bcm27xx: add support for linux v5.15

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0716-drm-vc4-Remove-entry-to-ULPS-from-vc4_dsi-post_disab.patch b/target/linux/bcm27xx/patches-5.15/950-0716-drm-vc4-Remove-entry-to-ULPS-from-vc4_dsi-post_disab.patch
new file mode 100644
index 0000000000..92377872f7
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0716-drm-vc4-Remove-entry-to-ULPS-from-vc4_dsi-post_disab.patch
@@ -0,0 +1,32 @@
+From ddcc0cd30d39445fe4f00ee355f5ec4a7d3405aa Mon Sep 17 00:00:00 2001
+From: Dave Stevenson <dave.stevenson@raspberrypi.com>
+Date: Fri, 11 Feb 2022 14:15:26 +0000
+Subject: [PATCH] drm/vc4: Remove entry to ULPS from vc4_dsi
+ post_disable
+
+Post_disable was sending the D-PHY sequence to put any device
+into ULPS suspend mode, and then cutting power to the DSI block.
+The power-on reset state of the DSI block is for DSI to be in
+an operational state, not ULPS, so it then never sent the sequence
+for exiting ULPS. Any attached device that didn't have an external
+reset therefore remained in ULPS / standby, and didn't function.
+
+Use of ULPS isn't well specified in DRM, therefore remove entering
+it to avoid the above situation.
+
+Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
+---
+ drivers/gpu/drm/vc4/vc4_dsi.c | 2 --
+ 1 file changed, 2 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_dsi.c
++++ b/drivers/gpu/drm/vc4/vc4_dsi.c
+@@ -816,8 +816,6 @@ static void vc4_dsi_bridge_post_disable(
+ 	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+ 	struct device *dev = &dsi->pdev->dev;
+ 
+-	vc4_dsi_ulps(dsi, true);
+-
+ 	clk_disable_unprepare(dsi->pll_phy_clock);
+ 	clk_disable_unprepare(dsi->escape_clock);
+ 	clk_disable_unprepare(dsi->pixel_clock);