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 #include "intel_pci_config.h"
77 
78 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->display.audio.lpe.platdev != NULL)
79 
80 static struct platform_device *
81 lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
82 {
83 	STUB();
84 	return NULL;
85 #ifdef notyet
86 	struct drm_device *dev = &dev_priv->drm;
87 	struct pci_dev *pdev = to_pci_dev(dev->dev);
88 	struct platform_device_info pinfo = {};
89 	struct resource *rsc;
90 	struct platform_device *platdev;
91 	struct intel_hdmi_lpe_audio_pdata *pdata;
92 
93 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
94 	if (!pdata)
95 		return ERR_PTR(-ENOMEM);
96 
97 	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
98 	if (!rsc) {
99 		kfree(pdata);
100 		return ERR_PTR(-ENOMEM);
101 	}
102 
103 	rsc[0].start    = rsc[0].end = dev_priv->display.audio.lpe.irq;
104 	rsc[0].flags    = IORESOURCE_IRQ;
105 	rsc[0].name     = "hdmi-lpe-audio-irq";
106 
107 	rsc[1].start    = pci_resource_start(pdev, GTTMMADR_BAR) +
108 		I915_HDMI_LPE_AUDIO_BASE;
109 	rsc[1].end      = pci_resource_start(pdev, GTTMMADR_BAR) +
110 		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
111 	rsc[1].flags    = IORESOURCE_MEM;
112 	rsc[1].name     = "hdmi-lpe-audio-mmio";
113 
114 	pinfo.parent = dev->dev;
115 	pinfo.name = "hdmi-lpe-audio";
116 	pinfo.id = -1;
117 	pinfo.res = rsc;
118 	pinfo.num_res = 2;
119 	pinfo.data = pdata;
120 	pinfo.size_data = sizeof(*pdata);
121 	pinfo.dma_mask = DMA_BIT_MASK(32);
122 
123 	pdata->num_pipes = INTEL_NUM_PIPES(dev_priv);
124 	pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
125 	pdata->port[0].pipe = -1;
126 	pdata->port[1].pipe = -1;
127 	pdata->port[2].pipe = -1;
128 	mtx_init(&pdata->lpe_audio_slock, IPL_TTY);
129 
130 	platdev = platform_device_register_full(&pinfo);
131 	kfree(rsc);
132 	kfree(pdata);
133 
134 	if (IS_ERR(platdev)) {
135 		drm_err(&dev_priv->drm,
136 			"Failed to allocate LPE audio platform device\n");
137 		return platdev;
138 	}
139 
140 	pm_runtime_no_callbacks(&platdev->dev);
141 
142 	return platdev;
143 #endif
144 }
145 
146 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
147 {
148 	/* XXX Note that platform_device_register_full() allocates a dma_mask
149 	 * and never frees it. We can't free it here as we cannot guarantee
150 	 * this is the last reference (i.e. that the dma_mask will not be
151 	 * used after our unregister). So ee choose to leak the sizeof(u64)
152 	 * allocation here - it should be fixed in the platform_device rather
153 	 * than us fiddle with its internals.
154 	 */
155 
156 #ifdef __linux__
157 	platform_device_unregister(dev_priv->display.audio.lpe.platdev);
158 #endif
159 }
160 
161 #ifdef __linux__
162 static void lpe_audio_irq_unmask(struct irq_data *d)
163 {
164 }
165 
166 static void lpe_audio_irq_mask(struct irq_data *d)
167 {
168 }
169 
170 static struct irq_chip lpe_audio_irqchip = {
171 	.name = "hdmi_lpe_audio_irqchip",
172 	.irq_mask = lpe_audio_irq_mask,
173 	.irq_unmask = lpe_audio_irq_unmask,
174 };
175 #endif
176 
177 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
178 {
179 	STUB();
180 	return -ENOSYS;
181 #ifdef notyet
182 	int irq = dev_priv->display.audio.lpe.irq;
183 
184 	drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv));
185 	irq_set_chip_and_handler_name(irq,
186 				&lpe_audio_irqchip,
187 				handle_simple_irq,
188 				"hdmi_lpe_audio_irq_handler");
189 
190 	return irq_set_chip_data(irq, dev_priv);
191 #endif
192 }
193 
194 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
195 {
196 	return false;
197 #ifdef notyet
198 	int lpe_present = false;
199 
200 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
201 		static const struct pci_device_id atom_hdaudio_ids[] = {
202 			/* Baytrail */
203 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
204 			/* Braswell */
205 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
206 			{}
207 		};
208 
209 		if (!pci_dev_present(atom_hdaudio_ids)) {
210 			drm_info(&dev_priv->drm,
211 				 "HDaudio controller not detected, using LPE audio instead\n");
212 			lpe_present = true;
213 		}
214 	}
215 	return lpe_present;
216 #endif
217 }
218 
219 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
220 {
221 	STUB();
222 	return -ENOSYS;
223 #ifdef notyet
224 	int ret;
225 
226 	dev_priv->display.audio.lpe.irq = irq_alloc_desc(0);
227 	if (dev_priv->display.audio.lpe.irq < 0) {
228 		drm_err(&dev_priv->drm, "Failed to allocate IRQ desc: %d\n",
229 			dev_priv->display.audio.lpe.irq);
230 		ret = dev_priv->display.audio.lpe.irq;
231 		goto err;
232 	}
233 
234 	drm_dbg(&dev_priv->drm, "irq = %d\n", dev_priv->display.audio.lpe.irq);
235 
236 	ret = lpe_audio_irq_init(dev_priv);
237 
238 	if (ret) {
239 		drm_err(&dev_priv->drm,
240 			"Failed to initialize irqchip for lpe audio: %d\n",
241 			ret);
242 		goto err_free_irq;
243 	}
244 
245 	dev_priv->display.audio.lpe.platdev = lpe_audio_platdev_create(dev_priv);
246 
247 	if (IS_ERR(dev_priv->display.audio.lpe.platdev)) {
248 		ret = PTR_ERR(dev_priv->display.audio.lpe.platdev);
249 		drm_err(&dev_priv->drm,
250 			"Failed to create lpe audio platform device: %d\n",
251 			ret);
252 		goto err_free_irq;
253 	}
254 
255 	/* enable chicken bit; at least this is required for Dell Wyse 3040
256 	 * with DP outputs (but only sometimes by some reason!)
257 	 */
258 	intel_de_write(dev_priv, VLV_AUD_CHICKEN_BIT_REG,
259 		       VLV_CHICKEN_BIT_DBG_ENABLE);
260 
261 	return 0;
262 err_free_irq:
263 	irq_free_desc(dev_priv->display.audio.lpe.irq);
264 err:
265 	dev_priv->display.audio.lpe.irq = -1;
266 	dev_priv->display.audio.lpe.platdev = NULL;
267 	return ret;
268 #endif
269 }
270 
271 /**
272  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
273  * @dev_priv: the i915 drm device private data
274  *
275  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
276  * driver.
277  */
278 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
279 {
280 	STUB();
281 #ifdef notyet
282 	int ret;
283 
284 	if (!HAS_LPE_AUDIO(dev_priv))
285 		return;
286 
287 	ret = generic_handle_irq(dev_priv->display.audio.lpe.irq);
288 	if (ret)
289 		drm_err_ratelimited(&dev_priv->drm,
290 				    "error handling LPE audio irq: %d\n", ret);
291 #endif
292 }
293 
294 /**
295  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
296  * driver and i915
297  * @dev_priv: the i915 drm device private data
298  *
299  * Return: 0 if successful. non-zero if detection or
300  * llocation/initialization fails
301  */
302 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
303 {
304 	int ret = -ENODEV;
305 
306 	if (lpe_audio_detect(dev_priv)) {
307 		ret = lpe_audio_setup(dev_priv);
308 		if (ret < 0)
309 			drm_err(&dev_priv->drm,
310 				"failed to setup LPE Audio bridge\n");
311 	}
312 	return ret;
313 }
314 
315 /**
316  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
317  * audio driver and i915
318  * @dev_priv: the i915 drm device private data
319  *
320  * release all the resources for LPE audio <-> i915 bridge.
321  */
322 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
323 {
324 	STUB();
325 #ifdef notyet
326 	if (!HAS_LPE_AUDIO(dev_priv))
327 		return;
328 
329 	lpe_audio_platdev_destroy(dev_priv);
330 
331 	irq_free_desc(dev_priv->display.audio.lpe.irq);
332 
333 	dev_priv->display.audio.lpe.irq = -1;
334 	dev_priv->display.audio.lpe.platdev = NULL;
335 #endif
336 }
337 
338 /**
339  * intel_lpe_audio_notify() - notify lpe audio event
340  * audio driver and i915
341  * @dev_priv: the i915 drm device private data
342  * @pipe: pipe
343  * @port: port
344  * @eld : ELD data
345  * @ls_clock: Link symbol clock in kHz
346  * @dp_output: Driving a DP output?
347  *
348  * Notify lpe audio driver of eld change.
349  */
350 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
351 			    enum pipe pipe, enum port port,
352 			    const void *eld, int ls_clock, bool dp_output)
353 {
354 #ifdef notyet
355 	unsigned long irqflags;
356 	struct intel_hdmi_lpe_audio_pdata *pdata;
357 	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
358 	u32 audio_enable;
359 
360 	if (!HAS_LPE_AUDIO(dev_priv))
361 		return;
362 
363 	pdata = dev_get_platdata(&dev_priv->display.audio.lpe.platdev->dev);
364 	ppdata = &pdata->port[port - PORT_B];
365 
366 	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
367 
368 	audio_enable = intel_de_read(dev_priv, VLV_AUD_PORT_EN_DBG(port));
369 
370 	if (eld != NULL) {
371 		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
372 		ppdata->pipe = pipe;
373 		ppdata->ls_clock = ls_clock;
374 		ppdata->dp_output = dp_output;
375 
376 		/* Unmute the amp for both DP and HDMI */
377 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
378 			       audio_enable & ~VLV_AMP_MUTE);
379 	} else {
380 		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
381 		ppdata->pipe = -1;
382 		ppdata->ls_clock = 0;
383 		ppdata->dp_output = false;
384 
385 		/* Mute the amp for both DP and HDMI */
386 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
387 			       audio_enable | VLV_AMP_MUTE);
388 	}
389 
390 	if (pdata->notify_audio_lpe)
391 		pdata->notify_audio_lpe(dev_priv->display.audio.lpe.platdev, port - PORT_B);
392 
393 	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
394 #endif
395 }
396