[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>
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_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 @@
{
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 @@
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;
}