From 0196285ebd08e08faab32016f09ae66e1da5d398 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 13 Jan 2015 10:16:31 -0700 Subject: [PATCH] staging: comedi: das16: introduce das16_isadma_program() Introduce a helper function to program the ISA DMA controller. Program the ISA DMA as described in Documentation/DMA-ISA-LPC.txt. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das16.c | 35 ++++++++++++++------------ 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c index f8c444c87f0b..f99796684978 100644 --- a/drivers/staging/comedi/drivers/das16.c +++ b/drivers/staging/comedi/drivers/das16.c @@ -461,6 +461,20 @@ struct das16_private_struct { unsigned int can_burst:1; }; +static void das16_isadma_program(unsigned int dma_chan, + struct das16_dma_desc *dma) +{ + unsigned long flags; + + flags = claim_dma_lock(); + clear_dma_ff(dma_chan); + set_dma_mode(dma_chan, DMA_MODE_READ); + set_dma_addr(dma_chan, dma->hw_addr); + set_dma_count(dma_chan, dma->size); + enable_dma(dma_chan); + release_dma_lock(flags); +} + static void das16_ai_enable(struct comedi_device *dev, unsigned int mode, unsigned int src) { @@ -547,6 +561,7 @@ static void das16_interrupt(struct comedi_device *dev) dma_flags = claim_dma_lock(); clear_dma_ff(devpriv->dma_chan); residue = disable_dma_on_even(dev); + release_dma_lock(dma_flags); /* figure out how many points to read */ if (residue > dma->size) { @@ -565,15 +580,12 @@ static void das16_interrupt(struct comedi_device *dev) devpriv->cur_dma = 1 - devpriv->cur_dma; devpriv->adc_byte_count -= num_bytes; - /* re-enable dma */ + /* re-enable dma */ if ((async->events & COMEDI_CB_EOA) == 0) { nxt_dma = &devpriv->dma_desc[devpriv->cur_dma]; - set_dma_addr(devpriv->dma_chan, nxt_dma->hw_addr); nxt_dma->size = DAS16_DMA_SIZE; - set_dma_count(devpriv->dma_chan, nxt_dma->size); - enable_dma(devpriv->dma_chan); + das16_isadma_program(devpriv->dma_chan, nxt_dma); } - release_dma_lock(dma_flags); spin_unlock_irqrestore(&dev->spinlock, spin_flags); @@ -798,18 +810,10 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s) } outb(byte, dev->iobase + DAS16_PACER_REG); - /* set up dma transfer */ - flags = claim_dma_lock(); - disable_dma(devpriv->dma_chan); - /* clear flip-flop to make sure 2-byte registers for - * count and address get set correctly */ - clear_dma_ff(devpriv->dma_chan); + /* set up dma transfer */ devpriv->cur_dma = 0; - set_dma_addr(devpriv->dma_chan, dma->hw_addr); dma->size = DAS16_DMA_SIZE; - set_dma_count(devpriv->dma_chan, dma->size); - enable_dma(devpriv->dma_chan); - release_dma_lock(flags); + das16_isadma_program(devpriv->dma_chan, dma); /* set up timer */ spin_lock_irqsave(&dev->spinlock, flags); @@ -1018,7 +1022,6 @@ static int das16_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) flags = claim_dma_lock(); disable_dma(devpriv->dma_chan); - set_dma_mode(devpriv->dma_chan, DMA_MODE_READ); release_dma_lock(flags); init_timer(&devpriv->timer); -- 2.30.2