root/drivers/gpu/drm/i915/display/intel_lpe_audio.c

DEFINITIONS

1. lpe_audio_platdev_create
2. lpe_audio_platdev_destroy
3. lpe_audio_irq_unmask
4. lpe_audio_irq_mask
5. lpe_audio_irq_init
6. lpe_audio_detect
7. lpe_audio_setup
8. intel_lpe_audio_irq_handler
9. intel_lpe_audio_init
10. intel_lpe_audio_teardown
11. intel_lpe_audio_notify

   1 /*
   2  * Copyright © 2016 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
  25  *    Jerome Anand <jerome.anand@intel.com>
  26  *    based on VED patches
  27  *
  28  */
  29 
  30 /**
  31  * DOC: LPE Audio integration for HDMI or DP playback
  32  *
  33  * Motivation:
  34  * Atom platforms (e.g. valleyview and cherryTrail) integrates a DMA-based
  35  * interface as an alternative to the traditional HDaudio path. While this
  36  * mode is unrelated to the LPE aka SST audio engine, the documentation refers
  37  * to this mode as LPE so we keep this notation for the sake of consistency.
  38  *
  39  * The interface is handled by a separate standalone driver maintained in the
  40  * ALSA subsystem for simplicity. To minimize the interaction between the two
  41  * subsystems, a bridge is setup between the hdmi-lpe-audio and i915:
  42  * 1. Create a platform device to share MMIO/IRQ resources
  43  * 2. Make the platform device child of i915 device for runtime PM.
  44  * 3. Create IRQ chip to forward the LPE audio irqs.
  45  * the hdmi-lpe-audio driver probes the lpe audio device and creates a new
  46  * sound card
  47  *
  48  * Threats:
  49  * Due to the restriction in Linux platform device model, user need manually
  50  * uninstall the hdmi-lpe-audio driver before uninstalling i915 module,
  51  * otherwise we might run into use-after-free issues after i915 removes the
  52  * platform device: even though hdmi-lpe-audio driver is released, the modules
  53  * is still in "installed" status.
  54  *
  55  * Implementation:
  56  * The MMIO/REG platform resources are created according to the registers
  57  * specification.
  58  * When forwarding LPE audio irqs, the flow control handler selection depends
  59  * on the platform, for example on valleyview handle_simple_irq is enough.
  60  *
  61  */
  62 
  63 #include <linux/acpi.h>
  64 #include <linux/delay.h>
  65 #include <linux/device.h>
  66 #include <linux/irq.h>
  67 #include <linux/pci.h>
  68 #include <linux/platform_device.h>
  69 #include <linux/pm_runtime.h>
  70 
  71 #include <drm/intel_lpe_audio.h>
  72 
  73 #include "i915_drv.h"
  74 #include "intel_lpe_audio.h"
  75 
  76 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
  77 
  78 static struct platform_device *
  79 lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
  80 {
  81         struct drm_device *dev = &dev_priv->drm;
  82         struct platform_device_info pinfo = {};
  83         struct resource *rsc;
  84         struct platform_device *platdev;
  85         struct intel_hdmi_lpe_audio_pdata *pdata;
  86 
  87         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
  88         if (!pdata)
  89                 return ERR_PTR(-ENOMEM);
  90 
  91         rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
  92         if (!rsc) {
  93                 kfree(pdata);
  94                 return ERR_PTR(-ENOMEM);
  95         }
  96 
  97         rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
  98         rsc[0].flags    = IORESOURCE_IRQ;
  99         rsc[0].name     = "hdmi-lpe-audio-irq";
 100 
 101         rsc[1].start    = pci_resource_start(dev->pdev, 0) +
 102                 I915_HDMI_LPE_AUDIO_BASE;
 103         rsc[1].end      = pci_resource_start(dev->pdev, 0) +
 104                 I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
 105         rsc[1].flags    = IORESOURCE_MEM;
 106         rsc[1].name     = "hdmi-lpe-audio-mmio";
 107 
 108         pinfo.parent = dev->dev;
 109         pinfo.name = "hdmi-lpe-audio";
 110         pinfo.id = -1;
 111         pinfo.res = rsc;
 112         pinfo.num_res = 2;
 113         pinfo.data = pdata;
 114         pinfo.size_data = sizeof(*pdata);
 115         pinfo.dma_mask = DMA_BIT_MASK(32);
 116 
 117         pdata->num_pipes = INTEL_INFO(dev_priv)->num_pipes;
 118         pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
 119         pdata->port[0].pipe = -1;
 120         pdata->port[1].pipe = -1;
 121         pdata->port[2].pipe = -1;
 122         spin_lock_init(&pdata->lpe_audio_slock);
 123 
 124         platdev = platform_device_register_full(&pinfo);
 125         kfree(rsc);
 126         kfree(pdata);
 127 
 128         if (IS_ERR(platdev)) {
 129                 DRM_ERROR("Failed to allocate LPE audio platform device\n");
 130                 return platdev;
 131         }
 132 
 133         pm_runtime_no_callbacks(&platdev->dev);
 134 
 135         return platdev;
 136 }
 137 
 138 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
 139 {
 140         /* XXX Note that platform_device_register_full() allocates a dma_mask
 141          * and never frees it. We can't free it here as we cannot guarantee
 142          * this is the last reference (i.e. that the dma_mask will not be
 143          * used after our unregister). So ee choose to leak the sizeof(u64)
 144          * allocation here - it should be fixed in the platform_device rather
 145          * than us fiddle with its internals.
 146          */
 147 
 148         platform_device_unregister(dev_priv->lpe_audio.platdev);
 149 }
 150 
 151 static void lpe_audio_irq_unmask(struct irq_data *d)
 152 {
 153 }
 154 
 155 static void lpe_audio_irq_mask(struct irq_data *d)
 156 {
 157 }
 158 
 159 static struct irq_chip lpe_audio_irqchip = {
 160         .name = "hdmi_lpe_audio_irqchip",
 161         .irq_mask = lpe_audio_irq_mask,
 162         .irq_unmask = lpe_audio_irq_unmask,
 163 };
 164 
 165 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
 166 {
 167         int irq = dev_priv->lpe_audio.irq;
 168 
 169         WARN_ON(!intel_irqs_enabled(dev_priv));
 170         irq_set_chip_and_handler_name(irq,
 171                                 &lpe_audio_irqchip,
 172                                 handle_simple_irq,
 173                                 "hdmi_lpe_audio_irq_handler");
 174 
 175         return irq_set_chip_data(irq, dev_priv);
 176 }
 177 
 178 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
 179 {
 180         int lpe_present = false;
 181 
 182         if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
 183                 static const struct pci_device_id atom_hdaudio_ids[] = {
 184                         /* Baytrail */
 185                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
 186                         /* Braswell */
 187                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
 188                         {}
 189                 };
 190 
 191                 if (!pci_dev_present(atom_hdaudio_ids)) {
 192                         DRM_INFO("HDaudio controller not detected, using LPE audio instead\n");
 193                         lpe_present = true;
 194                 }
 195         }
 196         return lpe_present;
 197 }
 198 
 199 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
 200 {
 201         int ret;
 202 
 203         dev_priv->lpe_audio.irq = irq_alloc_desc(0);
 204         if (dev_priv->lpe_audio.irq < 0) {
 205                 DRM_ERROR("Failed to allocate IRQ desc: %d\n",
 206                         dev_priv->lpe_audio.irq);
 207                 ret = dev_priv->lpe_audio.irq;
 208                 goto err;
 209         }
 210 
 211         DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);
 212 
 213         ret = lpe_audio_irq_init(dev_priv);
 214 
 215         if (ret) {
 216                 DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
 217                         ret);
 218                 goto err_free_irq;
 219         }
 220 
 221         dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
 222 
 223         if (IS_ERR(dev_priv->lpe_audio.platdev)) {
 224                 ret = PTR_ERR(dev_priv->lpe_audio.platdev);
 225                 DRM_ERROR("Failed to create lpe audio platform device: %d\n",
 226                         ret);
 227                 goto err_free_irq;
 228         }
 229 
 230         /* enable chicken bit; at least this is required for Dell Wyse 3040
 231          * with DP outputs (but only sometimes by some reason!)
 232          */
 233         I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);
 234 
 235         return 0;
 236 err_free_irq:
 237         irq_free_desc(dev_priv->lpe_audio.irq);
 238 err:
 239         dev_priv->lpe_audio.irq = -1;
 240         dev_priv->lpe_audio.platdev = NULL;
 241         return ret;
 242 }
 243 
 244 /**
 245  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
 246  * @dev_priv: the i915 drm device private data
 247  *
 248  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
 249  * driver.
 250  */
 251 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
 252 {
 253         int ret;
 254 
 255         if (!HAS_LPE_AUDIO(dev_priv))
 256                 return;
 257 
 258         ret = generic_handle_irq(dev_priv->lpe_audio.irq);
 259         if (ret)
 260                 DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
 261                                 ret);
 262 }
 263 
 264 /**
 265  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
 266  * driver and i915
 267  * @dev_priv: the i915 drm device private data
 268  *
 269  * Return: 0 if successful. non-zero if detection or
 270  * llocation/initialization fails
 271  */
 272 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
 273 {
 274         int ret = -ENODEV;
 275 
 276         if (lpe_audio_detect(dev_priv)) {
 277                 ret = lpe_audio_setup(dev_priv);
 278                 if (ret < 0)
 279                         DRM_ERROR("failed to setup LPE Audio bridge\n");
 280         }
 281         return ret;
 282 }
 283 
 284 /**
 285  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
 286  * audio driver and i915
 287  * @dev_priv: the i915 drm device private data
 288  *
 289  * release all the resources for LPE audio <-> i915 bridge.
 290  */
 291 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
 292 {
 293         struct irq_desc *desc;
 294 
 295         if (!HAS_LPE_AUDIO(dev_priv))
 296                 return;
 297 
 298         desc = irq_to_desc(dev_priv->lpe_audio.irq);
 299 
 300         lpe_audio_platdev_destroy(dev_priv);
 301 
 302         irq_free_desc(dev_priv->lpe_audio.irq);
 303 
 304         dev_priv->lpe_audio.irq = -1;
 305         dev_priv->lpe_audio.platdev = NULL;
 306 }
 307 
 308 /**
 309  * intel_lpe_audio_notify() - notify lpe audio event
 310  * audio driver and i915
 311  * @dev_priv: the i915 drm device private data
 312  * @pipe: pipe
 313  * @port: port
 314  * @eld : ELD data
 315  * @ls_clock: Link symbol clock in kHz
 316  * @dp_output: Driving a DP output?
 317  *
 318  * Notify lpe audio driver of eld change.
 319  */
 320 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
 321                             enum pipe pipe, enum port port,
 322                             const void *eld, int ls_clock, bool dp_output)
 323 {
 324         unsigned long irqflags;
 325         struct intel_hdmi_lpe_audio_pdata *pdata;
 326         struct intel_hdmi_lpe_audio_port_pdata *ppdata;
 327         u32 audio_enable;
 328 
 329         if (!HAS_LPE_AUDIO(dev_priv))
 330                 return;
 331 
 332         pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
 333         ppdata = &pdata->port[port - PORT_B];
 334 
 335         spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
 336 
 337         audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
 338 
 339         if (eld != NULL) {
 340                 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
 341                 ppdata->pipe = pipe;
 342                 ppdata->ls_clock = ls_clock;
 343                 ppdata->dp_output = dp_output;
 344 
 345                 /* Unmute the amp for both DP and HDMI */
 346                 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
 347                            audio_enable & ~VLV_AMP_MUTE);
 348         } else {
 349                 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
 350                 ppdata->pipe = -1;
 351                 ppdata->ls_clock = 0;
 352                 ppdata->dp_output = false;
 353 
 354                 /* Mute the amp for both DP and HDMI */
 355                 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
 356                            audio_enable | VLV_AMP_MUTE);
 357         }
 358 
 359         if (pdata->notify_audio_lpe)
 360                 pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
 361 
 362         spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
 363 }