drm/imx/dcss: allow using nearest neighbor interpolation scaling

This patch adds support for using NN interpolation scaling by setting the
SCALING_FILTER plane property to 1. Otherwise, the default method is used.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105145018.27255-1-laurentiu.palcu@oss.nxp.com

diff --git a/drivers/gpu/drm/imx/dcss/dcss-dev.h b/drivers/gpu/drm/imx/dcss/dcss-dev.h
index c642ae1..1e58227 100644 (file)
--- a/drivers/gpu/drm/imx/dcss/dcss-dev.h
+++ b/drivers/gpu/drm/imx/dcss/dcss-dev.h
@@ -7,6 +7,7 @@
 #define __DCSS_PRV_H__
 
 #include <drm/drm_fourcc.h>
+#include <drm/drm_plane.h>
 #include <linux/io.h>
 #include <video/videomode.h>
 
@@ -165,6 +166,8 @@ void dcss_ss_sync_set(struct dcss_ss *ss, struct videomode *vm,
 /* SCALER */
 int dcss_scaler_init(struct dcss_dev *dcss, unsigned long scaler_base);
 void dcss_scaler_exit(struct dcss_scaler *scl);
+void dcss_scaler_set_filter(struct dcss_scaler *scl, int ch_num,
+                           enum drm_scaling_filter scaling_filter);
 void dcss_scaler_setup(struct dcss_scaler *scl, int ch_num,
                       const struct drm_format_info *format,
                       int src_xres, int src_yres, int dst_xres, int dst_yres,

diff --git a/drivers/gpu/drm/imx/dcss/dcss-plane.c b/drivers/gpu/drm/imx/dcss/dcss-plane.c
index 5db093a..03ba88f 100644 (file)
--- a/drivers/gpu/drm/imx/dcss/dcss-plane.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-plane.c
@@ -257,7 +257,8 @@ static bool dcss_plane_needs_setup(struct drm_plane_state *state,
               state->src_h  != old_state->src_h  ||
               fb->format->format != old_fb->format->format ||
               fb->modifier  != old_fb->modifier ||
-              state->rotation != old_state->rotation;
+              state->rotation != old_state->rotation ||
+              state->scaling_filter != old_state->scaling_filter;
 }
 
 static void dcss_plane_atomic_update(struct drm_plane *plane,
@@ -313,6 +314,9 @@ static void dcss_plane_atomic_update(struct drm_plane *plane,
        is_rotation_90_or_270 = state->rotation & (DRM_MODE_ROTATE_90 |
                                                   DRM_MODE_ROTATE_270);
 
+       dcss_scaler_set_filter(dcss->scaler, dcss_plane->ch_num,
+                              state->scaling_filter);
+
        dcss_scaler_setup(dcss->scaler, dcss_plane->ch_num,
                          state->fb->format,
                          is_rotation_90_or_270 ? src_h : src_w,
@@ -394,6 +398,10 @@ struct dcss_plane *dcss_plane_init(struct drm_device *drm,
        if (ret)
                return ERR_PTR(ret);
 
+       drm_plane_create_scaling_filter_property(&dcss_plane->base,
+                                       BIT(DRM_SCALING_FILTER_DEFAULT) |
+                                       BIT(DRM_SCALING_FILTER_NEAREST_NEIGHBOR));
+
        drm_plane_create_rotation_property(&dcss_plane->base,
                                           DRM_MODE_ROTATE_0,
                                           DRM_MODE_ROTATE_0   |

diff --git a/drivers/gpu/drm/imx/dcss/dcss-scaler.c b/drivers/gpu/drm/imx/dcss/dcss-scaler.c
index cd21905..47852b9 100644 (file)
--- a/drivers/gpu/drm/imx/dcss/dcss-scaler.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-scaler.c
@@ -77,6 +77,8 @@ struct dcss_scaler_ch {
 
        u32 c_vstart;
        u32 c_hstart;
+
+       bool use_nn_interpolation;
 };
 
 struct dcss_scaler {
@@ -243,6 +245,17 @@ static void dcss_scaler_gaussian_filter(int fc_q, bool use_5_taps,
        }
 }
 
+static void dcss_scaler_nearest_neighbor_filter(bool use_5_taps,
+                                               int coef[][PSC_NUM_TAPS])
+{
+       int i, j;
+
+       for (i = 0; i < PSC_STORED_PHASES; i++)
+               for (j = 0; j < PSC_NUM_TAPS; j++)
+                       coef[i][j] = j == PSC_NUM_TAPS >> 1 ?
+                                               (1 << PSC_COEFF_PRECISION) : 0;
+}
+
 /**
  * dcss_scaler_filter_design() - Compute filter coefficients using
  *                              Gaussian filter.
@@ -253,7 +266,8 @@ static void dcss_scaler_gaussian_filter(int fc_q, bool use_5_taps,
  */
 static void dcss_scaler_filter_design(int src_length, int dst_length,
                                      bool use_5_taps, bool phase0_identity,
-                                     int coef[][PSC_NUM_TAPS])
+                                     int coef[][PSC_NUM_TAPS],
+                                     bool nn_interpolation)
 {
        int fc_q;
 
@@ -263,8 +277,11 @@ static void dcss_scaler_filter_design(int src_length, int dst_length,
        else
                fc_q = div_q(dst_length, src_length * PSC_NUM_PHASES);
 
-       /* compute gaussian filter coefficients */
-       dcss_scaler_gaussian_filter(fc_q, use_5_taps, phase0_identity, coef);
+       if (nn_interpolation)
+               dcss_scaler_nearest_neighbor_filter(use_5_taps, coef);
+       else
+               /* compute gaussian filter coefficients */
+               dcss_scaler_gaussian_filter(fc_q, use_5_taps, phase0_identity, coef);
 }
 
 static void dcss_scaler_write(struct dcss_scaler_ch *ch, u32 val, u32 ofs)
@@ -653,12 +670,14 @@ static void dcss_scaler_yuv_coef_set(struct dcss_scaler_ch *ch,
 
        /* horizontal luma */
        dcss_scaler_filter_design(src_xres, dst_xres, false,
-                                 src_xres == dst_xres, coef);
+                                 src_xres == dst_xres, coef,
+                                 ch->use_nn_interpolation);
        dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HLUM, coef);
 
        /* vertical luma */
        dcss_scaler_filter_design(src_yres, dst_yres, program_5_taps,
-                                 src_yres == dst_yres, coef);
+                                 src_yres == dst_yres, coef,
+                                 ch->use_nn_interpolation);
 
        if (program_5_taps)
                dcss_scaler_program_5_coef_set(ch, DCSS_SCALER_COEF_VLUM, coef);
@@ -678,14 +697,14 @@ static void dcss_scaler_yuv_coef_set(struct dcss_scaler_ch *ch,
        /* horizontal chroma */
        dcss_scaler_filter_design(src_xres, dst_xres, false,
                                  (src_xres == dst_xres) && (ch->c_hstart == 0),
-                                 coef);
+                                 coef, ch->use_nn_interpolation);
 
        dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HCHR, coef);
 
        /* vertical chroma */
        dcss_scaler_filter_design(src_yres, dst_yres, program_5_taps,
                                  (src_yres == dst_yres) && (ch->c_vstart == 0),
-                                 coef);
+                                 coef, ch->use_nn_interpolation);
        if (program_5_taps)
                dcss_scaler_program_5_coef_set(ch, DCSS_SCALER_COEF_VCHR, coef);
        else
@@ -700,12 +719,14 @@ static void dcss_scaler_rgb_coef_set(struct dcss_scaler_ch *ch,
 
        /* horizontal RGB */
        dcss_scaler_filter_design(src_xres, dst_xres, false,
-                                 src_xres == dst_xres, coef);
+                                 src_xres == dst_xres, coef,
+                                 ch->use_nn_interpolation);
        dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_HLUM, coef);
 
        /* vertical RGB */
        dcss_scaler_filter_design(src_yres, dst_yres, false,
-                                 src_yres == dst_yres, coef);
+                                 src_yres == dst_yres, coef,
+                                 ch->use_nn_interpolation);
        dcss_scaler_program_7_coef_set(ch, DCSS_SCALER_COEF_VLUM, coef);
 }
 
@@ -751,6 +772,14 @@ static void dcss_scaler_set_rgb10_order(struct dcss_scaler_ch *ch,
        ch->sdata_ctrl |= a2r10g10b10_format << A2R10G10B10_FORMAT_POS;
 }
 
+void dcss_scaler_set_filter(struct dcss_scaler *scl, int ch_num,
+                           enum drm_scaling_filter scaling_filter)
+{
+       struct dcss_scaler_ch *ch = &scl->ch[ch_num];
+
+       ch->use_nn_interpolation = scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR;
+}
+
 void dcss_scaler_setup(struct dcss_scaler *scl, int ch_num,
                       const struct drm_format_info *format,
                       int src_xres, int src_yres, int dst_xres, int dst_yres,