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