bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

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

1 files changed, 46 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0606-drm-vc4-Alter-the-HDMI-state-machine-clock-calc-to-a.patch b/target/linux/bcm27xx/patches-5.4/950-0606-drm-vc4-Alter-the-HDMI-state-machine-clock-calc-to-a.patch
new file mode 100644
index 0000000000..dc2d1a2a04
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0606-drm-vc4-Alter-the-HDMI-state-machine-clock-calc-to-a.patch
@@ -0,0 +1,46 @@
+From 37b204f22778f51cad7bdf678d7574ff6d7508a6 Mon Sep 17 00:00:00 2001
+From: Dave Stevenson <dave.stevenson@raspberrypi.com>
+Date: Wed, 25 Mar 2020 18:22:40 +0000
+Subject: [PATCH] drm/vc4: Alter the HDMI state machine clock calc to
+ allow for 1920x1200
+
+Whilst the documentation for BCM2835 states that the HDMI state machine
+clock needs to be 108% of the pixel clock, other documentation says
+that it only has to be greater than the pixel clock. The firmware
+uses 101%, and that allows 1920x1200@60Hz to work within the
+constraint of the HSM clock being < 163.68MHz.
+
+Adopt 101%, and increase the maximum pixel clock for vc4 to 162MHz
+so that it too supports 1920x1200@60.
+
+Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
+---
+ drivers/gpu/drm/vc4/vc4_hdmi.c | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
+@@ -581,10 +581,11 @@ static void vc4_hdmi_encoder_enable(stru
+ 	}
+ 
+ 	/*
+-	 * The HSM rate needs to be at 108% of the pixel clock, with a
+-	 * minimum of 108MHz.
++	 * The HSM rate needs to be slightly greater than the pixel clock, with
++	 * a minimum of 108MHz.
++	 * Use 101% as this is what the firmware uses.
+ 	 */
+-	hsm_rate = max_t(unsigned long, 108000000, (pixel_rate / 100) * 108);
++	hsm_rate = max_t(unsigned long, 108000000, (pixel_rate / 100) * 101);
+ 	ret = clk_set_rate(vc4_hdmi->hsm_clock, hsm_rate);
+ 	if (ret) {
+ 		DRM_ERROR("Failed to set HSM clock rate: %d\n", ret);
+@@ -1731,7 +1732,7 @@ static int vc4_hdmi_dev_remove(struct pl
+ }
+ 
+ static const struct vc4_hdmi_variant bcm2835_variant = {
+-	.max_pixel_clock	= 148500000,
++	.max_pixel_clock	= 162000000,
+ 	.audio_available	= true,
+ 	.cec_available		= true,
+ 	.registers		= vc4_hdmi_fields,