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 	struct irq_desc *desc;
301 
302 	if (!HAS_LPE_AUDIO(dev_priv))
303 		return;
304 
305 	desc = irq_to_desc(dev_priv->lpe_audio.irq);
306 
307 	lpe_audio_platdev_destroy(dev_priv);
308 
309 	irq_free_desc(dev_priv->lpe_audio.irq);
310 
311 	dev_priv->lpe_audio.irq = -1;
312 	dev_priv->lpe_audio.platdev = NULL;
313 }
314 
315 /**
316  * intel_lpe_audio_notify() - notify lpe audio event
317  * audio driver and i915
318  * @dev_priv: the i915 drm device private data
319  * @pipe: pipe
320  * @port: port
321  * @eld : ELD data
322  * @ls_clock: Link symbol clock in kHz
323  * @dp_output: Driving a DP output?
324  *
325  * Notify lpe audio driver of eld change.
326  */
327 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
328 			    enum pipe pipe, enum port port,
329 			    const void *eld, int ls_clock, bool dp_output)
330 {
331 	unsigned long irqflags;
332 	struct intel_hdmi_lpe_audio_pdata *pdata;
333 	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
334 	u32 audio_enable;
335 
336 	if (!HAS_LPE_AUDIO(dev_priv))
337 		return;
338 
339 	pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
340 	ppdata = &pdata->port[port - PORT_B];
341 
342 	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
343 
344 	audio_enable = intel_de_read(dev_priv, VLV_AUD_PORT_EN_DBG(port));
345 
346 	if (eld != NULL) {
347 		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
348 		ppdata->pipe = pipe;
349 		ppdata->ls_clock = ls_clock;
350 		ppdata->dp_output = dp_output;
351 
352 		/* Unmute the amp for both DP and HDMI */
353 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
354 			       audio_enable & ~VLV_AMP_MUTE);
355 	} else {
356 		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
357 		ppdata->pipe = -1;
358 		ppdata->ls_clock = 0;
359 		ppdata->dp_output = false;
360 
361 		/* Mute the amp for both DP and HDMI */
362 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
363 			       audio_enable | VLV_AMP_MUTE);
364 	}
365 
366 	if (pdata->notify_audio_lpe)
367 		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
368 
369 	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
370 }
371