V4L/DVB (10190): cx88: Fix some Kbuild troubles

As Randy Dunlap <randy.dunlap@oracle.com> reported, cx88 has some compilation issues:

drivers/built-in.o: In function `cx88_call_i2c_clients':
(.text+0x20af17): undefined reference to `videobuf_dvb_get_frontend'
drivers/built-in.o: In function `cx8802_probe':
cx88-mpeg.c:(.devinit.text+0x268c4): undefined reference to `videobuf_dvb_alloc_frontend'
cx88-mpeg.c:(.devinit.text+0x268ea): undefined reference to `videobuf_dvb_dealloc_frontends'

With those configs:

CONFIG_VIDEO_CX88=y
CONFIG_VIDEO_CX88_BLACKBIRD=y
CONFIG_VIDEO_CX88_DVB=m
CONFIG_DVB_CORE=m

After carefully examining the code, with the current code, several cx88 drivers
(cx8800, cx8802, cx88_dvb and cx88_blackbird) should be compiled as a module,
if one of them is marked as such. Just fixing Kconfig could create a very complex
set of rules. Also, this hides a problem with the current approach where the dvb
functionality weren't confined inside dvb module.

What happens is that:
	- cx88-i2c (part of cx8800) has some special rules if DVB;
	- cx88-mpeg (cx8802 module) has also part of DVB init code;
	- cx88-dvb has the rest of the dvb code;
	- cx88-blackbird can be used with cx88-mpeg, having cx88-dvb or not.

So, instead of doing some tricks at Kconfig and wait for a next breakage,
this patch moves the dvb code inside cx88-i2c and cx88-mpeg into cx88-dvb.

Another problem is that cx8802 were being compiled, even without cx88-dvb
and cx88-blackbird modules.

While on this code, let's fix also a reported problem:
http://www.linuxtv.org/pipermail/linux-dvb/2009-January/031225.html

A solution for the issue were proposed here:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg00021.html

Thanks to Randy, Andy, Gregoire and Thomas for helping us to detect
and solve the issues.

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

1 files changed, 5 insertions, 19 deletions

diff --git a/drivers/media/video/cx88/cx88-i2c.c b/drivers/media/video/cx88/cx88-i2c.c
index 1ab691d2069..c0ff2305d80 100644
--- a/drivers/media/video/cx88/cx88-i2c.c
+++ b/drivers/media/video/cx88/cx88-i2c.c
@@ -116,30 +116,16 @@ static int detach_inform(struct i2c_client *client)
 
 void cx88_call_i2c_clients(struct cx88_core *core, unsigned int cmd, void *arg)
 {
-#if defined(CONFIG_VIDEO_CX88_DVB) || defined(CONFIG_VIDEO_CX88_DVB_MODULE)
-	struct videobuf_dvb_frontends *f = &core->dvbdev->frontends;
-	struct videobuf_dvb_frontend *fe = NULL;
-#endif
 	if (0 != core->i2c_rc)
 		return;
 
-#if defined(CONFIG_VIDEO_CX88_DVB) || defined(CONFIG_VIDEO_CX88_DVB_MODULE)
-	if (core->dvbdev && f) {
-		if(f->gate <= 1) /* undefined or fe0 */
-			fe = videobuf_dvb_get_frontend(f, 1);
-		else
-			fe = videobuf_dvb_get_frontend(f, f->gate);
+	if (core->gate_ctrl)
+		core->gate_ctrl(core, 1);
 
-		if (fe && fe->dvb.frontend && fe->dvb.frontend->ops.i2c_gate_ctrl)
-			fe->dvb.frontend->ops.i2c_gate_ctrl(fe->dvb.frontend, 1);
+	i2c_clients_command(&core->i2c_adap, cmd, arg);
 
-		i2c_clients_command(&core->i2c_adap, cmd, arg);
-
-		if (fe && fe->dvb.frontend && fe->dvb.frontend->ops.i2c_gate_ctrl)
-			fe->dvb.frontend->ops.i2c_gate_ctrl(fe->dvb.frontend, 0);
-	} else
-#endif
-		i2c_clients_command(&core->i2c_adap, cmd, arg);
+	if (core->gate_ctrl)
+		core->gate_ctrl(core, 0);
 }
 
 static const struct i2c_algo_bit_data cx8800_i2c_algo_template = {