From 1ec64b74c9182e443e8ea26ea3d6df4cdda7e578 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 13 Jan 2015 10:16:33 -0700 Subject: [PATCH] staging: comedi: pcl812: introduce pcl812_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/pcl812.c | 49 +++++++++++++------------ 1 file changed, 25 insertions(+), 24 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index 2c2e7dd9d3a1..6b38147cf2ae 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -533,6 +533,20 @@ struct pcl812_private { unsigned int ai_eos:1; }; +static void pcl812_isadma_program(unsigned int dma_chan, + struct pcl812_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 pcl812_start_pacer(struct comedi_device *dev, bool load_timers) { struct pcl812_private *devpriv = dev->private; @@ -555,7 +569,6 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, struct pcl812_dma_desc *dma0 = &devpriv->dma_desc[0]; struct pcl812_dma_desc *dma1 = &devpriv->dma_desc[1]; struct comedi_cmd *cmd = &s->async->cmd; - unsigned int dma_flags; unsigned int bytes; /* we use EOS, so adapt DMA buffer to one scan */ @@ -595,13 +608,8 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, devpriv->ai_eos = 0; } devpriv->cur_dma = 0; - set_dma_mode(devpriv->dma, DMA_MODE_READ); - dma_flags = claim_dma_lock(); - clear_dma_ff(devpriv->dma); - set_dma_addr(devpriv->dma, dma0->hw_addr); - set_dma_count(devpriv->dma, dma0->size); - release_dma_lock(dma_flags); - enable_dma(devpriv->dma); + + pcl812_isadma_program(devpriv->dma, dma0); } static void pcl812_ai_setup_next_dma(struct comedi_device *dev, @@ -609,26 +617,19 @@ static void pcl812_ai_setup_next_dma(struct comedi_device *dev, { struct pcl812_private *devpriv = dev->private; struct pcl812_dma_desc *dma; - unsigned long dma_flags; + + disable_dma(devpriv->dma); devpriv->cur_dma = 1 - devpriv->cur_dma; dma = &devpriv->dma_desc[devpriv->cur_dma]; - disable_dma(devpriv->dma); - set_dma_mode(devpriv->dma, DMA_MODE_READ); - dma_flags = claim_dma_lock(); - set_dma_addr(devpriv->dma, dma->hw_addr); - if (devpriv->ai_eos) { - set_dma_count(devpriv->dma, dma->size); - } else { - if (devpriv->dma_runs_to_end) { - set_dma_count(devpriv->dma, dma->size); - } else { - set_dma_count(devpriv->dma, devpriv->last_dma_run); - } - devpriv->dma_runs_to_end--; + if (!devpriv->ai_eos) { + if (devpriv->dma_runs_to_end) + devpriv->dma_runs_to_end--; + else + dma->size = devpriv->last_dma_run; } - release_dma_lock(dma_flags); - enable_dma(devpriv->dma); + + pcl812_isadma_program(devpriv->dma, dma); } static void pcl812_ai_set_chan_range(struct comedi_device *dev, -- 2.20.1