From 16d87782c560fac81627ddc9368b4f7100a1c2f7 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 12 Jan 2015 10:56:02 -0700 Subject: [PATCH] staging: comedi: pcl816: introduce struct pcl816_dma_desc For aesthetics, introduce a struct to hold the DMA descriptor data. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/pcl816.c | 51 ++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 23 deletions(-) diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c index 4cff02a1f720..49c1f170f082 100644 --- a/drivers/staging/comedi/drivers/pcl816.c +++ b/drivers/staging/comedi/drivers/pcl816.c @@ -113,13 +113,17 @@ static const struct pcl816_board boardtypes[] = { }, }; +struct pcl816_dma_desc { + unsigned long virt_addr; /* virtual address of DMA buffer */ + unsigned int hw_addr; /* hardware (bus) address of DMA buffer */ +}; + struct pcl816_private { unsigned int dma; /* used DMA, 0=don't use DMA */ unsigned int dmapages; unsigned int hwdmasize; - unsigned long dmabuf[2]; /* pointers to begin of DMA buffers */ - unsigned int hwdmaptr[2]; /* hardware address of DMA buffers */ - int next_dma_buf; /* which DMA buffer will be used next round */ + struct pcl816_dma_desc dma_desc[2]; + int cur_dma; long dma_runs_to_end; /* how many we must permorm DMA transfer to end of record */ unsigned long last_dma_run; /* how many bytes we must transfer on last DMA page */ unsigned int ai_poll_ptr; /* how many sampes transfer poll */ @@ -152,6 +156,7 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl816_private *devpriv = dev->private; + struct pcl816_dma_desc *dma = &devpriv->dma_desc[0]; struct comedi_cmd *cmd = &s->async->cmd; unsigned int dma_flags; unsigned int bytes; @@ -172,11 +177,11 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev, } else devpriv->dma_runs_to_end = -1; - devpriv->next_dma_buf = 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, devpriv->hwdmaptr[0]); + set_dma_addr(devpriv->dma, dma->hw_addr); set_dma_count(devpriv->dma, bytes); release_dma_lock(dma_flags); enable_dma(devpriv->dma); @@ -187,16 +192,17 @@ static void pcl816_ai_setup_next_dma(struct comedi_device *dev, { struct pcl816_private *devpriv = dev->private; struct comedi_cmd *cmd = &s->async->cmd; + struct pcl816_dma_desc *dma; unsigned long dma_flags; disable_dma(devpriv->dma); if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) { /* switch dma bufs */ - devpriv->next_dma_buf = 1 - devpriv->next_dma_buf; + devpriv->cur_dma = 1 - devpriv->cur_dma; + dma = &devpriv->dma_desc[devpriv->cur_dma]; set_dma_mode(devpriv->dma, DMA_MODE_READ); dma_flags = claim_dma_lock(); - set_dma_addr(devpriv->dma, - devpriv->hwdmaptr[devpriv->next_dma_buf]); + set_dma_addr(devpriv->dma, dma->hw_addr); if (devpriv->dma_runs_to_end) set_dma_count(devpriv->dma, devpriv->hwdmasize); else @@ -318,7 +324,7 @@ static irqreturn_t pcl816_interrupt(int irq, void *d) struct comedi_device *dev = d; struct comedi_subdevice *s = dev->read_subdev; struct pcl816_private *devpriv = dev->private; - unsigned short *ptr; + struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma]; unsigned int bufptr; unsigned int len; @@ -333,15 +339,14 @@ static irqreturn_t pcl816_interrupt(int irq, void *d) return IRQ_HANDLED; } - ptr = (unsigned short *)devpriv->dmabuf[devpriv->next_dma_buf]; - pcl816_ai_setup_next_dma(dev, s); len = (devpriv->hwdmasize >> 1) - devpriv->ai_poll_ptr; bufptr = devpriv->ai_poll_ptr; devpriv->ai_poll_ptr = 0; - transfer_from_dma_buf(dev, s, ptr, bufptr, len); + transfer_from_dma_buf(dev, s, (unsigned short *)dma->virt_addr, + bufptr, len); pcl816_ai_clear_eoc(dev); @@ -521,6 +526,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl816_private *devpriv = dev->private; + struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma]; unsigned long flags; unsigned int top1, top2, i; @@ -546,9 +552,7 @@ static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) return 0; } - transfer_from_dma_buf(dev, s, - (unsigned short *)devpriv->dmabuf[devpriv-> - next_dma_buf], + transfer_from_dma_buf(dev, s, (unsigned short *)dma->virt_addr, devpriv->ai_poll_ptr, top2); devpriv->ai_poll_ptr = top1; /* new buffer position */ @@ -661,6 +665,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev, unsigned int irq_num, unsigned int dma_chan) { struct pcl816_private *devpriv = dev->private; + struct pcl816_dma_desc *dma; int i; /* @@ -692,14 +697,12 @@ static int pcl816_alloc_dma(struct comedi_device *dev, devpriv->hwdmasize = (1 << devpriv->dmapages) * PAGE_SIZE; for (i = 0; i < 2; i++) { - unsigned long dmabuf; + dma = &devpriv->dma_desc[i]; - dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages); - if (!dmabuf) + dma->virt_addr = __get_dma_pages(GFP_KERNEL, devpriv->dmapages); + if (!dma->virt_addr) return -ENOMEM; - - devpriv->dmabuf[i] = dmabuf; - devpriv->hwdmaptr[i] = virt_to_bus((void *)dmabuf); + dma->hw_addr = virt_to_bus((void *)dma->virt_addr); } return 0; } @@ -707,6 +710,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev, static void pcl816_free_dma(struct comedi_device *dev) { struct pcl816_private *devpriv = dev->private; + struct pcl816_dma_desc *dma; int i; if (!devpriv) @@ -715,8 +719,9 @@ static void pcl816_free_dma(struct comedi_device *dev) if (devpriv->dma) free_dma(devpriv->dma); for (i = 0; i < 2; i++) { - if (devpriv->dmabuf[i]) - free_pages(devpriv->dmabuf[i], devpriv->dmapages); + dma = &devpriv->dma_desc[i]; + if (dma->virt_addr) + free_pages(dma->virt_addr, devpriv->dmapages); } } -- 2.11.0