From 27f3f4d411cb700a5514bfdf93929d1402683061 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 17 Feb 2014 14:26:48 -0700 Subject: [PATCH] staging: comedi: pcl812: clarify dma channel request in pcl812_attach() All the board types that can do DMA can use DMA channels 3 or 1. Remove the 'DMAbits', which is a mask of the valid channels, from the boardinfo and replace it with a bit-field flag 'has_dma'. Refactor pcl812_attach() to use the new flag and remove the need for the goto. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/pcl812.c | 50 +++++++++++-------------- 1 file changed, 21 insertions(+), 29 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index 7b97dbe7276..7f3d3208009 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -340,7 +340,7 @@ struct pcl812_board { unsigned int ai_ns_min; const struct comedi_lrange *rangelist_ai; unsigned int IRQbits; - unsigned char DMAbits; + unsigned int has_dma:1; unsigned char haveMPC508; }; @@ -356,7 +356,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 33000, .rangelist_ai = &range_bipolar10, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "pcl812pg", .board_type = boardPCL812PG, @@ -368,7 +368,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 33000, .rangelist_ai = &range_pcl812pg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "acl8112pg", .board_type = boardPCL812PG, @@ -380,7 +380,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_pcl812pg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "acl8112dg", .board_type = boardACL8112, @@ -393,7 +393,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_acl8112dg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, .haveMPC508 = 1, }, { .name = "acl8112hg", @@ -407,7 +407,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_acl8112hg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, .haveMPC508 = 1, }, { .name = "a821pgl", @@ -454,7 +454,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_acl8112dg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "a822pgh", .board_type = boardACL8112, @@ -467,7 +467,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_acl8112hg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "a823pgl", .board_type = boardACL8112, @@ -480,7 +480,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 8000, .rangelist_ai = &range_acl8112dg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "a823pgh", .board_type = boardACL8112, @@ -493,7 +493,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 8000, .rangelist_ai = &range_acl8112hg_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, { .name = "pcl813", .board_type = boardPCL813, @@ -530,7 +530,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_pcl813b2_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, .haveMPC508 = 1, }, { .name = "a826pg", @@ -544,7 +544,7 @@ static const struct pcl812_board boardtypes[] = { .ai_ns_min = 10000, .rangelist_ai = &range_pcl813b2_ai, .IRQbits = 0xdcfc, - .DMAbits = 0x0a, + .has_dma = 1, }, }; @@ -1290,7 +1290,6 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) const struct pcl812_board *board = comedi_board(dev); struct pcl812_private *devpriv; int ret, subdev; - unsigned int dma; unsigned long pages; struct comedi_subdevice *s; int n_subdevices; @@ -1310,24 +1309,18 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) dev->irq = it->options[1]; } - dma = 0; - devpriv->dma = dma; - if (!dev->irq) - goto no_dma; /* if we haven't IRQ, we can't use DMA */ - if (board->DMAbits != 0) { /* board support DMA */ - dma = it->options[2]; - if (((1 << dma) & board->DMAbits) == 0) { - dev_err(dev->class_dev, - "DMA is out of allowed range, FAIL!\n"); - return -EINVAL; /* Bad DMA */ - } - ret = request_dma(dma, dev->board_name); + /* we need an IRQ to do DMA on channel 3 or 1 */ + if (dev->irq && board->has_dma && + (it->options[2] == 3 || it->options[2] == 1)) { + ret = request_dma(it->options[2], dev->board_name); if (ret) { dev_err(dev->class_dev, - "unable to allocate DMA %u, FAIL!\n", dma); - return -EBUSY; /* DMA isn't free */ + "unable to request DMA channel %d\n", + it->options[2]); + return -EBUSY; } - devpriv->dma = dma; + devpriv->dma = it->options[2]; + pages = 1; /* we want 8KB */ devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages); if (!devpriv->dmabuf[0]) { @@ -1352,7 +1345,6 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->hwdmaptr[1] = virt_to_bus((void *)devpriv->dmabuf[1]); devpriv->hwdmasize[1] = PAGE_SIZE * (1 << pages); } -no_dma: n_subdevices = 0; if (board->n_aichan > 0) -- 2.46.0