci	kfree(fe->tuner_priv);
25862306a36Sopenharmony_ci	fe->tuner_priv = NULL;
25962306a36Sopenharmony_ci}
26062306a36Sopenharmony_ci
26162306a36Sopenharmony_cistatic const struct dvb_tuner_ops tda18218_tuner_ops = {
26262306a36Sopenharmony_ci	.info = {
26362306a36Sopenharmony_ci		.name              = "NXP TDA18218",
26462306a36Sopenharmony_ci
26562306a36Sopenharmony_ci		.frequency_min_hz  = 174 * MHz,
26662306a36Sopenharmony_ci		.frequency_max_hz  = 864 * MHz,
26762306a36Sopenharmony_ci		.frequency_step_hz =   1 * kHz,
26862306a36Sopenharmony_ci	},
26962306a36Sopenharmony_ci
27062306a36Sopenharmony_ci	.release       = tda18218_release,
27162306a36Sopenharmony_ci	.init          = tda18218_init,
27262306a36Sopenharmony_ci	.sleep         = tda18218_sleep,
27362306a36Sopenharmony_ci
27462306a36Sopenharmony_ci	.set_params    = tda18218_set_params,
27562306a36Sopenharmony_ci
27662306a36Sopenharmony_ci	.get_if_frequency = tda18218_get_if_frequency,
27762306a36Sopenharmony_ci};
27862306a36Sopenharmony_ci
27962306a36Sopenharmony_cistruct dvb_frontend *tda18218_attach(struct dvb_frontend *fe,
28062306a36Sopenharmony_ci	struct i2c_adapter *i2c, struct tda18218_config *cfg)
28162306a36Sopenharmony_ci{
28262306a36Sopenharmony_ci	struct tda18218_priv *priv = NULL;
28362306a36Sopenharmony_ci	u8 val;
28462306a36Sopenharmony_ci	int ret;
28562306a36Sopenharmony_ci	/* chip default registers values */
28662306a36Sopenharmony_ci	static u8 def_regs[] = {
28762306a36Sopenharmony_ci		0xc0, 0x88, 0x00, 0x8e, 0x03, 0x00, 0x00, 0xd0, 0x00, 0x40,
28862306a36Sopenharmony_ci		0x00, 0x00, 0x07, 0xff, 0x84, 0x09, 0x00, 0x13, 0x00, 0x00,
28962306a36Sopenharmony_ci		0x01, 0x84, 0x09, 0xf0, 0x19, 0x0a, 0x8e, 0x69, 0x98, 0x01,
29062306a36Sopenharmony_ci		0x00, 0x58, 0x10, 0x40, 0x8c, 0x00, 0x0c, 0x48, 0x85, 0xc9,
29162306a36Sopenharmony_ci		0xa7, 0x00, 0x00, 0x00, 0x30, 0x81, 0x80, 0x00, 0x39, 0x00,
29262306a36Sopenharmony_ci		0x8a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf6, 0xf6
29362306a36Sopenharmony_ci	};
29462306a36Sopenharmony_ci
29562306a36Sopenharmony_ci	priv = kzalloc(sizeof(struct tda18218_priv), GFP_KERNEL);
29662306a36Sopenharmony_ci	if (priv == NULL)
29762306a36Sopenharmony_ci		return NULL;
29862306a36Sopenharmony_ci
29962306a36Sopenharmony_ci	priv->cfg = cfg;
30062306a36Sopenharmony_ci	priv->i2c = i2c;
30162306a36Sopenharmony_ci	fe->tuner_priv = priv;
30262306a36Sopenharmony_ci
30362306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
30462306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */
30562306a36Sopenharmony_ci
30662306a36Sopenharmony_ci	/* check if the tuner is there */
30762306a36Sopenharmony_ci	ret = tda18218_rd_reg(priv, R00_ID, &val);
30862306a36Sopenharmony_ci	if (!ret)
30962306a36Sopenharmony_ci		dev_dbg(&priv->i2c->dev, "%s: chip id=%02x\n", __func__, val);
31062306a36Sopenharmony_ci	if (ret || val != def_regs[R00_ID]) {
31162306a36Sopenharmony_ci		kfree(priv);
31262306a36Sopenharmony_ci		return NULL;
31362306a36Sopenharmony_ci	}
31462306a36Sopenharmony_ci
31562306a36Sopenharmony_ci	dev_info(&priv->i2c->dev,
31662306a36Sopenharmony_ci			"%s: NXP TDA18218HN successfully identified\n",
31762306a36Sopenharmony_ci			KBUILD_MODNAME);
31862306a36Sopenharmony_ci
31962306a36Sopenharmony_ci	memcpy(&fe->ops.tuner_ops, &tda18218_tuner_ops,
32062306a36Sopenharmony_ci		sizeof(struct dvb_tuner_ops));
32162306a36Sopenharmony_ci	memcpy(priv->regs, def_regs, sizeof(def_regs));
32262306a36Sopenharmony_ci
32362306a36Sopenharmony_ci	/* loop-through enabled chip default register values */
32462306a36Sopenharmony_ci	if (priv->cfg->loop_through) {
32562306a36Sopenharmony_ci		priv->regs[R17_PD1] = 0xb0;
32662306a36Sopenharmony_ci		priv->regs[R18_PD2] = 0x59;
32762306a36Sopenharmony_ci	}
32862306a36Sopenharmony_ci
32962306a36Sopenharmony_ci	/* standby */
33062306a36Sopenharmony_ci	ret = tda18218_wr_reg(priv, R17_PD1, priv->regs[R17_PD1] | (1 << 0));
33162306a36Sopenharmony_ci	if (ret)
33262306a36Sopenharmony_ci		dev_dbg(&priv->i2c->dev, "%s: failed=%d\n", __func__, ret);
33362306a36Sopenharmony_ci
33462306a36Sopenharmony_ci	if (fe->ops.i2c_gate_ctrl)
33562306a36Sopenharmony_ci		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
33662306a36Sopenharmony_ci
33762306a36Sopenharmony_ci	return fe;
33862306a36Sopenharmony_ci}
33962306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(tda18218_attach);
34062306a36Sopenharmony_ci
34162306a36Sopenharmony_ciMODULE_DESCRIPTION("NXP TDA18218HN silicon tuner driver");
34262306a36Sopenharmony_ciMODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
34362306a36Sopenharmony_ciMODULE_LICENSE("GPL");
344