diff options
author | Ian Abbott <abbotti@mev.co.uk> | 2023-09-13 20:07:01 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-05 14:34:04 +0300 |
commit | c62f5032f72a745542aa6a7e777c7819c96adfbe (patch) | |
tree | 88a020fa05f2c03975c60cd04346ca76d93f09bf /include | |
parent | 7b79e3d2c6333f410a9dc2e61f987120315f09c0 (diff) | |
download | linux-c62f5032f72a745542aa6a7e777c7819c96adfbe.tar.xz |
comedi: comedi_8254: Use a call-back function for register access
Rework the comedi_8254 module to use a call-back function for register
access. This will make it easier to isolate the parts that will depend
on the `CONFIG_HAS_IOPORT` macro being defined and also allows the
possibility of supplying an external callback function during
initialization by a variant of the `comedi_8254_init()` and
`comedi_8254_mm_init()` functions, although that has not been
implemented yet.
The `struct comedi_8254` members have been changed to use a pointer to a
callback function and a context of type `unsigned long`. The
`comedi_8254_init()` and `comedi_8254_mm_init()` functions use an
internal callback function and set the context to the base address of
the registers (for `comedi_8254_mm_init()` that involves converting a
`void __iomem *` to `unsigned long`).
A minor change to `dio200_subdev_8254_offset()` in the
amplc_dio200_common module has been made due to the changes in `struct
comedi_8254`.
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20230913170712.111719-3-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/comedi/comedi_8254.h | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/include/linux/comedi/comedi_8254.h b/include/linux/comedi/comedi_8254.h index d8264417e53c..18d12321c87d 100644 --- a/include/linux/comedi/comedi_8254.h +++ b/include/linux/comedi/comedi_8254.h @@ -57,10 +57,24 @@ struct comedi_subdevice; /* counter maps zero to 0x10000 */ #define I8254_MAX_COUNT 0x10000 +struct comedi_8254; + +/** + * typedef comedi_8254_iocb_fn - call-back function type for 8254 register access + * @i8254: pointer to struct comedi_8254 + * @dir: direction (0 = read, 1 = write) + * @reg: register number + * @val: value to write + * + * Return: Register value when reading, 0 when writing. + */ +typedef unsigned int comedi_8254_iocb_fn(struct comedi_8254 *i8254, int dir, + unsigned int reg, unsigned int val); + /** * struct comedi_8254 - private data used by this module - * @iobase: PIO base address of the registers (in/out) - * @mmio: MMIO base address of the registers (read/write) + * @iocb: I/O call-back function for register access + * @context: context for register access (e.g. a base address) * @iosize: I/O size used to access the registers (b/w/l) * @regshift: register gap shift * @osc_base: cascaded oscillator speed in ns @@ -76,8 +90,8 @@ struct comedi_subdevice; * @insn_config: driver specific (*insn_config) callback */ struct comedi_8254 { - unsigned long iobase; - void __iomem *mmio; + comedi_8254_iocb_fn *iocb; + unsigned long context; unsigned int iosize; unsigned int regshift; unsigned int osc_base; |