diff options
author | Antti Palosaari <crope@iki.fi> | 2010-10-07 16:34:55 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-10-21 01:17:55 -0200 |
commit | 9e35cd222bc913f34b8f69e2b41daa7aa041d79a (patch) | |
tree | d8384021c5c301b1d672524acbd400c566306072 /drivers/media/dvb/frontends/af9013.c | |
parent | edb709b61abd3ba475e59d1ad81aab21ad025db6 (diff) | |
download | op-kernel-dev-9e35cd222bc913f34b8f69e2b41daa7aa041d79a.zip op-kernel-dev-9e35cd222bc913f34b8f69e2b41daa7aa041d79a.tar.gz |
[media] af9013: cache some reg values to reduce reg reads
Demod + tuner specific RF AGC and IF AGC limit values are read from demod
memory in every signal strength query. Cache those to reduce I2C traffic.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/dvb/frontends/af9013.c')
-rw-r--r-- | drivers/media/dvb/frontends/af9013.c | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/drivers/media/dvb/frontends/af9013.c b/drivers/media/dvb/frontends/af9013.c index 6a205e6..e2a95c0 100644 --- a/drivers/media/dvb/frontends/af9013.c +++ b/drivers/media/dvb/frontends/af9013.c @@ -42,6 +42,8 @@ struct af9013_state { struct af9013_config config; + /* tuner/demod RF and IF AGC limits used for signal strength calc */ + u8 signal_strength_en, rf_50, rf_80, if_50, if_80; u16 signal_strength; u32 ber; u32 ucblocks; @@ -963,45 +965,31 @@ static int af9013_update_signal_strength(struct dvb_frontend *fe) { struct af9013_state *state = fe->demodulator_priv; int ret; - u8 tmp0; - u8 rf_gain, rf_50, rf_80, if_gain, if_50, if_80; + u8 rf_gain, if_gain; int signal_strength; deb_info("%s\n", __func__); - state->signal_strength = 0; - - ret = af9013_read_reg_bits(state, 0x9bee, 0, 1, &tmp0); - if (ret) - goto error; - if (tmp0) { - ret = af9013_read_reg(state, 0x9bbd, &rf_50); - if (ret) - goto error; - ret = af9013_read_reg(state, 0x9bd0, &rf_80); - if (ret) - goto error; - ret = af9013_read_reg(state, 0x9be2, &if_50); - if (ret) - goto error; - ret = af9013_read_reg(state, 0x9be4, &if_80); - if (ret) - goto error; + if (state->signal_strength_en) { ret = af9013_read_reg(state, 0xd07c, &rf_gain); if (ret) goto error; ret = af9013_read_reg(state, 0xd07d, &if_gain); if (ret) goto error; - signal_strength = (0xffff / (9 * (rf_50 + if_50) - \ - 11 * (rf_80 + if_80))) * (10 * (rf_gain + if_gain) - \ - 11 * (rf_80 + if_80)); + signal_strength = (0xffff / \ + (9 * (state->rf_50 + state->if_50) - \ + 11 * (state->rf_80 + state->if_80))) * \ + (10 * (rf_gain + if_gain) - \ + 11 * (state->rf_80 + state->if_80)); if (signal_strength < 0) signal_strength = 0; else if (signal_strength > 0xffff) signal_strength = 0xffff; state->signal_strength = signal_strength; + } else { + state->signal_strength = 0; } error: @@ -1306,6 +1294,27 @@ static int af9013_init(struct dvb_frontend *fe) if (ret) goto error; + /* read values needed for signal strength calculation */ + ret = af9013_read_reg_bits(state, 0x9bee, 0, 1, + &state->signal_strength_en); + if (ret) + goto error; + + if (state->signal_strength_en) { + ret = af9013_read_reg(state, 0x9bbd, &state->rf_50); + if (ret) + goto error; + ret = af9013_read_reg(state, 0x9bd0, &state->rf_80); + if (ret) + goto error; + ret = af9013_read_reg(state, 0x9be2, &state->if_50); + if (ret) + goto error; + ret = af9013_read_reg(state, 0x9be4, &state->if_80); + if (ret) + goto error; + } + error: return ret; } |