1 files changed, 363 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_lpe_audio.c b/drivers/gpu/drm/i915/display/intel_lpe_audio.c
new file mode 100644
index 000000000000..b19800b58442
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_lpe_audio.c
@@ -0,0 +1,363 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
+ *    Jerome Anand <jerome.anand@intel.com>
+ *    based on VED patches
+ *
+ */
+
+/**
+ * DOC: LPE Audio integration for HDMI or DP playback
+ *
+ * Motivation:
+ * Atom platforms (e.g. valleyview and cherryTrail) integrates a DMA-based
+ * interface as an alternative to the traditional HDaudio path. While this
+ * mode is unrelated to the LPE aka SST audio engine, the documentation refers
+ * to this mode as LPE so we keep this notation for the sake of consistency.
+ *
+ * The interface is handled by a separate standalone driver maintained in the
+ * ALSA subsystem for simplicity. To minimize the interaction between the two
+ * subsystems, a bridge is setup between the hdmi-lpe-audio and i915:
+ * 1. Create a platform device to share MMIO/IRQ resources
+ * 2. Make the platform device child of i915 device for runtime PM.
+ * 3. Create IRQ chip to forward the LPE audio irqs.
+ * the hdmi-lpe-audio driver probes the lpe audio device and creates a new
+ * sound card
+ *
+ * Threats:
+ * Due to the restriction in Linux platform device model, user need manually
+ * uninstall the hdmi-lpe-audio driver before uninstalling i915 module,
+ * otherwise we might run into use-after-free issues after i915 removes the
+ * platform device: even though hdmi-lpe-audio driver is released, the modules
+ * is still in "installed" status.
+ *
+ * Implementation:
+ * The MMIO/REG platform resources are created according to the registers
+ * specification.
+ * When forwarding LPE audio irqs, the flow control handler selection depends
+ * on the platform, for example on valleyview handle_simple_irq is enough.
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/intel_lpe_audio.h>
+
+#include "i915_drv.h"
+#include "intel_lpe_audio.h"
+
+#define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
+
+static struct platform_device *
+lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = &dev_priv->drm;
+	struct platform_device_info pinfo = {};
+	struct resource *rsc;
+	struct platform_device *platdev;
+	struct intel_hdmi_lpe_audio_pdata *pdata;
+
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
+	if (!rsc) {
+		kfree(pdata);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
+	rsc[0].flags    = IORESOURCE_IRQ;
+	rsc[0].name     = "hdmi-lpe-audio-irq";
+
+	rsc[1].start    = pci_resource_start(dev->pdev, 0) +
+		I915_HDMI_LPE_AUDIO_BASE;
+	rsc[1].end      = pci_resource_start(dev->pdev, 0) +
+		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
+	rsc[1].flags    = IORESOURCE_MEM;
+	rsc[1].name     = "hdmi-lpe-audio-mmio";
+
+	pinfo.parent = dev->dev;
+	pinfo.name = "hdmi-lpe-audio";
+	pinfo.id = -1;
+	pinfo.res = rsc;
+	pinfo.num_res = 2;
+	pinfo.data = pdata;
+	pinfo.size_data = sizeof(*pdata);
+	pinfo.dma_mask = DMA_BIT_MASK(32);
+
+	pdata->num_pipes = INTEL_INFO(dev_priv)->num_pipes;
+	pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
+	pdata->port[0].pipe = -1;
+	pdata->port[1].pipe = -1;
+	pdata->port[2].pipe = -1;
+	spin_lock_init(&pdata->lpe_audio_slock);
+
+	platdev = platform_device_register_full(&pinfo);
+	kfree(rsc);
+	kfree(pdata);
+
+	if (IS_ERR(platdev)) {
+		DRM_ERROR("Failed to allocate LPE audio platform device\n");
+		return platdev;
+	}
+
+	pm_runtime_no_callbacks(&platdev->dev);
+
+	return platdev;
+}
+
+static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
+{
+	/* XXX Note that platform_device_register_full() allocates a dma_mask
+	 * and never frees it. We can't free it here as we cannot guarantee
+	 * this is the last reference (i.e. that the dma_mask will not be
+	 * used after our unregister). So ee choose to leak the sizeof(u64)
+	 * allocation here - it should be fixed in the platform_device rather
+	 * than us fiddle with its internals.
+	 */
+
+	platform_device_unregister(dev_priv->lpe_audio.platdev);
+}
+
+static void lpe_audio_irq_unmask(struct irq_data *d)
+{
+}
+
+static void lpe_audio_irq_mask(struct irq_data *d)
+{
+}
+
+static struct irq_chip lpe_audio_irqchip = {
+	.name = "hdmi_lpe_audio_irqchip",
+	.irq_mask = lpe_audio_irq_mask,
+	.irq_unmask = lpe_audio_irq_unmask,
+};
+
+static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
+{
+	int irq = dev_priv->lpe_audio.irq;
+
+	WARN_ON(!intel_irqs_enabled(dev_priv));
+	irq_set_chip_and_handler_name(irq,
+				&lpe_audio_irqchip,
+				handle_simple_irq,
+				"hdmi_lpe_audio_irq_handler");
+
+	return irq_set_chip_data(irq, dev_priv);
+}
+
+static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
+{
+	int lpe_present = false;
+
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
+		static const struct pci_device_id atom_hdaudio_ids[] = {
+			/* Baytrail */
+			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
+			/* Braswell */
+			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
+			{}
+		};
+
+		if (!pci_dev_present(atom_hdaudio_ids)) {
+			DRM_INFO("HDaudio controller not detected, using LPE audio instead\n");
+			lpe_present = true;
+		}
+	}
+	return lpe_present;
+}
+
+static int lpe_audio_setup(struct drm_i915_private *dev_priv)
+{
+	int ret;
+
+	dev_priv->lpe_audio.irq = irq_alloc_desc(0);
+	if (dev_priv->lpe_audio.irq < 0) {
+		DRM_ERROR("Failed to allocate IRQ desc: %d\n",
+			dev_priv->lpe_audio.irq);
+		ret = dev_priv->lpe_audio.irq;
+		goto err;
+	}
+
+	DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);
+
+	ret = lpe_audio_irq_init(dev_priv);
+
+	if (ret) {
+		DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
+			ret);
+		goto err_free_irq;
+	}
+
+	dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
+
+	if (IS_ERR(dev_priv->lpe_audio.platdev)) {
+		ret = PTR_ERR(dev_priv->lpe_audio.platdev);
+		DRM_ERROR("Failed to create lpe audio platform device: %d\n",
+			ret);
+		goto err_free_irq;
+	}
+
+	/* enable chicken bit; at least this is required for Dell Wyse 3040
+	 * with DP outputs (but only sometimes by some reason!)
+	 */
+	I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);
+
+	return 0;
+err_free_irq:
+	irq_free_desc(dev_priv->lpe_audio.irq);
+err:
+	dev_priv->lpe_audio.irq = -1;
+	dev_priv->lpe_audio.platdev = NULL;
+	return ret;
+}
+
+/**
+ * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
+ * @dev_priv: the i915 drm device private data
+ *
+ * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
+ * driver.
+ */
+void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
+{
+	int ret;
+
+	if (!HAS_LPE_AUDIO(dev_priv))
+		return;
+
+	ret = generic_handle_irq(dev_priv->lpe_audio.irq);
+	if (ret)
+		DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
+				ret);
+}
+
+/**
+ * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
+ * driver and i915
+ * @dev_priv: the i915 drm device private data
+ *
+ * Return: 0 if successful. non-zero if detection or
+ * llocation/initialization fails
+ */
+int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
+{
+	int ret = -ENODEV;
+
+	if (lpe_audio_detect(dev_priv)) {
+		ret = lpe_audio_setup(dev_priv);
+		if (ret < 0)
+			DRM_ERROR("failed to setup LPE Audio bridge\n");
+	}
+	return ret;
+}
+
+/**
+ * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
+ * audio driver and i915
+ * @dev_priv: the i915 drm device private data
+ *
+ * release all the resources for LPE audio <-> i915 bridge.
+ */
+void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
+{
+	struct irq_desc *desc;
+
+	if (!HAS_LPE_AUDIO(dev_priv))
+		return;
+
+	desc = irq_to_desc(dev_priv->lpe_audio.irq);
+
+	lpe_audio_platdev_destroy(dev_priv);
+
+	irq_free_desc(dev_priv->lpe_audio.irq);
+
+	dev_priv->lpe_audio.irq = -1;
+	dev_priv->lpe_audio.platdev = NULL;
+}
+
+/**
+ * intel_lpe_audio_notify() - notify lpe audio event
+ * audio driver and i915
+ * @dev_priv: the i915 drm device private data
+ * @pipe: pipe
+ * @port: port
+ * @eld : ELD data
+ * @ls_clock: Link symbol clock in kHz
+ * @dp_output: Driving a DP output?
+ *
+ * Notify lpe audio driver of eld change.
+ */
+void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
+			    enum pipe pipe, enum port port,
+			    const void *eld, int ls_clock, bool dp_output)
+{
+	unsigned long irqflags;
+	struct intel_hdmi_lpe_audio_pdata *pdata;
+	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
+	u32 audio_enable;
+
+	if (!HAS_LPE_AUDIO(dev_priv))
+		return;
+
+	pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
+	ppdata = &pdata->port[port - PORT_B];
+
+	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
+
+	audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
+
+	if (eld != NULL) {
+		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
+		ppdata->pipe = pipe;
+		ppdata->ls_clock = ls_clock;
+		ppdata->dp_output = dp_output;
+
+		/* Unmute the amp for both DP and HDMI */
+		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
+			   audio_enable & ~VLV_AMP_MUTE);
+	} else {
+		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
+		ppdata->pipe = -1;
+		ppdata->ls_clock = 0;
+		ppdata->dp_output = false;
+
+		/* Mute the amp for both DP and HDMI */
+		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
+			   audio_enable | VLV_AMP_MUTE);
+	}
+
+	if (pdata->notify_audio_lpe)
+		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
+
+	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
+}