drivers/gpu/drm/i915/display/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/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_de.h"
  75 #include "intel_lpe_audio.h"
  76
  77 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
  78
  79 static struct platform_device *
  80 lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
  81 {
  82         struct drm_device *dev = &dev_priv->drm;
  83         struct platform_device_info pinfo = {};
  84         struct resource *rsc;
  85         struct platform_device *platdev;
  86         struct intel_hdmi_lpe_audio_pdata *pdata;
  87
  88         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
  89         if (!pdata)
  90                 return ERR_PTR(-ENOMEM);
  91
  92         rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
  93         if (!rsc) {
  94                 kfree(pdata);
  95                 return ERR_PTR(-ENOMEM);
  96         }
  97
  98         rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
  99         rsc[0].flags    = IORESOURCE_IRQ;
 100         rsc[0].name     = "hdmi-lpe-audio-irq";
 101
 102         rsc[1].start    = pci_resource_start(dev->pdev, 0) +
 103                 I915_HDMI_LPE_AUDIO_BASE;
 104         rsc[1].end      = pci_resource_start(dev->pdev, 0) +
 105                 I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
 106         rsc[1].flags    = IORESOURCE_MEM;
 107         rsc[1].name     = "hdmi-lpe-audio-mmio";
 108
 109         pinfo.parent = dev->dev;
 110         pinfo.name = "hdmi-lpe-audio";
 111         pinfo.id = -1;
 112         pinfo.res = rsc;
 113         pinfo.num_res = 2;
 114         pinfo.data = pdata;
 115         pinfo.size_data = sizeof(*pdata);
 116         pinfo.dma_mask = DMA_BIT_MASK(32);
 117
 118         pdata->num_pipes = INTEL_NUM_PIPES(dev_priv);
 119         pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
 120         pdata->port[0].pipe = -1;
 121         pdata->port[1].pipe = -1;
 122         pdata->port[2].pipe = -1;
 123         spin_lock_init(&pdata->lpe_audio_slock);
 124
 125         platdev = platform_device_register_full(&pinfo);
 126         kfree(rsc);
 127         kfree(pdata);
 128
 129         if (IS_ERR(platdev)) {
 130                 drm_err(&dev_priv->drm,
 131                         "Failed to allocate LPE audio platform device\n");
 132                 return platdev;
 133         }
 134
 135         pm_runtime_no_callbacks(&platdev->dev);
 136
 137         return platdev;
 138 }
 139
 140 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
 141 {
 142         /* XXX Note that platform_device_register_full() allocates a dma_mask
 143          * and never frees it. We can't free it here as we cannot guarantee
 144          * this is the last reference (i.e. that the dma_mask will not be
 145          * used after our unregister). So ee choose to leak the sizeof(u64)
 146          * allocation here - it should be fixed in the platform_device rather
 147          * than us fiddle with its internals.
 148          */
 149
 150         platform_device_unregister(dev_priv->lpe_audio.platdev);
 151 }
 152
 153 static void lpe_audio_irq_unmask(struct irq_data *d)
 154 {
 155 }
 156
 157 static void lpe_audio_irq_mask(struct irq_data *d)
 158 {
 159 }
 160
 161 static struct irq_chip lpe_audio_irqchip = {
 162         .name = "hdmi_lpe_audio_irqchip",
 163         .irq_mask = lpe_audio_irq_mask,
 164         .irq_unmask = lpe_audio_irq_unmask,
 165 };
 166
 167 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
 168 {
 169         int irq = dev_priv->lpe_audio.irq;
 170
 171         drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv));
 172         irq_set_chip_and_handler_name(irq,
 173                                 &lpe_audio_irqchip,
 174                                 handle_simple_irq,
 175                                 "hdmi_lpe_audio_irq_handler");
 176
 177         return irq_set_chip_data(irq, dev_priv);
 178 }
 179
 180 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
 181 {
 182         int lpe_present = false;
 183
 184         if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
 185                 static const struct pci_device_id atom_hdaudio_ids[] = {
 186                         /* Baytrail */
 187                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
 188                         /* Braswell */
 189                         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
 190                         {}
 191                 };
 192
 193                 if (!pci_dev_present(atom_hdaudio_ids)) {
 194                         drm_info(&dev_priv->drm,
 195                                  "HDaudio controller not detected, using LPE audio instead\n");
 196                         lpe_present = true;
 197                 }
 198         }
 199         return lpe_present;
 200 }
 201
 202 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
 203 {
 204         int ret;
 205
 206         dev_priv->lpe_audio.irq = irq_alloc_desc(0);
 207         if (dev_priv->lpe_audio.irq < 0) {
 208                 drm_err(&dev_priv->drm, "Failed to allocate IRQ desc: %d\n",
 209                         dev_priv->lpe_audio.irq);
 210                 ret = dev_priv->lpe_audio.irq;
 211                 goto err;
 212         }
 213
 214         drm_dbg(&dev_priv->drm, "irq = %d\n", dev_priv->lpe_audio.irq);
 215
 216         ret = lpe_audio_irq_init(dev_priv);
 217
 218         if (ret) {
 219                 drm_err(&dev_priv->drm,
 220                         "Failed to initialize irqchip for lpe audio: %d\n",
 221                         ret);
 222                 goto err_free_irq;
 223         }
 224
 225         dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
 226
 227         if (IS_ERR(dev_priv->lpe_audio.platdev)) {
 228                 ret = PTR_ERR(dev_priv->lpe_audio.platdev);
 229                 drm_err(&dev_priv->drm,
 230                         "Failed to create lpe audio platform device: %d\n",
 231                         ret);
 232                 goto err_free_irq;
 233         }
 234
 235         /* enable chicken bit; at least this is required for Dell Wyse 3040
 236          * with DP outputs (but only sometimes by some reason!)
 237          */
 238         intel_de_write(dev_priv, VLV_AUD_CHICKEN_BIT_REG,
 239                        VLV_CHICKEN_BIT_DBG_ENABLE);
 240
 241         return 0;
 242 err_free_irq:
 243         irq_free_desc(dev_priv->lpe_audio.irq);
 244 err:
 245         dev_priv->lpe_audio.irq = -1;
 246         dev_priv->lpe_audio.platdev = NULL;
 247         return ret;
 248 }
 249
 250 /**
 251  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
 252  * @dev_priv: the i915 drm device private data
 253  *
 254  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
 255  * driver.
 256  */
 257 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
 258 {
 259         int ret;
 260
 261         if (!HAS_LPE_AUDIO(dev_priv))
 262                 return;
 263
 264         ret = generic_handle_irq(dev_priv->lpe_audio.irq);
 265         if (ret)
 266                 drm_err_ratelimited(&dev_priv->drm,
 267                                     "error handling LPE audio irq: %d\n", ret);
 268 }
 269
 270 /**
 271  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
 272  * driver and i915
 273  * @dev_priv: the i915 drm device private data
 274  *
 275  * Return: 0 if successful. non-zero if detection or
 276  * llocation/initialization fails
 277  */
 278 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
 279 {
 280         int ret = -ENODEV;
 281
 282         if (lpe_audio_detect(dev_priv)) {
 283                 ret = lpe_audio_setup(dev_priv);
 284                 if (ret < 0)
 285                         drm_err(&dev_priv->drm,
 286                                 "failed to setup LPE Audio bridge\n");
 287         }
 288         return ret;
 289 }
 290
 291 /**
 292  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
 293  * audio driver and i915
 294  * @dev_priv: the i915 drm device private data
 295  *
 296  * release all the resources for LPE audio <-> i915 bridge.
 297  */
 298 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
 299 {
 300         if (!HAS_LPE_AUDIO(dev_priv))
 301                 return;
 302
 303         lpe_audio_platdev_destroy(dev_priv);
 304
 305         irq_free_desc(dev_priv->lpe_audio.irq);
 306
 307         dev_priv->lpe_audio.irq = -1;
 308         dev_priv->lpe_audio.platdev = NULL;
 309 }
 310
 311 /**
 312  * intel_lpe_audio_notify() - notify lpe audio event
 313  * audio driver and i915
 314  * @dev_priv: the i915 drm device private data
 315  * @pipe: pipe
 316  * @port: port
 317  * @eld : ELD data
 318  * @ls_clock: Link symbol clock in kHz
 319  * @dp_output: Driving a DP output?
 320  *
 321  * Notify lpe audio driver of eld change.
 322  */
 323 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
 324                             enum pipe pipe, enum port port,
 325                             const void *eld, int ls_clock, bool dp_output)
 326 {
 327         unsigned long irqflags;
 328         struct intel_hdmi_lpe_audio_pdata *pdata;
 329         struct intel_hdmi_lpe_audio_port_pdata *ppdata;
 330         u32 audio_enable;
 331
 332         if (!HAS_LPE_AUDIO(dev_priv))
 333                 return;
 334
 335         pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
 336         ppdata = &pdata->port[port - PORT_B];
 337
 338         spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
 339
 340         audio_enable = intel_de_read(dev_priv, VLV_AUD_PORT_EN_DBG(port));
 341
 342         if (eld != NULL) {
 343                 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
 344                 ppdata->pipe = pipe;
 345                 ppdata->ls_clock = ls_clock;
 346                 ppdata->dp_output = dp_output;
 347
 348                 /* Unmute the amp for both DP and HDMI */
 349                 intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
 350                                audio_enable & ~VLV_AMP_MUTE);
 351         } else {
 352                 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
 353                 ppdata->pipe = -1;
 354                 ppdata->ls_clock = 0;
 355                 ppdata->dp_output = false;
 356
 357                 /* Mute the amp for both DP and HDMI */
 358                 intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
 359                                audio_enable | VLV_AMP_MUTE);
 360         }
 361
 362         if (pdata->notify_audio_lpe)
 363                 pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
 364
 365         spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
 366 }