diff options
Diffstat (limited to 'drivers/media/dvb-frontends/rtl2832.c')
| -rw-r--r-- | drivers/media/dvb-frontends/rtl2832.c | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c index 6e28444d6526..dad8ab5aba8e 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, }; |