drivers/gpu/drm/i915/intel_lpe_audio.c

   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/device.h>
  65 #include <linux/irq.h>
  66 #include <linux/pci.h>
  67 #include <linux/pm_runtime.h>
  68
  69 #include "i915_drv.h"
  70 #include <linux/delay.h>
  71 #include <drm/intel_lpe_audio.h>
  72
  73 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
  74
  75 static struct platform_device *
  76 lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
  77 {
  78         struct drm_device *dev = &dev_priv->drm;
  79         struct platform_device_info pinfo = {};
  80         struct resource *rsc;
  81         struct platform_device *platdev;
  82         struct intel_hdmi_lpe_audio_pdata *pdata;
  83
  84         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
  85         if (!pdata)
  86                 return ERR_PTR(-ENOMEM);
  87
  88         rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
  89         if (!rsc) {
  90                 kfree(pdata);
  91                 return ERR_PTR(-ENOMEM);
  92         }
  93
  94         rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
  95         rsc[0].flags    = IORESOURCE_IRQ;
  96         rsc[0].name     = "hdmi-lpe-audio-irq";
  97
  98         rsc[1].start    = pci_resource_start(dev->pdev, 0) +
  99                 I915_HDMI_LPE_AUDIO_BASE;
 100         rsc[1].end      = pci_resource_start(dev->pdev, 0) +
 101                 I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
 102         rsc[1].flags    = IORESOURCE_MEM;
 103         rsc[1].name     = "hdmi-lpe-audio-mmio";
 104
 105         pinfo.parent = dev->dev;
 106         pinfo.name = "hdmi-lpe-audio";
 107         pinfo.id = -1;
 108         pinfo.res = rsc;
 109         pinfo.num_res = 2;
 110         pinfo.data = pdata;
 111         pinfo.size_data = sizeof(*pdata);
 112         pinfo.dma_mask = DMA_BIT_MASK(32);
 113
 114         pdata->num_pipes = INTEL_INFO(dev_priv)->num_pipes;
 115         pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
 116         pdata->port[0].pipe = -1;
 117         pdata->port[1].pipe = -1;
 118         pdata->port[2].pipe = -1;
 119         spin_lock_init(&pdata->lpe_audio_slock);
 120
 121         platdev = platform_device_register_full(&pinfo);
 122         kfree(rsc);
 123         kfree(pdata);
 124
 125         if (IS_ERR(platdev)) {
 126                 DRM_ERROR("Failed to allocate LPE audio platform device\n");
 127                 return platdev;
 128         }
 129
 130         pm_runtime_no_callbacks(&platdev->dev);
 131
 132         return platdev;
 133 }
 134
 135 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
 136 {
 137         /* XXX Note that platform_device_register_full() allocates a dma_mask
 138          * and never frees it. We can't free it here as we cannot guarantee
 139          * this is the last reference (i.e. that the dma_mask will not be
 140          * used after our unregister). So ee choose to leak the sizeof(u64)
 141          * allocation here - it should be fixed in the platform_device rather
 142          * than us fiddle with its internals.
 143          */
 144
 145         platform_device_unregister(dev_priv->lpe_audio.platdev);
 146 }
 147
 148 static void lpe_audio_irq_unmask(struct irq_data *d)
 149 {
 150 }
 151
 152 static void lpe_audio_irq_mask(struct irq_data *d)
 153 {
 154 }
 155
 156 static struct irq_chip lpe_audio_irqchip = {
 157         .name = "hdmi_lpe_audio_irqchip",
 158         .irq_mask = lpe_audio_irq_mask,
 159         .irq_unmask = lpe_audio_irq_unmask,
 160 };
 161
 162 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
 163 {
 164         int irq = dev_priv->lpe_audio.irq;
 165
 166         WARN_ON(!intel_irqs_enabled(dev_priv));
 167         irq_set_chip_and_handler_name(irq,
 168                                 &lpe_audio_irqchip,
 169                                 handle_simple_irq,
 170                                 "hdmi_lpe_audio_irq_handler");
 171
 172         return irq_set_chip_data(irq, dev_priv);
 173 }
 174
 175 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
 176 {
 177         int lpe_present = false;
 178
 179         if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
 180                 static const struct pci_device_id atom_hdaudio_ids[] = {
 181                         /* Baytrail */
 182                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
 183                         /* Braswell */
 184                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
 185                         {}
 186                 };
 187
 188                 if (!pci_dev_present(atom_hdaudio_ids)) {
 189                         DRM_INFO("HDaudio controller not detected, using LPE audio instead\n");
 190                         lpe_present = true;
 191                 }
 192         }
 193         return lpe_present;
 194 }
 195
 196 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
 197 {
 198         int ret;
 199
 200         dev_priv->lpe_audio.irq = irq_alloc_desc(0);
 201         if (dev_priv->lpe_audio.irq < 0) {
 202                 DRM_ERROR("Failed to allocate IRQ desc: %d\n",
 203                         dev_priv->lpe_audio.irq);
 204                 ret = dev_priv->lpe_audio.irq;
 205                 goto err;
 206         }
 207
 208         DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);
 209
 210         ret = lpe_audio_irq_init(dev_priv);
 211
 212         if (ret) {
 213                 DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
 214                         ret);
 215                 goto err_free_irq;
 216         }
 217
 218         dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
 219
 220         if (IS_ERR(dev_priv->lpe_audio.platdev)) {
 221                 ret = PTR_ERR(dev_priv->lpe_audio.platdev);
 222                 DRM_ERROR("Failed to create lpe audio platform device: %d\n",
 223                         ret);
 224                 goto err_free_irq;
 225         }
 226
 227         /* enable chicken bit; at least this is required for Dell Wyse 3040
 228          * with DP outputs (but only sometimes by some reason!)
 229          */
 230         I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);
 231
 232         return 0;
 233 err_free_irq:
 234         irq_free_desc(dev_priv->lpe_audio.irq);
 235 err:
 236         dev_priv->lpe_audio.irq = -1;
 237         dev_priv->lpe_audio.platdev = NULL;
 238         return ret;
 239 }
 240
 241 /**
 242  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
 243  * @dev_priv: the i915 drm device private data
 244  *
 245  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
 246  * driver.
 247  */
 248 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
 249 {
 250         int ret;
 251
 252         if (!HAS_LPE_AUDIO(dev_priv))
 253                 return;
 254
 255         ret = generic_handle_irq(dev_priv->lpe_audio.irq);
 256         if (ret)
 257                 DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
 258                                 ret);
 259 }
 260
 261 /**
 262  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
 263  * driver and i915
 264  * @dev_priv: the i915 drm device private data
 265  *
 266  * Return: 0 if successful. non-zero if detection or
 267  * llocation/initialization fails
 268  */
 269 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
 270 {
 271         int ret = -ENODEV;
 272
 273         if (lpe_audio_detect(dev_priv)) {
 274                 ret = lpe_audio_setup(dev_priv);
 275                 if (ret < 0)
 276                         DRM_ERROR("failed to setup LPE Audio bridge\n");
 277         }
 278         return ret;
 279 }
 280
 281 /**
 282  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
 283  * audio driver and i915
 284  * @dev_priv: the i915 drm device private data
 285  *
 286  * release all the resources for LPE audio <-> i915 bridge.
 287  */
 288 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
 289 {
 290         struct irq_desc *desc;
 291
 292         if (!HAS_LPE_AUDIO(dev_priv))
 293                 return;
 294
 295         desc = irq_to_desc(dev_priv->lpe_audio.irq);
 296
 297         lpe_audio_platdev_destroy(dev_priv);
 298
 299         irq_free_desc(dev_priv->lpe_audio.irq);
 300
 301         dev_priv->lpe_audio.irq = -1;
 302         dev_priv->lpe_audio.platdev = NULL;
 303 }
 304
 305 /**
 306  * intel_lpe_audio_notify() - notify lpe audio event
 307  * audio driver and i915
 308  * @dev_priv: the i915 drm device private data
 309  * @pipe: pipe
 310  * @port: port
 311  * @eld : ELD data
 312  * @ls_clock: Link symbol clock in kHz
 313  * @dp_output: Driving a DP output?
 314  *
 315  * Notify lpe audio driver of eld change.
 316  */
 317 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
 318                             enum pipe pipe, enum port port,
 319                             const void *eld, int ls_clock, bool dp_output)
 320 {
 321         unsigned long irqflags;
 322         struct intel_hdmi_lpe_audio_pdata *pdata;
 323         struct intel_hdmi_lpe_audio_port_pdata *ppdata;
 324         u32 audio_enable;
 325
 326         if (!HAS_LPE_AUDIO(dev_priv))
 327                 return;
 328
 329         pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
 330         ppdata = &pdata->port[port - PORT_B];
 331
 332         spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
 333
 334         audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
 335
 336         if (eld != NULL) {
 337                 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
 338                 ppdata->pipe = pipe;
 339                 ppdata->ls_clock = ls_clock;
 340                 ppdata->dp_output = dp_output;
 341
 342                 /* Unmute the amp for both DP and HDMI */
 343                 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
 344                            audio_enable & ~VLV_AMP_MUTE);
 345         } else {
 346                 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
 347                 ppdata->pipe = -1;
 348                 ppdata->ls_clock = 0;
 349                 ppdata->dp_output = false;
 350
 351                 /* Mute the amp for both DP and HDMI */
 352                 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
 353                            audio_enable | VLV_AMP_MUTE);
 354         }
 355
 356         if (pdata->notify_audio_lpe)
 357                 pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
 358
 359         spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
 360 }