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[media] tda18271: allow restricting max out to 4 bytes

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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: Michael Krufky <mkrufky@kernellabs.com>
Acked-by: Sri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2010-09-26 22:58:28 -03:00
parent 78bb6df6f2
commit e350d44fed
3 changed files with 38 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

59
drivers/media/common/tuners/tda18271-common.c
View file

@ -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)));
buf[0] = idx;
for (i = 1; i <= len; i++)
buf[i] = regs[idx - 1 + i];
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;
/* write registers */
ret = i2c_transfer(priv->i2c_props.adap, &msg, 1);
buf[0] = idx;
for (i = 1; i <= max; i++)
buf[i] = regs[idx - 1 + i];
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;
}
tda18271_write_regs(fe, 0x00, TDA18271_NUM_REGS);
/* setup agc1 gain */
regs[R_EB17] = 0x00;

5
drivers/media/common/tuners/tda18271.h
View file

@ -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 {

2
drivers/media/video/tuner-core.c
View file

@ -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,