[media] v4l: ti-vpe: Add helper to perform color conversion

The CSC block can be used for color space conversion between YUV and RGB
formats.

It is configurable via a programmable set of coefficients. Add functionality to
choose the appropriate CSC coefficients and program them in the CSC registers.
We take the source and destination colorspace formats as the arguments, and
choose the coefficient table accordingly.

YUV to RGB coefficients are provided for standard and high definition
colorspaces. The coefficients can also be limited or full range. For now, only
full range coefficients are chosen. We would need some sort of control ioctl for
the user to specify the range needed. Not sure if there is a generic control
ioctl for this already?

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/platform/ti-vpe/csc.c b/drivers/media/platform/ti-vpe/csc.c
index 62e2fecd1798d1a6f8733ee464d8fa6f0880e75a..acfea500710e4ba5dc7cfa232fd01351251cecd1 100644 (file)
--- a/drivers/media/platform/ti-vpe/csc.c
+++ b/drivers/media/platform/ti-vpe/csc.c
@@ -16,9 +16,79 @@
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/videodev2.h>
 
 #include "csc.h"
 
+/*
+ * 16 coefficients in the order:
+ * a0, b0, c0, a1, b1, c1, a2, b2, c2, d0, d1, d2
+ * (we may need to pass non-default values from user space later on, we might
+ * need to make the coefficient struct more easy to populate)
+ */
+struct colorspace_coeffs {
+       u16     sd[12];
+       u16     hd[12];
+};
+
+/* VIDEO_RANGE: limited range, GRAPHICS_RANGE: full range */
+#define        CSC_COEFFS_VIDEO_RANGE_Y2R      0
+#define        CSC_COEFFS_GRAPHICS_RANGE_Y2R   1
+#define        CSC_COEFFS_VIDEO_RANGE_R2Y      2
+#define        CSC_COEFFS_GRAPHICS_RANGE_R2Y   3
+
+/* default colorspace coefficients */
+static struct colorspace_coeffs colorspace_coeffs[4] = {
+       [CSC_COEFFS_VIDEO_RANGE_Y2R] = {
+               {
+                       /* SDTV */
+                       0x0400, 0x0000, 0x057D, 0x0400, 0x1EA7, 0x1D35,
+                       0x0400, 0x06EF, 0x1FFE, 0x0D40, 0x0210, 0x0C88,
+               },
+               {
+                       /* HDTV */
+                       0x0400, 0x0000, 0x0629, 0x0400, 0x1F45, 0x1E2B,
+                       0x0400, 0x0742, 0x0000, 0x0CEC, 0x0148, 0x0C60,
+               },
+       },
+       [CSC_COEFFS_GRAPHICS_RANGE_Y2R] = {
+               {
+                       /* SDTV */
+                       0x04A8, 0x1FFE, 0x0662, 0x04A8, 0x1E6F, 0x1CBF,
+                       0x04A8, 0x0812, 0x1FFF, 0x0C84, 0x0220, 0x0BAC,
+               },
+               {
+                       /* HDTV */
+                       0x04A8, 0x0000, 0x072C, 0x04A8, 0x1F26, 0x1DDE,
+                       0x04A8, 0x0873, 0x0000, 0x0C20, 0x0134, 0x0B7C,
+               },
+       },
+       [CSC_COEFFS_VIDEO_RANGE_R2Y] = {
+               {
+                       /* SDTV */
+                       0x0132, 0x0259, 0x0075, 0x1F50, 0x1EA5, 0x020B,
+                       0x020B, 0x1E4A, 0x1FAB, 0x0000, 0x0200, 0x0200,
+               },
+               {
+                       /* HDTV */
+                       0x00DA, 0x02DC, 0x004A, 0x1F88, 0x1E6C, 0x020C,
+                       0x020C, 0x1E24, 0x1FD0, 0x0000, 0x0200, 0x0200,
+               },
+       },
+       [CSC_COEFFS_GRAPHICS_RANGE_R2Y] = {
+               {
+                       /* SDTV */
+                       0x0107, 0x0204, 0x0064, 0x1F68, 0x1ED6, 0x01C2,
+                       0x01C2, 0x1E87, 0x1FB7, 0x0040, 0x0200, 0x0200,
+               },
+               {
+                       /* HDTV */
+                       0x04A8, 0x0000, 0x072C, 0x04A8, 0x1F26, 0x1DDE,
+                       0x04A8, 0x0873, 0x0000, 0x0C20, 0x0134, 0x0B7C,
+               },
+       },
+};
+
 void csc_dump_regs(struct csc_data *csc)
 {
        struct device *dev = &csc->pdev->dev;
@@ -45,6 +115,56 @@ void csc_set_coeff_bypass(struct csc_data *csc, u32 *csc_reg5)
        *csc_reg5 |= CSC_BYPASS;
 }
 
+/*
+ * set the color space converter coefficient shadow register values
+ */
+void csc_set_coeff(struct csc_data *csc, u32 *csc_reg0,
+               enum v4l2_colorspace src_colorspace,
+               enum v4l2_colorspace dst_colorspace)
+{
+       u32 *csc_reg5 = csc_reg0 + 5;
+       u32 *shadow_csc = csc_reg0;
+       struct colorspace_coeffs *sd_hd_coeffs;
+       u16 *coeff, *end_coeff;
+       enum v4l2_colorspace yuv_colorspace;
+       int sel = 0;
+
+       /*
+        * support only graphics data range(full range) for now, a control ioctl
+        * would be nice here
+        */
+       /* Y2R */
+       if (dst_colorspace == V4L2_COLORSPACE_SRGB &&
+                       (src_colorspace == V4L2_COLORSPACE_SMPTE170M ||
+                       src_colorspace == V4L2_COLORSPACE_REC709)) {
+               /* Y2R */
+               sel = 1;
+               yuv_colorspace = src_colorspace;
+       } else if ((dst_colorspace == V4L2_COLORSPACE_SMPTE170M ||
+                       dst_colorspace == V4L2_COLORSPACE_REC709) &&
+                       src_colorspace == V4L2_COLORSPACE_SRGB) {
+               /* R2Y */
+               sel = 3;
+               yuv_colorspace = dst_colorspace;
+       } else {
+               *csc_reg5 |= CSC_BYPASS;
+               return;
+       }
+
+       sd_hd_coeffs = &colorspace_coeffs[sel];
+
+       /* select between SD or HD coefficients */
+       if (yuv_colorspace == V4L2_COLORSPACE_SMPTE170M)
+               coeff = sd_hd_coeffs->sd;
+       else
+               coeff = sd_hd_coeffs->hd;
+
+       end_coeff = coeff + 12;
+
+       for (; coeff < end_coeff; coeff += 2)
+               *shadow_csc++ = (*(coeff + 1) << 16) | *coeff;
+}
+
 struct csc_data *csc_create(struct platform_device *pdev)
 {
        struct csc_data *csc;

diff --git a/drivers/media/platform/ti-vpe/csc.h b/drivers/media/platform/ti-vpe/csc.h
index 57b5ed60039484aa08dcce2b35cc7412e34d6f1e..1ad2b6dad561e96ec3c73243ff1fc44319fab48c 100644 (file)
--- a/drivers/media/platform/ti-vpe/csc.h
+++ b/drivers/media/platform/ti-vpe/csc.h
@@ -60,6 +60,9 @@ struct csc_data {
 
 void csc_dump_regs(struct csc_data *csc);
 void csc_set_coeff_bypass(struct csc_data *csc, u32 *csc_reg5);
+void csc_set_coeff(struct csc_data *csc, u32 *csc_reg0,
+               enum v4l2_colorspace src_colorspace,
+               enum v4l2_colorspace dst_colorspace);
 struct csc_data *csc_create(struct platform_device *pdev);
 
 #endif