dmaengine: dw: fix byte order of hw descriptor fields
If the DMA controller uses a different byte order than the host CPU,
the hardware linked list descriptor fields need to be byte-swapped.
This patch makes the driver write these fields using the same byte
order it uses for mmio accesses to the DMA engine. I do not know
if this is guaranteed to always be correct.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index a63d62b..6571100 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -308,26 +308,44 @@
return container_of(ddev, struct dw_dma, dma);
}
+#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO
+typedef __be32 __dw32;
+#else
+typedef __le32 __dw32;
+#endif
+
/* LLI == Linked List Item; a.k.a. DMA block descriptor */
struct dw_lli {
/* values that are not changed by hardware */
- u32 sar;
- u32 dar;
- u32 llp; /* chain to next lli */
- u32 ctllo;
+ __dw32 sar;
+ __dw32 dar;
+ __dw32 llp; /* chain to next lli */
+ __dw32 ctllo;
/* values that may get written back: */
- u32 ctlhi;
+ __dw32 ctlhi;
/* sstat and dstat can snapshot peripheral register state.
* silicon config may discard either or both...
*/
- u32 sstat;
- u32 dstat;
+ __dw32 sstat;
+ __dw32 dstat;
};
struct dw_desc {
/* FIRST values the hardware uses */
struct dw_lli lli;
+#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO
+#define lli_set(d, reg, v) ((d)->lli.reg |= cpu_to_be32(v))
+#define lli_clear(d, reg, v) ((d)->lli.reg &= ~cpu_to_be32(v))
+#define lli_read(d, reg) be32_to_cpu((d)->lli.reg)
+#define lli_write(d, reg, v) ((d)->lli.reg = cpu_to_be32(v))
+#else
+#define lli_set(d, reg, v) ((d)->lli.reg |= cpu_to_le32(v))
+#define lli_clear(d, reg, v) ((d)->lli.reg &= ~cpu_to_le32(v))
+#define lli_read(d, reg) le32_to_cpu((d)->lli.reg)
+#define lli_write(d, reg, v) ((d)->lli.reg = cpu_to_le32(v))
+#endif
+
/* THEN values for driver housekeeping */
struct list_head desc_node;
struct list_head tx_list;