media: mb86a20s: make the bit rate estimation function more generic

[linux-2.6-microblaze.git] / drivers / media / dvb-frontends / mb86a20s.c

diff --git a/drivers/media/dvb-frontends/mb86a20s.c b/drivers/media/dvb-frontends/mb86a20s.c
index 4e50441..a7faf0c 100644 (file)
--- a/drivers/media/dvb-frontends/mb86a20s.c
+++ b/drivers/media/dvb-frontends/mb86a20s.c
@@ -517,7 +517,7 @@ static void mb86a20s_reset_frontend_cache(struct dvb_frontend *fe)
  * Estimates the bit rate using the per-segment bit rate given by
  * ABNT/NBR 15601 spec (table 4).
  */
-static u32 isdbt_rate[3][5][4] = {
+static const u32 isdbt_rate[3][5][4] = {
        {       /* DQPSK/QPSK */
                {  280850,  312060,  330420,  340430 }, /* 1/2 */
                {  374470,  416080,  440560,  453910 }, /* 2/3 */
@@ -539,13 +539,9 @@ static u32 isdbt_rate[3][5][4] = {
        }
 };
 
-static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
-                                  u32 modulation, u32 forward_error_correction,
-                                  u32 guard_interval,
-                                  u32 segment)
+static u32 isdbt_layer_min_bitrate(struct dtv_frontend_properties *c,
+                                  u32 layer)
 {
-       struct mb86a20s_state *state = fe->demodulator_priv;
-       u32 rate;
        int mod, fec, guard;
 
        /*
@@ -553,7 +549,7 @@ static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
         * to consider the lowest bit rate, to avoid taking too long time
         * to get BER.
         */
-       switch (modulation) {
+       switch (c->layer[layer].modulation) {
        case DQPSK:
        case QPSK:
        default:
@@ -567,7 +563,7 @@ static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
                break;
        }
 
-       switch (forward_error_correction) {
+       switch (c->layer[layer].fec) {
        default:
        case FEC_1_2:
        case FEC_AUTO:
@@ -587,7 +583,7 @@ static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
                break;
        }
 
-       switch (guard_interval) {
+       switch (c->guard_interval) {
        default:
        case GUARD_INTERVAL_1_4:
                guard = 0;
@@ -603,29 +599,14 @@ static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
                break;
        }
 
-       /* Samples BER at BER_SAMPLING_RATE seconds */
-       rate = isdbt_rate[mod][fec][guard] * segment * BER_SAMPLING_RATE;
-
-       /* Avoids sampling too quickly or to overflow the register */
-       if (rate < 256)
-               rate = 256;
-       else if (rate > (1 << 24) - 1)
-               rate = (1 << 24) - 1;
-
-       dev_dbg(&state->i2c->dev,
-               "%s: layer %c bitrate: %d kbps; counter = %d (0x%06x)\n",
-               __func__, 'A' + layer,
-               segment * isdbt_rate[mod][fec][guard]/1000,
-               rate, rate);
-
-       state->estimated_rate[layer] = rate;
+       return isdbt_rate[mod][fec][guard] * c->layer[layer].segment_count;
 }
 
 static int mb86a20s_get_frontend(struct dvb_frontend *fe)
 {
        struct mb86a20s_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-       int layer, rc;
+       int layer, rc, rate, counter;
 
        dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
 
@@ -676,10 +657,21 @@ static int mb86a20s_get_frontend(struct dvb_frontend *fe)
                dev_dbg(&state->i2c->dev, "%s: interleaving %d.\n",
                        __func__, rc);
                c->layer[layer].interleaving = rc;
-               mb86a20s_layer_bitrate(fe, layer, c->layer[layer].modulation,
-                                      c->layer[layer].fec,
-                                      c->guard_interval,
-                                      c->layer[layer].segment_count);
+
+               rate = isdbt_layer_min_bitrate(c, layer);
+               counter = rate * BER_SAMPLING_RATE;
+
+               /* Avoids sampling too quickly or to overflow the register */
+               if (counter < 256)
+                       counter = 256;
+               else if (counter > (1 << 24) - 1)
+                       counter = (1 << 24) - 1;
+
+               dev_dbg(&state->i2c->dev,
+                       "%s: layer %c bitrate: %d kbps; counter = %d (0x%06x)\n",
+                       __func__, 'A' + layer, rate / 1000, counter, counter);
+
+               state->estimated_rate[layer] = counter;
        }
 
        rc = mb86a20s_writereg(state, 0x6d, 0x84);