diff options
| -rw-r--r-- | drivers/dma/mxs-dma.c | 96 |
1 files changed, 60 insertions, 36 deletions
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c index 7ab7cec..1d1b6e9 100644 --- a/drivers/dma/mxs-dma.c +++ b/drivers/dma/mxs-dma.c @@ -27,6 +27,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_dma.h> +#include <linux/list.h> #include <asm/irq.h> @@ -272,58 +273,81 @@ static void mxs_dma_tasklet(unsigned long data) mxs_chan->desc.callback(mxs_chan->desc.callback_param); } +static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq) +{ + int i; + + for (i = 0; i != mxs_dma->nr_channels; ++i) + if (mxs_dma->mxs_chans[i].chan_irq == irq) + return i; + + return -EINVAL; +} + static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id) { struct mxs_dma_engine *mxs_dma = dev_id; - u32 stat1, stat2; + struct mxs_dma_chan *mxs_chan; + u32 completed; + u32 err; + int chan = mxs_dma_irq_to_chan(mxs_dma, irq); + + if (chan < 0) + return IRQ_NONE; /* completion status */ - stat1 = readl(mxs_dma->base + HW_APBHX_CTRL1); - stat1 &= MXS_DMA_CHANNELS_MASK; - writel(stat1, mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR); + completed = readl(mxs_dma->base + HW_APBHX_CTRL1); + completed = (completed >> chan) & 0x1; + + /* Clear interrupt */ + writel((1 << chan), + mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR); /* error status */ - stat2 = readl(mxs_dma->base + HW_APBHX_CTRL2); - writel(stat2, mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR); + err = readl(mxs_dma->base + HW_APBHX_CTRL2); + err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan); + + /* + * error status bit is in the upper 16 bits, error irq bit in the lower + * 16 bits. We transform it into a simpler error code: + * err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR + */ + err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan); + + /* Clear error irq */ + writel((1 << chan), + mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR); /* * When both completion and error of termination bits set at the * same time, we do not take it as an error. IOW, it only becomes - * an error we need to handle here in case of either it's (1) a bus - * error or (2) a termination error with no completion. + * an error we need to handle here in case of either it's a bus + * error or a termination error with no completion. 0x01 is termination + * error, so we can subtract err & completed to get the real error case. */ - stat2 = ((stat2 >> MXS_DMA_CHANNELS) & stat2) | /* (1) */ - (~(stat2 >> MXS_DMA_CHANNELS) & stat2 & ~stat1); /* (2) */ - - /* combine error and completion status for checking */ - stat1 = (stat2 << MXS_DMA_CHANNELS) | stat1; - while (stat1) { - int channel = fls(stat1) - 1; - struct mxs_dma_chan *mxs_chan = - &mxs_dma->mxs_chans[channel % MXS_DMA_CHANNELS]; - - if (channel >= MXS_DMA_CHANNELS) { - dev_dbg(mxs_dma->dma_device.dev, - "%s: error in channel %d\n", __func__, - channel - MXS_DMA_CHANNELS); - mxs_chan->status = DMA_ERROR; - mxs_dma_reset_chan(mxs_chan); - } else { - if (mxs_chan->flags & MXS_DMA_SG_LOOP) - mxs_chan->status = DMA_IN_PROGRESS; - else - mxs_chan->status = DMA_COMPLETE; - } + err -= err & completed; - stat1 &= ~(1 << channel); + mxs_chan = &mxs_dma->mxs_chans[chan]; - if (mxs_chan->status == DMA_COMPLETE) - dma_cookie_complete(&mxs_chan->desc); - - /* schedule tasklet on this channel */ - tasklet_schedule(&mxs_chan->tasklet); + if (err) { + dev_dbg(mxs_dma->dma_device.dev, + "%s: error in channel %d\n", __func__, + chan); + mxs_chan->status = DMA_ERROR; + mxs_dma_reset_chan(mxs_chan); + } else { + if (mxs_chan->flags & MXS_DMA_SG_LOOP) + mxs_chan->status = DMA_IN_PROGRESS; + else + mxs_chan->status = DMA_COMPLETE; } + if (mxs_chan->status == DMA_COMPLETE) + dma_cookie_complete(&mxs_chan->desc); + + /* schedule tasklet on this channel */ + tasklet_schedule(&mxs_chan->tasklet); + return IRQ_HANDLED; } |
