V4L/DVB (6402): s5h1409: Fix broken QAM support

This patch enables QAM Annex-B support (US digital cable)
for the s5h1409 VSB/QAM demodulator.

Tested successfully with the mt2131 tuner,
present on the following supported boards:

Hauppauge WinTV-HVR-1250
Hauppauge WinTV-HVR-1800
Hauppauge WinTV-HVR-1800lp

This patch is also known to work with an upcoming XC5000 tuner driver.

Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 86 insertions, 10 deletions

diff --git a/drivers/media/dvb/frontends/s5h1409.c b/drivers/media/dvb/frontends/s5h1409.c
index 30e8a705fad4..8dee7ec9456a 100644
--- a/drivers/media/dvb/frontends/s5h1409.c
+++ b/drivers/media/dvb/frontends/s5h1409.c
@@ -42,6 +42,9 @@ struct s5h1409_state {
         fe_modulation_t current_modulation;
 
         u32 current_frequency;
+
+        u32 is_qam_locked;
+        u32 qam_state;
 };
 
 static int debug = 0;
@@ -94,6 +97,7 @@ static struct init_tab {
         { 0xac, 0x1003, },
         { 0xad, 0x103f, },
         { 0xe2, 0x0100, },
+        { 0xe3, 0x0000, },
         { 0x28, 0x1010, },
         { 0xb1, 0x000e, },
 };
@@ -335,6 +339,8 @@ static int s5h1409_softreset(struct dvb_frontend* fe)
 
         s5h1409_writereg(state, 0xf5, 0);
         s5h1409_writereg(state, 0xf5, 1);
+        state->is_qam_locked = 0;
+        state->qam_state = 0;
         return 0;
 }
 
@@ -349,6 +355,11 @@ static int s5h1409_set_if_freq(struct dvb_frontend* fe, int KHz)
                 s5h1409_writereg(state, 0x87, 0x01be);
                 s5h1409_writereg(state, 0x88, 0x0436);
                 s5h1409_writereg(state, 0x89, 0x054d);
+        } else
+        if (KHz == 4000) {
+                s5h1409_writereg(state, 0x87, 0x014b);
+                s5h1409_writereg(state, 0x88, 0x0cb5);
+                s5h1409_writereg(state, 0x89, 0x03e2);
         } else {
                 printk("%s() Invalid arg = %d KHz\n", __FUNCTION__, KHz);
                 ret = -1;
@@ -361,7 +372,7 @@ static int s5h1409_set_spectralinversion(struct dvb_frontend* fe, int inverted)
 {
         struct s5h1409_state* state = fe->demodulator_priv;
 
-        dprintk("%s()\n", __FUNCTION__);
+        dprintk("%s(%d)\n", __FUNCTION__, inverted);
 
         if(inverted == 1)
                 return s5h1409_writereg(state, 0x1b, 0x1101); /* Inverted */
@@ -382,14 +393,10 @@ static int s5h1409_enable_modulation(struct dvb_frontend* fe,
                 s5h1409_writereg(state, 0xf4, 0);
                 break;
         case QAM_64:
-                dprintk("%s() QAM_64\n", __FUNCTION__);
-                s5h1409_writereg(state, 0xf4, 1);
-                s5h1409_writereg(state, 0x85, 0x100);
-                break;
         case QAM_256:
-                dprintk("%s() QAM_256\n", __FUNCTION__);
+                dprintk("%s() QAM_AUTO (64/256)\n", __FUNCTION__);
                 s5h1409_writereg(state, 0xf4, 1);
-                s5h1409_writereg(state, 0x85, 0x101);
+                s5h1409_writereg(state, 0x85, 0x110);
                 break;
         default:
                 dprintk("%s() Invalid modulation\n", __FUNCTION__);
@@ -423,7 +430,7 @@ static int s5h1409_set_gpio(struct dvb_frontend* fe, int enable)
         if (enable)
                 return s5h1409_writereg(state, 0xe3, 0x1100);
         else
-                return s5h1409_writereg(state, 0xe3, 0);
+                return s5h1409_writereg(state, 0xe3, 0x1000);
 }
 
 static int s5h1409_sleep(struct dvb_frontend* fe, int enable)
@@ -444,6 +451,66 @@ static int s5h1409_register_reset(struct dvb_frontend* fe)
         return s5h1409_writereg(state, 0xfa, 0);
 }
 
+static void s5h1409_set_qam_amhum_mode(struct dvb_frontend *fe)
+{
+        struct s5h1409_state *state = fe->demodulator_priv;
+        u16 reg;
+
+        if (state->is_qam_locked)
+                return;
+
+        /* QAM EQ lock check */
+        reg = s5h1409_readreg(state, 0xf0);
+
+        if ((reg >> 13) & 0x1) {
+
+                state->is_qam_locked = 1;
+                reg &= 0xff;
+
+                s5h1409_writereg(state, 0x96, 0x00c);
+                if ((reg < 0x38) || (reg > 0x68) ) {
+                        s5h1409_writereg(state, 0x93, 0x3332);
+                        s5h1409_writereg(state, 0x9e, 0x2c37);
+                } else {
+                        s5h1409_writereg(state, 0x93, 0x3130);
+                        s5h1409_writereg(state, 0x9e, 0x2836);
+                }
+
+        } else {
+                s5h1409_writereg(state, 0x96, 0x0008);
+                s5h1409_writereg(state, 0x93, 0x3332);
+                s5h1409_writereg(state, 0x9e, 0x2c37);
+        }
+}
+
+static void s5h1409_set_qam_interleave_mode(struct dvb_frontend *fe)
+{
+        struct s5h1409_state *state = fe->demodulator_priv;
+        u16 reg, reg1, reg2;
+
+        reg = s5h1409_readreg(state, 0xf1);
+
+        /* Master lock */
+        if ((reg >> 15) & 0x1) {
+                if (state->qam_state != 2) {
+                        state->qam_state = 2;
+                        reg1 = s5h1409_readreg(state, 0xb2);
+                        reg2 = s5h1409_readreg(state, 0xad);
+
+                        s5h1409_writereg(state, 0x96, 0x20);
+                        s5h1409_writereg(state, 0xad,
+                                ( ((reg1 & 0xf000) >> 4) | (reg2 & 0xf0ff)) );
+                        s5h1409_writereg(state, 0xab, 0x1100);
+                }
+        } else {
+                if (state->qam_state != 1) {
+                        state->qam_state = 1;
+                        s5h1409_writereg(state, 0x96, 0x08);
+                        s5h1409_writereg(state, 0xab, 0x1101);
+                }
+        }
+}
+
 /* Talk to the demod, set the FEC, GUARD, QAM settings etc */
 static int s5h1409_set_frontend (struct dvb_frontend* fe,
                                  struct dvb_frontend_parameters *p)
@@ -458,12 +525,21 @@ static int s5h1409_set_frontend (struct dvb_frontend* fe,
 
         s5h1409_enable_modulation(fe, p->u.vsb.modulation);
 
+        /* Allow the demod to settle */
+        msleep(100);
+
         if (fe->ops.tuner_ops.set_params) {
                 if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 1);
                 fe->ops.tuner_ops.set_params(fe, p);
                 if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
         }
 
+        /* Optimize the demod for QAM */
+        if (p->u.vsb.modulation != VSB_8) {
+                s5h1409_set_qam_amhum_mode(fe);
+                s5h1409_set_qam_interleave_mode(fe);
+        }
+
         return 0;
 }
 
@@ -495,8 +571,8 @@ static int s5h1409_init (struct dvb_frontend* fe)
         s5h1409_set_gpio(fe, state->config->gpio);
         s5h1409_softreset(fe);
 
-        /* Note: Leaving the I2C gate open here. */
-        s5h1409_i2c_gate_ctrl(fe, 1);
+        /* Note: Leaving the I2C gate closed. */
+        s5h1409_i2c_gate_ctrl(fe, 0);
 
         return 0;
 }