dmaengine: hdmac: Add memset capabilities

Just like for the XDMAC, the SoCs that embed the HDMAC don't have any kind
of GPU, and need to accelerate a few framebuffer-related operations through
their DMA controller.

However, unlike the XDMAC, the HDMAC doesn't have the memset capability
built-in. That can be easily emulated though, by doing a transfer with a
fixed address on the variable that holds the value we want to set.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index bc8d5ebedd19..a2283886dd87 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -201,6 +201,11 @@ struct at_desc {
 	size_t				boundary;
 	size_t				dst_hole;
 	size_t				src_hole;
+
+	/* Memset temporary buffer */
+	bool				memset;
+	dma_addr_t			memset_paddr;
+	int				*memset_vaddr;
 };
 
 static inline struct at_desc *
@@ -331,6 +336,7 @@ struct at_dma {
 	u8			all_chan_mask;
 
 	struct dma_pool		*dma_desc_pool;
+	struct dma_pool		*memset_pool;
 	/* AT THE END channels table */
 	struct at_dma_chan	chan[0];
 };