summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/stm
diff options
context:
space:
mode:
authorPhilippe CORNU <philippe.cornu@st.com>2018-01-25 17:01:01 +0100
committerBenjamin Gaignard <benjamin.gaignard@linaro.org>2018-01-29 11:07:16 +0100
commit1a32a938b6438afe70c0a2a6dd666f4a49f6c384 (patch)
treed04395cac7edff153153d4a69ead2b2dbca7dff9 /drivers/gpu/drm/stm
parent41d2f5fa89e3fa772ea27c0e1b7bf0e7c6f295b1 (diff)
downloadlinux-1a32a938b6438afe70c0a2a6dd666f4a49f6c384.tar.gz
linux-1a32a938b6438afe70c0a2a6dd666f4a49f6c384.tar.bz2
linux-1a32a938b6438afe70c0a2a6dd666f4a49f6c384.zip
drm/stm: ltdc: use crtc_mode_fixup to update adjusted_mode clock
There is a difference between the panel/bridge requested pixel clock value and the real one due to the hw platform clock preciseness (pll, dividers...). This patch updates the adjusted_mode clock value with the real hw clock value so then attached encoder & connector can use it for precise timing computations. Signed-off-by: Philippe Cornu <philippe.cornu@st.com> Reviewed-by: Yannick Fertré <yannick.fertre@st.com> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20180125160101.9102-1-philippe.cornu@st.com
Diffstat (limited to 'drivers/gpu/drm/stm')
-rw-r--r--drivers/gpu/drm/stm/ltdc.c35
1 files changed, 25 insertions, 10 deletions
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index b48589343ae1..90b3de516c91 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -428,12 +428,35 @@ static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
}
+static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
+{
+ struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+ int rate = mode->clock * 1000;
+
+ /*
+ * TODO clk_round_rate() does not work yet. When ready, it can
+ * be used instead of clk_set_rate() then clk_get_rate().
+ */
+
+ clk_disable(ldev->pixel_clk);
+ if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
+ DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
+ return false;
+ }
+ clk_enable(ldev->pixel_clk);
+
+ adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
+
+ return true;
+}
+
static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
struct ltdc_device *ldev = crtc_to_ltdc(crtc);
struct drm_display_mode *mode = &crtc->state->adjusted_mode;
struct videomode vm;
- int rate = mode->clock * 1000;
u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
u32 total_width, total_height;
u32 val;
@@ -456,15 +479,6 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
total_width = accum_act_w + vm.hfront_porch;
total_height = accum_act_h + vm.vfront_porch;
- clk_disable(ldev->pixel_clk);
-
- if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
- DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
- return;
- }
-
- clk_enable(ldev->pixel_clk);
-
/* Configures the HS, VS, DE and PC polarities. Default Active Low */
val = 0;
@@ -528,6 +542,7 @@ static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
}
static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
+ .mode_fixup = ltdc_crtc_mode_fixup,
.mode_set_nofb = ltdc_crtc_mode_set_nofb,
.atomic_flush = ltdc_crtc_atomic_flush,
.atomic_enable = ltdc_crtc_atomic_enable,