linux/drivers/media/tuners/tuner-xc2028.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

73 lines
1.7 KiB
C

/* tuner-xc2028
*
* Copyright (c) 2007-2008 Mauro Carvalho Chehab (mchehab@infradead.org)
* This code is placed under the terms of the GNU General Public License v2
*/
#ifndef __TUNER_XC2028_H__
#define __TUNER_XC2028_H__
#include "dvb_frontend.h"
#define XC2028_DEFAULT_FIRMWARE "xc3028-v27.fw"
#define XC3028L_DEFAULT_FIRMWARE "xc3028L-v36.fw"
/* Dmoduler IF (kHz) */
#define XC3028_FE_DEFAULT 0 /* Don't load SCODE */
#define XC3028_FE_LG60 6000
#define XC3028_FE_ATI638 6380
#define XC3028_FE_OREN538 5380
#define XC3028_FE_OREN36 3600
#define XC3028_FE_TOYOTA388 3880
#define XC3028_FE_TOYOTA794 7940
#define XC3028_FE_DIBCOM52 5200
#define XC3028_FE_ZARLINK456 4560
#define XC3028_FE_CHINA 5200
enum firmware_type {
XC2028_AUTO = 0, /* By default, auto-detects */
XC2028_D2633,
XC2028_D2620,
};
struct xc2028_ctrl {
char *fname;
int max_len;
int msleep;
unsigned int scode_table;
unsigned int mts :1;
unsigned int input1:1;
unsigned int vhfbw7:1;
unsigned int uhfbw8:1;
unsigned int disable_power_mgmt:1;
unsigned int read_not_reliable:1;
unsigned int demod;
enum firmware_type type:2;
};
struct xc2028_config {
struct i2c_adapter *i2c_adap;
u8 i2c_addr;
struct xc2028_ctrl *ctrl;
};
/* xc2028 commands for callback */
#define XC2028_TUNER_RESET 0
#define XC2028_RESET_CLK 1
#define XC2028_I2C_FLUSH 2
#if IS_REACHABLE(CONFIG_MEDIA_TUNER_XC2028)
extern struct dvb_frontend *xc2028_attach(struct dvb_frontend *fe,
struct xc2028_config *cfg);
#else
static inline struct dvb_frontend *xc2028_attach(struct dvb_frontend *fe,
struct xc2028_config *cfg)
{
printk(KERN_INFO "%s: not probed - driver disabled by Kconfig\n",
__func__);
return NULL;
}
#endif
#endif /* __TUNER_XC2028_H__ */