Add support for drawing the SMPTE pattern in buffers using a
color-indexed frame buffer formats with two, four, or sixteen colors.
Note that this still uses 256 as the CLUT size, as
DRM_IOCTL_MODE_SETGAMMA enforces that the size matches against the
(fixed) gamma size, while the CLUT size depends on the format.
Move clearing the color LUT entries from util_smpte_index_gamma() to its
caller, as only the caller knows how many entries there really are
(currently DRM always assumes 256 entries).
Signed-off-by: Geert Uytterhoeven <ge...@linux-m68k.org>
Acked-by: Sam Ravnborg <s...@ravnborg.org>
---
v4:
- Add missing C[12] to oneline-summary,
- Do not remove memset() of full lut, else some entries may stay
uninitialized,
v3:
- Add Acked-by,
v2:
- Split off changes to tests/modetest/modetest.c,
- Add C1 and C2 support.
The linuxdoc comments say userspace can query the gamma size:
* drm_mode_gamma_set_ioctl - set the gamma table
*
* Set the gamma table of a CRTC to the one passed in by the user. Userspace can
* inquire the required gamma table size through drm_mode_gamma_get_ioctl.
* drm_mode_gamma_get_ioctl - get the gamma table
*
* Copy the current gamma table into the storage provided. This also provides
* the gamma table size the driver expects, which can be used to size the
* allocated storage.
but the code doesn't seem to support that in an easy way (like setting
red/green/blue to NULL on input, retrieving gamma_size on output), only
by providing big enough buffers for red/green/blue, and looping over
gamma_size until -EINVAL is no longer returned.
---
tests/modetest/modetest.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/tests/modetest/modetest.c b/tests/modetest/modetest.c
index 9504fbd8af59ff21..9b1aa537be8716cf 100644
--- a/tests/modetest/modetest.c
+++ b/tests/modetest/modetest.c
@@ -1149,13 +1149,16 @@ static bool add_property_optional(struct device *dev,
uint32_t obj_id,
static void set_gamma(struct device *dev, unsigned crtc_id, unsigned fourcc)
{
unsigned blob_id = 0;
+ const struct util_format_info *info;
/* TODO: support 1024-sized LUTs, when the use-case arises */
struct drm_color_lut gamma_lut[256];
int i, ret;
- if (fourcc == DRM_FORMAT_C8) {
- /* TODO: Add C8 support for more patterns */
- util_smpte_fill_lut(256, gamma_lut);
+ info = util_format_info_find(fourcc);
+ if (info->ncolors) {
+ memset(gamma_lut, 0, sizeof(gamma_lut));
+ /* TODO: Add index support for more patterns */
+ util_smpte_fill_lut(info->ncolors, gamma_lut);
drmModeCreatePropertyBlob(dev->fd, gamma_lut,
sizeof(gamma_lut), &blob_id);
} else {
/*
--
2.34.1
