1 /* $NetBSD: intel_lpe_audio.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $ */ 2 3 /* 4 * Copyright 2016 Intel Corporation 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 23 * IN THE SOFTWARE. 24 * 25 * Authors: 26 * Pierre-Louis Bossart <pierre-louis.bossart (at) linux.intel.com> 27 * Jerome Anand <jerome.anand (at) intel.com> 28 * based on VED patches 29 * 30 */ 31 32 /** 33 * DOC: LPE Audio integration for HDMI or DP playback 34 * 35 * Motivation: 36 * Atom platforms (e.g. valleyview and cherryTrail) integrates a DMA-based 37 * interface as an alternative to the traditional HDaudio path. While this 38 * mode is unrelated to the LPE aka SST audio engine, the documentation refers 39 * to this mode as LPE so we keep this notation for the sake of consistency. 40 * 41 * The interface is handled by a separate standalone driver maintained in the 42 * ALSA subsystem for simplicity. To minimize the interaction between the two 43 * subsystems, a bridge is setup between the hdmi-lpe-audio and i915: 44 * 1. Create a platform device to share MMIO/IRQ resources 45 * 2. Make the platform device child of i915 device for runtime PM. 46 * 3. Create IRQ chip to forward the LPE audio irqs. 47 * the hdmi-lpe-audio driver probes the lpe audio device and creates a new 48 * sound card 49 * 50 * Threats: 51 * Due to the restriction in Linux platform device model, user need manually 52 * uninstall the hdmi-lpe-audio driver before uninstalling i915 module, 53 * otherwise we might run into use-after-free issues after i915 removes the 54 * platform device: even though hdmi-lpe-audio driver is released, the modules 55 * is still in "installed" status. 56 * 57 * Implementation: 58 * The MMIO/REG platform resources are created according to the registers 59 * specification. 60 * When forwarding LPE audio irqs, the flow control handler selection depends 61 * on the platform, for example on valleyview handle_simple_irq is enough. 62 * 63 */ 64 65 #include <sys/cdefs.h> 66 __KERNEL_RCSID(0, "$NetBSD: intel_lpe_audio.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $"); 67 68 #include <linux/acpi.h> 69 #include <linux/delay.h> 70 #include <linux/device.h> 71 #include <linux/irq.h> 72 #include <linux/pci.h> 73 #include <linux/platform_device.h> 74 #include <linux/pm_runtime.h> 75 76 #include <drm/intel_lpe_audio.h> 77 78 #include "i915_drv.h" 79 #include "intel_lpe_audio.h" 80 81 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL) 82 83 static struct platform_device * 84 lpe_audio_platdev_create(struct drm_i915_private *dev_priv) 85 { 86 struct drm_device *dev = &dev_priv->drm; 87 struct platform_device_info pinfo = {}; 88 struct resource *rsc; 89 struct platform_device *platdev; 90 struct intel_hdmi_lpe_audio_pdata *pdata; 91 92 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 93 if (!pdata) 94 return ERR_PTR(-ENOMEM); 95 96 rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL); 97 if (!rsc) { 98 kfree(pdata); 99 return ERR_PTR(-ENOMEM); 100 } 101 102 rsc[0].start = rsc[0].end = dev_priv->lpe_audio.irq; 103 rsc[0].flags = IORESOURCE_IRQ; 104 rsc[0].name = "hdmi-lpe-audio-irq"; 105 106 rsc[1].start = pci_resource_start(dev->pdev, 0) + 107 I915_HDMI_LPE_AUDIO_BASE; 108 rsc[1].end = pci_resource_start(dev->pdev, 0) + 109 I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1; 110 rsc[1].flags = IORESOURCE_MEM; 111 rsc[1].name = "hdmi-lpe-audio-mmio"; 112 113 pinfo.parent = dev->dev; 114 pinfo.name = "hdmi-lpe-audio"; 115 pinfo.id = -1; 116 pinfo.res = rsc; 117 pinfo.num_res = 2; 118 pinfo.data = pdata; 119 pinfo.size_data = sizeof(*pdata); 120 pinfo.dma_mask = DMA_BIT_MASK(32); 121 122 pdata->num_pipes = INTEL_NUM_PIPES(dev_priv); 123 pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */ 124 pdata->port[0].pipe = -1; 125 pdata->port[1].pipe = -1; 126 pdata->port[2].pipe = -1; 127 spin_lock_init(&pdata->lpe_audio_slock); 128 129 platdev = platform_device_register_full(&pinfo); 130 kfree(rsc); 131 kfree(pdata); 132 133 if (IS_ERR(platdev)) { 134 DRM_ERROR("Failed to allocate LPE audio platform device\n"); 135 return platdev; 136 } 137 138 pm_runtime_no_callbacks(&platdev->dev); 139 140 return platdev; 141 } 142 143 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv) 144 { 145 /* XXX Note that platform_device_register_full() allocates a dma_mask 146 * and never frees it. We can't free it here as we cannot guarantee 147 * this is the last reference (i.e. that the dma_mask will not be 148 * used after our unregister). So ee choose to leak the sizeof(u64) 149 * allocation here - it should be fixed in the platform_device rather 150 * than us fiddle with its internals. 151 */ 152 153 platform_device_unregister(dev_priv->lpe_audio.platdev); 154 } 155 156 static void lpe_audio_irq_unmask(struct irq_data *d) 157 { 158 } 159 160 static void lpe_audio_irq_mask(struct irq_data *d) 161 { 162 } 163 164 static struct irq_chip lpe_audio_irqchip = { 165 .name = "hdmi_lpe_audio_irqchip", 166 .irq_mask = lpe_audio_irq_mask, 167 .irq_unmask = lpe_audio_irq_unmask, 168 }; 169 170 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv) 171 { 172 int irq = dev_priv->lpe_audio.irq; 173 174 WARN_ON(!intel_irqs_enabled(dev_priv)); 175 irq_set_chip_and_handler_name(irq, 176 &lpe_audio_irqchip, 177 handle_simple_irq, 178 "hdmi_lpe_audio_irq_handler"); 179 180 return irq_set_chip_data(irq, dev_priv); 181 } 182 183 static bool lpe_audio_detect(struct drm_i915_private *dev_priv) 184 { 185 int lpe_present = false; 186 187 if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) { 188 static const struct pci_device_id atom_hdaudio_ids[] = { 189 /* Baytrail */ 190 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)}, 191 /* Braswell */ 192 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)}, 193 {} 194 }; 195 196 if (!pci_dev_present(atom_hdaudio_ids)) { 197 DRM_INFO("HDaudio controller not detected, using LPE audio instead\n"); 198 lpe_present = true; 199 } 200 } 201 return lpe_present; 202 } 203 204 static int lpe_audio_setup(struct drm_i915_private *dev_priv) 205 { 206 int ret; 207 208 dev_priv->lpe_audio.irq = irq_alloc_desc(0); 209 if (dev_priv->lpe_audio.irq < 0) { 210 DRM_ERROR("Failed to allocate IRQ desc: %d\n", 211 dev_priv->lpe_audio.irq); 212 ret = dev_priv->lpe_audio.irq; 213 goto err; 214 } 215 216 DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq); 217 218 ret = lpe_audio_irq_init(dev_priv); 219 220 if (ret) { 221 DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n", 222 ret); 223 goto err_free_irq; 224 } 225 226 dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv); 227 228 if (IS_ERR(dev_priv->lpe_audio.platdev)) { 229 ret = PTR_ERR(dev_priv->lpe_audio.platdev); 230 DRM_ERROR("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 I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE); 239 240 return 0; 241 err_free_irq: 242 irq_free_desc(dev_priv->lpe_audio.irq); 243 err: 244 dev_priv->lpe_audio.irq = -1; 245 dev_priv->lpe_audio.platdev = NULL; 246 return ret; 247 } 248 249 /** 250 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq 251 * @dev_priv: the i915 drm device private data 252 * 253 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio 254 * driver. 255 */ 256 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv) 257 { 258 int ret; 259 260 if (!HAS_LPE_AUDIO(dev_priv)) 261 return; 262 263 ret = generic_handle_irq(dev_priv->lpe_audio.irq); 264 if (ret) 265 DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n", 266 ret); 267 } 268 269 /** 270 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio 271 * driver and i915 272 * @dev_priv: the i915 drm device private data 273 * 274 * Return: 0 if successful. non-zero if detection or 275 * llocation/initialization fails 276 */ 277 int intel_lpe_audio_init(struct drm_i915_private *dev_priv) 278 { 279 int ret = -ENODEV; 280 281 if (lpe_audio_detect(dev_priv)) { 282 ret = lpe_audio_setup(dev_priv); 283 if (ret < 0) 284 DRM_ERROR("failed to setup LPE Audio bridge\n"); 285 } 286 return ret; 287 } 288 289 /** 290 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE 291 * audio driver and i915 292 * @dev_priv: the i915 drm device private data 293 * 294 * release all the resources for LPE audio <-> i915 bridge. 295 */ 296 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv) 297 { 298 struct irq_desc *desc; 299 300 if (!HAS_LPE_AUDIO(dev_priv)) 301 return; 302 303 desc = irq_to_desc(dev_priv->lpe_audio.irq); 304 305 lpe_audio_platdev_destroy(dev_priv); 306 307 irq_free_desc(dev_priv->lpe_audio.irq); 308 309 dev_priv->lpe_audio.irq = -1; 310 dev_priv->lpe_audio.platdev = NULL; 311 } 312 313 /** 314 * intel_lpe_audio_notify() - notify lpe audio event 315 * audio driver and i915 316 * @dev_priv: the i915 drm device private data 317 * @pipe: pipe 318 * @port: port 319 * @eld : ELD data 320 * @ls_clock: Link symbol clock in kHz 321 * @dp_output: Driving a DP output? 322 * 323 * Notify lpe audio driver of eld change. 324 */ 325 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv, 326 enum pipe pipe, enum port port, 327 const void *eld, int ls_clock, bool dp_output) 328 { 329 unsigned long irqflags; 330 struct intel_hdmi_lpe_audio_pdata *pdata; 331 struct intel_hdmi_lpe_audio_port_pdata *ppdata; 332 u32 audio_enable; 333 334 if (!HAS_LPE_AUDIO(dev_priv)) 335 return; 336 337 pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev); 338 ppdata = &pdata->port[port - PORT_B]; 339 340 spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags); 341 342 audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port)); 343 344 if (eld != NULL) { 345 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES); 346 ppdata->pipe = pipe; 347 ppdata->ls_clock = ls_clock; 348 ppdata->dp_output = dp_output; 349 350 /* Unmute the amp for both DP and HDMI */ 351 I915_WRITE(VLV_AUD_PORT_EN_DBG(port), 352 audio_enable & ~VLV_AMP_MUTE); 353 } else { 354 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES); 355 ppdata->pipe = -1; 356 ppdata->ls_clock = 0; 357 ppdata->dp_output = false; 358 359 /* Mute the amp for both DP and HDMI */ 360 I915_WRITE(VLV_AUD_PORT_EN_DBG(port), 361 audio_enable | VLV_AMP_MUTE); 362 } 363 364 if (pdata->notify_audio_lpe) 365 pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B); 366 367 spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags); 368 } 369
Indexes created Fri Sep 26 08:10:20 GMT 2025