linux/drivers/media/dvb-frontends/stv0297.h

58 lines
1.7 KiB
C
Raw Normal View History

/*
Driver for STV0297 demodulator
Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef STV0297_H
#define STV0297_H
#include <linux/dvb/frontend.h>
#include <media/dvb_frontend.h>
struct stv0297_config
{
/* the demodulator's i2c address */
u8 demod_address;
/* inittab - array of pairs of values.
* First of each pair is the register, second is the value.
* List should be terminated with an 0xff, 0xff pair.
*/
u8* inittab;
/* does the "inversion" need inverted? */
u8 invert:1;
/* set to 1 if the device requires an i2c STOP during reading */
u8 stop_during_read:1;
};
[media] Add and use IS_REACHABLE macro In the media drivers, the v4l2 core knows about all submodules and calls into them from a common function. However this cannot work if the modules that get called are loadable and the core is built-in. In that case we get drivers/built-in.o: In function `set_type': drivers/media/v4l2-core/tuner-core.c:301: undefined reference to `tea5767_attach' drivers/media/v4l2-core/tuner-core.c:307: undefined reference to `tea5761_attach' drivers/media/v4l2-core/tuner-core.c:349: undefined reference to `tda9887_attach' drivers/media/v4l2-core/tuner-core.c:405: undefined reference to `xc4000_attach' This was working previously, until the IS_ENABLED() macro was used to replace the construct like #if defined(CONFIG_DVB_CX24110) || (defined(CONFIG_DVB_CX24110_MODULE) && defined(MODULE)) with the difference that the new code no longer checks whether it is being built as a loadable module itself. To fix this, this new patch adds an 'IS_REACHABLE' macro, which evaluates true in exactly the condition that was used previously. The downside of this is that this trades an obvious link error for a more subtle runtime failure, but it is clear that the change that introduced the link error was unintentional and it seems better to revert it for now. Also, a similar change was originally created by Trent Piepho and then reverted by teh change to the IS_ENABLED macro. Ideally Kconfig would be used to avoid the case of a broken dependency, or the code restructured in a way to turn around the dependency, but either way would require much larger changes here. Fixes: 7b34be71db53 ("[media] use IS_ENABLED() macro") See-also: c5dec9fb248e ("V4L/DVB (4751): Fix DBV_FE_CUSTOMISE for card drivers compiled into kernel") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-02-19 01:12:42 +08:00
#if IS_REACHABLE(CONFIG_DVB_STV0297)
extern struct dvb_frontend* stv0297_attach(const struct stv0297_config* config,
struct i2c_adapter* i2c);
#else
static inline struct dvb_frontend* stv0297_attach(const struct stv0297_config* config,
struct i2c_adapter* i2c)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return NULL;
}
#endif // CONFIG_DVB_STV0297
#endif // STV0297_H