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, 87 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0631-drm-vc4-hdmi-Move-clock-calculation-into-its-own-fun.patch b/target/linux/bcm27xx/patches-5.15/950-0631-drm-vc4-hdmi-Move-clock-calculation-into-its-own-fun.patch
new file mode 100644
index 0000000000..506b0cc5d8
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0631-drm-vc4-hdmi-Move-clock-calculation-into-its-own-fun.patch
@@ -0,0 +1,87 @@
+From 60b7ddb0b3c9d906a20d8a84e527ccf5a792a64b Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Thu, 2 Dec 2021 17:04:18 +0100
+Subject: [PATCH] drm/vc4: hdmi: Move clock calculation into its own
+ function
+
+The code to compute our clock rate for a given setup will be called in
+multiple places in the next patches, so let's create a separate function
+for it.
+
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_hdmi.c | 49 +++++++++++++++++++++++-----------
+ 1 file changed, 34 insertions(+), 15 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
+@@ -1263,6 +1263,35 @@ vc4_hdmi_encoder_clock_valid(const struc
+ 	return MODE_OK;
+ }
+ 
++static unsigned long long
++vc4_hdmi_encoder_compute_mode_clock(const struct drm_display_mode *mode,
++				    unsigned int bpc)
++{
++	unsigned long long clock = mode->crtc_clock * 1000;
++
++	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
++		clock = clock * 2;
++
++	return clock * bpc / 8;
++}
++
++static int
++vc4_hdmi_encoder_compute_clock(const struct vc4_hdmi *vc4_hdmi,
++			       struct vc4_hdmi_connector_state *vc4_state,
++			       const struct drm_display_mode *mode,
++			       unsigned int bpc)
++{
++	unsigned long long clock;
++
++	clock = vc4_hdmi_encoder_compute_mode_clock(mode, bpc);
++	if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, clock) != MODE_OK)
++		return -EINVAL;
++
++	vc4_state->pixel_rate = clock;
++
++	return 0;
++}
++
+ #define WIFI_2_4GHz_CH1_MIN_FREQ	2400000000ULL
+ #define WIFI_2_4GHz_CH1_MAX_FREQ	2422000000ULL
+ 
+@@ -1275,6 +1304,7 @@ static int vc4_hdmi_encoder_atomic_check
+ 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+ 	unsigned long long pixel_rate = mode->clock * 1000;
+ 	unsigned long long tmds_rate;
++	int ret;
+ 
+ 	if (vc4_hdmi->variant->unsupported_odd_h_timings &&
+ 	    !(mode->flags & DRM_MODE_FLAG_DBLCLK) &&
+@@ -1296,21 +1326,10 @@ static int vc4_hdmi_encoder_atomic_check
+ 		pixel_rate = mode->clock * 1000;
+ 	}
+ 
+-	if (conn_state->max_bpc == 12) {
+-		pixel_rate = pixel_rate * 150;
+-		do_div(pixel_rate, 100);
+-	} else if (conn_state->max_bpc == 10) {
+-		pixel_rate = pixel_rate * 125;
+-		do_div(pixel_rate, 100);
+-	}
+-
+-	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+-		pixel_rate = pixel_rate * 2;
+-
+-	if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, pixel_rate) != MODE_OK)
+-		return -EINVAL;
+-
+-	vc4_state->pixel_rate = pixel_rate;
++	ret = vc4_hdmi_encoder_compute_clock(vc4_hdmi, vc4_state, mode,
++					     conn_state->max_bpc);
++	if (ret)
++		return ret;
+ 
+ 	return 0;
+ }