From 08f81bf121ff6a1bc40901e62e4cb222b9825f03 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 6 Jun 2013 15:39:31 -0700 Subject: [PATCH] staging: comedi: pcl730: clean up the register map documentation This driver supports a number of simple digital i/o boards with slight variations in the register map. Clean up the comment about the register map to better document the driver. Remove the #define's used for the registers since thet don't apply to all the board variations supported by the driver. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/pcl730.c | 60 ++++++++++++++++++------- 1 file changed, 43 insertions(+), 17 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl730.c b/drivers/staging/comedi/drivers/pcl730.c index f9e99278152..862e75fd68f 100644 --- a/drivers/staging/comedi/drivers/pcl730.c +++ b/drivers/staging/comedi/drivers/pcl730.c @@ -32,19 +32,46 @@ #include /* - * Register I/O map + * Register map * - * The pcm3730 PC/104 board does not have the PCL730_IDIO_HI register. - * The pcl725 ISA board uses separate registers for isolated digital I/O. - * The p8r8dio, acl7225b, and p16r16dio boards have isolated digital output - * readback and separate registers for isolated digital I/O. - * The pcl733 ISA board uses all four registers for isolated digital inputs. - * The pcl734 ISA board uses all four registers for isolated digital outputs. + * The register map varies slightly depending on the board type but + * all registers are 8-bit. + * + * The boardinfo 'io_range' is used to allow comedi to request the + * proper range required by the board. + * + * The comedi_subdevice 'private' data is used to pass the register + * offset to the (*insn_bits) functions to read/write the correct + * registers. + * + * The basic register mapping looks like this: + * + * BASE+0 Isolated outputs 0-7 (write) / inputs 0-7 (read) + * BASE+1 Isolated outputs 8-15 (write) / inputs 8-15 (read) + * BASE+2 TTL outputs 0-7 (write) / inputs 0-7 (read) + * BASE+3 TTL outputs 8-15 (write) / inputs 8-15 (read) + * + * The pcm3730 board does not have register BASE+1. + * + * The pcl725 and p8r8dio only have registers BASE+0 and BASE+1: + * + * BASE+0 Isolated outputs 0-7 (write) (read back on p8r8dio) + * BASE+1 Isolated inputs 0-7 (read) + * + * The acl7225b and p16r16dio boards have this register mapping: + * + * BASE+0 Isolated outputs 0-7 (write) (read back) + * BASE+1 Isolated outputs 8-15 (write) (read back) + * BASE+2 Isolated inputs 0-7 (read) + * BASE+3 Isolated inputs 8-15 (read) + * + * The pcl733 and pcl733 boards have this register mapping: + * + * BASE+0 Isolated outputs 0-7 (write) or inputs 0-7 (read) + * BASE+1 Isolated outputs 8-15 (write) or inputs 8-15 (read) + * BASE+2 Isolated outputs 16-23 (write) or inputs 16-23 (read) + * BASE+3 Isolated outputs 24-31 (write) or inputs 24-31 (read) */ -#define PCL730_IDIO_LO 0 /* Isolated Digital I/O low byte (ID0-ID7) */ -#define PCL730_IDIO_HI 1 /* Isolated Digital I/O high byte (ID8-ID15) */ -#define PCL730_DIO_LO 2 /* TTL Digital I/O low byte (D0-D7) */ -#define PCL730_DIO_HI 3 /* TTL Digital I/O high byte (D8-D15) */ struct pcl730_board { const char *name; @@ -217,7 +244,7 @@ static int pcl730_attach(struct comedi_device *dev, s->maxdata = 1; s->range_table = &range_digital; s->insn_bits = pcl730_do_insn_bits; - s->private = (void *)PCL730_IDIO_LO; + s->private = (void *)0; /* get the initial state if supported */ if (board->has_readback) @@ -233,9 +260,8 @@ static int pcl730_attach(struct comedi_device *dev, s->maxdata = 1; s->range_table = &range_digital; s->insn_bits = pcl730_di_insn_bits; - s->private = board->is_acl7225b ? (void *)PCL730_DIO_LO : - board->is_pcl725 ? (void *)PCL730_IDIO_HI - : (void *)PCL730_IDIO_LO; + s->private = board->is_acl7225b ? (void *)2 : + board->is_pcl725 ? (void *)1 : (void *)0; } if (board->has_ttl_io) { @@ -247,7 +273,7 @@ static int pcl730_attach(struct comedi_device *dev, s->maxdata = 1; s->range_table = &range_digital; s->insn_bits = pcl730_do_insn_bits; - s->private = (void *)PCL730_DIO_LO; + s->private = (void *)2; /* TTL Digital Inputs */ s = &dev->subdevices[subdev++]; @@ -257,7 +283,7 @@ static int pcl730_attach(struct comedi_device *dev, s->maxdata = 1; s->range_table = &range_digital; s->insn_bits = pcl730_di_insn_bits; - s->private = (void *)PCL730_DIO_LO; + s->private = (void *)2; } return 0; -- 2.46.0