From 56194b0b30f7158beef2f089883f001ad423a46d Mon Sep 17 00:00:00 2001
From: Marek Vasut <marex@denx.de>
Date: Tue, 29 Mar 2022 10:50:09 +0200
Subject: drm/bridge: tc358767: Implement atomic_check callback
Git-commit: 65fdbb714d7f5764b6571b86f0617782cbe28ab1
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Implement .atomic_check callback which prevents user space from setting
unsupported mode. The tc_edp_common_atomic_check() variant is already
prepared for DSI-to-DPI mode addition, which has different frequency
limits.

Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de> # In both DPI to eDP and DSI to DPI mode.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329085015.39159-6-marex@denx.de
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/bridge/tc358767.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 780fb94609f1..59cba91554b4 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -1289,6 +1289,31 @@ static bool tc_bridge_mode_fixup(struct drm_bridge *bridge,
 	return true;
 }
 
+static int tc_common_atomic_check(struct drm_bridge *bridge,
+				  struct drm_bridge_state *bridge_state,
+				  struct drm_crtc_state *crtc_state,
+				  struct drm_connector_state *conn_state,
+				  const unsigned int max_khz)
+{
+	tc_bridge_mode_fixup(bridge, &crtc_state->mode,
+			     &crtc_state->adjusted_mode);
+
+	if (crtc_state->adjusted_mode.clock > max_khz)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int tc_edp_atomic_check(struct drm_bridge *bridge,
+			       struct drm_bridge_state *bridge_state,
+			       struct drm_crtc_state *crtc_state,
+			       struct drm_connector_state *conn_state)
+{
+	/* DPI->(e)DP interface clock limitation: upto 154 MHz */
+	return tc_common_atomic_check(bridge, bridge_state, crtc_state,
+				      conn_state, 154000);
+}
+
 static enum drm_mode_status
 tc_edp_mode_valid(struct drm_bridge *bridge,
 		  const struct drm_display_info *info,
@@ -1463,6 +1488,7 @@ static const struct drm_bridge_funcs tc_edp_bridge_funcs = {
 	.detach = tc_edp_bridge_detach,
 	.mode_valid = tc_edp_mode_valid,
 	.mode_set = tc_bridge_mode_set,
+	.atomic_check = tc_edp_atomic_check,
 	.atomic_enable = tc_edp_bridge_atomic_enable,
 	.atomic_disable = tc_edp_bridge_atomic_disable,
 	.mode_fixup = tc_bridge_mode_fixup,
-- 
2.38.1