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 *
lpe_audio_platdev_create(struct drm_i915_private * dev_priv)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
lpe_audio_platdev_destroy(struct drm_i915_private * dev_priv)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
lpe_audio_irq_unmask(struct irq_data * d)148 static void lpe_audio_irq_unmask(struct irq_data *d)
149 {
150 }
151
lpe_audio_irq_mask(struct irq_data * d)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
lpe_audio_irq_init(struct drm_i915_private * dev_priv)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
lpe_audio_detect(struct drm_i915_private * dev_priv)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
lpe_audio_setup(struct drm_i915_private * dev_priv)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 */
intel_lpe_audio_irq_handler(struct drm_i915_private * dev_priv)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 */
intel_lpe_audio_init(struct drm_i915_private * dev_priv)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 */
intel_lpe_audio_teardown(struct drm_i915_private * dev_priv)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
302
303 /**
304 * intel_lpe_audio_notify() - notify lpe audio event
305 * audio driver and i915
306 * @dev_priv: the i915 drm device private data
307 * @pipe: pipe
308 * @port: port
309 * @eld : ELD data
310 * @ls_clock: Link symbol clock in kHz
311 * @dp_output: Driving a DP output?
312 *
313 * Notify lpe audio driver of eld change.
314 */
intel_lpe_audio_notify(struct drm_i915_private * dev_priv,enum pipe pipe,enum port port,const void * eld,int ls_clock,bool dp_output)315 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
316 enum pipe pipe, enum port port,
317 const void *eld, int ls_clock, bool dp_output)
318 {
319 unsigned long irqflags;
320 struct intel_hdmi_lpe_audio_pdata *pdata;
321 struct intel_hdmi_lpe_audio_port_pdata *ppdata;
322 u32 audio_enable;
323
324 if (!HAS_LPE_AUDIO(dev_priv))
325 return;
326
327 pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
328 ppdata = &pdata->port[port - PORT_B];
329
330 spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
331
332 audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
333
334 if (eld != NULL) {
335 memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
336 ppdata->pipe = pipe;
337 ppdata->ls_clock = ls_clock;
338 ppdata->dp_output = dp_output;
339
340 /* Unmute the amp for both DP and HDMI */
341 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
342 audio_enable & ~VLV_AMP_MUTE);
343 } else {
344 memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
345 ppdata->pipe = -1;
346 ppdata->ls_clock = 0;
347 ppdata->dp_output = false;
348
349 /* Mute the amp for both DP and HDMI */
350 I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
351 audio_enable | VLV_AMP_MUTE);
352 }
353
354 if (pdata->notify_audio_lpe)
355 pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
356
357 spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
358 }
359
