From f609c29dfb7a5729bfab9384fad45fbf12653c67 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 13 Jan 2015 10:16:24 -0700 Subject: [PATCH] staging: comedi: dt282x: introduce dt282x_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/dt282x.c | 36 ++++++++++++------------- 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c index f24ad6684bf5..2d01c6cfbb4d 100644 --- a/drivers/staging/comedi/drivers/dt282x.c +++ b/drivers/staging/comedi/drivers/dt282x.c @@ -305,6 +305,7 @@ struct dt282x_dma_desc { void *virt_addr; /* virtual address of DMA buffer */ dma_addr_t hw_addr; /* hardware (bus) address of DMA buffer */ unsigned int size; /* transfer size (in bytes) */ + char mode; /* DMA_MODE_* */ }; struct dt282x_private { @@ -325,11 +326,23 @@ struct dt282x_private { int dma_dir; }; +static void dt282x_isadma_program(struct dt282x_dma_desc *dma) +{ + unsigned long flags; + + flags = claim_dma_lock(); + clear_dma_ff(dma->chan); + set_dma_mode(dma->chan, dma->mode); + set_dma_addr(dma->chan, dma->hw_addr); + set_dma_count(dma->chan, dma->size); + enable_dma(dma->chan); + release_dma_lock(flags); +} + static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n) { struct dt282x_private *devpriv = dev->private; struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index]; - unsigned long flags; if (!devpriv->ntrig) return 0; @@ -341,15 +354,9 @@ static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n) devpriv->ntrig -= n / 2; dma->size = n; + dma->mode = DMA_MODE_READ; - set_dma_mode(dma->chan, DMA_MODE_READ); - flags = claim_dma_lock(); - clear_dma_ff(dma->chan); - set_dma_addr(dma->chan, dma->hw_addr); - set_dma_count(dma->chan, dma->size); - release_dma_lock(flags); - - enable_dma(dma->chan); + dt282x_isadma_program(dma); return n; } @@ -358,18 +365,11 @@ static int dt282x_prep_ao_dma(struct comedi_device *dev, int dma_index, int n) { struct dt282x_private *devpriv = dev->private; struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index]; - unsigned long flags; dma->size = n; + dma->mode = DMA_MODE_WRITE; - set_dma_mode(dma->chan, DMA_MODE_WRITE); - flags = claim_dma_lock(); - clear_dma_ff(dma->chan); - set_dma_addr(dma->chan, dma->hw_addr); - set_dma_count(dma->chan, dma->size); - release_dma_lock(flags); - - enable_dma(dma->chan); + dt282x_isadma_program(dma); return n; } -- 2.20.1