From ee34785cfd07e279b92f6fb1d44573118116841e Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 17 Feb 2014 14:26:49 -0700 Subject: [PATCH] staging: comedi: pcl816: clarify dma channel request in pcl816_attach() All the board types can do DMA using DMA channels 3 or 1. Remove the 'DMAbits', which is a mask of the valid channels, from the boardinfo. Refactor pcl816_attach() to 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/pcl816.c | 33 ++++++------------------- 1 file changed, 7 insertions(+), 26 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c index 5af687ab6b2..e67d24af912 100644 --- a/drivers/staging/comedi/drivers/pcl816.c +++ b/drivers/staging/comedi/drivers/pcl816.c @@ -100,7 +100,6 @@ struct pcl816_board { int n_dochan; const struct comedi_lrange *ai_range_type; unsigned int IRQbits; - unsigned int DMAbits; int ai_maxdata; int ao_maxdata; int ai_chanlist; @@ -118,7 +117,6 @@ static const struct pcl816_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl816, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0xffff, .ao_maxdata = 0xffff, .ai_chanlist = 1024, @@ -133,7 +131,6 @@ static const struct pcl816_board boardtypes[] = { .n_dochan = 16, .ai_range_type = &range_pcl816, .IRQbits = 0x00fc, - .DMAbits = 0x0a, .ai_maxdata = 0x3fff, .ao_maxdata = 0x3fff, .ai_chanlist = 1024, @@ -866,7 +863,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) const struct pcl816_board *board = comedi_board(dev); struct pcl816_private *devpriv; int ret; - unsigned int dma; unsigned long pages; /* int i; */ struct comedi_subdevice *s; @@ -894,30 +890,17 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->irq_blocked = 0; /* number of subdevice which use IRQ */ devpriv->int816_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) { - 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 && (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 = it->options[2]; - devpriv->dma = dma; pages = 2; /* we need 16KB */ devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages); @@ -945,8 +928,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE; } -no_dma: - /* if (board->n_aochan > 0) subdevs[1] = COMEDI_SUBD_AO; if (board->n_dichan > 0) -- 2.46.0