[PATCH v2 3/5] drm/mgag200: Use helpers for programming gamma ramps
Thomas Zimmermann
tzimmermann at suse.de
Tue May 20 09:40:05 UTC 2025
Replace mgag200's code for programming the hardware gamma LUT with
DRM helpers. Either load a provided gamma ramp or program a default.
Set the individual entries with a callback.
Each gamma value is given as 3 individual 16-bit values for red,
green and blue. The driver reduces them to 8 bit to make them fit
into hardware registers.
v2:
- fix coding style
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>
---
drivers/gpu/drm/mgag200/mgag200_drv.h | 8 +--
drivers/gpu/drm/mgag200/mgag200_g200er.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200ev.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200se.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_mode.c | 82 ++++++++++--------------
5 files changed, 44 insertions(+), 58 deletions(-)
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index 819a7e9381e3..f4bf40cd7c88 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -382,10 +382,10 @@ int mgag200_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
.destroy = drm_plane_cleanup, \
DRM_GEM_SHADOW_PLANE_FUNCS
-void mgag200_crtc_set_gamma_linear(struct mga_device *mdev, const struct drm_format_info *format);
-void mgag200_crtc_set_gamma(struct mga_device *mdev,
- const struct drm_format_info *format,
- struct drm_color_lut *lut);
+void mgag200_crtc_fill_gamma(struct mga_device *mdev, const struct drm_format_info *format);
+void mgag200_crtc_load_gamma(struct mga_device *mdev,
+ const struct drm_format_info *format,
+ struct drm_color_lut *lut);
enum drm_mode_status mgag200_crtc_helper_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode);
diff --git a/drivers/gpu/drm/mgag200/mgag200_g200er.c b/drivers/gpu/drm/mgag200/mgag200_g200er.c
index c20ed0ab50ec..23debc70dc54 100644
--- a/drivers/gpu/drm/mgag200/mgag200_g200er.c
+++ b/drivers/gpu/drm/mgag200/mgag200_g200er.c
@@ -200,9 +200,9 @@ static void mgag200_g200er_crtc_helper_atomic_enable(struct drm_crtc *crtc,
mgag200_g200er_reset_tagfifo(mdev);
if (crtc_state->gamma_lut)
- mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
+ mgag200_crtc_load_gamma(mdev, format, crtc_state->gamma_lut->data);
else
- mgag200_crtc_set_gamma_linear(mdev, format);
+ mgag200_crtc_fill_gamma(mdev, format);
mgag200_enable_display(mdev);
}
diff --git a/drivers/gpu/drm/mgag200/mgag200_g200ev.c b/drivers/gpu/drm/mgag200/mgag200_g200ev.c
index 78be964eb97c..f8796e2b7a0f 100644
--- a/drivers/gpu/drm/mgag200/mgag200_g200ev.c
+++ b/drivers/gpu/drm/mgag200/mgag200_g200ev.c
@@ -201,9 +201,9 @@ static void mgag200_g200ev_crtc_helper_atomic_enable(struct drm_crtc *crtc,
mgag200_g200ev_set_hiprilvl(mdev);
if (crtc_state->gamma_lut)
- mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
+ mgag200_crtc_load_gamma(mdev, format, crtc_state->gamma_lut->data);
else
- mgag200_crtc_set_gamma_linear(mdev, format);
+ mgag200_crtc_fill_gamma(mdev, format);
mgag200_enable_display(mdev);
}
diff --git a/drivers/gpu/drm/mgag200/mgag200_g200se.c b/drivers/gpu/drm/mgag200/mgag200_g200se.c
index 7a32d3b1d226..e80da12ba1fe 100644
--- a/drivers/gpu/drm/mgag200/mgag200_g200se.c
+++ b/drivers/gpu/drm/mgag200/mgag200_g200se.c
@@ -332,9 +332,9 @@ static void mgag200_g200se_crtc_helper_atomic_enable(struct drm_crtc *crtc,
mgag200_g200se_set_hiprilvl(mdev, adjusted_mode, format);
if (crtc_state->gamma_lut)
- mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
+ mgag200_crtc_load_gamma(mdev, format, crtc_state->gamma_lut->data);
else
- mgag200_crtc_set_gamma_linear(mdev, format);
+ mgag200_crtc_fill_gamma(mdev, format);
mgag200_enable_display(mdev);
}
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 6067d08aeee3..951d715dea30 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -13,6 +13,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
+#include <drm/drm_color_mgmt.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_format_helper.h>
@@ -30,35 +31,37 @@
* This file contains setup code for the CRTC.
*/
-void mgag200_crtc_set_gamma_linear(struct mga_device *mdev,
- const struct drm_format_info *format)
+static void mgag200_set_gamma_lut(struct drm_crtc *crtc, unsigned int index,
+ u16 red, u16 green, u16 blue)
{
- int i;
+ struct drm_device *dev = crtc->dev;
+ struct mga_device *mdev = to_mga_device(dev);
+ u8 i8 = index & 0xff;
+ u8 r8 = red >> 8;
+ u8 g8 = green >> 8;
+ u8 b8 = blue >> 8;
+
+ if (drm_WARN_ON_ONCE(dev, index != i8))
+ return; /* driver bug */
+
+ WREG8(DAC_INDEX + MGA1064_INDEX, i8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, r8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, g8);
+ WREG8(DAC_INDEX + MGA1064_COL_PAL, b8);
+}
- WREG8(DAC_INDEX + MGA1064_INDEX, 0);
+void mgag200_crtc_fill_gamma(struct mga_device *mdev,
+ const struct drm_format_info *format)
+{
+ struct drm_crtc *crtc = &mdev->crtc;
switch (format->format) {
case DRM_FORMAT_RGB565:
- /* Use better interpolation, to take 32 values from 0 to 255 */
- for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 8 + i / 4);
- }
- /* Green has one more bit, so add padding with 0 for red and blue. */
- for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i * 4 + i / 16);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
- }
+ drm_crtc_fill_gamma_565(crtc, mgag200_set_gamma_lut);
break;
case DRM_FORMAT_RGB888:
case DRM_FORMAT_XRGB8888:
- for (i = 0; i < MGAG200_LUT_SIZE; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, i);
- }
+ drm_crtc_fill_gamma_888(crtc, mgag200_set_gamma_lut);
break;
default:
drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
@@ -67,36 +70,19 @@ void mgag200_crtc_set_gamma_linear(struct mga_device *mdev,
}
}
-void mgag200_crtc_set_gamma(struct mga_device *mdev,
- const struct drm_format_info *format,
- struct drm_color_lut *lut)
+void mgag200_crtc_load_gamma(struct mga_device *mdev,
+ const struct drm_format_info *format,
+ struct drm_color_lut *lut)
{
- int i;
-
- WREG8(DAC_INDEX + MGA1064_INDEX, 0);
+ struct drm_crtc *crtc = &mdev->crtc;
switch (format->format) {
case DRM_FORMAT_RGB565:
- /* Use better interpolation, to take 32 values from lut[0] to lut[255] */
- for (i = 0; i < MGAG200_LUT_SIZE / 8; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].red >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 8 + i / 4].blue >> 8);
- }
- /* Green has one more bit, so add padding with 0 for red and blue. */
- for (i = MGAG200_LUT_SIZE / 8; i < MGAG200_LUT_SIZE / 4; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i * 4 + i / 16].green >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, 0);
- }
+ drm_crtc_load_gamma_565_from_888(crtc, lut, mgag200_set_gamma_lut);
break;
case DRM_FORMAT_RGB888:
case DRM_FORMAT_XRGB8888:
- for (i = 0; i < MGAG200_LUT_SIZE; i++) {
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].red >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].green >> 8);
- WREG8(DAC_INDEX + MGA1064_COL_PAL, lut[i].blue >> 8);
- }
+ drm_crtc_load_gamma_888(crtc, lut, mgag200_set_gamma_lut);
break;
default:
drm_warn_once(&mdev->base, "Unsupported format %p4cc for gamma correction\n",
@@ -642,9 +628,9 @@ void mgag200_crtc_helper_atomic_flush(struct drm_crtc *crtc, struct drm_atomic_s
const struct drm_format_info *format = mgag200_crtc_state->format;
if (crtc_state->gamma_lut)
- mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
+ mgag200_crtc_load_gamma(mdev, format, crtc_state->gamma_lut->data);
else
- mgag200_crtc_set_gamma_linear(mdev, format);
+ mgag200_crtc_fill_gamma(mdev, format);
}
}
@@ -665,9 +651,9 @@ void mgag200_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_
funcs->pixpllc_atomic_update(crtc, old_state);
if (crtc_state->gamma_lut)
- mgag200_crtc_set_gamma(mdev, format, crtc_state->gamma_lut->data);
+ mgag200_crtc_load_gamma(mdev, format, crtc_state->gamma_lut->data);
else
- mgag200_crtc_set_gamma_linear(mdev, format);
+ mgag200_crtc_fill_gamma(mdev, format);
mgag200_enable_display(mdev);
}
--
2.49.0
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