linux/drivers/media/dvb-frontends/dib3000mc.h
Arnd Bergmann 9b174527e7 [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: 7b34be71db ("[media] use IS_ENABLED() macro")
See-also: c5dec9fb24 ("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>
2015-04-08 15:02:07 -03:00

87 lines
2.2 KiB
C

/*
* Driver for DiBcom DiB3000MC/P-demodulator.
*
* Copyright (C) 2004-6 DiBcom (http://www.dibcom.fr/)
* Copyright (C) 2004-5 Patrick Boettcher (patrick.boettcher\@desy.de)
*
* This code is partially based on the previous dib3000mc.c .
*
* 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, version 2.
*/
#ifndef DIB3000MC_H
#define DIB3000MC_H
#include <linux/kconfig.h>
#include "dibx000_common.h"
struct dib3000mc_config {
struct dibx000_agc_config *agc;
u8 phase_noise_mode;
u8 impulse_noise_mode;
u8 pwm3_inversion;
u8 use_pwm3;
u16 pwm3_value;
u16 max_time;
u16 ln_adc_level;
u8 agc_command1 :1;
u8 agc_command2 :1;
u8 mobile_mode;
u8 output_mpeg2_in_188_bytes;
};
#define DEFAULT_DIB3000MC_I2C_ADDRESS 16
#define DEFAULT_DIB3000P_I2C_ADDRESS 24
#if IS_REACHABLE(CONFIG_DVB_DIB3000MC)
extern struct dvb_frontend *dib3000mc_attach(struct i2c_adapter *i2c_adap,
u8 i2c_addr,
struct dib3000mc_config *cfg);
extern int dib3000mc_i2c_enumeration(struct i2c_adapter *i2c,
int no_of_demods, u8 default_addr,
struct dib3000mc_config cfg[]);
extern
struct i2c_adapter *dib3000mc_get_tuner_i2c_master(struct dvb_frontend *demod,
int gating);
#else
static inline
struct dvb_frontend *dib3000mc_attach(struct i2c_adapter *i2c_adap, u8 i2c_addr,
struct dib3000mc_config *cfg)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return NULL;
}
static inline
int dib3000mc_i2c_enumeration(struct i2c_adapter *i2c,
int no_of_demods, u8 default_addr,
struct dib3000mc_config cfg[])
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return -ENODEV;
}
static inline
struct i2c_adapter *dib3000mc_get_tuner_i2c_master(struct dvb_frontend *demod,
int gating)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return NULL;
}
#endif // CONFIG_DVB_DIB3000MC
extern int dib3000mc_pid_control(struct dvb_frontend *fe, int index, int pid,int onoff);
extern int dib3000mc_pid_parse(struct dvb_frontend *fe, int onoff);
extern void dib3000mc_set_config(struct dvb_frontend *, struct dib3000mc_config *);
#endif