Commit c06cb85a authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/vesadrm: Use helpers for programming gamma ramps 



Replace vesadrm'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.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250520094203.30545-6-tzimmermann@suse.de
parent a4871e62

drivers/gpu/drm/sysfb/vesadrm.c

+36 −64
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <drm/clients/drm_client_setup.h>

#include <drm/drm_atomic.h>

#include <drm/drm_atomic_state_helper.h>

#include <drm/drm_color_mgmt.h>

#include <drm/drm_connector.h>

#include <drm/drm_damage_helper.h>

#include <drm/drm_device.h>
@@ -87,15 +88,10 @@ static struct vesadrm_device *to_vesadrm_device(struct drm_device *dev) 
static void vesadrm_vga_cmap_write(struct vesadrm_device *vesa, unsigned int index,

				   u16 red, u16 green, u16 blue)

{

	u8 i8, r8, g8, b8;



	if (index > 255)

		return;



	i8 = index;

	r8 = red >> 8;

	g8 = green >> 8;

	b8 = blue >> 8;

	u8 i8 = index;

	u8 r8 = red >> 8;

	u8 g8 = green >> 8;

	u8 b8 = blue >> 8;



	outb_p(i8, VGA_PEL_IW);

	outb_p(r8, VGA_PEL_D);
@@ -120,9 +116,6 @@ static void vesadrm_pmi_cmap_write(struct vesadrm_device *vesa, unsigned int ind 
		0x00,

	};



	if (index > 255)

		return;



	__asm__ __volatile__ (

		"call *(%%esi)"

		: /* no return value */
@@ -135,43 +128,36 @@ static void vesadrm_pmi_cmap_write(struct vesadrm_device *vesa, unsigned int ind 
}

#endif



static void vesadrm_set_gamma_linear(struct vesadrm_device *vesa,

static void vesadrm_set_gamma_lut(struct drm_crtc *crtc, unsigned int index,

				  u16 red, u16 green, u16 blue)

{

	struct drm_device *dev = crtc->dev;

	struct vesadrm_device *vesa = to_vesadrm_device(dev);

	u8 i8 = index & 0xff;



	if (drm_WARN_ON_ONCE(dev, index != i8))

		return; /* driver bug */



	vesa->cmap_write(vesa, i8, red, green, blue);

}



static void vesadrm_fill_gamma_lut(struct vesadrm_device *vesa,

				   const struct drm_format_info *format)

{

	struct drm_device *dev = &vesa->sysfb.dev;

	size_t i;

	u16 r16, g16, b16;

	struct drm_crtc *crtc = &vesa->crtc;



	switch (format->format) {

	case DRM_FORMAT_XRGB1555:

		for (i = 0; i < 32; ++i) {

			r16 = i * 8 + i / 4;

			r16 |= (r16 << 8) | r16;

			vesa->cmap_write(vesa, i, r16, r16, r16);

		}

		drm_crtc_fill_gamma_555(crtc, vesadrm_set_gamma_lut);

		break;

	case DRM_FORMAT_RGB565:

		for (i = 0; i < 32; ++i) {

			r16 = i * 8 + i / 4;

			r16 |= (r16 << 8) | r16;

			g16 = i * 4 + i / 16;

			g16 |= (g16 << 8) | g16;

			b16 = r16;

			vesa->cmap_write(vesa, i, r16, g16, b16);

		}

		for (i = 32; i < 64; ++i) {

			g16 = i * 4 + i / 16;

			g16 |= (g16 << 8) | g16;

			vesa->cmap_write(vesa, i, 0, g16, 0);

		}

		drm_crtc_fill_gamma_565(crtc, vesadrm_set_gamma_lut);

		break;

	case DRM_FORMAT_RGB888:

	case DRM_FORMAT_XRGB8888:

	case DRM_FORMAT_BGRX8888:

		for (i = 0; i < 256; ++i) {

			r16 = (i << 8) | i;

			vesa->cmap_write(vesa, i, r16, r16, r16);

		}

		drm_crtc_fill_gamma_888(crtc, vesadrm_set_gamma_lut);

		break;

	default:

		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
@@ -180,38 +166,24 @@ static void vesadrm_set_gamma_linear(struct vesadrm_device *vesa, 
	}

}



static void vesadrm_set_gamma_lut(struct vesadrm_device *vesa,

static void vesadrm_load_gamma_lut(struct vesadrm_device *vesa,

				   const struct drm_format_info *format,

				   struct drm_color_lut *lut)

{

	struct drm_device *dev = &vesa->sysfb.dev;

	size_t i;

	u16 r16, g16, b16;

	struct drm_crtc *crtc = &vesa->crtc;



	switch (format->format) {

	case DRM_FORMAT_XRGB1555:

		for (i = 0; i < 32; ++i) {

			r16 = lut[i * 8 + i / 4].red;

			g16 = lut[i * 8 + i / 4].green;

			b16 = lut[i * 8 + i / 4].blue;

			vesa->cmap_write(vesa, i, r16, g16, b16);

		}

		drm_crtc_load_gamma_555_from_888(crtc, lut, vesadrm_set_gamma_lut);

		break;

	case DRM_FORMAT_RGB565:

		for (i = 0; i < 32; ++i) {

			r16 = lut[i * 8 + i / 4].red;

			g16 = lut[i * 4 + i / 16].green;

			b16 = lut[i * 8 + i / 4].blue;

			vesa->cmap_write(vesa, i, r16, g16, b16);

		}

		for (i = 32; i < 64; ++i)

			vesa->cmap_write(vesa, i, 0, lut[i * 4 + i / 16].green, 0);

		drm_crtc_load_gamma_565_from_888(crtc, lut, vesadrm_set_gamma_lut);

		break;

	case DRM_FORMAT_RGB888:

	case DRM_FORMAT_XRGB8888:

	case DRM_FORMAT_BGRX8888:

		for (i = 0; i < 256; ++i)

			vesa->cmap_write(vesa, i, lut[i].red, lut[i].green, lut[i].blue);

		drm_crtc_load_gamma_888(crtc, lut, vesadrm_set_gamma_lut);

		break;

	default:

		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
@@ -253,13 +225,13 @@ static void vesadrm_crtc_helper_atomic_flush(struct drm_crtc *crtc, 
	if (crtc_state->enable && crtc_state->color_mgmt_changed) {

		if (sysfb_crtc_state->format == sysfb->fb_format) {

			if (crtc_state->gamma_lut)

				vesadrm_set_gamma_lut(vesa,

				vesadrm_load_gamma_lut(vesa,

						       sysfb_crtc_state->format,

						       crtc_state->gamma_lut->data);

			else

				vesadrm_set_gamma_linear(vesa, sysfb_crtc_state->format);

				vesadrm_fill_gamma_lut(vesa, sysfb_crtc_state->format);

		} else {

			vesadrm_set_gamma_linear(vesa, sysfb_crtc_state->format);

			vesadrm_fill_gamma_lut(vesa, sysfb_crtc_state->format);

		}

	}

}