From 0afa6153fb6fd2b1865248d96058b26ae2f1bcf5 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 13 Jan 2015 10:16:42 -0700 Subject: [PATCH] staging: comedi: ni_labpc_isadma: introduce labpc_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 --- .../staging/comedi/drivers/ni_labpc_isadma.c | 37 +++++++++---------- 1 file changed, 18 insertions(+), 19 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c index af13f4b37daa..3100549b365c 100644 --- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c +++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c @@ -31,6 +31,19 @@ /* size in bytes of dma buffer */ #define LABPC_ISADMA_BUFFER_SIZE 0xff00 +static void labpc_isadma_program(struct labpc_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 unsigned int labpc_isadma_disable(struct labpc_dma_desc *dma) { unsigned long flags; @@ -77,22 +90,15 @@ void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s) struct labpc_dma_desc *dma = &devpriv->dma_desc; struct comedi_cmd *cmd = &s->async->cmd; unsigned int sample_size = comedi_bytes_per_sample(s); - unsigned long irq_flags; - irq_flags = claim_dma_lock(); - /* clear flip-flop to make sure 2-byte registers for - * count and address get set correctly */ - clear_dma_ff(dma->chan); - set_dma_mode(dma->chan, DMA_MODE_READ); - set_dma_addr(dma->chan, dma->hw_addr); /* set appropriate size of transfer */ dma->size = labpc_suggest_transfer_size(dev, s); if (cmd->stop_src == TRIG_COUNT && devpriv->count * sample_size < dma->size) dma->size = devpriv->count * sample_size; - set_dma_count(dma->chan, dma->size); - enable_dma(dma->chan); - release_dma_lock(irq_flags); + + labpc_isadma_program(dma); + /* set CMD3 bits for caller to enable DMA and interrupt */ devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN); } @@ -145,18 +151,11 @@ static void handle_isa_dma(struct comedi_device *dev) { struct labpc_private *devpriv = dev->private; struct labpc_dma_desc *dma = &devpriv->dma_desc; - unsigned long flags; labpc_drain_dma(dev); - if (dma->size) { - flags = claim_dma_lock(); - 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); - } + if (dma->size) + labpc_isadma_program(dma); /* clear dma tc interrupt */ devpriv->write_byte(dev, 0x1, DMATC_CLEAR_REG); -- 2.34.1