[media] marvell-cam: Working s/g DMA

The core Marvell camera driver can now do scatter/gather DMA on controllers
which support that functionality.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/marvell-ccic/Kconfig

@@ -3,6 +3,8 @@ config VIDEO_CAFE_CCIC
 	depends on PCI && I2C && VIDEO_V4L2
 	select VIDEO_OV7670
 	select VIDEOBUF2_VMALLOC
+	select VIDEOBUF2_DMA_CONTIG
+	select VIDEOBUF2_DMA_SG
 	---help---
 	  This is a video4linux2 driver for the Marvell 88ALP01 integrated
 	  CMOS camera controller.  This is the controller found on first-
@@ -15,6 +17,7 @@ config VIDEO_MMP_CAMERA
 	select I2C_GPIO
 	select VIDEOBUF2_VMALLOC
 	select VIDEOBUF2_DMA_CONTIG
+	select VIDEOBUF2_DMA_SG
 	---help---
 	  This is a Video4Linux2 driver for the integrated camera
 	  controller found on Marvell Armada 610 application

drivers/media/video/marvell-ccic/mcam-core.h

@@ -38,7 +38,8 @@ enum mcam_state {
  */
 enum mcam_buffer_mode {
 	B_vmalloc = 0,
-	B_DMA_contig
+	B_DMA_contig,
+	B_DMA_sg
 };
 
 /*
@@ -250,8 +251,11 @@ int mccic_resume(struct mcam_camera *cam);
 #define	  C0_SIF_HVSYNC	  0x00000000	/* Use H/VSYNC */
 #define	  CO_SOF_NOSYNC	  0x40000000	/* Use inband active signaling */
 
-
+/* Bits below C1_444ALPHA are not present in Cafe */
 #define REG_CTRL1	0x40	/* Control 1 */
+#define	  C1_CLKGATE	  0x00000001	/* Sensor clock gate */
+#define   C1_DESC_ENA	  0x00000100	/* DMA descriptor enable */
+#define   C1_DESC_3WORD   0x00000200	/* Three-word descriptors used */
 #define	  C1_444ALPHA	  0x00f00000	/* Alpha field in RGB444 */
 #define	  C1_ALPHA_SHFT	  20
 #define	  C1_DMAB32	  0x00000000	/* 32-byte DMA burst */
@@ -267,6 +271,14 @@ int mccic_resume(struct mcam_camera *cam);
 /* This appears to be a Cafe-only register */
 #define REG_UBAR	0xc4	/* Upper base address register */
 
+/* Armada 610 DMA descriptor registers */
+#define	REG_DMA_DESC_Y	0x200
+#define	REG_DMA_DESC_U	0x204
+#define	REG_DMA_DESC_V	0x208
+#define REG_DESC_LEN_Y	0x20c	/* Lengths are in bytes */
+#define	REG_DESC_LEN_U	0x210
+#define REG_DESC_LEN_V	0x214
+
 /*
  * Useful stuff that probably belongs somewhere global.
  */