kernels: add linux-libre-aarch64

Some System On a Chip (SOC) have 64bit ARM CPUs that are also
capable of running arm 32bit applications.

Since:
- Parabola doesn't have an aarch64 package repository yet
- The devicetree of devices using such System On a Chip
  are not compiled when using the armv7 defconfig
- Drivers or other platform support code for such hardware
  might also not be compiled in with the armv7 defconfig
- This approach has already been tested with the linux-libre-x86_64
  kenrel

It's then a good idea to add support for such devices by adding
an arrch64 kernel as the maintenance and work is minimal.

The downside is that the external kernel modules that are either
compiled against the kernel or using DKMS will not work by default.

It's however still possible to compile them by hand by using
ARCH= and CROSS_COMPILE= as it is done for this kernel, so it
should be relatively easy to add support for the non-dkms modules.

As for DKMS, someone would need to look into it to understand how
to pass it the make flags (ARCH= and CROSS_COMPILE=) that are
required to automatically build modules.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

1 files changed, 87 insertions, 0 deletions

diff --git a/kernels/linux-libre-arm64/0009-drm-i915-save-AUD_FREQ_CNTRL-state-at-audio-domain-s.patch b/kernels/linux-libre-arm64/0009-drm-i915-save-AUD_FREQ_CNTRL-state-at-audio-domain-s.patch
new file mode 100644
index 000000000..c876a8628
--- /dev/null
+++ b/kernels/linux-libre-arm64/0009-drm-i915-save-AUD_FREQ_CNTRL-state-at-audio-domain-s.patch
@@ -0,0 +1,87 @@
+From e0d783c7ee43a39dadeb96ac669c45f3a3192d96 Mon Sep 17 00:00:00 2001
+From: Kai Vehmanen <kai.vehmanen@linux.intel.com>
+Date: Fri, 20 Sep 2019 11:39:18 +0300
+Subject: [PATCH 09/13] drm/i915: save AUD_FREQ_CNTRL state at audio domain
+ suspend
+
+When audio power domain is suspended, the display driver must
+save state of AUD_FREQ_CNTRL on Tiger Lake and Ice Lake
+systems. The initial value of the register is set by BIOS and
+is read by driver during the audio component init sequence.
+
+Cc: Jani Nikula <jani.nikula@intel.com>
+Cc: Imre Deak <imre.deak@intel.com>
+Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
+Signed-off-by: Jani Nikula <jani.nikula@intel.com>
+Link: https://patchwork.freedesktop.org/patch/msgid/20190920083918.27057-1-kai.vehmanen@linux.intel.com
+---
+ drivers/gpu/drm/i915/display/intel_audio.c | 17 +++++++++++++++--
+ drivers/gpu/drm/i915/i915_drv.h            |  1 +
+ drivers/gpu/drm/i915/i915_reg.h            |  2 ++
+ 3 files changed, 18 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
+index ddcccf4408c3..439bc0a93410 100644
+--- a/drivers/gpu/drm/i915/display/intel_audio.c
++++ b/drivers/gpu/drm/i915/display/intel_audio.c
+@@ -850,10 +850,17 @@ static unsigned long i915_audio_component_get_power(struct device *kdev)
+ 
+ 	ret = intel_display_power_get(dev_priv, POWER_DOMAIN_AUDIO);
+ 
+-	/* Force CDCLK to 2*BCLK as long as we need audio to be powered. */
+-	if (dev_priv->audio_power_refcount++ == 0)
++	if (dev_priv->audio_power_refcount++ == 0) {
++		if (IS_TIGERLAKE(dev_priv) || IS_ICELAKE(dev_priv)) {
++			I915_WRITE(AUD_FREQ_CNTRL, dev_priv->audio_freq_cntrl);
++			DRM_DEBUG_KMS("restored AUD_FREQ_CNTRL to 0x%x\n",
++				      dev_priv->audio_freq_cntrl);
++		}
++
++		/* Force CDCLK to 2*BCLK as long as we need audio powered. */
+ 		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+ 			glk_force_audio_cdclk(dev_priv, true);
++	}
+ 
+ 	return ret;
+ }
+@@ -1114,6 +1121,12 @@ static void i915_audio_component_init(struct drm_i915_private *dev_priv)
+ 		return;
+ 	}
+ 
++	if (IS_TIGERLAKE(dev_priv) || IS_ICELAKE(dev_priv)) {
++		dev_priv->audio_freq_cntrl = I915_READ(AUD_FREQ_CNTRL);
++		DRM_DEBUG_KMS("init value of AUD_FREQ_CNTRL of 0x%x\n",
++			      dev_priv->audio_freq_cntrl);
++	}
++
+ 	dev_priv->audio_component_registered = true;
+ }
+ 
+diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
+index 89b6112bd66b..043ce1b47aeb 100644
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -1530,6 +1530,7 @@ struct drm_i915_private {
+ 	 */
+ 	struct mutex av_mutex;
+ 	int audio_power_refcount;
++	u32 audio_freq_cntrl;
+ 
+ 	struct {
+ 		struct mutex mutex;
+diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
+index f8ee9aba3955..e1fe356463ec 100644
+--- a/drivers/gpu/drm/i915/i915_reg.h
++++ b/drivers/gpu/drm/i915/i915_reg.h
+@@ -9104,6 +9104,8 @@ enum {
+ #define HSW_AUD_CHICKENBIT			_MMIO(0x65f10)
+ #define   SKL_AUD_CODEC_WAKE_SIGNAL		(1 << 15)
+ 
++#define AUD_FREQ_CNTRL			_MMIO(0x65900)
++
+ /*
+  * HSW - ICL power wells
+  *
+-- 
+2.24.1
+