drm: mali-dp: Enable image enhancement when scaling

Apply image enhacement when we are upscaling by a factor of 2
or more in either direction.
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

drivers/gpu/drm/arm/malidp_crtc.c

@@ -288,6 +288,9 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
 		if (!(h_upscale_factor >> 16) || !(v_upscale_factor >> 16))
 			return -EINVAL;
 
+		s->enhancer_enable = ((h_upscale_factor >> 16) >= 2 ||
+				      (v_upscale_factor >> 16) >= 2);
+
 		s->input_w = pstate->src_w >> 16;
 		s->input_h = pstate->src_h >> 16;
 		s->output_w = pstate->crtc_w;
@@ -530,9 +533,11 @@ int malidp_crtc_init(struct drm_device *drm)
 
 	drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
 	drm_mode_crtc_set_gamma_size(&malidp->crtc, MALIDP_GAMMA_LUT_SIZE);
-	/* No inverse-gamma: it is per-plane */
+	/* No inverse-gamma: it is per-plane. */
 	drm_crtc_enable_color_mgmt(&malidp->crtc, 0, true, MALIDP_GAMMA_LUT_SIZE);
 
+	malidp_se_set_enh_coeffs(malidp->dev);
+
 	return 0;
 
 crtc_cleanup_planes:

drivers/gpu/drm/arm/malidp_drv.c

@@ -138,6 +138,9 @@ static void malidp_atomic_commit_se_config(struct drm_crtc *crtc,
 	val = malidp_hw_read(hwdev, se_control);
 	val |= MALIDP_SE_SCALING_EN | MALIDP_SE_ALPHA_EN;
 
+	val &= ~MALIDP_SE_ENH(MALIDP_SE_ENH_MASK);
+	val |= s->enhancer_enable ? MALIDP_SE_ENH(3) : 0;
+
 	val |= MALIDP_SE_RGBO_IF_EN;
 	malidp_hw_write(hwdev, val, se_control);
 

drivers/gpu/drm/arm/malidp_hw.h

@@ -71,6 +71,7 @@ enum malidp_scaling_coeff_set {
 
 struct malidp_se_config {
 	u8 scale_enable : 1;
+	u8 enhancer_enable : 1;
 	u8 hcoeff : 3;
 	u8 vcoeff : 3;
 	u8 plane_src_id;
@@ -295,6 +296,25 @@ malidp_se_select_coeffs(u32 upscale_factor)
 #undef FP_0_50000
 #undef FP_0_66667
 #undef FP_1_00000
+
+static inline void malidp_se_set_enh_coeffs(struct malidp_hw_device *hwdev)
+{
+	static const s32 enhancer_coeffs[] = {
+		-8, -8, -8, -8, 128, -8, -8, -8, -8
+	};
+	u32 val = MALIDP_SE_SET_ENH_LIMIT_LOW(MALIDP_SE_ENH_LOW_LEVEL) |
+		  MALIDP_SE_SET_ENH_LIMIT_HIGH(MALIDP_SE_ENH_HIGH_LEVEL);
+	u32 image_enh = hwdev->map.se_base +
+			((hwdev->map.features & MALIDP_REGMAP_HAS_CLEARIRQ) ?
+			 0x10 : 0xC) + MALIDP_SE_IMAGE_ENH;
+	u32 enh_coeffs = image_enh + MALIDP_SE_ENH_COEFF0;
+	int i;
+
+	malidp_hw_write(hwdev, val, image_enh);
+	for (i = 0; i < ARRAY_SIZE(enhancer_coeffs); ++i)
+		malidp_hw_write(hwdev, enhancer_coeffs[i], enh_coeffs + i * 4);
+}
+
 /*
  * background color components are defined as 12bits values,
  * they will be shifted right when stored on hardware that

drivers/gpu/drm/arm/malidp_regs.h

@@ -109,6 +109,8 @@
 /* Scaling engine registers and masks. */
 #define   MALIDP_SE_SCALING_EN			(1 << 0)
 #define   MALIDP_SE_ALPHA_EN			(1 << 1)
+#define   MALIDP_SE_ENH_MASK			3
+#define   MALIDP_SE_ENH(x)			(((x) & MALIDP_SE_ENH_MASK) << 2)
 #define   MALIDP_SE_RGBO_IF_EN			(1 << 4)
 #define   MALIDP550_SE_CTL_SEL_MASK		7
 #define   MALIDP550_SE_CTL_VCSEL(x) \
@@ -139,6 +141,17 @@
 #define     MALIDP_SE_COEFFTAB_DATA_MASK	0x3fff
 #define     MALIDP_SE_SET_COEFFTAB_DATA(x) \
 		((x) & MALIDP_SE_COEFFTAB_DATA_MASK)
+/* Enhance coeffents reigster offset */
+#define MALIDP_SE_IMAGE_ENH			0x3C
+/* ENH_LIMITS offset 0x0 */
+#define     MALIDP_SE_ENH_LOW_LEVEL		24
+#define     MALIDP_SE_ENH_HIGH_LEVEL		63
+#define     MALIDP_SE_ENH_LIMIT_MASK		0xfff
+#define     MALIDP_SE_SET_ENH_LIMIT_LOW(x) \
+		((x) & MALIDP_SE_ENH_LIMIT_MASK)
+#define     MALIDP_SE_SET_ENH_LIMIT_HIGH(x) \
+		(((x) & MALIDP_SE_ENH_LIMIT_MASK) << 16)
+#define   MALIDP_SE_ENH_COEFF0			0x04
 
 /* register offsets and bits specific to DP500 */
 #define MALIDP500_ADDR_SPACE_SIZE	0x01000