Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 179 insertions, 0 deletions

diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
new file mode 100644
index 000000000..161a9711c
--- /dev/null
+++ b/sound/hda/hdac_i915.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  hdac_i915.c - routines for sync between HD-A core and i915 display driver
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <sound/core.h>
+#include <sound/hdaudio.h>
+#include <sound/hda_i915.h>
+#include <sound/hda_register.h>
+
+#define IS_HSW_CONTROLLER(pci) (((pci)->device == 0x0a0c) || \
+				((pci)->device == 0x0c0c) || \
+				((pci)->device == 0x0d0c) || \
+				((pci)->device == 0x160c))
+
+/**
+ * snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW
+ * @bus: HDA core bus
+ *
+ * Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
+ * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)
+ * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:
+ * BCLK = CDCLK * M / N
+ * The values will be lost when the display power well is disabled and need to
+ * be restored to avoid abnormal playback speed.
+ *
+ * Call this function at initializing and changing power well, as well as
+ * at ELD notifier for the hotplug.
+ */
+void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
+{
+	struct drm_audio_component *acomp = bus->audio_component;
+	struct pci_dev *pci = to_pci_dev(bus->dev);
+	int cdclk_freq;
+	unsigned int bclk_m, bclk_n;
+
+	if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq)
+		return; /* only for i915 binding */
+	if (!IS_HSW_CONTROLLER(pci))
+		return; /* only HSW/BDW */
+
+	cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev);
+	switch (cdclk_freq) {
+	case 337500:
+		bclk_m = 16;
+		bclk_n = 225;
+		break;
+
+	case 450000:
+	default: /* default CDCLK 450MHz */
+		bclk_m = 4;
+		bclk_n = 75;
+		break;
+
+	case 540000:
+		bclk_m = 4;
+		bclk_n = 90;
+		break;
+
+	case 675000:
+		bclk_m = 8;
+		bclk_n = 225;
+		break;
+	}
+
+	snd_hdac_chip_writew(bus, HSW_EM4, bclk_m);
+	snd_hdac_chip_writew(bus, HSW_EM5, bclk_n);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);
+
+/* returns true if the devices can be connected for audio */
+static bool connectivity_check(struct pci_dev *i915, struct pci_dev *hdac)
+{
+	struct pci_bus *bus_a = i915->bus, *bus_b = hdac->bus;
+
+	/* directly connected on the same bus */
+	if (bus_a == bus_b)
+		return true;
+
+	/*
+	 * on i915 discrete GPUs with embedded HDA audio, the two
+	 * devices are connected via 2nd level PCI bridge
+	 */
+	bus_a = bus_a->parent;
+	bus_b = bus_b->parent;
+	if (!bus_a || !bus_b)
+		return false;
+	bus_a = bus_a->parent;
+	bus_b = bus_b->parent;
+	if (bus_a && bus_a == bus_b)
+		return true;
+
+	return false;
+}
+
+static int i915_component_master_match(struct device *dev, int subcomponent,
+				       void *data)
+{
+	struct pci_dev *hdac_pci, *i915_pci;
+	struct hdac_bus *bus = data;
+
+	if (!dev_is_pci(dev))
+		return 0;
+
+	hdac_pci = to_pci_dev(bus->dev);
+	i915_pci = to_pci_dev(dev);
+
+	if (!strcmp(dev->driver->name, "i915") &&
+	    subcomponent == I915_COMPONENT_AUDIO &&
+	    connectivity_check(i915_pci, hdac_pci))
+		return 1;
+
+	return 0;
+}
+
+/* check whether Intel graphics is present and reachable */
+static int i915_gfx_present(struct pci_dev *hdac_pci)
+{
+	struct pci_dev *display_dev = NULL;
+
+	for_each_pci_dev(display_dev) {
+		if (display_dev->vendor == PCI_VENDOR_ID_INTEL &&
+		    (display_dev->class >> 16) == PCI_BASE_CLASS_DISPLAY &&
+		    connectivity_check(display_dev, hdac_pci)) {
+			pci_dev_put(display_dev);
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/**
+ * snd_hdac_i915_init - Initialize i915 audio component
+ * @bus: HDA core bus
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with i915 graphics.
+ *
+ * This function initializes and sets up the audio component to communicate
+ * with i915 graphics driver.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_i915_init(struct hdac_bus *bus)
+{
+	struct drm_audio_component *acomp;
+	int err;
+
+	if (!i915_gfx_present(to_pci_dev(bus->dev)))
+		return -ENODEV;
+
+	err = snd_hdac_acomp_init(bus, NULL,
+				  i915_component_master_match,
+				  sizeof(struct i915_audio_component) - sizeof(*acomp));
+	if (err < 0)
+		return err;
+	acomp = bus->audio_component;
+	if (!acomp)
+		return -ENODEV;
+	if (!acomp->ops) {
+		if (!IS_ENABLED(CONFIG_MODULES) ||
+		    !request_module("i915")) {
+			/* 60s timeout */
+			wait_for_completion_killable_timeout(&acomp->master_bind_complete,
+							     msecs_to_jiffies(60 * 1000));
+		}
+	}
+	if (!acomp->ops) {
+		dev_info(bus->dev, "couldn't bind with audio component\n");
+		snd_hdac_acomp_exit(bus);
+		return -ENODEV;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_i915_init);