[media] af9033: implement .read_snr()
Returns values as 0.1 dB resolution as preferred nowadays.
Actual resolution is 1 dB.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/frontends/af9033.c b/drivers/media/dvb/frontends/af9033.c
index 9ade510..40ef4b1 100644
--- a/drivers/media/dvb/frontends/af9033.c
+++ b/drivers/media/dvb/frontends/af9033.c
@@ -540,9 +540,56 @@
static int af9033_read_snr(struct dvb_frontend *fe, u16 *snr)
{
- *snr = 0;
+ struct af9033_state *state = fe->demodulator_priv;
+ int ret, i, len;
+ u8 buf[3], tmp;
+ u32 snr_val;
+ const struct val_snr *uninitialized_var(snr_lut);
+
+ /* read value */
+ ret = af9033_rd_regs(state, 0x80002c, buf, 3);
+ if (ret < 0)
+ goto err;
+
+ snr_val = (buf[2] << 16) | (buf[1] << 8) | buf[0];
+
+ /* read current modulation */
+ ret = af9033_rd_reg(state, 0x80f903, &tmp);
+ if (ret < 0)
+ goto err;
+
+ switch ((tmp >> 0) & 3) {
+ case 0:
+ len = ARRAY_SIZE(qpsk_snr_lut);
+ snr_lut = qpsk_snr_lut;
+ break;
+ case 1:
+ len = ARRAY_SIZE(qam16_snr_lut);
+ snr_lut = qam16_snr_lut;
+ break;
+ case 2:
+ len = ARRAY_SIZE(qam64_snr_lut);
+ snr_lut = qam64_snr_lut;
+ break;
+ default:
+ goto err;
+ }
+
+ for (i = 0; i < len; i++) {
+ tmp = snr_lut[i].snr;
+
+ if (snr_val < snr_lut[i].val)
+ break;
+ }
+
+ *snr = tmp * 10; /* dB/10 */
return 0;
+
+err:
+ pr_debug("%s: failed=%d\n", __func__, ret);
+
+ return ret;
}
static int af9033_read_signal_strength(struct dvb_frontend *fe, u16 *strength)