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[media] rtl2832: implement .read_snr()

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Based rtl2830 implementation.

Cc: Thomas Mair <thomas.mair86@googlemail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Antti Palosaari 2012-08-21 19:56:21 -03:00 committed by Mauro Carvalho Chehab
parent 0ce67a2a59
commit 73983497ff
1 changed files with 49 additions and 3 deletions
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52
drivers/media/dvb-frontends/rtl2832.c
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@ -19,6 +19,7 @@
*/
#include "rtl2832_priv.h"
#include "dvb_math.h"
#include <linux/bitops.h>
int rtl2832_debug;
@ -355,7 +356,6 @@ err:
}
static int rtl2832_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
{
int ret;
@ -379,8 +379,6 @@ err:
return ret;
}
static int rtl2832_init(struct dvb_frontend *fe)
{
struct rtl2832_priv *priv = fe->demodulator_priv;
@ -780,6 +778,52 @@ err:
return ret;
}
static int rtl2832_read_snr(struct dvb_frontend *fe, u16 *snr)
{
struct rtl2832_priv *priv = fe->demodulator_priv;
int ret, hierarchy, constellation;
u8 buf[2], tmp;
u16 tmp16;
#define CONSTELLATION_NUM 3
#define HIERARCHY_NUM 4
static const u32 snr_constant[CONSTELLATION_NUM][HIERARCHY_NUM] = {
{ 85387325, 85387325, 85387325, 85387325 },
{ 86676178, 86676178, 87167949, 87795660 },
{ 87659938, 87659938, 87885178, 88241743 },
};
/* reports SNR in resolution of 0.1 dB */
ret = rtl2832_rd_reg(priv, 0x3c, 3, &tmp);
if (ret)
goto err;
constellation = (tmp >> 2) & 0x03; /* [3:2] */
if (constellation > CONSTELLATION_NUM - 1)
goto err;
hierarchy = (tmp >> 4) & 0x07; /* [6:4] */
if (hierarchy > HIERARCHY_NUM - 1)
goto err;
ret = rtl2832_rd_regs(priv, 0x0c, 4, buf, 2);
if (ret)
goto err;
tmp16 = buf[0] << 8 | buf[1];
if (tmp16)
*snr = (snr_constant[constellation][hierarchy] -
intlog10(tmp16)) / ((1 << 24) / 100);
else
*snr = 0;
return 0;
err:
dbg("%s: failed=%d", __func__, ret);
return ret;
}
static struct dvb_frontend_ops rtl2832_ops;
static void rtl2832_release(struct dvb_frontend *fe)
@ -864,6 +908,8 @@ static struct dvb_frontend_ops rtl2832_ops = {
.get_frontend = rtl2832_get_frontend,
.read_status = rtl2832_read_status,
.read_snr = rtl2832_read_snr,
.i2c_gate_ctrl = rtl2832_i2c_gate_ctrl,
};