Commit 90d25675 authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

comedi: comedi_8254: Conditionally remove I/O port support 



The comedi_8254 module supports both port I/O and memory-mapped I/O.
In a future patch, the port I/O functions (`inb()`, `outb()`, and
friends) will only be declared if the `HAS_IOPORT` configuration option
is enabled.

Conditionally compile the parts of the module that use port I/O so they
are compiled if and only if the `CONFIG_HAS_IOPORT` macro is defined, so
that it can still be built if the port I/O functions have not been
declared.  If `CONFIG_HAS_IOPORT` is undefined, replace the GPL-exported
`comedi_8254_io_alloc()` function with a dummy static inline version
that just returns `ERR_PTR(-ENXIO)`.

Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20230913170712.111719-5-abbotti@mev.co.uk


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fade5e5b

drivers/comedi/drivers/comedi_8254.c

+8 −0
Original line number Diff line number Diff line
@@ -122,6 +122,8 @@ 
#include <linux/comedi/comedidev.h>

#include <linux/comedi/comedi_8254.h>



#ifdef CONFIG_HAS_IOPORT



static unsigned int i8254_io8_cb(struct comedi_8254 *i8254, int dir,

				unsigned int reg, unsigned int val)

{
@@ -164,6 +166,8 @@ static unsigned int i8254_io32_cb(struct comedi_8254 *i8254, int dir, 
	}

}



#endif	/* CONFIG_HAS_IOPORT */



static unsigned int i8254_mmio8_cb(struct comedi_8254 *i8254, int dir,

				   unsigned int reg, unsigned int val)

{
@@ -648,6 +652,8 @@ static struct comedi_8254 *__i8254_init(comedi_8254_iocb_fn *iocb, 
	return i8254;

}



#ifdef CONFIG_HAS_IOPORT



/**

 * comedi_8254_io_alloc - allocate and initialize the 8254 device for pio access

 * @iobase:	port I/O base address
@@ -682,6 +688,8 @@ struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase, 
}

EXPORT_SYMBOL_GPL(comedi_8254_io_alloc);



#endif	/* CONFIG_HAS_IOPORT */



/**

 * comedi_8254_mm_alloc - allocate and initialize the 8254 device for mmio access

 * @mmio:	memory mapped I/O base address

include/linux/comedi/comedi_8254.h

+13 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 
#define _COMEDI_8254_H



#include <linux/types.h>

#include <linux/errno.h>

#include <linux/err.h>



struct comedi_device;

struct comedi_insn;
@@ -136,10 +138,21 @@ void comedi_8254_set_busy(struct comedi_8254 *i8254, 
void comedi_8254_subdevice_init(struct comedi_subdevice *s,

				struct comedi_8254 *i8254);



#ifdef CONFIG_HAS_IOPORT

struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,

					 unsigned int osc_base,

					 unsigned int iosize,

					 unsigned int regshift);

#else

static inline struct comedi_8254 *comedi_8254_io_alloc(unsigned long iobase,

						       unsigned int osc_base,

						       unsigned int iosize,

						       unsigned int regshift)

{

	return ERR_PTR(-ENXIO);

}

#endif



struct comedi_8254 *comedi_8254_mm_alloc(void __iomem *mmio,

					 unsigned int osc_base,

					 unsigned int iosize,