summaryrefslogtreecommitdiffstats
path: root/drivers/dma/dw/core.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/dma/dw/core.c')
-rw-r--r--drivers/dma/dw/core.c60
1 files changed, 47 insertions, 13 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 21cb2a58dbd2..4700f2e87a62 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -118,16 +118,11 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
- if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
- return;
-
dw->initialize_chan(dwc);
/* Enable interrupts */
channel_set_bit(dw, MASK.XFER, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask);
-
- set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
}
/*----------------------------------------------------------------------*/
@@ -791,6 +786,11 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
+ dwc->dma_sconfig.src_maxburst =
+ clamp(dwc->dma_sconfig.src_maxburst, 0U, dwc->max_burst);
+ dwc->dma_sconfig.dst_maxburst =
+ clamp(dwc->dma_sconfig.dst_maxburst, 0U, dwc->max_burst);
+
dw->encode_maxburst(dwc, &dwc->dma_sconfig.src_maxburst);
dw->encode_maxburst(dwc, &dwc->dma_sconfig.dst_maxburst);
@@ -954,8 +954,6 @@ static void dwc_issue_pending(struct dma_chan *chan)
void do_dw_dma_off(struct dw_dma *dw)
{
- unsigned int i;
-
dma_writel(dw, CFG, 0);
channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
@@ -966,9 +964,6 @@ void do_dw_dma_off(struct dw_dma *dw)
while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
cpu_relax();
-
- for (i = 0; i < dw->dma.chancnt; i++)
- clear_bit(DW_DMA_IS_INITIALIZED, &dw->chan[i].flags);
}
void do_dw_dma_on(struct dw_dma *dw)
@@ -1032,8 +1027,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
/* Clear custom channel configuration */
memset(&dwc->dws, 0, sizeof(struct dw_dma_slave));
- clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
-
/* Disable interrupts */
channel_clear_bit(dw, MASK.XFER, dwc->mask);
channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
@@ -1049,6 +1042,25 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
}
+static void dwc_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
+{
+ struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+
+ caps->max_burst = dwc->max_burst;
+
+ /*
+ * It might be crucial for some devices to have the hardware
+ * accelerated multi-block transfers supported, aka LLPs in DW DMAC
+ * notation. So if LLPs are supported then max_sg_burst is set to
+ * zero which means unlimited number of SG entries can be handled in a
+ * single DMA transaction, otherwise it's just one SG entry.
+ */
+ if (dwc->nollp)
+ caps->max_sg_burst = 1;
+ else
+ caps->max_sg_burst = 0;
+}
+
int do_dma_probe(struct dw_dma_chip *chip)
{
struct dw_dma *dw = chip->dw;
@@ -1178,11 +1190,23 @@ int do_dma_probe(struct dw_dma_chip *chip)
*/
dwc->block_size =
(4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1;
+
+ /*
+ * According to the DW DMA databook the true scatter-
+ * gether LLPs aren't available if either multi-block
+ * config is disabled (CHx_MULTI_BLK_EN == 0) or the
+ * LLP register is hard-coded to zeros
+ * (CHx_HC_LLP == 1).
+ */
dwc->nollp =
- (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0;
+ (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0 ||
+ (dwc_params >> DWC_PARAMS_HC_LLP & 0x1) == 1;
+ dwc->max_burst =
+ (0x4 << (dwc_params >> DWC_PARAMS_MSIZE & 0x7));
} else {
dwc->block_size = pdata->block_size;
dwc->nollp = !pdata->multi_block[i];
+ dwc->max_burst = pdata->max_burst[i] ?: DW_DMA_MAX_BURST;
}
}
@@ -1205,6 +1229,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
+ dw->dma.device_caps = dwc_caps;
dw->dma.device_config = dwc_config;
dw->dma.device_pause = dwc_pause;
dw->dma.device_resume = dwc_resume;
@@ -1214,12 +1239,21 @@ int do_dma_probe(struct dw_dma_chip *chip)
dw->dma.device_issue_pending = dwc_issue_pending;
/* DMA capabilities */
+ dw->dma.min_burst = DW_DMA_MIN_BURST;
+ dw->dma.max_burst = DW_DMA_MAX_BURST;
dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
BIT(DMA_MEM_TO_MEM);
dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ /*
+ * For now there is no hardware with non uniform maximum block size
+ * across all of the device channels, so we set the maximum segment
+ * size as the block size found for the very first channel.
+ */
+ dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size);
+
err = dma_async_device_register(&dw->dma);
if (err)
goto err_dma_register;