From 9b4dd5d1afb0dea80ab4274433b25a1c0598e855 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 17 Feb 2014 14:27:01 -0700 Subject: [PATCH] staging: comedi: pcl812: tidy up differential ai user option Some of the boards supported by this driver can do differential analog input when configureg with jumpers on the board. When diff. ai is used the number of input channels is half the single-ended number of channels. The user specifies the analog input mode for these boards when attaching to the driver by using a configuration option. Remove the unnecessary 'n_aichan_diff' member from the boardinfo. Add a comment for the boards that can do differential ai. Refactor pcl812_attach() to parse the user option before setting up the subdevices. We can then use the 'use_diff' flag to determine if the ai is single-ended or differential and set the subdev_flags and n_chan. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/pcl812.c | 77 ++++++++++--------------- 1 file changed, 29 insertions(+), 48 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index 4909a106b2c..54bbd9e5926 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -332,7 +332,6 @@ struct pcl812_board { const char *name; int board_type; int n_aichan; - int n_aichan_diff; int n_aochan; int ai_maxdata; unsigned int ai_ns_min; @@ -380,8 +379,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "acl8112dg", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -393,8 +391,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "acl8112hg", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -406,8 +403,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a821pgl", .board_type = boardA821, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 1, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -417,8 +413,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a821pglnda", .board_type = boardA821, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .ai_maxdata = 0x0fff, .ai_ns_min = 10000, .rangelist_ai = &range_pcl813b_ai, @@ -426,8 +421,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a821pgh", .board_type = boardA821, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 1, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -437,8 +431,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a822pgl", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -449,8 +442,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a822pgh", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 10000, @@ -461,8 +453,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a823pgl", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 8000, @@ -473,8 +464,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a823pgh", .board_type = boardACL8112, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0x0fff, .ai_ns_min = 8000, @@ -509,8 +499,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "acl8216", .board_type = boardACL8216, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0xffff, .ai_ns_min = 10000, @@ -522,8 +511,7 @@ static const struct pcl812_board boardtypes[] = { }, { .name = "a826pg", .board_type = boardACL8216, - .n_aichan = 16, - .n_aichan_diff = 8, + .n_aichan = 16, /* 8 differential */ .n_aochan = 2, .ai_maxdata = 0xffff, .ai_ns_min = 10000, @@ -1422,6 +1410,19 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->hwdmasize[1] = PAGE_SIZE * (1 << pages); } + /* differential analog inputs? */ + switch (board->board_type) { + case boardA821: + if (it->options[2] == 1) + devpriv->use_diff = 1; + break; + case boardACL8112: + case boardACL8216: + if (it->options[4] == 1) + devpriv->use_diff = 1; + break; + } + n_subdevices = 1; /* all boardtypes have analog inputs */ if (board->n_aochan > 0) n_subdevices++; @@ -1438,32 +1439,12 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) s = &dev->subdevices[subdev]; s->type = COMEDI_SUBD_AI; s->subdev_flags = SDF_READABLE; - switch (board->board_type) { - case boardA821: - if (it->options[2] == 1) { - s->n_chan = board->n_aichan_diff; - s->subdev_flags |= SDF_DIFF; - devpriv->use_diff = 1; - } else { - s->n_chan = board->n_aichan; - s->subdev_flags |= SDF_GROUND; - } - break; - case boardACL8112: - case boardACL8216: - if (it->options[4] == 1) { - s->n_chan = board->n_aichan_diff; - s->subdev_flags |= SDF_DIFF; - devpriv->use_diff = 1; - } else { - s->n_chan = board->n_aichan; - s->subdev_flags |= SDF_GROUND; - } - break; - default: - s->n_chan = board->n_aichan; + if (devpriv->use_diff) { + s->subdev_flags |= SDF_DIFF; + s->n_chan = board->n_aichan / 2; + } else { s->subdev_flags |= SDF_GROUND; - break; + s->n_chan = board->n_aichan; } s->maxdata = board->ai_maxdata; -- 2.46.0