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 --- drivers/gpu/drm/stm/ltdc.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 7be6710..d5c8a42 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -174,6 +174,8 @@
#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 */ @@ -362,6 +364,28 @@ static irqreturn_t ltdc_irq(int irq, void *arg) * 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) { @@ -485,6 +509,8 @@ static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
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);
@@ -532,6 +558,7 @@ void ltdc_crtc_disable_vblank(struct drm_device *ddev, unsigned int pipe) .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, };
/* @@ -764,6 +791,9 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
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 */