dmaengine: pl330: support transfer that doesn't align with (burst len * burst size)

Below code transfers 0x10002 bytes:
First loop 256*16*16=0x10000, burst size is 1, burst length is 16.
Then the second loop 2 bytes, burst size is 1, burst length is 1.

f0041000:        DMAMOV CCR 0xbc02f1
f0041006:        DMAMOV SAR 0xdd6c0000
f004100c:        DMAMOV DAR 0xff1d0400
f0041012:        DMALP_0 15
f0041014:        DMALP_1 255
f0041016:        DMAWFPB 12
f0041018:        DMALDA
f0041019:        DMASTPB 12
f004101b:        DMAFLUSHP 12
f004101d:        DMALPENDA_1 bjmpto_7
f004101f:        DMALPENDA_0 bjmpto_b
f0041021:        DMAMOV CCR 0x800201
f0041027:        DMALP_1 1
f0041029:        DMAWFPB 12
f004102b:        DMALDA
f004102c:        DMASTPB 12
f004102e:        DMAFLUSHP 12
f0041030:        DMALPENDA_1 bjmpto_7
f0041032:        DMASEV 0
f0041034:        DMAEND

Change-Id: I97ef33aeac8ebe18c63201cf4c1c04f5548e9a4a
Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index dece7d2d024f48478ac7c82bf3404020f75945f5..63db9e30e02a45de5034a4b7be341bb2c4b813bd 100644 (file)
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -240,6 +240,7 @@ enum pl330_byteswap {
 
 #define BYTE_TO_BURST(b, ccr)  ((b) / BRST_SIZE(ccr) / BRST_LEN(ccr))
 #define BURST_TO_BYTE(c, ccr)  ((c) * BRST_SIZE(ccr) * BRST_LEN(ccr))
+#define BYTE_MOD_BURST_LEN(b, ccr)     (((b) / BRST_SIZE(ccr)) % BRST_LEN(ccr))
 
 /*
  * With 256 bytes, we can do more than 2.5MB and 5MB xfers per req
@@ -1331,6 +1332,20 @@ static inline int _setup_xfer(struct pl330_dmac *pl330,
        /* Setup Loop(s) */
        off += _setup_loops(pl330, dry_run, &buf[off], pxs);
 
+       if (pl330->peripherals_req_type == BURST) {
+               unsigned int ccr = pxs->ccr;
+               unsigned long c = 0;
+
+               c = BYTE_MOD_BURST_LEN(x->bytes, pxs->ccr);
+
+               if (c) {
+                       ccr &= ~(0xf << CC_SRCBRSTLEN_SHFT);
+                       ccr &= ~(0xf << CC_DSTBRSTLEN_SHFT);
+                       off += _emit_MOV(dry_run, &buf[off], CCR, ccr);
+                       off += _loop(pl330, dry_run, &buf[off], &c, pxs);
+               }
+       }
+
        return off;
 }
 
@@ -1353,9 +1368,11 @@ static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run,
        off += _emit_MOV(dry_run, &buf[off], CCR, pxs->ccr);
 
        x = &pxs->desc->px;
-       /* Error if xfer length is not aligned at burst size */
-       if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
-               return -EINVAL;
+       if (pl330->peripherals_req_type != BURST) {
+               /* Error if xfer length is not aligned at burst size */
+               if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
+                       return -EINVAL;
+       }
 
        off += _setup_xfer(pl330, dry_run, &buf[off], pxs);