viafb: Add a simple VX855 DMA engine driver
This code provides a minimal amount of access to the DMA engine as
needed by the camera driver. VX855 only; it's guaranteed not to work
on other chipsets, so it won't try.
Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/drivers/video/via/via-core.h b/drivers/video/via/via-core.h
index ba64b36d..3d03141 100644
--- a/drivers/video/via/via-core.h
+++ b/drivers/video/via/via-core.h
@@ -131,4 +131,33 @@
#define VDE_I_LVDSSIEN 0x40000000 /* LVDS Sense enable */
#define VDE_I_ENABLE 0x80000000 /* Global interrupt enable */
+/*
+ * DMA management.
+ */
+int viafb_request_dma(void);
+void viafb_release_dma(void);
+/* void viafb_dma_copy_out(unsigned int offset, dma_addr_t paddr, int len); */
+int viafb_dma_copy_out_sg(unsigned int offset, struct scatterlist *sg, int nsg);
+
+/*
+ * DMA Controller registers.
+ */
+#define VDMA_MR0 0xe00 /* Mod reg 0 */
+#define VDMA_MR_CHAIN 0x01 /* Chaining mode */
+#define VDMA_MR_TDIE 0x02 /* Transfer done int enable */
+#define VDMA_CSR0 0xe04 /* Control/status */
+#define VDMA_C_ENABLE 0x01 /* DMA Enable */
+#define VDMA_C_START 0x02 /* Start a transfer */
+#define VDMA_C_ABORT 0x04 /* Abort a transfer */
+#define VDMA_C_DONE 0x08 /* Transfer is done */
+#define VDMA_MARL0 0xe20 /* Mem addr low */
+#define VDMA_MARH0 0xe24 /* Mem addr high */
+#define VDMA_DAR0 0xe28 /* Device address */
+#define VDMA_DQWCR0 0xe2c /* Count (16-byte) */
+#define VDMA_TMR0 0xe30 /* Tile mode reg */
+#define VDMA_DPRL0 0xe34 /* Not sure */
+#define VDMA_DPR_IN 0x08 /* Inbound transfer to FB */
+#define VDMA_DPRH0 0xe38
+#define VDMA_PMR0 (0xe00 + 0x134) /* Pitch mode */
+
#endif /* __VIA_CORE_H__ */