From 4ba4a2d307de7b60b47506346ad5e2bdf37e211a Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 17 Feb 2014 14:26:50 -0700 Subject: [PATCH] staging: comedi: pcl818: clarify dma channel request in pcl818_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 pcl818_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/pcl818.c | 45 +++++++++++++-------------------- 1 file changed, 18 insertions(+), 27 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl818.c b/drivers/staging/comedi/drivers/pcl818.c index a000f742b0bf..9cb3e460c915 100644 --- a/drivers/staging/comedi/drivers/pcl818.c +++ b/drivers/staging/comedi/drivers/pcl818.c @@ -267,9 +267,9 @@ struct pcl818_board { int n_dochan; const struct comedi_lrange *ai_range_type; unsigned int IRQbits; - unsigned int DMAbits; int ai_maxdata; int ao_maxdata; + unsigned int has_dma:1; unsigned int has_fifo:1; int is_818; }; @@ -286,9 +286,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818l_l_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .is_818 = 1, }, { .name = "pcl818h", @@ -301,9 +301,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818h_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .is_818 = 1, }, { .name = "pcl818hd", @@ -316,9 +316,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818h_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .has_fifo = 1, .is_818 = 1, }, { @@ -332,9 +332,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818hg_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .has_fifo = 1, .is_818 = 1, }, { @@ -348,9 +348,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818h_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .is_818 = 1, }, { .name = "pcl718", @@ -363,9 +363,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_unipolar5, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, }, { .name = "pcm3718", .n_ranges = 9, @@ -376,9 +376,9 @@ static const struct pcl818_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl818h_ai, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xfff, .ao_maxdata = 0xfff, + .has_dma = 1, .is_818 = 1, }, }; @@ -1315,7 +1315,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) const struct pcl818_board *board = comedi_board(dev); struct pcl818_private *devpriv; int ret; - int dma; unsigned long pages; struct comedi_subdevice *s; @@ -1347,24 +1346,18 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->irq_blocked = 0; /* number of subdevice which use IRQ */ devpriv->ai_mode = 0; /* mode of irq */ - /* grab our DMA */ - 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 (dma < 1) - goto no_dma; /* DMA disabled */ - if (((1 << dma) & board->DMAbits) == 0) { + /* 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, - "DMA is out of allowed range, FAIL!\n"); - return -EINVAL; /* Bad DMA */ + "unable to request DMA channel %d\n", + it->options[2]); + return -EBUSY; } - ret = request_dma(dma, dev->board_name); - if (ret) - return -EBUSY; /* DMA isn't free */ - devpriv->dma = dma; + devpriv->dma = it->options[2]; + pages = 2; /* we need 16KB */ devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages); if (!devpriv->dmabuf[0]) @@ -1381,8 +1374,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE; } -no_dma: - ret = comedi_alloc_subdevices(dev, 4); if (ret) return ret; -- 2.11.4.GIT