Commit 1a32a938 authored by Philippe CORNU's avatar Philippe CORNU Committed by Benjamin Gaignard
Browse files

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: default avatarPhilippe Cornu <philippe.cornu@st.com>
Reviewed-by: default avatarYannick Fertré <yannick.fertre@st.com>
Signed-off-by: default avatarBenjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125160101.9102-1-philippe.cornu@st.com
parent 41d2f5fa

drivers/gpu/drm/stm/ltdc.c

+25 −10
Original line number Diff line number Diff line
@@ -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,

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