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 	STUB();
83 	return NULL;
84 #ifdef notyet
85 	struct drm_device *dev = &dev_priv->drm;
86 	struct platform_device_info pinfo = {};
87 	struct resource *rsc;
88 	struct platform_device *platdev;
89 	struct intel_hdmi_lpe_audio_pdata *pdata;
90 
91 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
92 	if (!pdata)
93 		return ERR_PTR(-ENOMEM);
94 
95 	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
96 	if (!rsc) {
97 		kfree(pdata);
98 		return ERR_PTR(-ENOMEM);
99 	}
100 
101 	rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
102 	rsc[0].flags    = IORESOURCE_IRQ;
103 	rsc[0].name     = "hdmi-lpe-audio-irq";
104 
105 	rsc[1].start    = pci_resource_start(dev->pdev, 0) +
106 		I915_HDMI_LPE_AUDIO_BASE;
107 	rsc[1].end      = pci_resource_start(dev->pdev, 0) +
108 		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
109 	rsc[1].flags    = IORESOURCE_MEM;
110 	rsc[1].name     = "hdmi-lpe-audio-mmio";
111 
112 	pinfo.parent = dev->dev;
113 	pinfo.name = "hdmi-lpe-audio";
114 	pinfo.id = -1;
115 	pinfo.res = rsc;
116 	pinfo.num_res = 2;
117 	pinfo.data = pdata;
118 	pinfo.size_data = sizeof(*pdata);
119 	pinfo.dma_mask = DMA_BIT_MASK(32);
120 
121 	pdata->num_pipes = INTEL_NUM_PIPES(dev_priv);
122 	pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
123 	pdata->port[0].pipe = -1;
124 	pdata->port[1].pipe = -1;
125 	pdata->port[2].pipe = -1;
126 	mtx_init(&pdata->lpe_audio_slock, IPL_TTY);
127 
128 	platdev = platform_device_register_full(&pinfo);
129 	kfree(rsc);
130 	kfree(pdata);
131 
132 	if (IS_ERR(platdev)) {
133 		drm_err(&dev_priv->drm,
134 			"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 #endif
142 }
143 
144 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
145 {
146 	/* XXX Note that platform_device_register_full() allocates a dma_mask
147 	 * and never frees it. We can't free it here as we cannot guarantee
148 	 * this is the last reference (i.e. that the dma_mask will not be
149 	 * used after our unregister). So ee choose to leak the sizeof(u64)
150 	 * allocation here - it should be fixed in the platform_device rather
151 	 * than us fiddle with its internals.
152 	 */
153 
154 #ifdef __linux__
155 	platform_device_unregister(dev_priv->lpe_audio.platdev);
156 #endif
157 }
158 
159 #ifdef __linux__
160 static void lpe_audio_irq_unmask(struct irq_data *d)
161 {
162 }
163 
164 static void lpe_audio_irq_mask(struct irq_data *d)
165 {
166 }
167 
168 static struct irq_chip lpe_audio_irqchip = {
169 	.name = "hdmi_lpe_audio_irqchip",
170 	.irq_mask = lpe_audio_irq_mask,
171 	.irq_unmask = lpe_audio_irq_unmask,
172 };
173 #endif
174 
175 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
176 {
177 	STUB();
178 	return -ENOSYS;
179 #ifdef notyet
180 	int irq = dev_priv->lpe_audio.irq;
181 
182 	drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv));
183 	irq_set_chip_and_handler_name(irq,
184 				&lpe_audio_irqchip,
185 				handle_simple_irq,
186 				"hdmi_lpe_audio_irq_handler");
187 
188 	return irq_set_chip_data(irq, dev_priv);
189 #endif
190 }
191 
192 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
193 {
194 	return false;
195 #ifdef notyet
196 	int lpe_present = false;
197 
198 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
199 		static const struct pci_device_id atom_hdaudio_ids[] = {
200 			/* Baytrail */
201 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
202 			/* Braswell */
203 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
204 			{}
205 		};
206 
207 		if (!pci_dev_present(atom_hdaudio_ids)) {
208 			drm_info(&dev_priv->drm,
209 				 "HDaudio controller not detected, using LPE audio instead\n");
210 			lpe_present = true;
211 		}
212 	}
213 	return lpe_present;
214 #endif
215 }
216 
217 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
218 {
219 	STUB();
220 	return -ENOSYS;
221 #ifdef notyet
222 	int ret;
223 
224 	dev_priv->lpe_audio.irq = irq_alloc_desc(0);
225 	if (dev_priv->lpe_audio.irq < 0) {
226 		drm_err(&dev_priv->drm, "Failed to allocate IRQ desc: %d\n",
227 			dev_priv->lpe_audio.irq);
228 		ret = dev_priv->lpe_audio.irq;
229 		goto err;
230 	}
231 
232 	drm_dbg(&dev_priv->drm, "irq = %d\n", dev_priv->lpe_audio.irq);
233 
234 	ret = lpe_audio_irq_init(dev_priv);
235 
236 	if (ret) {
237 		drm_err(&dev_priv->drm,
238 			"Failed to initialize irqchip for lpe audio: %d\n",
239 			ret);
240 		goto err_free_irq;
241 	}
242 
243 	dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
244 
245 	if (IS_ERR(dev_priv->lpe_audio.platdev)) {
246 		ret = PTR_ERR(dev_priv->lpe_audio.platdev);
247 		drm_err(&dev_priv->drm,
248 			"Failed to create lpe audio platform device: %d\n",
249 			ret);
250 		goto err_free_irq;
251 	}
252 
253 	/* enable chicken bit; at least this is required for Dell Wyse 3040
254 	 * with DP outputs (but only sometimes by some reason!)
255 	 */
256 	intel_de_write(dev_priv, VLV_AUD_CHICKEN_BIT_REG,
257 		       VLV_CHICKEN_BIT_DBG_ENABLE);
258 
259 	return 0;
260 err_free_irq:
261 	irq_free_desc(dev_priv->lpe_audio.irq);
262 err:
263 	dev_priv->lpe_audio.irq = -1;
264 	dev_priv->lpe_audio.platdev = NULL;
265 	return ret;
266 #endif
267 }
268 
269 /**
270  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
271  * @dev_priv: the i915 drm device private data
272  *
273  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
274  * driver.
275  */
276 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
277 {
278 	STUB();
279 #ifdef notyet
280 	int ret;
281 
282 	if (!HAS_LPE_AUDIO(dev_priv))
283 		return;
284 
285 	ret = generic_handle_irq(dev_priv->lpe_audio.irq);
286 	if (ret)
287 		drm_err_ratelimited(&dev_priv->drm,
288 				    "error handling LPE audio irq: %d\n", ret);
289 #endif
290 }
291 
292 /**
293  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
294  * driver and i915
295  * @dev_priv: the i915 drm device private data
296  *
297  * Return: 0 if successful. non-zero if detection or
298  * llocation/initialization fails
299  */
300 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
301 {
302 	int ret = -ENODEV;
303 
304 	if (lpe_audio_detect(dev_priv)) {
305 		ret = lpe_audio_setup(dev_priv);
306 		if (ret < 0)
307 			drm_err(&dev_priv->drm,
308 				"failed to setup LPE Audio bridge\n");
309 	}
310 	return ret;
311 }
312 
313 /**
314  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
315  * audio driver and i915
316  * @dev_priv: the i915 drm device private data
317  *
318  * release all the resources for LPE audio <-> i915 bridge.
319  */
320 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
321 {
322 	STUB();
323 #ifdef notyet
324 	struct irq_desc *desc;
325 
326 	if (!HAS_LPE_AUDIO(dev_priv))
327 		return;
328 
329 	desc = irq_to_desc(dev_priv->lpe_audio.irq);
330 
331 	lpe_audio_platdev_destroy(dev_priv);
332 
333 	irq_free_desc(dev_priv->lpe_audio.irq);
334 
335 	dev_priv->lpe_audio.irq = -1;
336 	dev_priv->lpe_audio.platdev = NULL;
337 #endif
338 }
339 
340 /**
341  * intel_lpe_audio_notify() - notify lpe audio event
342  * audio driver and i915
343  * @dev_priv: the i915 drm device private data
344  * @pipe: pipe
345  * @port: port
346  * @eld : ELD data
347  * @ls_clock: Link symbol clock in kHz
348  * @dp_output: Driving a DP output?
349  *
350  * Notify lpe audio driver of eld change.
351  */
352 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
353 			    enum pipe pipe, enum port port,
354 			    const void *eld, int ls_clock, bool dp_output)
355 {
356 #ifdef notyet
357 	unsigned long irqflags;
358 	struct intel_hdmi_lpe_audio_pdata *pdata;
359 	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
360 	u32 audio_enable;
361 
362 	if (!HAS_LPE_AUDIO(dev_priv))
363 		return;
364 
365 	pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
366 	ppdata = &pdata->port[port - PORT_B];
367 
368 	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
369 
370 	audio_enable = intel_de_read(dev_priv, VLV_AUD_PORT_EN_DBG(port));
371 
372 	if (eld != NULL) {
373 		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
374 		ppdata->pipe = pipe;
375 		ppdata->ls_clock = ls_clock;
376 		ppdata->dp_output = dp_output;
377 
378 		/* Unmute the amp for both DP and HDMI */
379 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
380 			       audio_enable & ~VLV_AMP_MUTE);
381 	} else {
382 		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
383 		ppdata->pipe = -1;
384 		ppdata->ls_clock = 0;
385 		ppdata->dp_output = false;
386 
387 		/* Mute the amp for both DP and HDMI */
388 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
389 			       audio_enable | VLV_AMP_MUTE);
390 	}
391 
392 	if (pdata->notify_audio_lpe)
393 		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
394 
395 	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
396 #endif
397 }
398