[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>

1 files changed, 43 insertions, 23 deletions

diff --git a/drivers/media/dvb/frontends/tda10023.c b/drivers/media/dvb/frontends/tda10023.c
index a3c34eecdee9..e6c321e799d7 100644
--- 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;
 }