From: Philippe CORNU 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 Signed-off-by: Benjamin Gaignard Link: https://patchwork.freedesktop.org/patch/msgid/1509016666-18927-1-git-send-email-philippe.cornu@st.com Acked-by: Petr Tesarik --- 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 */