cregit-Linux how code gets into the kernel

Release 4.11 drivers/gpu/drm/i915/intel_lpe_audio.c

/*
 * 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/device.h>
#include <linux/pci.h>

#include "i915_drv.h"
#include <linux/delay.h>
#include <drm/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) { int ret; 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); spin_lock_init(&pdata->lpe_audio_slock); platdev = platform_device_register_full(&pinfo); if (IS_ERR(platdev)) { ret = PTR_ERR(platdev); DRM_ERROR("Failed to allocate LPE audio platform device\n"); goto err; } kfree(rsc); return platdev; err: kfree(rsc); kfree(pdata); return ERR_PTR(ret); }

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Jerome Anand326100.00%1100.00%
Total326100.00%1100.00%


static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv) { platform_device_unregister(dev_priv->lpe_audio.platdev); kfree(dev_priv->lpe_audio.platdev->dev.dma_mask); }

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Jerome Anand33100.00%1100.00%
Total33100.00%1100.00%


static void lpe_audio_irq_unmask(struct irq_data *d) { struct drm_i915_private *dev_priv = d->chip_data; unsigned long irqflags; u32 val = (I915_LPE_PIPE_A_INTERRUPT | I915_LPE_PIPE_B_INTERRUPT); if (IS_CHERRYVIEW(dev_priv)) val |= I915_LPE_PIPE_C_INTERRUPT; spin_lock_irqsave(&dev_priv->irq_lock, irqflags); dev_priv->irq_mask &= ~val; I915_WRITE(VLV_IIR, val); I915_WRITE(VLV_IIR, val); I915_WRITE(VLV_IMR, dev_priv->irq_mask); POSTING_READ(VLV_IMR); spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); }

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Jerome Anand99100.00%1100.00%
Total99100.00%1100.00%


static void lpe_audio_irq_mask(struct irq_data *d) { struct drm_i915_private *dev_priv = d->chip_data; unsigned long irqflags; u32 val = (I915_LPE_PIPE_A_INTERRUPT | I915_LPE_PIPE_B_INTERRUPT); if (IS_CHERRYVIEW(dev_priv)) val |= I915_LPE_PIPE_C_INTERRUPT; spin_lock_irqsave(&dev_priv->irq_lock, irqflags); dev_priv->irq_mask |= val; I915_WRITE(VLV_IMR, dev_priv->irq_mask); I915_WRITE(VLV_IIR, val); I915_WRITE(VLV_IIR, val); POSTING_READ(VLV_IIR); spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); }

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Jerome Anand98100.00%1100.00%
Total98100.00%1100.00%

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); }

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Jerome Anand49100.00%1100.00%
Total49100.00%1100.00%


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("%s\n", "HDaudio controller not detected, using LPE audio instead\n"); lpe_present = true; } } return lpe_present; }

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Jerome Anand85100.00%1100.00%
Total85100.00%1100.00%


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; }

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Jerome Anand17495.60%150.00%
Takashi Iwai84.40%150.00%
Total182100.00%2100.00%

/** * 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); }

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Jerome Anand44100.00%1100.00%
Total44100.00%1100.00%

/** * 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; }

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Jerome Anand46100.00%1100.00%
Total46100.00%1100.00%

/** * 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_irq_mask(&desc->irq_data); lpe_audio_platdev_destroy(dev_priv); irq_free_desc(dev_priv->lpe_audio.irq); }

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Jerome Anand57100.00%1100.00%
Total57100.00%1100.00%

/** * intel_lpe_audio_notify() - notify lpe audio event * audio driver and i915 * @dev_priv: the i915 drm device private data * @eld : ELD data * @port: port id * @tmds_clk_speed: tmds clock frequency in Hz * * Notify lpe audio driver of eld change. */
void intel_lpe_audio_notify(struct drm_i915_private *dev_priv, void *eld, int port, int pipe, int tmds_clk_speed, bool dp_output, int link_rate) { unsigned long irq_flags; struct intel_hdmi_lpe_audio_pdata *pdata = NULL; u32 audio_enable; if (!HAS_LPE_AUDIO(dev_priv)) return; pdata = dev_get_platdata( &(dev_priv->lpe_audio.platdev->dev)); spin_lock_irqsave(&pdata->lpe_audio_slock, irq_flags); audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port)); if (eld != NULL) { memcpy(pdata->eld.eld_data, eld, HDMI_MAX_ELD_BYTES); pdata->eld.port_id = port; pdata->eld.pipe_id = pipe; pdata->hdmi_connected = true; pdata->dp_output = dp_output; if (tmds_clk_speed) pdata->tmds_clock_speed = tmds_clk_speed; if (link_rate) pdata->link_rate = link_rate; /* Unmute the amp for both DP and HDMI */ I915_WRITE(VLV_AUD_PORT_EN_DBG(port), audio_enable & ~VLV_AMP_MUTE); } else { memset(pdata->eld.eld_data, 0, HDMI_MAX_ELD_BYTES); pdata->hdmi_connected = false; pdata->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); else pdata->notify_pending = true; spin_unlock_irqrestore(&pdata->lpe_audio_slock, irq_flags); }

Contributors

PersonTokensPropCommitsCommitProp
Jerome Anand16366.26%120.00%
Pierre-Louis Bossart6827.64%240.00%
Takashi Iwai156.10%240.00%
Total246100.00%5100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Jerome Anand122793.10%228.57%
Pierre-Louis Bossart685.16%228.57%
Takashi Iwai231.75%342.86%
Total1318100.00%7100.00%
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