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Commit e350d44f authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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[media] tda18271: allow restricting max out to 4 bytes 



By default, tda18271 tries to optimize I2C bus by updating all registers
at the same time. Unfortunately, some devices doesn't support it.

The current logic has a problem when small_i2c is equal to 8, since there
are some transfers using 11 + 1 bytes.

Fix the problem by enforcing the max size at the right place, and allows
reducing it to max = 3 + 1.

Acked-by: default avatarMichael Krufky <mkrufky@kernellabs.com>
Acked-by: default avatarSri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 78bb6df6

drivers/media/common/tuners/tda18271-common.c

+34 −25
Original line number Diff line number Diff line
@@ -193,20 +193,46 @@ int tda18271_write_regs(struct dvb_frontend *fe, int idx, int len) 
	unsigned char *regs = priv->tda18271_regs;

	unsigned char buf[TDA18271_NUM_REGS + 1];

	struct i2c_msg msg = { .addr = priv->i2c_props.addr, .flags = 0,

			       .buf = buf, .len = len + 1 };

	int i, ret;

			       .buf = buf };

	int i, ret = 1, max;



	BUG_ON((len == 0) || (idx + len > sizeof(buf)));





	switch (priv->small_i2c) {

	case TDA18271_03_BYTE_CHUNK_INIT:

		max = 3;

		break;

	case TDA18271_08_BYTE_CHUNK_INIT:

		max = 8;

		break;

	case TDA18271_16_BYTE_CHUNK_INIT:

		max = 16;

		break;

	case TDA18271_39_BYTE_CHUNK_INIT:

	default:

		max = 39;

	}



	tda18271_i2c_gate_ctrl(fe, 1);

	while (len) {

		if (max > len)

			max = len;



		buf[0] = idx;

	for (i = 1; i <= len; i++)

		for (i = 1; i <= max; i++)

			buf[i] = regs[idx - 1 + i];



	tda18271_i2c_gate_ctrl(fe, 1);

		msg.len = max + 1;



		/* write registers */

		ret = i2c_transfer(priv->i2c_props.adap, &msg, 1);

		if (ret != 1)

			break;



		idx += max;

		len -= max;

	}

	tda18271_i2c_gate_ctrl(fe, 0);



	if (ret != 1)
@@ -326,24 +352,7 @@ int tda18271_init_regs(struct dvb_frontend *fe) 
	regs[R_EB22] = 0x48;

	regs[R_EB23] = 0xb0;



	switch (priv->small_i2c) {

	case TDA18271_08_BYTE_CHUNK_INIT:

		tda18271_write_regs(fe, 0x00, 0x08);

		tda18271_write_regs(fe, 0x08, 0x08);

		tda18271_write_regs(fe, 0x10, 0x08);

		tda18271_write_regs(fe, 0x18, 0x08);

		tda18271_write_regs(fe, 0x20, 0x07);

		break;

	case TDA18271_16_BYTE_CHUNK_INIT:

		tda18271_write_regs(fe, 0x00, 0x10);

		tda18271_write_regs(fe, 0x10, 0x10);

		tda18271_write_regs(fe, 0x20, 0x07);

		break;

	case TDA18271_39_BYTE_CHUNK_INIT:

	default:

	tda18271_write_regs(fe, 0x00, TDA18271_NUM_REGS);

		break;

	}



	/* setup agc1 gain */

	regs[R_EB17] = 0x00;

drivers/media/common/tuners/tda18271.h

+3 −2
Original line number Diff line number Diff line
@@ -80,8 +80,9 @@ enum tda18271_output_options { 


enum tda18271_small_i2c {

	TDA18271_39_BYTE_CHUNK_INIT = 0,

	TDA18271_16_BYTE_CHUNK_INIT = 1,

	TDA18271_08_BYTE_CHUNK_INIT = 2,

	TDA18271_16_BYTE_CHUNK_INIT = 16,

	TDA18271_08_BYTE_CHUNK_INIT = 8,

	TDA18271_03_BYTE_CHUNK_INIT = 3,

};



struct tda18271_config {

drivers/media/video/tuner-core.c

+1 −1
Original line number Diff line number Diff line
@@ -427,7 +427,7 @@ static void set_type(struct i2c_client *c, unsigned int type, 
	{

		struct tda18271_config cfg = {

			.config = t->config,

			.small_i2c = TDA18271_08_BYTE_CHUNK_INIT,

			.small_i2c = TDA18271_03_BYTE_CHUNK_INIT,

		};



		if (!dvb_attach(tda18271_attach, &t->fe, t->i2c->addr,