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[media] rtl2832: wrap DVBv5 CNR to DVBv3 SNR
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Change legacy DVBv3 read SNR to return values calculated by DVBv5
statistics.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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Antti Palosaari authored and Mauro Carvalho Chehab committed Feb 3, 2015
1 parent 6b4fd01 commit f7caf93
Showing 2 changed files with 5 additions and 38 deletions.
42 changes: 4 additions & 38 deletions drivers/media/dvb-frontends/rtl2832.c
Original file line number Diff line number Diff line change
@@ -791,49 +791,15 @@ static int rtl2832_read_status(struct dvb_frontend *fe, fe_status_t *status)

static int rtl2832_read_snr(struct dvb_frontend *fe, u16 *snr)
{
struct rtl2832_dev *dev = fe->demodulator_priv;
struct i2c_client *client = dev->client;
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(dev, 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(dev, 0x0c, 4, buf, 2);
if (ret)
goto err;

tmp16 = buf[0] << 8 | buf[1];
struct dtv_frontend_properties *c = &fe->dtv_property_cache;

if (tmp16)
*snr = (snr_constant[constellation][hierarchy] -
intlog10(tmp16)) / ((1 << 24) / 100);
/* report SNR in resolution of 0.1 dB */
if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL)
*snr = div_s64(c->cnr.stat[0].svalue, 100);
else
*snr = 0;

return 0;
err:
dev_dbg(&client->dev, "failed=%d\n", ret);
return ret;
}

static int rtl2832_read_ber(struct dvb_frontend *fe, u32 *ber)
1 change: 1 addition & 0 deletions drivers/media/dvb-frontends/rtl2832_priv.h
Original file line number Diff line number Diff line change
@@ -25,6 +25,7 @@
#include "rtl2832.h"
#include <linux/i2c-mux.h>
#include <linux/regmap.h>
#include <linux/math64.h>

struct rtl2832_dev {
struct rtl2832_platform_data *pdata;

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