From: Philippe CORNU <philippe.cornu@st.com>
Date: Thu, 26 Oct 2017 13:17:46 +0200
Subject: drm/stm: ltdc: add clut mode support
Git-commit: b706a25eaed083a54afd113db86ee9747cc2f28b
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Add the 8-bit clut mode support at crtc level.
Useful for low memory footprint user interfaces but also for
8-bit old games (including color shifting visual effects).
Tested with fbdev FBIOPUTCMAP & drm DRM_IOCTL_MODE_SETGAMMA
ioctls.
Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1509016666-18927-1-git-send-email-philippe.cornu@st.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/stm/ltdc.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -175,6 +175,8 @@
#define LXCFBLNR_CFBLN GENMASK(10, 0) /* Color Frame Buffer Line Number */
+#define CLUT_SIZE 256
+
#define CONSTA_MAX 0xFF /* CONSTant Alpha MAX= 1.0 */
#define BF1_PAXCA 0x600 /* Pixel Alpha x Constant Alpha */
#define BF1_CA 0x400 /* Constant Alpha */
@@ -363,6 +365,28 @@ static irqreturn_t ltdc_irq(int irq, voi
* DRM_CRTC
*/
+static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
+{
+ struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+ struct drm_color_lut *lut;
+ u32 val;
+ int i;
+
+ if (!crtc || !crtc->state)
+ return;
+
+ if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
+ return;
+
+ lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
+
+ for (i = 0; i < CLUT_SIZE; i++, lut++) {
+ val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
+ (lut->blue >> 8) | (i << 24);
+ reg_write(ldev->regs, LTDC_L1CLUTWR, val);
+ }
+}
+
static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
@@ -486,6 +510,8 @@ static void ltdc_crtc_atomic_flush(struc
DRM_DEBUG_ATOMIC("\n");
+ ltdc_crtc_update_clut(crtc);
+
/* Commit shadow registers = update planes at next vblank */
reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
@@ -533,6 +559,7 @@ static const struct drm_crtc_funcs ltdc_
.reset = drm_atomic_helper_crtc_reset,
.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+ .gamma_set = drm_atomic_helper_legacy_gamma_set,
};
/*
@@ -765,6 +792,9 @@ static int ltdc_crtc_init(struct drm_dev
drm_crtc_helper_add(crtc, <dc_crtc_helper_funcs);
+ drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
+ drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
+
DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
/* Add planes. Note : the first layer is used by primary plane */