linux/drivers/media/dvb-frontends/dib0070.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

77 lines
2.1 KiB
C

/*
* Linux-DVB Driver for DiBcom's DiB0070 base-band RF Tuner.
*
* Copyright (C) 2005-7 DiBcom (http://www.dibcom.fr/)
*
* 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 DIB0070_H
#define DIB0070_H
struct dvb_frontend;
struct i2c_adapter;
#define DEFAULT_DIB0070_I2C_ADDRESS 0x60
struct dib0070_wbd_gain_cfg {
u16 freq;
u16 wbd_gain_val;
};
struct dib0070_config {
u8 i2c_address;
/* tuner pins controlled externally */
int (*reset) (struct dvb_frontend *, int);
int (*sleep) (struct dvb_frontend *, int);
/* offset in kHz */
int freq_offset_khz_uhf;
int freq_offset_khz_vhf;
u8 osc_buffer_state; /* 0= normal, 1= tri-state */
u32 clock_khz;
u8 clock_pad_drive; /* (Drive + 1) * 2mA */
u8 invert_iq; /* invert Q - in case I or Q is inverted on the board */
u8 force_crystal_mode; /* if == 0 -> decision is made in the driver default: <24 -> 2, >=24 -> 1 */
u8 flip_chip;
u8 enable_third_order_filter;
u8 charge_pump;
const struct dib0070_wbd_gain_cfg *wbd_gain;
u8 vga_filter;
};
#if IS_REACHABLE(CONFIG_DVB_TUNER_DIB0070)
extern struct dvb_frontend *dib0070_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct dib0070_config *cfg);
extern u16 dib0070_wbd_offset(struct dvb_frontend *);
extern void dib0070_ctrl_agc_filter(struct dvb_frontend *, u8 open);
extern u8 dib0070_get_rf_output(struct dvb_frontend *fe);
extern int dib0070_set_rf_output(struct dvb_frontend *fe, u8 no);
#else
static inline struct dvb_frontend *dib0070_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct dib0070_config *cfg)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return NULL;
}
static inline u16 dib0070_wbd_offset(struct dvb_frontend *fe)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
return 0;
}
static inline void dib0070_ctrl_agc_filter(struct dvb_frontend *fe, u8 open)
{
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
}
#endif
#endif