diff options
| -rw-r--r-- | drivers/dma/mmp_pdma.c | 87 |
1 files changed, 84 insertions, 3 deletions
diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index 7affa533d2a..a7b186d536b 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -29,8 +29,8 @@ #define DALGN 0x00a0 #define DINT 0x00f0 #define DDADR 0x0200 -#define DSADR 0x0204 -#define DTADR 0x0208 +#define DSADR(n) (0x0204 + ((n) << 4)) +#define DTADR(n) (0x0208 + ((n) << 4)) #define DCMD 0x020c #define DCSR_RUN BIT(31) /* Run Bit (read / write) */ @@ -748,11 +748,92 @@ static int mmp_pdma_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, return 0; } +static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan, + dma_cookie_t cookie) +{ + struct mmp_pdma_desc_sw *sw; + u32 curr, residue = 0; + bool passed = false; + bool cyclic = chan->cyclic_first != NULL; + + /* + * If the channel does not have a phy pointer anymore, it has already + * been completed. Therefore, its residue is 0. + */ + if (!chan->phy) + return 0; + + if (chan->dir == DMA_DEV_TO_MEM) + curr = readl(chan->phy->base + DTADR(chan->phy->idx)); + else + curr = readl(chan->phy->base + DSADR(chan->phy->idx)); + + list_for_each_entry(sw, &chan->chain_running, node) { + u32 start, end, len; + + if (chan->dir == DMA_DEV_TO_MEM) + start = sw->desc.dtadr; + else + start = sw->desc.dsadr; + + len = sw->desc.dcmd & DCMD_LENGTH; + end = start + len; + + /* + * 'passed' will be latched once we found the descriptor which + * lies inside the boundaries of the curr pointer. All + * descriptors that occur in the list _after_ we found that + * partially handled descriptor are still to be processed and + * are hence added to the residual bytes counter. + */ + + if (passed) { + residue += len; + } else if (curr >= start && curr <= end) { + residue += end - curr; + passed = true; + } + + /* + * Descriptors that have the ENDIRQEN bit set mark the end of a + * transaction chain, and the cookie assigned with it has been + * returned previously from mmp_pdma_tx_submit(). + * + * In case we have multiple transactions in the running chain, + * and the cookie does not match the one the user asked us + * about, reset the state variables and start over. + * + * This logic does not apply to cyclic transactions, where all + * descriptors have the ENDIRQEN bit set, and for which we + * can't have multiple transactions on one channel anyway. + */ + if (cyclic || !(sw->desc.dcmd & DCMD_ENDIRQEN)) + continue; + + if (sw->async_tx.cookie == cookie) { + return residue; + } else { + residue = 0; + passed = false; + } + } + + /* We should only get here in case of cyclic transactions */ + return residue; +} + static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *txstate) { - return dma_cookie_status(dchan, cookie, txstate); + struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan); + enum dma_status ret; + + ret = dma_cookie_status(dchan, cookie, txstate); + if (likely(ret != DMA_ERROR)) + dma_set_residue(txstate, mmp_pdma_residue(chan, cookie)); + + return ret; } /** |