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