[PATCH v2] dmaengine: at_xdmac: rework slave configuration part
From: Ludovic Desroches
Date: Mon Jun 01 2015 - 11:42:18 EST
Rework slave configuration part in order to no more report wrong errors
about the configuration.
Only maxburst and addr width values are checked when doing the slave
configuration. The validity of the channel configuration is done at
prepare time.
Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 4.0 and later
---
Changes from v1:
- rework to not use implicitly direction in slave config function.
drivers/dma/at_xdmac.c | 156 ++++++++++++++++++++++++++++++-------------------
1 file changed, 96 insertions(+), 60 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index d9891d3..dcd1a4ed 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -174,6 +174,8 @@
#define AT_XDMAC_MBR_UBC_NDV3 (0x3 << 27) /* Next Descriptor View 3 */
#define AT_XDMAC_MAX_CHAN 0x20
+#define AT_XDMAC_MAX_CSIZE 16 /* 16 data */
+#define AT_XDMAC_MAX_DWIDTH 8 /* 64 bits */
#define AT_XDMAC_DMA_BUSWIDTHS\
(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
@@ -192,20 +194,17 @@ struct at_xdmac_chan {
struct dma_chan chan;
void __iomem *ch_regs;
u32 mask; /* Channel Mask */
- u32 cfg[2]; /* Channel Configuration Register */
- #define AT_XDMAC_DEV_TO_MEM_CFG 0 /* Predifined dev to mem channel conf */
- #define AT_XDMAC_MEM_TO_DEV_CFG 1 /* Predifined mem to dev channel conf */
+ u32 cfg; /* Channel Configuration Register */
u8 perid; /* Peripheral ID */
u8 perif; /* Peripheral Interface */
u8 memif; /* Memory Interface */
- u32 per_src_addr;
- u32 per_dst_addr;
u32 save_cc;
u32 save_cim;
u32 save_cnda;
u32 save_cndc;
unsigned long status;
struct tasklet_struct tasklet;
+ struct dma_slave_config sconfig;
spinlock_t lock;
@@ -494,61 +493,94 @@ static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec,
return chan;
}
+static int at_xdmac_compute_chan_conf(struct dma_chan *chan,
+ enum dma_transfer_direction direction)
+{
+ struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
+ int csize, dwidth;
+
+ if (direction == DMA_DEV_TO_MEM) {
+ atchan->cfg =
+ AT91_XDMAC_DT_PERID(atchan->perid)
+ | AT_XDMAC_CC_DAM_INCREMENTED_AM
+ | AT_XDMAC_CC_SAM_FIXED_AM
+ | AT_XDMAC_CC_DIF(atchan->memif)
+ | AT_XDMAC_CC_SIF(atchan->perif)
+ | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
+ | AT_XDMAC_CC_DSYNC_PER2MEM
+ | AT_XDMAC_CC_MBSIZE_SIXTEEN
+ | AT_XDMAC_CC_TYPE_PER_TRAN;
+ csize = ffs(atchan->sconfig.src_maxburst) - 1;
+ if (csize < 0) {
+ dev_err(chan2dev(chan), "invalid src maxburst value\n");
+ return -EINVAL;
+ }
+ atchan->cfg |= AT_XDMAC_CC_CSIZE(csize);
+ dwidth = ffs(atchan->sconfig.src_addr_width) - 1;
+ if (dwidth < 0) {
+ dev_err(chan2dev(chan), "invalid src addr width value\n");
+ return -EINVAL;
+ }
+ atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth);
+ } else if (direction == DMA_MEM_TO_DEV) {
+ atchan->cfg =
+ AT91_XDMAC_DT_PERID(atchan->perid)
+ | AT_XDMAC_CC_DAM_FIXED_AM
+ | AT_XDMAC_CC_SAM_INCREMENTED_AM
+ | AT_XDMAC_CC_DIF(atchan->perif)
+ | AT_XDMAC_CC_SIF(atchan->memif)
+ | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
+ | AT_XDMAC_CC_DSYNC_MEM2PER
+ | AT_XDMAC_CC_MBSIZE_SIXTEEN
+ | AT_XDMAC_CC_TYPE_PER_TRAN;
+ csize = ffs(atchan->sconfig.dst_maxburst) - 1;
+ if (csize < 0) {
+ dev_err(chan2dev(chan), "invalid src maxburst value\n");
+ return -EINVAL;
+ }
+ atchan->cfg |= AT_XDMAC_CC_CSIZE(csize);
+ dwidth = ffs(atchan->sconfig.dst_addr_width) - 1;
+ if (dwidth < 0) {
+ dev_err(chan2dev(chan), "invalid dst addr width value\n");
+ return -EINVAL;
+ }
+ atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth);
+ }
+
+ dev_dbg(chan2dev(chan), "%s: cfg=0x%08x\n", __func__, atchan->cfg);
+
+ return 0;
+}
+
+/*
+ * Only check that maxburst and addr width values are supported by the
+ * the controller but not that the configuration is good to perform the
+ * transfer since we don't know the direction at this stage.
+ */
+static int at_xdmac_check_slave_config(struct dma_slave_config *sconfig)
+{
+ if ((sconfig->src_maxburst > AT_XDMAC_MAX_CSIZE)
+ || (sconfig->dst_maxburst > AT_XDMAC_MAX_CSIZE))
+ return -EINVAL;
+
+ if ((sconfig->src_addr_width > AT_XDMAC_MAX_DWIDTH)
+ || (sconfig->dst_addr_width > AT_XDMAC_MAX_DWIDTH))
+ return -EINVAL;
+
+ return 0;
+}
+
static int at_xdmac_set_slave_config(struct dma_chan *chan,
struct dma_slave_config *sconfig)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
- u8 dwidth;
- int csize;
- atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] =
- AT91_XDMAC_DT_PERID(atchan->perid)
- | AT_XDMAC_CC_DAM_INCREMENTED_AM
- | AT_XDMAC_CC_SAM_FIXED_AM
- | AT_XDMAC_CC_DIF(atchan->memif)
- | AT_XDMAC_CC_SIF(atchan->perif)
- | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
- | AT_XDMAC_CC_DSYNC_PER2MEM
- | AT_XDMAC_CC_MBSIZE_SIXTEEN
- | AT_XDMAC_CC_TYPE_PER_TRAN;
- csize = at_xdmac_csize(sconfig->src_maxburst);
- if (csize < 0) {
- dev_err(chan2dev(chan), "invalid src maxburst value\n");
+ if (at_xdmac_check_slave_config(sconfig)) {
+ dev_err(chan2dev(chan), "invalid slave configuration\n");
return -EINVAL;
}
- atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] |= AT_XDMAC_CC_CSIZE(csize);
- dwidth = ffs(sconfig->src_addr_width) - 1;
- atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] |= AT_XDMAC_CC_DWIDTH(dwidth);
-
-
- atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] =
- AT91_XDMAC_DT_PERID(atchan->perid)
- | AT_XDMAC_CC_DAM_FIXED_AM
- | AT_XDMAC_CC_SAM_INCREMENTED_AM
- | AT_XDMAC_CC_DIF(atchan->perif)
- | AT_XDMAC_CC_SIF(atchan->memif)
- | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
- | AT_XDMAC_CC_DSYNC_MEM2PER
- | AT_XDMAC_CC_MBSIZE_SIXTEEN
- | AT_XDMAC_CC_TYPE_PER_TRAN;
- csize = at_xdmac_csize(sconfig->dst_maxburst);
- if (csize < 0) {
- dev_err(chan2dev(chan), "invalid src maxburst value\n");
- return -EINVAL;
- }
- atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] |= AT_XDMAC_CC_CSIZE(csize);
- dwidth = ffs(sconfig->dst_addr_width) - 1;
- atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] |= AT_XDMAC_CC_DWIDTH(dwidth);
-
- /* Src and dst addr are needed to configure the link list descriptor. */
- atchan->per_src_addr = sconfig->src_addr;
- atchan->per_dst_addr = sconfig->dst_addr;
- dev_dbg(chan2dev(chan),
- "%s: cfg[dev2mem]=0x%08x, cfg[mem2dev]=0x%08x, per_src_addr=0x%08x, per_dst_addr=0x%08x\n",
- __func__, atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG],
- atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG],
- atchan->per_src_addr, atchan->per_dst_addr);
+ memcpy(&atchan->sconfig, sconfig, sizeof(atchan->sconfig));
return 0;
}
@@ -604,16 +636,18 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
return NULL;
}
+ if (at_xdmac_compute_chan_conf(chan, direction))
+ return NULL;
+
/* Linked list descriptor setup. */
if (direction == DMA_DEV_TO_MEM) {
- desc->lld.mbr_sa = atchan->per_src_addr;
+ desc->lld.mbr_sa = atchan->sconfig.src_addr;
desc->lld.mbr_da = mem;
- desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG];
} else {
desc->lld.mbr_sa = mem;
- desc->lld.mbr_da = atchan->per_dst_addr;
- desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG];
+ desc->lld.mbr_da = atchan->sconfig.dst_addr;
}
+ desc->lld.mbr_cfg = atchan->cfg;
dwidth = at_xdmac_get_dwidth(desc->lld.mbr_cfg);
fixed_dwidth = IS_ALIGNED(len, 1 << dwidth)
? at_xdmac_get_dwidth(desc->lld.mbr_cfg)
@@ -696,15 +730,17 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
"%s: desc=0x%p, tx_dma_desc.phys=%pad\n",
__func__, desc, &desc->tx_dma_desc.phys);
+ if (at_xdmac_compute_chan_conf(chan, direction))
+ return NULL;
+
if (direction == DMA_DEV_TO_MEM) {
- desc->lld.mbr_sa = atchan->per_src_addr;
+ desc->lld.mbr_sa = atchan->sconfig.src_addr;
desc->lld.mbr_da = buf_addr + i * period_len;
- desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG];
} else {
desc->lld.mbr_sa = buf_addr + i * period_len;
- desc->lld.mbr_da = atchan->per_dst_addr;
- desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG];
+ desc->lld.mbr_da = atchan->sconfig.dst_addr;
}
+ desc->lld.mbr_cfg = atchan->cfg;
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV1
| AT_XDMAC_MBR_UBC_NDEN
| AT_XDMAC_MBR_UBC_NSEN
--
2.2.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/