From: H Hartley Sweeten Date: Mon, 12 Jan 2015 17:56:07 +0000 (-0700) Subject: staging: comedi: pcl812: introduce struct pcl812_dma_desc X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=d8332a68976fc58ef79284548636f86b3f1c124e;p=deliverable%2Flinux.git staging: comedi: pcl812: introduce struct pcl812_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 --- diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index b628f061d8bc..d9f94c982916 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -506,6 +506,12 @@ static const struct pcl812_board boardtypes[] = { }, }; +struct pcl812_dma_desc { + unsigned long virt_addr; /* virtual address of DMA buffer */ + unsigned int hw_addr; /* hardware (bus) address of DMA buffer */ + unsigned int size; /* transfer size (in bytes) */ +}; + struct pcl812_private { unsigned char dma; /* >0 use dma ( usedDMA channel) */ unsigned char range_correction; /* =1 we must add 1 to range number */ @@ -514,10 +520,8 @@ struct pcl812_private { unsigned int ai_poll_ptr; /* how many sampes transfer poll */ unsigned int dmapages; unsigned int hwdmasize; - unsigned long dmabuf[2]; /* PTR to DMA buf */ - unsigned int hwdmaptr[2]; /* HW PTR to DMA buf */ - unsigned int dmabytestomove[2]; /* how many bytes DMA transfer */ - int next_dma_buf; /* which buffer is next to use */ + struct pcl812_dma_desc dma_desc[2]; + int cur_dma; unsigned int dma_runs_to_end; /* how many times we must switch DMA buffers */ unsigned int last_dma_run; /* how many bytes to transfer on last DMA buffer */ unsigned int max_812_ai_mode0_rangewait; /* setling time for gain */ @@ -549,23 +553,23 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl812_private *devpriv = dev->private; + 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 */ if (devpriv->ai_eos) { - devpriv->dmabytestomove[0] = comedi_bytes_per_scan(s); - devpriv->dmabytestomove[1] = comedi_bytes_per_scan(s); + dma0->size = comedi_bytes_per_scan(s); + dma1->size = comedi_bytes_per_scan(s); devpriv->dma_runs_to_end = 1; } else { - devpriv->dmabytestomove[0] = devpriv->hwdmasize; - devpriv->dmabytestomove[1] = devpriv->hwdmasize; + dma0->size = devpriv->hwdmasize; + dma1->size = devpriv->hwdmasize; if (s->async->prealloc_bufsz < devpriv->hwdmasize) { - devpriv->dmabytestomove[0] = - s->async->prealloc_bufsz; - devpriv->dmabytestomove[1] = - s->async->prealloc_bufsz; + dma0->size = s->async->prealloc_bufsz; + dma1->size = s->async->prealloc_bufsz; } if (cmd->stop_src == TRIG_NONE) { devpriv->dma_runs_to_end = 1; @@ -574,32 +578,29 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev, bytes = cmd->stop_arg * comedi_bytes_per_scan(s); /* how many DMA pages we must fill */ - devpriv->dma_runs_to_end = - bytes / devpriv->dmabytestomove[0]; + devpriv->dma_runs_to_end = bytes / dma0->size; /* on last dma transfer must be moved */ - devpriv->last_dma_run = - bytes % devpriv->dmabytestomove[0]; + devpriv->last_dma_run = bytes % dma0->size; if (devpriv->dma_runs_to_end == 0) - devpriv->dmabytestomove[0] = - devpriv->last_dma_run; + dma0->size = devpriv->last_dma_run; devpriv->dma_runs_to_end--; } } - if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) { - devpriv->dmabytestomove[0] = devpriv->hwdmasize; + if (dma0->size > devpriv->hwdmasize) { + dma0->size = devpriv->hwdmasize; devpriv->ai_eos = 0; } - if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) { - devpriv->dmabytestomove[1] = devpriv->hwdmasize; + if (dma1->size > devpriv->hwdmasize) { + dma1->size = devpriv->hwdmasize; devpriv->ai_eos = 0; } - 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_count(devpriv->dma, devpriv->dmabytestomove[0]); + set_dma_addr(devpriv->dma, dma0->hw_addr); + set_dma_count(devpriv->dma, dma0->size); release_dma_lock(dma_flags); enable_dma(devpriv->dma); } @@ -608,21 +609,20 @@ static void pcl812_ai_setup_next_dma(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl812_private *devpriv = dev->private; + struct pcl812_dma_desc *dma; unsigned long dma_flags; - devpriv->next_dma_buf = 1 - devpriv->next_dma_buf; + 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, devpriv->hwdmaptr[devpriv->next_dma_buf]); + set_dma_addr(devpriv->dma, dma->hw_addr); if (devpriv->ai_eos) { - set_dma_count(devpriv->dma, - devpriv->dmabytestomove[devpriv->next_dma_buf]); + set_dma_count(devpriv->dma, dma->size); } else { if (devpriv->dma_runs_to_end) { - set_dma_count(devpriv->dma, - devpriv->dmabytestomove[devpriv-> - next_dma_buf]); + set_dma_count(devpriv->dma, dma->size); } else { set_dma_count(devpriv->dma, devpriv->last_dma_run); } @@ -895,19 +895,17 @@ static void pcl812_handle_dma(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl812_private *devpriv = dev->private; - int len, bufptr; - unsigned short *ptr; - - ptr = (unsigned short *)devpriv->dmabuf[devpriv->next_dma_buf]; - len = (devpriv->dmabytestomove[devpriv->next_dma_buf] >> 1) - - devpriv->ai_poll_ptr; + struct pcl812_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma]; + unsigned int nsamples; + int bufptr; pcl812_ai_setup_next_dma(dev, s); + nsamples = comedi_bytes_to_samples(s, dma->size) - 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, (void *)dma->virt_addr, bufptr, nsamples); } static irqreturn_t pcl812_interrupt(int irq, void *d) @@ -935,6 +933,7 @@ static irqreturn_t pcl812_interrupt(int irq, void *d) static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) { struct pcl812_private *devpriv = dev->private; + struct pcl812_dma_desc *dma; unsigned long flags; unsigned int top1, top2, i; @@ -956,7 +955,8 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) return 0; } /* where is now DMA in buffer */ - top1 = devpriv->dmabytestomove[1 - devpriv->next_dma_buf] - top1; + dma = &devpriv->dma_desc[1 - devpriv->cur_dma]; + top1 = dma->size - top1; top1 >>= 1; /* sample position */ top2 = top1 - devpriv->ai_poll_ptr; if (top2 < 1) { /* no new samples */ @@ -964,9 +964,7 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s) return 0; } - transfer_from_dma_buf(dev, s, - (void *)devpriv->dmabuf[1 - - devpriv->next_dma_buf], + transfer_from_dma_buf(dev, s, (void *)dma->virt_addr, devpriv->ai_poll_ptr, top2); devpriv->ai_poll_ptr = top1; /* new buffer position */ @@ -1195,6 +1193,7 @@ static void pcl812_set_ai_range_table(struct comedi_device *dev, static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) { struct pcl812_private *devpriv = dev->private; + struct pcl812_dma_desc *dma; int i; if (!(dma_chan == 3 || dma_chan == 1)) @@ -1208,14 +1207,13 @@ static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) 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; } @@ -1223,14 +1221,16 @@ static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan) static void pcl812_free_dma(struct comedi_device *dev) { struct pcl812_private *devpriv = dev->private; + struct pcl812_dma_desc *dma; int i; if (!devpriv) return; 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); } if (devpriv->dma) free_dma(devpriv->dma);