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Commit 7868e507 authored by Yannick Fertre's avatar Yannick Fertre Committed by Benjamin Gaignard
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drm/stm: ltdc: filter mode pixel clock vs pad constraint 



Filter the requested mode pixel clock frequency according
to the pad maximum supported frequency.

Signed-off-by: default avatarYannick Fertre <yannick.fertre@st.com>
Reviewed-by: default avatarPhilippe Cornu <philippe.cornu@st.com>
Tested-by: default avatarPhilippe Cornu <philippe.cornu@st.com>
Signed-off-by: default avatarBenjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1530271342-5532-1-git-send-email-yannick.fertre@st.com
parent f8878bb2

drivers/gpu/drm/stm/ltdc.c

+12 −4
Original line number Diff line number Diff line
@@ -457,6 +457,14 @@ ltdc_crtc_mode_valid(struct drm_crtc *crtc, 
	int target_max = target + CLK_TOLERANCE_HZ;

	int result;



	result = clk_round_rate(ldev->pixel_clk, target);



	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);



	/* Filter modes according to the max frequency supported by the pads */

	if (result > ldev->caps.pad_max_freq_hz)

		return MODE_CLOCK_HIGH;



	/*

	 * Accept all "preferred" modes:

	 * - this is important for panels because panel clock tolerances are
@@ -468,10 +476,6 @@ ltdc_crtc_mode_valid(struct drm_crtc *crtc, 
	if (mode->type & DRM_MODE_TYPE_PREFERRED)

		return MODE_OK;



	result = clk_round_rate(ldev->pixel_clk, target);



	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);



	/*

	 * Filter modes according to the clock value, particularly useful for

	 * hdmi modes that require precise pixel clocks.
@@ -991,11 +995,15 @@ static int ltdc_get_caps(struct drm_device *ddev) 
		 * does not work on 2nd layer.

		 */

		ldev->caps.non_alpha_only_l1 = true;

		ldev->caps.pad_max_freq_hz = 90000000;

		if (ldev->caps.hw_version == HWVER_10200)

			ldev->caps.pad_max_freq_hz = 65000000;

		break;

	case HWVER_20101:

		ldev->caps.reg_ofs = REG_OFS_4;

		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;

		ldev->caps.non_alpha_only_l1 = false;

		ldev->caps.pad_max_freq_hz = 150000000;

		break;

	default:

		return -ENODEV;

drivers/gpu/drm/stm/ltdc.h

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ struct ltdc_caps { 
	u32 bus_width;		/* bus width (32 or 64 bits) */

	const u32 *pix_fmt_hw;	/* supported pixel formats */

	bool non_alpha_only_l1; /* non-native no-alpha formats on layer 1 */

	int pad_max_freq_hz;	/* max frequency supported by pad */

};



#define LTDC_MAX_LAYER	4