From 7868e5079228b4c07cf61b5ad5d35af5c29f7375 Mon Sep 17 00:00:00 2001 From: Yannick Fertre Date: Fri, 29 Jun 2018 13:22:22 +0200 Subject: [PATCH] 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: Yannick Fertre Reviewed-by: Philippe Cornu Tested-by: Philippe Cornu Signed-off-by: Benjamin Gaignard Link: https://patchwork.freedesktop.org/patch/msgid/1530271342-5532-1-git-send-email-yannick.fertre@st.com --- drivers/gpu/drm/stm/ltdc.c | 16 ++++++++++++---- drivers/gpu/drm/stm/ltdc.h | 1 + 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index d997a60..f1f3733 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -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; diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h index 1e16d6a..d5afb89 100644 --- a/drivers/gpu/drm/stm/ltdc.h +++ b/drivers/gpu/drm/stm/ltdc.h @@ -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 -- 2.7.4