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 "i915_irq.h"
75 #include "i915_reg.h"
76 #include "intel_de.h"
77 #include "intel_lpe_audio.h"
78 #include "intel_pci_config.h"
79 
80 #define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->display.audio.lpe.platdev != NULL)
81 
82 static struct platform_device *
83 lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
84 {
85 	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
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->display.audio.lpe.irq;
102 	rsc[0].flags    = IORESOURCE_IRQ;
103 	rsc[0].name     = "hdmi-lpe-audio-irq";
104 
105 	rsc[1].start    = pci_resource_start(pdev, GTTMMADR_BAR) +
106 		I915_HDMI_LPE_AUDIO_BASE;
107 	rsc[1].end      = pci_resource_start(pdev, GTTMMADR_BAR) +
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_priv->drm.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 	spin_lock_init(&pdata->lpe_audio_slock);
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 }
142 
143 static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
144 {
145 	/* XXX Note that platform_device_register_full() allocates a dma_mask
146 	 * and never frees it. We can't free it here as we cannot guarantee
147 	 * this is the last reference (i.e. that the dma_mask will not be
148 	 * used after our unregister). So ee choose to leak the sizeof(u64)
149 	 * allocation here - it should be fixed in the platform_device rather
150 	 * than us fiddle with its internals.
151 	 */
152 
153 	platform_device_unregister(dev_priv->display.audio.lpe.platdev);
154 }
155 
156 static void lpe_audio_irq_unmask(struct irq_data *d)
157 {
158 }
159 
160 static void lpe_audio_irq_mask(struct irq_data *d)
161 {
162 }
163 
164 static struct irq_chip lpe_audio_irqchip = {
165 	.name = "hdmi_lpe_audio_irqchip",
166 	.irq_mask = lpe_audio_irq_mask,
167 	.irq_unmask = lpe_audio_irq_unmask,
168 };
169 
170 static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
171 {
172 	int irq = dev_priv->display.audio.lpe.irq;
173 
174 	drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv));
175 	irq_set_chip_and_handler_name(irq,
176 				&lpe_audio_irqchip,
177 				handle_simple_irq,
178 				"hdmi_lpe_audio_irq_handler");
179 
180 	return irq_set_chip_data(irq, dev_priv);
181 }
182 
183 static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
184 {
185 	int lpe_present = false;
186 
187 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
188 		static const struct pci_device_id atom_hdaudio_ids[] = {
189 			/* Baytrail */
190 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
191 			/* Braswell */
192 			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
193 			{}
194 		};
195 
196 		if (!pci_dev_present(atom_hdaudio_ids)) {
197 			drm_info(&dev_priv->drm,
198 				 "HDaudio controller not detected, using LPE audio instead\n");
199 			lpe_present = true;
200 		}
201 	}
202 	return lpe_present;
203 }
204 
205 static int lpe_audio_setup(struct drm_i915_private *dev_priv)
206 {
207 	int ret;
208 
209 	dev_priv->display.audio.lpe.irq = irq_alloc_desc(0);
210 	if (dev_priv->display.audio.lpe.irq < 0) {
211 		drm_err(&dev_priv->drm, "Failed to allocate IRQ desc: %d\n",
212 			dev_priv->display.audio.lpe.irq);
213 		ret = dev_priv->display.audio.lpe.irq;
214 		goto err;
215 	}
216 
217 	drm_dbg(&dev_priv->drm, "irq = %d\n", dev_priv->display.audio.lpe.irq);
218 
219 	ret = lpe_audio_irq_init(dev_priv);
220 
221 	if (ret) {
222 		drm_err(&dev_priv->drm,
223 			"Failed to initialize irqchip for lpe audio: %d\n",
224 			ret);
225 		goto err_free_irq;
226 	}
227 
228 	dev_priv->display.audio.lpe.platdev = lpe_audio_platdev_create(dev_priv);
229 
230 	if (IS_ERR(dev_priv->display.audio.lpe.platdev)) {
231 		ret = PTR_ERR(dev_priv->display.audio.lpe.platdev);
232 		drm_err(&dev_priv->drm,
233 			"Failed to create lpe audio platform device: %d\n",
234 			ret);
235 		goto err_free_irq;
236 	}
237 
238 	/* enable chicken bit; at least this is required for Dell Wyse 3040
239 	 * with DP outputs (but only sometimes by some reason!)
240 	 */
241 	intel_de_write(dev_priv, VLV_AUD_CHICKEN_BIT_REG,
242 		       VLV_CHICKEN_BIT_DBG_ENABLE);
243 
244 	return 0;
245 err_free_irq:
246 	irq_free_desc(dev_priv->display.audio.lpe.irq);
247 err:
248 	dev_priv->display.audio.lpe.irq = -1;
249 	dev_priv->display.audio.lpe.platdev = NULL;
250 	return ret;
251 }
252 
253 /**
254  * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
255  * @dev_priv: the i915 drm device private data
256  *
257  * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
258  * driver.
259  */
260 void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
261 {
262 	int ret;
263 
264 	if (!HAS_LPE_AUDIO(dev_priv))
265 		return;
266 
267 	ret = generic_handle_irq(dev_priv->display.audio.lpe.irq);
268 	if (ret)
269 		drm_err_ratelimited(&dev_priv->drm,
270 				    "error handling LPE audio irq: %d\n", ret);
271 }
272 
273 /**
274  * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
275  * driver and i915
276  * @dev_priv: the i915 drm device private data
277  *
278  * Return: 0 if successful. non-zero if detection or
279  * llocation/initialization fails
280  */
281 int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
282 {
283 	int ret = -ENODEV;
284 
285 	if (lpe_audio_detect(dev_priv)) {
286 		ret = lpe_audio_setup(dev_priv);
287 		if (ret < 0)
288 			drm_err(&dev_priv->drm,
289 				"failed to setup LPE Audio bridge\n");
290 	}
291 	return ret;
292 }
293 
294 /**
295  * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
296  * audio driver and i915
297  * @dev_priv: the i915 drm device private data
298  *
299  * release all the resources for LPE audio <-> i915 bridge.
300  */
301 void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
302 {
303 	if (!HAS_LPE_AUDIO(dev_priv))
304 		return;
305 
306 	lpe_audio_platdev_destroy(dev_priv);
307 
308 	irq_free_desc(dev_priv->display.audio.lpe.irq);
309 
310 	dev_priv->display.audio.lpe.irq = -1;
311 	dev_priv->display.audio.lpe.platdev = NULL;
312 }
313 
314 /**
315  * intel_lpe_audio_notify() - notify lpe audio event
316  * audio driver and i915
317  * @dev_priv: the i915 drm device private data
318  * @pipe: pipe
319  * @port: port
320  * @eld : ELD data
321  * @ls_clock: Link symbol clock in kHz
322  * @dp_output: Driving a DP output?
323  *
324  * Notify lpe audio driver of eld change.
325  */
326 void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
327 			    enum pipe pipe, enum port port,
328 			    const void *eld, int ls_clock, bool dp_output)
329 {
330 	unsigned long irqflags;
331 	struct intel_hdmi_lpe_audio_pdata *pdata;
332 	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
333 	u32 audio_enable;
334 
335 	if (!HAS_LPE_AUDIO(dev_priv))
336 		return;
337 
338 	pdata = dev_get_platdata(&dev_priv->display.audio.lpe.platdev->dev);
339 	ppdata = &pdata->port[port - PORT_B];
340 
341 	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
342 
343 	audio_enable = intel_de_read(dev_priv, VLV_AUD_PORT_EN_DBG(port));
344 
345 	if (eld != NULL) {
346 		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
347 		ppdata->pipe = pipe;
348 		ppdata->ls_clock = ls_clock;
349 		ppdata->dp_output = dp_output;
350 
351 		/* Unmute the amp for both DP and HDMI */
352 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
353 			       audio_enable & ~VLV_AMP_MUTE);
354 	} else {
355 		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
356 		ppdata->pipe = -1;
357 		ppdata->ls_clock = 0;
358 		ppdata->dp_output = false;
359 
360 		/* Mute the amp for both DP and HDMI */
361 		intel_de_write(dev_priv, VLV_AUD_PORT_EN_DBG(port),
362 			       audio_enable | VLV_AMP_MUTE);
363 	}
364 
365 	if (pdata->notify_audio_lpe)
366 		pdata->notify_audio_lpe(dev_priv->display.audio.lpe.platdev, port - PORT_B);
367 
368 	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
369 }
370