Based rtl2830 implementation.
Cc: Thomas Mair <thomas.mair86@xxxxxxxxxxxxxx>
Signed-off-by: Antti Palosaari <crope@xxxxxx>
---
drivers/media/dvb-frontends/rtl2832.c | 52 +++++++++++++++++++++++++++++++++--
1 file changed, 49 insertions(+), 3 deletions(-)
diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index 6e28444..dad8ab5 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -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,
};
--
1.7.11.4
--
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