From 6e89008b06c344b49e27febdeb5fc7b84d35fb25 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 12 Jan 2015 10:55:43 -0700 Subject: [PATCH] staging: comedi: das1800: tidy up das1800_init_dma() Refactor this function so that a for loop can be used to request and set up the two DMA descriptors. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das1800.c | 52 ++++++++++++------------ 1 file changed, 25 insertions(+), 27 deletions(-) diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c index 2d376fde2aad..df28d36aa580 100644 --- a/drivers/staging/comedi/drivers/das1800.c +++ b/drivers/staging/comedi/drivers/das1800.c @@ -1228,15 +1228,24 @@ static int das1800_do_wbits(struct comedi_device *dev, return insn->n; } -static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0, - unsigned int dma1) +static int das1800_init_dma(struct comedi_device *dev, + struct comedi_devconfig *it) { struct das1800_private *devpriv = dev->private; struct das1800_dma_desc *dma; + unsigned int *dma_chan; unsigned long flags; + int i; + + /* + * it->options[2] is DMA channel 0 + * it->options[3] is DMA channel 1 + * + * Encode the DMA channels into 2 digit hexadecimal for switch. + */ + dma_chan = &it->options[2]; - /* encode dma0 and dma1 into 2 digit hexadecimal for switch */ - switch ((dma0 & 0x7) | (dma1 << 4)) { + switch ((dma_chan[0] & 0x7) | (dma_chan[1] << 4)) { case 0x5: /* dma0 == 5 */ devpriv->dma_bits |= DMA_CH5; break; @@ -1265,33 +1274,24 @@ static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0, return -EINVAL; } - dma = &devpriv->dma_desc[0]; - if (request_dma(dma0, dev->driver->driver_name)) { - dev_err(dev->class_dev, - "failed to allocate dma channel %i\n", dma0); - return -EINVAL; - } - dma->chan = dma0; - dma->virt_addr = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); - if (!dma->virt_addr) - return -ENOMEM; - flags = claim_dma_lock(); - disable_dma(dma->chan); - set_dma_mode(dma->chan, DMA_MODE_READ); - release_dma_lock(flags); + for (i = 0; i < 2; i++) { + dma = &devpriv->dma_desc[i]; - if (dma1) { - dma = &devpriv->dma_desc[1]; - if (request_dma(dma1, dev->driver->driver_name)) { + if (dma_chan[i] == 0) + break; + + if (request_dma(dma_chan[i], dev->board_name)) { dev_err(dev->class_dev, "failed to allocate dma channel %i\n", - dma1); + dma_chan[i]); return -EINVAL; } - dma->chan = dma1; + dma->chan = dma_chan[i]; + dma->virt_addr = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); if (!dma->virt_addr) return -ENOMEM; + flags = claim_dma_lock(); disable_dma(dma->chan); set_dma_mode(dma->chan, DMA_MODE_READ); @@ -1366,8 +1366,6 @@ static int das1800_attach(struct comedi_device *dev, struct das1800_private *devpriv; struct comedi_subdevice *s; unsigned int irq = it->options[1]; - unsigned int dma0 = it->options[2]; - unsigned int dma1 = it->options[3]; int board; int ret; @@ -1430,8 +1428,8 @@ static int das1800_attach(struct comedi_device *dev, } /* an irq and one dma channel is required to use dma */ - if (dev->irq & dma0) { - ret = das1800_init_dma(dev, dma0, dma1); + if (dev->irq & it->options[2]) { + ret = das1800_init_dma(dev, it); if (ret < 0) return ret; } -- 2.39.5