[media] tda10023: Don't use a magic numbers for QAM modulation

Convert the existing data struct to use the QAM modulation macros,
instead of assuming that they're numbered from 0 to 5.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/dvb/frontends/tda10023.c b/drivers/media/dvb/frontends/tda10023.c
index a3c34eecdee9a81315bf68b44c5d6f23923c5cda..e6c321e799d7b18646a586bc735b2de9470476b0 100644 (file)
--- a/drivers/media/dvb/frontends/tda10023.c
+++ b/drivers/media/dvb/frontends/tda10023.c
@@ -298,25 +298,43 @@ static int tda10023_init (struct dvb_frontend *fe)
        return 0;
 }
 
+struct qam_params {
+       u8 qam, lockthr, mseth, aref, agcrefnyq, eragnyq_thd;
+};
+
 static int tda10023_set_parameters (struct dvb_frontend *fe,
                            struct dvb_frontend_parameters *p)
 {
        struct tda10023_state* state = fe->demodulator_priv;
-
-       static int qamvals[6][6] = {
-               //  QAM   LOCKTHR  MSETH   AREF AGCREFNYQ  ERAGCNYQ_THD
-               { (5<<2),  0x78,    0x8c,   0x96,   0x78,   0x4c  },  // 4 QAM
-               { (0<<2),  0x87,    0xa2,   0x91,   0x8c,   0x57  },  // 16 QAM
-               { (1<<2),  0x64,    0x74,   0x96,   0x8c,   0x57  },  // 32 QAM
-               { (2<<2),  0x46,    0x43,   0x6a,   0x6a,   0x44  },  // 64 QAM
-               { (3<<2),  0x36,    0x34,   0x7e,   0x78,   0x4c  },  // 128 QAM
-               { (4<<2),  0x26,    0x23,   0x6c,   0x5c,   0x3c  },  // 256 QAM
+       static const struct qam_params qam_params[] = {
+               /* Modulation  QAM    LOCKTHR   MSETH   AREF AGCREFNYQ ERAGCNYQ_THD */
+               [QPSK]    = { (5<<2),  0x78,    0x8c,   0x96,   0x78,   0x4c  },
+               [QAM_16]  = { (0<<2),  0x87,    0xa2,   0x91,   0x8c,   0x57  },
+               [QAM_32]  = { (1<<2),  0x64,    0x74,   0x96,   0x8c,   0x57  },
+               [QAM_64]  = { (2<<2),  0x46,    0x43,   0x6a,   0x6a,   0x44  },
+               [QAM_128] = { (3<<2),  0x36,    0x34,   0x7e,   0x78,   0x4c  },
+               [QAM_256] = { (4<<2),  0x26,    0x23,   0x6c,   0x5c,   0x3c  },
        };
-
-       int qam = p->u.qam.modulation;
-
-       if (qam < 0 || qam > 5)
+       unsigned qam = p->u.qam.modulation;
+
+       /*
+        * gcc optimizes the code bellow the same way as it would code:
+        *               "if (qam > 5) return -EINVAL;"
+        * Yet, the code is clearer, as it shows what QAM standards are
+        * supported by the driver, and avoids the usage of magic numbers on
+        * it.
+        */
+       switch (qam) {
+       case QPSK:
+       case QAM_16:
+       case QAM_32:
+       case QAM_64:
+       case QAM_128:
+       case QAM_256:
+               break;
+       default:
                return -EINVAL;
+       }
 
        if (fe->ops.tuner_ops.set_params) {
                fe->ops.tuner_ops.set_params(fe, p);
@@ -324,16 +342,18 @@ static int tda10023_set_parameters (struct dvb_frontend *fe,
        }
 
        tda10023_set_symbolrate (state, p->u.qam.symbol_rate);
-       tda10023_writereg (state, 0x05, qamvals[qam][1]);
-       tda10023_writereg (state, 0x08, qamvals[qam][2]);
-       tda10023_writereg (state, 0x09, qamvals[qam][3]);
-       tda10023_writereg (state, 0xb4, qamvals[qam][4]);
-       tda10023_writereg (state, 0xb6, qamvals[qam][5]);
-
-//     tda10023_writereg (state, 0x04, (p->inversion?0x12:0x32));
-//     tda10023_writebit (state, 0x04, 0x60, (p->inversion?0:0x20));
-       tda10023_writebit (state, 0x04, 0x40, 0x40);
-       tda10023_setup_reg0 (state, qamvals[qam][0]);
+       tda10023_writereg(state, 0x05, qam_params[qam].lockthr);
+       tda10023_writereg(state, 0x08, qam_params[qam].mseth);
+       tda10023_writereg(state, 0x09, qam_params[qam].aref);
+       tda10023_writereg(state, 0xb4, qam_params[qam].agcrefnyq);
+       tda10023_writereg(state, 0xb6, qam_params[qam].eragnyq_thd);
+
+#if 0
+       tda10023_writereg(state, 0x04, (p->inversion ? 0x12 : 0x32));
+       tda10023_writebit(state, 0x04, 0x60, (p->inversion ? 0 : 0x20));
+#endif
+       tda10023_writebit(state, 0x04, 0x40, 0x40);
+       tda10023_setup_reg0(state, qam_params[qam].qam);
 
        return 0;
 }