[PATCH 3.11 086/233] [media] m88rs2000: set symbol rate accurately

[Luis Henriques]

3.11.10.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Malcolm Priestley <tvboxspy at gmail.com>

commit dd4491dfb9eb4fa3bfa7dc73ba989e69fbce2e10 upstream.

Current setting of symbol rate is not very actuate causing
loss of lock.

Covert temp to u64 and use mclk to calculate from big number.

Calculate symbol rate by dividing symbol rate by 1000 times
1 << 24 and dividing sum by mclk.

Add other symbol rate settings to function registers 0xa0-0xa3.

In set_frontend add changes to register 0xf1 this must be done
prior call to fe_reset. Register 0x00 doesn't need a second
write of 0x1

Applied after patch
m88rs2000: add m88rs2000_set_carrieroffset

Signed-off-by: Malcolm Priestley <tvboxspy at gmail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab at samsung.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/media/dvb-frontends/m88rs2000.c | 42 ++++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/drivers/media/dvb-frontends/m88rs2000.c b/drivers/media/dvb-frontends/m88rs2000.c
index 8091653..02699c1 100644
--- a/drivers/media/dvb-frontends/m88rs2000.c
+++ b/drivers/media/dvb-frontends/m88rs2000.c
@@ -160,24 +160,44 @@ static int m88rs2000_set_symbolrate(struct dvb_frontend *fe, u32 srate)
 {
 	struct m88rs2000_state *state = fe->demodulator_priv;
 	int ret;
-	u32 temp;
+	u64 temp;
+	u32 mclk;
 	u8 b[3];
 
 	if ((srate < 1000000) || (srate > 45000000))
 		return -EINVAL;
 
+	mclk = m88rs2000_get_mclk(fe);
+	if (!mclk)
+		return -EINVAL;
+
 	temp = srate / 1000;
-	temp *= 11831;
-	temp /= 68;
-	temp -= 3;
+	temp *= 1 << 24;
+
+	do_div(temp, mclk);
 
 	b[0] = (u8) (temp >> 16) & 0xff;
 	b[1] = (u8) (temp >> 8) & 0xff;
 	b[2] = (u8) temp & 0xff;
+
 	ret = m88rs2000_writereg(state, 0x93, b[2]);
 	ret |= m88rs2000_writereg(state, 0x94, b[1]);
 	ret |= m88rs2000_writereg(state, 0x95, b[0]);
 
+	if (srate > 10000000)
+		ret |= m88rs2000_writereg(state, 0xa0, 0x20);
+	else
+		ret |= m88rs2000_writereg(state, 0xa0, 0x60);
+
+	ret |= m88rs2000_writereg(state, 0xa1, 0xe0);
+
+	if (srate > 12000000)
+		ret |= m88rs2000_writereg(state, 0xa3, 0x20);
+	else if (srate > 2800000)
+		ret |= m88rs2000_writereg(state, 0xa3, 0x98);
+	else
+		ret |= m88rs2000_writereg(state, 0xa3, 0x90);
+
 	deb_info("m88rs2000: m88rs2000_set_symbolrate\n");
 	return ret;
 }
@@ -307,8 +327,6 @@ struct inittab m88rs2000_shutdown[] = {
 
 struct inittab fe_reset[] = {
 	{DEMOD_WRITE, 0x00, 0x01},
-	{DEMOD_WRITE, 0xf1, 0xbf},
-	{DEMOD_WRITE, 0x00, 0x01},
 	{DEMOD_WRITE, 0x20, 0x81},
 	{DEMOD_WRITE, 0x21, 0x80},
 	{DEMOD_WRITE, 0x10, 0x33},
@@ -351,9 +369,6 @@ struct inittab fe_trigger[] = {
 	{DEMOD_WRITE, 0x9b, 0x64},
 	{DEMOD_WRITE, 0x9e, 0x00},
 	{DEMOD_WRITE, 0x9f, 0xf8},
-	{DEMOD_WRITE, 0xa0, 0x20},
-	{DEMOD_WRITE, 0xa1, 0xe0},
-	{DEMOD_WRITE, 0xa3, 0x38},
 	{DEMOD_WRITE, 0x98, 0xff},
 	{DEMOD_WRITE, 0xc0, 0x0f},
 	{DEMOD_WRITE, 0x89, 0x01},
@@ -625,8 +640,13 @@ static int m88rs2000_set_frontend(struct dvb_frontend *fe)
 	if (ret < 0)
 		return -ENODEV;
 
-	/* Reset Demod */
-	ret = m88rs2000_tab_set(state, fe_reset);
+	/* Reset demod by symbol rate */
+	if (c->symbol_rate > 27500000)
+		ret = m88rs2000_writereg(state, 0xf1, 0xa4);
+	else
+		ret = m88rs2000_writereg(state, 0xf1, 0xbf);
+
+	ret |= m88rs2000_tab_set(state, fe_reset);
 	if (ret < 0)
 		return -ENODEV;
 
-- 
1.8.3.2