Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
authored by
Ian Abbott
and committed by
Greg Kroah-Hartman
c62f5032
7b79e3d2
+145
-60
+2
-2
drivers/comedi/drivers/amplc_dio200_common.c
+2
-2
drivers/comedi/drivers/amplc_dio200_common.c
···
149
149
150
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/* get the offset that was passed to comedi_8254_*_init() */
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if (dev->mmio)
152
-
offset = i8254->mmio - dev->mmio;
152
+
offset = (void __iomem *)i8254->context - dev->mmio;
153
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else
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-
offset = i8254->iobase - dev->iobase;
154
+
offset = i8254->context - dev->iobase;
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/* remove the shift that was added for PCIe boards */
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if (board->is_pcie)
+125
-54
drivers/comedi/drivers/comedi_8254.c
+125
-54
drivers/comedi/drivers/comedi_8254.c
···
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#include <linux/comedi/comedidev.h>
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#include <linux/comedi/comedi_8254.h>
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+
static unsigned int i8254_io8_cb(struct comedi_8254 *i8254, int dir,
123
+
unsigned int reg, unsigned int val)
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+
{
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+
unsigned long iobase = i8254->context;
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+
unsigned int reg_offset = (reg * I8254_IO8) << i8254->regshift;
127
+
128
+
if (dir) {
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+
outb(val, iobase + reg_offset);
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+
return 0;
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+
} else {
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+
return inb(iobase + reg_offset);
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+
}
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+
}
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+
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+
static unsigned int i8254_io16_cb(struct comedi_8254 *i8254, int dir,
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+
unsigned int reg, unsigned int val)
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+
{
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+
unsigned long iobase = i8254->context;
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+
unsigned int reg_offset = (reg * I8254_IO16) << i8254->regshift;
141
+
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+
if (dir) {
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+
outw(val, iobase + reg_offset);
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+
return 0;
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+
} else {
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+
return inw(iobase + reg_offset);
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+
}
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+
}
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+
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+
static unsigned int i8254_io32_cb(struct comedi_8254 *i8254, int dir,
151
+
unsigned int reg, unsigned int val)
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+
{
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+
unsigned long iobase = i8254->context;
154
+
unsigned int reg_offset = (reg * I8254_IO32) << i8254->regshift;
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+
156
+
if (dir) {
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+
outl(val, iobase + reg_offset);
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+
return 0;
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+
} else {
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+
return inl(iobase + reg_offset);
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+
}
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+
}
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+
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+
static unsigned int i8254_mmio8_cb(struct comedi_8254 *i8254, int dir,
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+
unsigned int reg, unsigned int val)
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+
{
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+
void __iomem *mmiobase = (void __iomem *)i8254->context;
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+
unsigned int reg_offset = (reg * I8254_IO8) << i8254->regshift;
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+
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+
if (dir) {
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+
writeb(val, mmiobase + reg_offset);
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+
return 0;
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+
} else {
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+
return readb(mmiobase + reg_offset);
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+
}
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+
}
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+
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+
static unsigned int i8254_mmio16_cb(struct comedi_8254 *i8254, int dir,
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+
unsigned int reg, unsigned int val)
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+
{
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+
void __iomem *mmiobase = (void __iomem *)i8254->context;
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+
unsigned int reg_offset = (reg * I8254_IO16) << i8254->regshift;
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+
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+
if (dir) {
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+
writew(val, mmiobase + reg_offset);
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+
return 0;
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+
} else {
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+
return readw(mmiobase + reg_offset);
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+
}
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+
}
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+
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+
static unsigned int i8254_mmio32_cb(struct comedi_8254 *i8254, int dir,
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+
unsigned int reg, unsigned int val)
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+
{
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+
void __iomem *mmiobase = (void __iomem *)i8254->context;
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+
unsigned int reg_offset = (reg * I8254_IO32) << i8254->regshift;
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+
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+
if (dir) {
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+
writel(val, mmiobase + reg_offset);
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+
return 0;
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+
} else {
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+
return readl(mmiobase + reg_offset);
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+
}
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+
}
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+
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static unsigned int __i8254_read(struct comedi_8254 *i8254, unsigned int reg)
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{
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-
unsigned int reg_offset = (reg * i8254->iosize) << i8254->regshift;
125
-
unsigned int val;
126
-
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-
switch (i8254->iosize) {
128
-
default:
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-
case I8254_IO8:
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-
if (i8254->mmio)
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-
val = readb(i8254->mmio + reg_offset);
132
-
else
133
-
val = inb(i8254->iobase + reg_offset);
134
-
break;
135
-
case I8254_IO16:
136
-
if (i8254->mmio)
137
-
val = readw(i8254->mmio + reg_offset);
138
-
else
139
-
val = inw(i8254->iobase + reg_offset);
140
-
break;
141
-
case I8254_IO32:
142
-
if (i8254->mmio)
143
-
val = readl(i8254->mmio + reg_offset);
144
-
else
145
-
val = inl(i8254->iobase + reg_offset);
146
-
break;
147
-
}
148
-
return val & 0xff;
208
+
return 0xff & i8254->iocb(i8254, 0, reg, 0);
149
209
}
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210
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static void __i8254_write(struct comedi_8254 *i8254,
152
212
unsigned int val, unsigned int reg)
153
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{
154
-
unsigned int reg_offset = (reg * i8254->iosize) << i8254->regshift;
155
-
156
-
switch (i8254->iosize) {
157
-
default:
158
-
case I8254_IO8:
159
-
if (i8254->mmio)
160
-
writeb(val, i8254->mmio + reg_offset);
161
-
else
162
-
outb(val, i8254->iobase + reg_offset);
163
-
break;
164
-
case I8254_IO16:
165
-
if (i8254->mmio)
166
-
writew(val, i8254->mmio + reg_offset);
167
-
else
168
-
outw(val, i8254->iobase + reg_offset);
169
-
break;
170
-
case I8254_IO32:
171
-
if (i8254->mmio)
172
-
writel(val, i8254->mmio + reg_offset);
173
-
else
174
-
outl(val, i8254->iobase + reg_offset);
175
-
break;
176
-
}
214
+
i8254->iocb(i8254, 1, reg, val);
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215
}
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179
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/**
···
609
571
}
610
572
EXPORT_SYMBOL_GPL(comedi_8254_subdevice_init);
611
573
612
-
static struct comedi_8254 *__i8254_init(unsigned long iobase,
613
-
void __iomem *mmio,
574
+
static struct comedi_8254 *__i8254_init(comedi_8254_iocb_fn *iocb,
575
+
unsigned long context,
614
576
unsigned int osc_base,
615
577
unsigned int iosize,
616
578
unsigned int regshift)
···
623
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iosize == I8254_IO32))
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return NULL;
625
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588
+
if (!iocb)
589
+
return NULL;
590
+
626
591
i8254 = kzalloc(sizeof(*i8254), GFP_KERNEL);
627
592
if (!i8254)
628
593
return NULL;
629
594
630
-
i8254->iobase = iobase;
631
-
i8254->mmio = mmio;
595
+
i8254->iocb = iocb;
596
+
i8254->context = context;
632
597
i8254->iosize = iosize;
633
598
i8254->regshift = regshift;
634
599
···
658
617
unsigned int iosize,
659
618
unsigned int regshift)
660
619
{
661
-
return __i8254_init(iobase, NULL, osc_base, iosize, regshift);
620
+
comedi_8254_iocb_fn *iocb;
621
+
622
+
switch (iosize) {
623
+
case I8254_IO8:
624
+
iocb = i8254_io8_cb;
625
+
break;
626
+
case I8254_IO16:
627
+
iocb = i8254_io16_cb;
628
+
break;
629
+
case I8254_IO32:
630
+
iocb = i8254_io32_cb;
631
+
break;
632
+
default:
633
+
return NULL;
634
+
}
635
+
return __i8254_init(iocb, iobase, osc_base, iosize, regshift);
662
636
}
663
637
EXPORT_SYMBOL_GPL(comedi_8254_init);
664
638
···
690
634
unsigned int iosize,
691
635
unsigned int regshift)
692
636
{
693
-
return __i8254_init(0, mmio, osc_base, iosize, regshift);
637
+
comedi_8254_iocb_fn *iocb;
638
+
639
+
switch (iosize) {
640
+
case I8254_IO8:
641
+
iocb = i8254_mmio8_cb;
642
+
break;
643
+
case I8254_IO16:
644
+
iocb = i8254_mmio16_cb;
645
+
break;
646
+
case I8254_IO32:
647
+
iocb = i8254_mmio32_cb;
648
+
break;
649
+
default:
650
+
return NULL;
651
+
}
652
+
return __i8254_init(iocb, (unsigned long)mmio, osc_base, iosize, regshift);
694
653
}
695
654
EXPORT_SYMBOL_GPL(comedi_8254_mm_init);
696
655
+18
-4
include/linux/comedi/comedi_8254.h
+18
-4
include/linux/comedi/comedi_8254.h
···
57
57
/* counter maps zero to 0x10000 */
58
58
#define I8254_MAX_COUNT 0x10000
59
59
60
+
struct comedi_8254;
61
+
62
+
/**
63
+
* typedef comedi_8254_iocb_fn - call-back function type for 8254 register access
64
+
* @i8254: pointer to struct comedi_8254
65
+
* @dir: direction (0 = read, 1 = write)
66
+
* @reg: register number
67
+
* @val: value to write
68
+
*
69
+
* Return: Register value when reading, 0 when writing.
70
+
*/
71
+
typedef unsigned int comedi_8254_iocb_fn(struct comedi_8254 *i8254, int dir,
72
+
unsigned int reg, unsigned int val);
73
+
60
74
/**
61
75
* struct comedi_8254 - private data used by this module
62
-
* @iobase: PIO base address of the registers (in/out)
63
-
* @mmio: MMIO base address of the registers (read/write)
76
+
* @iocb: I/O call-back function for register access
77
+
* @context: context for register access (e.g. a base address)
64
78
* @iosize: I/O size used to access the registers (b/w/l)
65
79
* @regshift: register gap shift
66
80
* @osc_base: cascaded oscillator speed in ns
···
90
76
* @insn_config: driver specific (*insn_config) callback
91
77
*/
92
78
struct comedi_8254 {
93
-
unsigned long iobase;
94
-
void __iomem *mmio;
79
+
comedi_8254_iocb_fn *iocb;
80
+
unsigned long context;
95
81
unsigned int iosize;
96
82
unsigned int regshift;
97
83
unsigned int osc_base;