drm/sun4i: Add DE2 CSC library

DE2 have many CSC units - channel input CSC, channel output CSC and
mixer output CSC and maybe more.

Fortunately, they have all same register layout, only base offsets
differs.

Add support only for channel output CSC for now.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171201060550.10392-24-jernej.skrabec@siol.net

drivers/gpu/drm/sun4i/Makefile

@@ -11,7 +11,7 @@ sun4i-drm-hdmi-y		+= sun4i_hdmi_tmds_clk.o
 
 sun8i-mixer-y			+= sun8i_mixer.o sun8i_ui_layer.o \
 				   sun8i_vi_layer.o sun8i_ui_scaler.o \
-				   sun8i_vi_scaler.o
+				   sun8i_vi_scaler.o sun8i_csc.o
 
 sun4i-tcon-y			+= sun4i_crtc.o
 sun4i-tcon-y			+= sun4i_dotclock.o

drivers/gpu/drm/sun4i/sun8i_csc.c

+/*
+ * Copyright (C) Jernej Skrabec <jernej.skrabec@siol.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <drm/drmP.h>
+
+#include "sun8i_csc.h"
+#include "sun8i_mixer.h"
+
+static const u32 ccsc_base[2][2] = {
+	{CCSC00_OFFSET, CCSC01_OFFSET},
+	{CCSC10_OFFSET, CCSC11_OFFSET},
+};
+
+/*
+ * Factors are in two's complement format, 10 bits for fractinal part.
+ * First tree values in each line are multiplication factor and last
+ * value is constant, which is added at the end.
+ */
+static const u32 yuv2rgb[] = {
+	0x000004A8, 0x00000000, 0x00000662, 0xFFFC845A,
+	0x000004A8, 0xFFFFFE6F, 0xFFFFFCBF, 0x00021DF4,
+	0x000004A8, 0x00000813, 0x00000000, 0xFFFBAC4A,
+};
+
+static const u32 yvu2rgb[] = {
+	0x000004A8, 0x00000662, 0x00000000, 0xFFFC845A,
+	0x000004A8, 0xFFFFFCBF, 0xFFFFFE6F, 0x00021DF4,
+	0x000004A8, 0x00000000, 0x00000813, 0xFFFBAC4A,
+};
+
+static void sun8i_csc_set_coefficients(struct regmap *map, u32 base,
+				       enum sun8i_csc_mode mode)
+{
+	const u32 *table;
+	int i, data;
+
+	switch (mode) {
+	case SUN8I_CSC_MODE_YUV2RGB:
+		table = yuv2rgb;
+		break;
+	case SUN8I_CSC_MODE_YVU2RGB:
+		table = yvu2rgb;
+		break;
+	default:
+		DRM_WARN("Wrong CSC mode specified.\n");
+		return;
+	}
+
+	for (i = 0; i < 12; i++) {
+		data = table[i];
+		/* For some reason, 0x200 must be added to constant parts */
+		if (((i + 1) & 3) == 0)
+			data += 0x200;
+		regmap_write(map, SUN8I_CSC_COEFF(base, i), data);
+	}
+}
+
+static void sun8i_csc_enable(struct regmap *map, u32 base, bool enable)
+{
+	u32 val;
+
+	if (enable)
+		val = SUN8I_CSC_CTRL_EN;
+	else
+		val = 0;
+
+	regmap_update_bits(map, SUN8I_CSC_CTRL(base), SUN8I_CSC_CTRL_EN, val);
+}
+
+void sun8i_csc_set_ccsc_coefficients(struct sun8i_mixer *mixer, int layer,
+				     enum sun8i_csc_mode mode)
+{
+	u32 base;
+
+	base = ccsc_base[mixer->cfg->ccsc][layer];
+
+	sun8i_csc_set_coefficients(mixer->engine.regs, base, mode);
+}
+
+void sun8i_csc_enable_ccsc(struct sun8i_mixer *mixer, int layer, bool enable)
+{
+	u32 base;
+
+	base = ccsc_base[mixer->cfg->ccsc][layer];
+
+	sun8i_csc_enable(mixer->engine.regs, base, enable);
+}

drivers/gpu/drm/sun4i/sun8i_csc.h

+/*
+ * Copyright (C) Jernej Skrabec <jernej.skrabec@siol.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#ifndef _SUN8I_CSC_H_
+#define _SUN8I_CSC_H_
+
+struct sun8i_mixer;
+
+/* VI channel CSC units offsets */
+#define CCSC00_OFFSET 0xAA050
+#define CCSC01_OFFSET 0xFA000
+#define CCSC10_OFFSET 0xA0000
+#define CCSC11_OFFSET 0xF0000
+
+#define SUN8I_CSC_CTRL(base)		(base + 0x0)
+#define SUN8I_CSC_COEFF(base, i)	(base + 0x10 + 4 * i)
+
+#define SUN8I_CSC_CTRL_EN		BIT(0)
+
+enum sun8i_csc_mode {
+	SUN8I_CSC_MODE_OFF,
+	SUN8I_CSC_MODE_YUV2RGB,
+	SUN8I_CSC_MODE_YVU2RGB,
+};
+
+void sun8i_csc_set_ccsc_coefficients(struct sun8i_mixer *mixer, int layer,
+				     enum sun8i_csc_mode mode);
+void sun8i_csc_enable_ccsc(struct sun8i_mixer *mixer, int layer, bool enable);
+
+#endif