From f19810d21becb4f3a92ce8d0b7cc2a0657a153de Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 12 Jan 2015 10:55:40 -0700 Subject: [PATCH] staging: comedi: das1800: reduce indent level of das1800_init_dma() An IRQ and at least one DMA channel are required to use DMA with this driver. Move the check to the caller to reduce the indent level of this function. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das1800.c | 129 ++++++++++++----------- 1 file changed, 65 insertions(+), 64 deletions(-) diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c index be825d21a185..c415b578f5fb 100644 --- a/drivers/staging/comedi/drivers/das1800.c +++ b/drivers/staging/comedi/drivers/das1800.c @@ -1240,72 +1240,70 @@ static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0, struct das1800_private *devpriv = dev->private; unsigned long flags; - /* need an irq to do dma */ - if (dev->irq && dma0) { - /* encode dma0 and dma1 into 2 digit hexadecimal for switch */ - switch ((dma0 & 0x7) | (dma1 << 4)) { - case 0x5: /* dma0 == 5 */ - devpriv->dma_bits |= DMA_CH5; - break; - case 0x6: /* dma0 == 6 */ - devpriv->dma_bits |= DMA_CH6; - break; - case 0x7: /* dma0 == 7 */ - devpriv->dma_bits |= DMA_CH7; - break; - case 0x65: /* dma0 == 5, dma1 == 6 */ - devpriv->dma_bits |= DMA_CH5_CH6; - break; - case 0x76: /* dma0 == 6, dma1 == 7 */ - devpriv->dma_bits |= DMA_CH6_CH7; - break; - case 0x57: /* dma0 == 7, dma1 == 5 */ - devpriv->dma_bits |= DMA_CH7_CH5; - break; - default: - dev_err(dev->class_dev, - "only supports dma channels 5 through 7\n"); - dev_err(dev->class_dev, - "Dual dma only allows the following combinations:\n"); - dev_err(dev->class_dev, - "dma 5,6 / 6,7 / or 7,5\n"); - return -EINVAL; - } - if (request_dma(dma0, dev->driver->driver_name)) { + /* encode dma0 and dma1 into 2 digit hexadecimal for switch */ + switch ((dma0 & 0x7) | (dma1 << 4)) { + case 0x5: /* dma0 == 5 */ + devpriv->dma_bits |= DMA_CH5; + break; + case 0x6: /* dma0 == 6 */ + devpriv->dma_bits |= DMA_CH6; + break; + case 0x7: /* dma0 == 7 */ + devpriv->dma_bits |= DMA_CH7; + break; + case 0x65: /* dma0 == 5, dma1 == 6 */ + devpriv->dma_bits |= DMA_CH5_CH6; + break; + case 0x76: /* dma0 == 6, dma1 == 7 */ + devpriv->dma_bits |= DMA_CH6_CH7; + break; + case 0x57: /* dma0 == 7, dma1 == 5 */ + devpriv->dma_bits |= DMA_CH7_CH5; + break; + default: + dev_err(dev->class_dev, + "only supports dma channels 5 through 7\n"); + dev_err(dev->class_dev, + "Dual dma only allows the following combinations:\n"); + dev_err(dev->class_dev, + "dma 5,6 / 6,7 / or 7,5\n"); + return -EINVAL; + } + if (request_dma(dma0, dev->driver->driver_name)) { + dev_err(dev->class_dev, + "failed to allocate dma channel %i\n", dma0); + return -EINVAL; + } + devpriv->dma0 = dma0; + devpriv->dma_current = dma0; + if (dma1) { + if (request_dma(dma1, dev->driver->driver_name)) { dev_err(dev->class_dev, - "failed to allocate dma channel %i\n", dma0); + "failed to allocate dma channel %i\n", + dma1); return -EINVAL; } - devpriv->dma0 = dma0; - devpriv->dma_current = dma0; - if (dma1) { - if (request_dma(dma1, dev->driver->driver_name)) { - dev_err(dev->class_dev, - "failed to allocate dma channel %i\n", - dma1); - return -EINVAL; - } - devpriv->dma1 = dma1; - } - devpriv->ai_buf0 = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); - if (devpriv->ai_buf0 == NULL) + devpriv->dma1 = dma1; + } + devpriv->ai_buf0 = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); + if (devpriv->ai_buf0 == NULL) + return -ENOMEM; + devpriv->dma_current_buf = devpriv->ai_buf0; + if (dma1) { + devpriv->ai_buf1 = + kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); + if (devpriv->ai_buf1 == NULL) return -ENOMEM; - devpriv->dma_current_buf = devpriv->ai_buf0; - if (dma1) { - devpriv->ai_buf1 = - kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA); - if (devpriv->ai_buf1 == NULL) - return -ENOMEM; - } - flags = claim_dma_lock(); - disable_dma(devpriv->dma0); - set_dma_mode(devpriv->dma0, DMA_MODE_READ); - if (dma1) { - disable_dma(devpriv->dma1); - set_dma_mode(devpriv->dma1, DMA_MODE_READ); - } - release_dma_lock(flags); } + flags = claim_dma_lock(); + disable_dma(devpriv->dma0); + set_dma_mode(devpriv->dma0, DMA_MODE_READ); + if (dma1) { + disable_dma(devpriv->dma1); + set_dma_mode(devpriv->dma1, DMA_MODE_READ); + } + release_dma_lock(flags); + return 0; } @@ -1437,9 +1435,12 @@ static int das1800_attach(struct comedi_device *dev, } } - ret = das1800_init_dma(dev, dma0, dma1); - if (ret < 0) - return ret; + /* an irq and one dma channel is required to use dma */ + if (dev->irq & dma0) { + ret = das1800_init_dma(dev, dma0, dma1); + if (ret < 0) + return ret; + } if (devpriv->ai_buf0 == NULL) { devpriv->ai_buf0 = -- 2.20.1