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-rw-r--r--drivers/dma/dw/core.c16
-rw-r--r--drivers/dma/dw/of.c5
-rw-r--r--drivers/dma/dw/regs.h2
-rw-r--r--include/linux/platform_data/dma-dw.h3
4 files changed, 26 insertions, 0 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index afe5a2e465af..588b9bae827c 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -791,6 +791,11 @@ 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);
@@ -1049,6 +1054,13 @@ 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;
+}
+
int do_dma_probe(struct dw_dma_chip *chip)
{
struct dw_dma *dw = chip->dw;
@@ -1189,9 +1201,12 @@ int do_dma_probe(struct dw_dma_chip *chip)
dwc->nollp =
(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;
}
}
@@ -1214,6 +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;
diff --git a/drivers/dma/dw/of.c b/drivers/dma/dw/of.c
index 9e27831dee32..1474b3817ef4 100644
--- a/drivers/dma/dw/of.c
+++ b/drivers/dma/dw/of.c
@@ -98,6 +98,11 @@ struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
pdata->multi_block[tmp] = 1;
}
+ if (of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst,
+ nr_channels)) {
+ memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels);
+ }
+
if (!of_property_read_u32(np, "snps,dma-protection-control", &tmp)) {
if (tmp > CHAN_PROTCTL_MASK)
return NULL;
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 1ab840b06e79..76654bd13c1a 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -126,6 +126,7 @@ struct dw_dma_regs {
/* Bitfields in DWC_PARAMS */
#define DWC_PARAMS_MBLK_EN 11 /* multi block transfer */
#define DWC_PARAMS_HC_LLP 13 /* set LLP register to zero */
+#define DWC_PARAMS_MSIZE 16 /* max group transaction size */
/* bursts size */
enum dw_dma_msize {
@@ -284,6 +285,7 @@ struct dw_dma_chan {
/* hardware configuration */
unsigned int block_size;
bool nollp;
+ u32 max_burst;
/* custom slave configuration */
struct dw_dma_slave dws;
diff --git a/include/linux/platform_data/dma-dw.h b/include/linux/platform_data/dma-dw.h
index 369e41e9dcc9..4f681df85c27 100644
--- a/include/linux/platform_data/dma-dw.h
+++ b/include/linux/platform_data/dma-dw.h
@@ -44,6 +44,8 @@ struct dw_dma_slave {
* @data_width: Maximum data width supported by hardware per AHB master
* (in bytes, power of 2)
* @multi_block: Multi block transfers supported by hardware per channel.
+ * @max_burst: Maximum value of burst transaction size supported by hardware
+ * per channel (in units of CTL.SRC_TR_WIDTH/CTL.DST_TR_WIDTH).
* @protctl: Protection control signals setting per channel.
*/
struct dw_dma_platform_data {
@@ -58,6 +60,7 @@ struct dw_dma_platform_data {
unsigned char nr_masters;
unsigned char data_width[DW_DMA_MAX_NR_MASTERS];
unsigned char multi_block[DW_DMA_MAX_NR_CHANNELS];
+ u32 max_burst[DW_DMA_MAX_NR_CHANNELS];
#define CHAN_PROTCTL_PRIVILEGED BIT(0)
#define CHAN_PROTCTL_BUFFERABLE BIT(1)
#define CHAN_PROTCTL_CACHEABLE BIT(2)