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V4L/DVB (5362): Dvb-pll: add code for doing tuner initialization

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Some tuners need or benefit from initialization, to change certain
settings from their power on default values.

Typically, tuners with TUA603x PLLs can benefit from setting the AGC TOP
value to something else.  This patch includes code to set the AGC TOP to
103 dBuV for the Thomson DTT-761x tuners, which I have experimentally
verified gives the best SNR readings, increasing SNR by about 0.19 dB
over the default value.

Other tuners can make use of this as well.  For example, the separate LG
TDVS-H06xF driver's only difference from dvb-pll is this same setting of
AGC TOP value.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Trent Piepho 2007-04-27 12:31:29 -03:00 committed by Mauro Carvalho Chehab
parent 9ab1ba38e6
commit 26aed92289
2 changed files with 40 additions and 0 deletions
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39
drivers/media/dvb/frontends/dvb-pll.c
View file

@ -27,6 +27,17 @@
/* ----------------------------------------------------------- */
/* descriptions */
/* Set AGC TOP value to 103 dBuV:
0x80 = Control Byte
0x40 = 250 uA charge pump (irrelevant)
0x18 = Aux Byte to follow
0x06 = 64.5 kHz divider (irrelevant)
0x01 = Disable Vt (aka sleep)
0x00 = AGC Time constant 2s Iagc = 300 nA (vs 0x80 = 9 nA)
0x50 = AGC Take over point = 103 dBuV */
static u8 tua603x_agc103[] = { 2, 0x80|0x40|0x18|0x06|0x01, 0x00|0x50 };
struct dvb_pll_desc dvb_pll_thomson_dtt7579 = {
.name = "Thomson dtt7579",
.min = 177000000,
@ -113,6 +124,7 @@ struct dvb_pll_desc dvb_pll_thomson_dtt761x = {
.min = 57000000,
.max = 863000000,
.count = 3,
.initdata = tua603x_agc103,
.entries = {
{ 147000000, 44000000, 62500, 0x8e, 0x39 },
{ 417000000, 44000000, 62500, 0x8e, 0x3a },
@ -599,6 +611,31 @@ static int dvb_pll_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
return 0;
}
static int dvb_pll_init(struct dvb_frontend *fe)
{
struct dvb_pll_priv *priv = fe->tuner_priv;
if (priv->i2c == NULL)
return -EINVAL;
if (priv->pll_desc->initdata) {
struct i2c_msg msg = { .flags = 0,
.addr = priv->pll_i2c_address,
.buf = priv->pll_desc->initdata + 1,
.len = priv->pll_desc->initdata[0] };
int result;
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
if ((result = i2c_transfer(priv->i2c, &msg, 1)) != 1) {
return result;
}
return 0;
}
/* Shouldn't be called when initdata is NULL, maybe BUG()? */
return -EINVAL;
}
static struct dvb_tuner_ops dvb_pll_tuner_ops = {
.release = dvb_pll_release,
.sleep = dvb_pll_sleep,
@ -644,6 +681,8 @@ struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe, int pll_addr,
sizeof(fe->ops.tuner_ops.info.name));
fe->ops.tuner_ops.info.frequency_min = desc->min;
fe->ops.tuner_ops.info.frequency_min = desc->max;
if (desc->initdata)
fe->ops.tuner_ops.init = dvb_pll_init;
fe->tuner_priv = priv;
return fe;

1
drivers/media/dvb/frontends/dvb-pll.h
View file

@ -13,6 +13,7 @@ struct dvb_pll_desc {
u32 min;
u32 max;
void (*setbw)(u8 *buf, u32 freq, int bandwidth);
u8 *initdata;
int count;
struct {
u32 limit;