[PATCH 14/15] si2165: Add DVBv3 wrapper for ber statistics

[Matthias Schwarzott]

Add read_ber function that reads from property cache to support DVBv3.
The implementation is inspired by the cx24120 driver.

Signed-off-by: Matthias Schwarzott <z...@gentoo.org>
---
 drivers/media/dvb-frontends/si2165.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/media/dvb-frontends/si2165.c 
b/drivers/media/dvb-frontends/si2165.c
index ceb5a2bb0dea..2ad6409dd6b1 100644
--- a/drivers/media/dvb-frontends/si2165.c
+++ b/drivers/media/dvb-frontends/si2165.c
@@ -57,6 +57,9 @@ struct si2165_state {
        u32 sys_clk;
        u32 adc_clk;
 
+       /* DVBv3 stats */
+       u64 ber_prev;
+
        bool has_dvbc;
        bool has_dvbt;
        bool firmware_loaded;
@@ -757,6 +760,12 @@ static int si2165_read_status(struct dvb_frontend *fe, 
enum fe_status *status)
                        c->post_bit_error.stat[0].uvalue = 0;
                        c->post_bit_count.stat[0].uvalue = 0;
 
+                       /*
+                        * reset DVBv3 value to deliver a good result
+                        * for the first call
+                        */
+                       state->ber_prev = 0;
+
                } else {
                        ret = si2165_readreg8(state, REG_BER_AVAIL, &u8tmp);
                        if (ret < 0)
@@ -805,6 +814,22 @@ static int si2165_read_snr(struct dvb_frontend *fe, u16 
*snr)
        return 0;
 }
 
+static int si2165_read_ber(struct dvb_frontend *fe, u32 *ber)
+{
+       struct si2165_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+       if (c->post_bit_error.stat[0].scale != FE_SCALE_COUNTER) {
+               *ber = 0;
+               return 0;
+       }
+
+       *ber = c->post_bit_error.stat[0].uvalue - state->ber_prev;
+       state->ber_prev = c->post_bit_error.stat[0].uvalue;
+
+       return 0;
+}
+
 static int si2165_set_oversamp(struct si2165_state *state, u32 dvb_rate)
 {
        u64 oversamp;
@@ -1123,6 +1148,7 @@ static const struct dvb_frontend_ops si2165_ops = {
        .set_frontend      = si2165_set_frontend,
        .read_status       = si2165_read_status,
        .read_snr          = si2165_read_snr,
+       .read_ber          = si2165_read_ber,
 };
 
 static int si2165_probe(struct i2c_client *client,
-- 
2.15.0