[media] Add support for TechniSat Skystar S2

This patch adds support for the Technisat Skystar S2 - this
has been tried before but the cx24120 driver was a bit out of shape
and it didn't got any further:

https://patchwork.linuxtv.org/patch/10575/

It is an old card, but currently being sold off for next to nothing,
so it's proving quite popular of late. Noticing it's quite similar
to the cx24116 and cx24117 I've rewritten the driver in a similar way.

There were a few registers and commands from those drivers
missing from this one I've tested out and found they do something so
they've been added in to speed up tuning and to make get_frontend
return something useful.

Signed-off-by: Jemma Denson <jdenson@gmail.com>
Signed-off-by: Patrick.Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/common/b2c2/Kconfig

@@ -14,6 +14,7 @@ config DVB_B2C2_FLEXCOP
 	select DVB_S5H1420 if MEDIA_SUBDRV_AUTOSELECT
 	select DVB_TUNER_ITD1000 if MEDIA_SUBDRV_AUTOSELECT
 	select DVB_ISL6421 if MEDIA_SUBDRV_AUTOSELECT
+	select DVB_CX24120 if MEDIA_SUBDRV_AUTOSELECT
 	select DVB_CX24123 if MEDIA_SUBDRV_AUTOSELECT
 	select MEDIA_TUNER_SIMPLE if MEDIA_SUBDRV_AUTOSELECT
 	select DVB_TUNER_CX24113 if MEDIA_SUBDRV_AUTOSELECT

drivers/media/common/b2c2/flexcop-fe-tuner.c

@@ -12,6 +12,7 @@
 #include "cx24113.h"
 #include "cx24123.h"
 #include "isl6421.h"
+#include "cx24120.h"
 #include "mt352.h"
 #include "bcm3510.h"
 #include "nxt200x.h"
@@ -26,6 +27,16 @@
 #define FE_SUPPORTED(fe) (defined(CONFIG_DVB_##fe) || \
 	(defined(CONFIG_DVB_##fe##_MODULE) && defined(MODULE)))
 
+#if FE_SUPPORTED(BCM3510) || FE_SUPPORTED(CX24120)
+static int flexcop_fe_request_firmware(struct dvb_frontend *fe,
+	const struct firmware **fw, char *name)
+{
+	struct flexcop_device *fc = fe->dvb->priv;
+
+	return request_firmware(fw, name, fc->dev);
+}
+#endif
+
 /* lnb control */
 #if FE_SUPPORTED(MT312) || FE_SUPPORTED(STV0299)
 static int flexcop_set_voltage(struct dvb_frontend *fe, fe_sec_voltage_t voltage)
@@ -445,13 +456,6 @@ static int airstar_dvbt_attach(struct flexcop_device *fc,
 
 /* AirStar ATSC 1st generation */
 #if FE_SUPPORTED(BCM3510)
-static int flexcop_fe_request_firmware(struct dvb_frontend *fe,
-	const struct firmware **fw, char* name)
-{
-	struct flexcop_device *fc = fe->dvb->priv;
-	return request_firmware(fw, name, fc->dev);
-}
-
 static struct bcm3510_config air2pc_atsc_first_gen_config = {
 	.demod_address    = 0x0f,
 	.request_firmware = flexcop_fe_request_firmware,
@@ -619,6 +623,38 @@ fail:
 #define cablestar2_attach NULL
 #endif
 
+/* SkyStar S2 PCI DVB-S/S2 card based on Conexant cx24120/cx24118 */
+#if FE_SUPPORTED(CX24120) && FE_SUPPORTED(ISL6421)
+static const struct cx24120_config skystar2_rev3_3_cx24120_config = {
+	.i2c_addr = 0x55,
+	.xtal_khz = 10111,
+	.initial_mpeg_config = { 0xa1, 0x76, 0x07 },
+	.request_firmware = flexcop_fe_request_firmware,
+};
+
+static int skystarS2_rev33_attach(struct flexcop_device *fc,
+	struct i2c_adapter *i2c)
+{
+	fc->fe = dvb_attach(cx24120_attach,
+		&skystar2_rev3_3_cx24120_config, i2c);
+	if (fc->fe == NULL)
+		return 0;
+
+	fc->dev_type = FC_SKYS2_REV33;
+	fc->fc_i2c_adap[2].no_base_addr = 1;
+	if ((dvb_attach(isl6421_attach, fc->fe,
+		&fc->fc_i2c_adap[2].i2c_adap, 0x08, 0, 0, false) == NULL)) {
+		err("ISL6421 could NOT be attached!");
+		return 0;
+	}
+	info("ISL6421 successfully attached.");
+
+	return 1;
+}
+#else
+#define skystarS2_rev33_attach NULL
+#endif
+
 static struct {
 	flexcop_device_type_t type;
 	int (*attach)(struct flexcop_device *, struct i2c_adapter *);
@@ -632,6 +668,7 @@ static struct {
 	{ FC_AIR_ATSC1, airstar_atsc1_attach },
 	{ FC_CABLE, cablestar2_attach },
 	{ FC_SKY_REV23, skystar2_rev23_attach },
+	{ FC_SKYS2_REV33, skystarS2_rev33_attach },
 };
 
 /* try to figure out the frontend */

drivers/media/common/b2c2/flexcop-misc.c

@@ -56,6 +56,7 @@ static const char *flexcop_device_names[] = {
 	[FC_SKY_REV26]	= "Sky2PC/SkyStar 2 DVB-S rev 2.6",
 	[FC_SKY_REV27]	= "Sky2PC/SkyStar 2 DVB-S rev 2.7a/u",
 	[FC_SKY_REV28]	= "Sky2PC/SkyStar 2 DVB-S rev 2.8",
+	[FC_SKYS2_REV33] = "Sky2PC/SkyStar S2 DVB-S/S2 rev 3.3",
 };
 
 static const char *flexcop_bus_names[] = {

drivers/media/common/b2c2/flexcop-reg.h

@@ -24,6 +24,7 @@ typedef enum {
 	FC_SKY_REV26,
 	FC_SKY_REV27,
 	FC_SKY_REV28,
+	FC_SKYS2_REV33,
 } flexcop_device_type_t;
 
 typedef enum {