24  * digital I/O subdevice with 24 channels.  The channel 0 corresponds to
25  * the 8255's port A, bit 0; channel 23 corresponds to port C, bit 7.
26  * Direction configuration is done in blocks, with channels 0-7, 8-15,
28  * supported is mode 0.
48 		return 0;  in subdev_8255_io()
60 		return 0;  in subdev_8255_mmio()
77 		if (mask & 0xff)  in subdev_8255_insn()
79 				  s->state & 0xff, context);  in subdev_8255_insn()
80 		if (mask & 0xff00)  in subdev_8255_insn()
82 				  (s->state >> 8) & 0xff, context);  in subdev_8255_insn()
83 		if (mask & 0xff0000)  in subdev_8255_insn()
85 				  (s->state >> 16) & 0xff, context);  in subdev_8255_insn()
88 	v = spriv->io(dev, 0, I8255_DATA_A_REG, 0, context);  in subdev_8255_insn()
89 	v |= (spriv->io(dev, 0, I8255_DATA_B_REG, 0, context) << 8);  in subdev_8255_insn()
90 	v |= (spriv->io(dev, 0, I8255_DATA_C_REG, 0, context) << 16);  in subdev_8255_insn()
106 	if (!(s->io_bits & 0x0000ff))  in subdev_8255_do_config()
108 	if (!(s->io_bits & 0x00ff00))  in subdev_8255_do_config()
110 	if (!(s->io_bits & 0x0f0000))  in subdev_8255_do_config()
112 	if (!(s->io_bits & 0xf00000))  in subdev_8255_do_config()
128 		mask = 0x0000ff;  in subdev_8255_insn_config()
130 		mask = 0x00ff00;  in subdev_8255_insn_config()
132 		mask = 0x0f0000;  in subdev_8255_insn_config()
134 		mask = 0xf00000;  in subdev_8255_insn_config()
174 	return 0;  in __subdev_8255_init()
230  * 'port' is the 8255 port number 0 to 3 (including the control port), 'dir'
231  * is the direction (0 for read, 1 for write) and 'data' is the value to be
232  * written.  It should return 0 if writing or the value read if reading.
264 	return 0;  in comedi_8255_module_init()