cxd2820r: by default SNR output is scaled to full 0-65535 range;
output in dBx10 can be enabled through a module parameter;
Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
---
drivers/media/dvb-frontends/cxd2820r_core.c | 4 ++++
drivers/media/dvb-frontends/cxd2820r_priv.h | 1 +
drivers/media/dvb-frontends/cxd2820r_t.c | 27 ++++++++++++++++++++++-
drivers/media/dvb-frontends/cxd2820r_t2.c | 31 ++++++++++++++++++++++++++-
4 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/drivers/media/dvb-frontends/cxd2820r_core.c b/drivers/media/dvb-frontends/cxd2820r_core.c
index 9b658c1..35477aa 100644
--- a/drivers/media/dvb-frontends/cxd2820r_core.c
+++ b/drivers/media/dvb-frontends/cxd2820r_core.c
@@ -21,6 +21,10 @@
#include "cxd2820r_priv.h"
+int cxd2820r_snrdb;
+module_param_named(snrdb,cxd2820r_snrdb, int, 0644);
+MODULE_PARM_DESC(snrdb, "Turn on/off SNR output in dBx10 (default:off).");
+
/* write multiple registers */
static int cxd2820r_wr_regs_i2c(struct cxd2820r_priv *priv, u8 i2c, u8 reg,
u8 *val, int len)
diff --git a/drivers/media/dvb-frontends/cxd2820r_priv.h b/drivers/media/dvb-frontends/cxd2820r_priv.h
index 7ff5f60..f742169 100644
--- a/drivers/media/dvb-frontends/cxd2820r_priv.h
+++ b/drivers/media/dvb-frontends/cxd2820r_priv.h
@@ -55,6 +55,7 @@ struct cxd2820r_priv {
/* cxd2820r_core.c */
extern int cxd2820r_debug;
+extern int cxd2820r_snrdb;
int cxd2820r_gpio(struct dvb_frontend *fe, u8 *gpio);
diff --git a/drivers/media/dvb-frontends/cxd2820r_t.c b/drivers/media/dvb-frontends/cxd2820r_t.c
index fa184ca..4268c53 100644
--- a/drivers/media/dvb-frontends/cxd2820r_t.c
+++ b/drivers/media/dvb-frontends/cxd2820r_t.c
@@ -317,7 +317,7 @@ int cxd2820r_read_snr_t(struct dvb_frontend *fe, u16 *snr)
struct cxd2820r_priv *priv = fe->demodulator_priv;
int ret;
u8 buf[2];
- u16 tmp;
+ u16 tmp, max_snr;
/* report SNR in dB * 10 */
ret = cxd2820r_rd_regs(priv, 0x00028, buf, sizeof(buf));
@@ -332,6 +332,31 @@ int cxd2820r_read_snr_t(struct dvb_frontend *fe, u16 *snr)
else
*snr = 0;
+ if (cxd2820r_snrdb)
+ goto db_out;
+
+ /* scale SNR to full range */
+ ret = cxd2820r_rd_regs(priv, 0x0002f, buf, 1);
+ if (ret)
+ goto error;
+
+ switch ((buf[0] >> 6) & 0x03) {
+ case 0: /* QPSK */
+ max_snr = 230;
+ break;
+ case 1: /* QAM_16 */
+ max_snr = 260;
+ break;
+ case 2: /* QAM_64 */
+ default:
+ max_snr = 290;
+ break;
+ }
+
+ *snr = (*snr >= max_snr) ? 0xffff : (0xffff / max_snr) * *snr;
+ dev_dbg(&priv->i2c->dev, "%s: SNR=%d val=%04x", __func__, *snr, tmp);
+ return ret;
+db_out:
dev_dbg(&priv->i2c->dev, "%s: dBx10=%d val=%04x\n", __func__, *snr,
tmp);
diff --git a/drivers/media/dvb-frontends/cxd2820r_t2.c b/drivers/media/dvb-frontends/cxd2820r_t2.c
index e82d82a..69945cc 100644
--- a/drivers/media/dvb-frontends/cxd2820r_t2.c
+++ b/drivers/media/dvb-frontends/cxd2820r_t2.c
@@ -351,7 +351,7 @@ int cxd2820r_read_snr_t2(struct dvb_frontend *fe, u16 *snr)
struct cxd2820r_priv *priv = fe->demodulator_priv;
int ret;
u8 buf[2];
- u16 tmp;
+ u16 tmp, max_snr;
/* report SNR in dB * 10 */
ret = cxd2820r_rd_regs(priv, 0x02028, buf, sizeof(buf));
@@ -366,6 +366,35 @@ int cxd2820r_read_snr_t2(struct dvb_frontend *fe, u16 *snr)
else
*snr = 0;
+ if (cxd2820r_snrdb)
+ goto db_out;
+
+ /* scale SNR to full range */
+ ret = cxd2820r_rd_regs(priv, 0x0205d, buf, 1);
+ if (ret)
+ goto error;
+
+ switch (buf[0] & 0x07) {
+ /* FIXME: check the values */
+ case 0: /* QPSK */
+ max_snr = 170;
+ break;
+ case 1: /* QAM_16 */
+ max_snr = 200;
+ break;
+ case 2: /* QAM_64 */
+ max_snr = 230;
+ break;
+ case 3: /* QAM_256 */
+ default:
+ max_snr = 260;
+ break;
+ }
+
+ *snr = (*snr >= max_snr) ? 0xffff : (0xffff / max_snr) * *snr;
+ dev_dbg(&priv->i2c->dev, "%s: SNR=%d val=%04x", __func__, *snr, tmp);
+ return ret;
+db_out:
dev_dbg(&priv->i2c->dev, "%s: dBx10=%d val=%04x\n", __func__, *snr,
tmp);
--
1.7.9.5