summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/intel_lpe_audio.c
blob: 668f00480d97c0ff0418c19dfaaffec31fc65341 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
 *    Jerome Anand <jerome.anand@intel.com>
 *    based on VED patches
 *
 */

/**
 * DOC: LPE Audio integration for HDMI or DP playback
 *
 * Motivation:
 * Atom platforms (e.g. valleyview and cherryTrail) integrates a DMA-based
 * interface as an alternative to the traditional HDaudio path. While this
 * mode is unrelated to the LPE aka SST audio engine, the documentation refers
 * to this mode as LPE so we keep this notation for the sake of consistency.
 *
 * The interface is handled by a separate standalone driver maintained in the
 * ALSA subsystem for simplicity. To minimize the interaction between the two
 * subsystems, a bridge is setup between the hdmi-lpe-audio and i915:
 * 1. Create a platform device to share MMIO/IRQ resources
 * 2. Make the platform device child of i915 device for runtime PM.
 * 3. Create IRQ chip to forward the LPE audio irqs.
 * the hdmi-lpe-audio driver probes the lpe audio device and creates a new
 * sound card
 *
 * Threats:
 * Due to the restriction in Linux platform device model, user need manually
 * uninstall the hdmi-lpe-audio driver before uninstalling i915 module,
 * otherwise we might run into use-after-free issues after i915 removes the
 * platform device: even though hdmi-lpe-audio driver is released, the modules
 * is still in "installed" status.
 *
 * Implementation:
 * The MMIO/REG platform resources are created according to the registers
 * specification.
 * When forwarding LPE audio irqs, the flow control handler selection depends
 * on the platform, for example on valleyview handle_simple_irq is enough.
 *
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>

#include "i915_drv.h"
#include <linux/delay.h>
#include <drm/intel_lpe_audio.h>

#define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)

static struct platform_device *
lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
{
	int ret;
	struct drm_device *dev = &dev_priv->drm;
	struct platform_device_info pinfo = {};
	struct resource *rsc;
	struct platform_device *platdev;
	struct intel_hdmi_lpe_audio_pdata *pdata;

	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return ERR_PTR(-ENOMEM);

	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
	if (!rsc) {
		kfree(pdata);
		return ERR_PTR(-ENOMEM);
	}

	rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
	rsc[0].flags    = IORESOURCE_IRQ;
	rsc[0].name     = "hdmi-lpe-audio-irq";

	rsc[1].start    = pci_resource_start(dev->pdev, 0) +
		I915_HDMI_LPE_AUDIO_BASE;
	rsc[1].end      = pci_resource_start(dev->pdev, 0) +
		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
	rsc[1].flags    = IORESOURCE_MEM;
	rsc[1].name     = "hdmi-lpe-audio-mmio";

	pinfo.parent = dev->dev;
	pinfo.name = "hdmi-lpe-audio";
	pinfo.id = -1;
	pinfo.res = rsc;
	pinfo.num_res = 2;
	pinfo.data = pdata;
	pinfo.size_data = sizeof(*pdata);
	pinfo.dma_mask = DMA_BIT_MASK(32);

	spin_lock_init(&pdata->lpe_audio_slock);

	platdev = platform_device_register_full(&pinfo);
	if (IS_ERR(platdev)) {
		ret = PTR_ERR(platdev);
		DRM_ERROR("Failed to allocate LPE audio platform device\n");
		goto err;
	}

	kfree(rsc);

	pm_runtime_forbid(&platdev->dev);
	pm_runtime_set_active(&platdev->dev);
	pm_runtime_enable(&platdev->dev);

	return platdev;

err:
	kfree(rsc);
	kfree(pdata);
	return ERR_PTR(ret);
}

static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
{
	/* XXX Note that platform_device_register_full() allocates a dma_mask
	 * and never frees it. We can't free it here as we cannot guarantee
	 * this is the last reference (i.e. that the dma_mask will not be
	 * used after our unregister). So ee choose to leak the sizeof(u64)
	 * allocation here - it should be fixed in the platform_device rather
	 * than us fiddle with its internals.
	 */

	platform_device_unregister(dev_priv->lpe_audio.platdev);
}

static void lpe_audio_irq_unmask(struct irq_data *d)
{
	struct drm_i915_private *dev_priv = d->chip_data;
	unsigned long irqflags;
	u32 val = (I915_LPE_PIPE_A_INTERRUPT |
		I915_LPE_PIPE_B_INTERRUPT);

	if (IS_CHERRYVIEW(dev_priv))
		val |= I915_LPE_PIPE_C_INTERRUPT;

	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);

	dev_priv->irq_mask &= ~val;
	I915_WRITE(VLV_IIR, val);
	I915_WRITE(VLV_IIR, val);
	I915_WRITE(VLV_IMR, dev_priv->irq_mask);
	POSTING_READ(VLV_IMR);

	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static void lpe_audio_irq_mask(struct irq_data *d)
{
	struct drm_i915_private *dev_priv = d->chip_data;
	unsigned long irqflags;
	u32 val = (I915_LPE_PIPE_A_INTERRUPT |
		I915_LPE_PIPE_B_INTERRUPT);

	if (IS_CHERRYVIEW(dev_priv))
		val |= I915_LPE_PIPE_C_INTERRUPT;

	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);

	dev_priv->irq_mask |= val;
	I915_WRITE(VLV_IMR, dev_priv->irq_mask);
	I915_WRITE(VLV_IIR, val);
	I915_WRITE(VLV_IIR, val);
	POSTING_READ(VLV_IIR);

	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}

static struct irq_chip lpe_audio_irqchip = {
	.name = "hdmi_lpe_audio_irqchip",
	.irq_mask = lpe_audio_irq_mask,
	.irq_unmask = lpe_audio_irq_unmask,
};

static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
{
	int irq = dev_priv->lpe_audio.irq;

	WARN_ON(!intel_irqs_enabled(dev_priv));
	irq_set_chip_and_handler_name(irq,
				&lpe_audio_irqchip,
				handle_simple_irq,
				"hdmi_lpe_audio_irq_handler");

	return irq_set_chip_data(irq, dev_priv);
}

static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
{
	int lpe_present = false;

	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
		static const struct pci_device_id atom_hdaudio_ids[] = {
			/* Baytrail */
			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
			/* Braswell */
			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
			{}
		};

		if (!pci_dev_present(atom_hdaudio_ids)) {
			DRM_INFO("%s\n", "HDaudio controller not detected, using LPE audio instead\n");
			lpe_present = true;
		}
	}
	return lpe_present;
}

static int lpe_audio_setup(struct drm_i915_private *dev_priv)
{
	int ret;

	dev_priv->lpe_audio.irq = irq_alloc_desc(0);
	if (dev_priv->lpe_audio.irq < 0) {
		DRM_ERROR("Failed to allocate IRQ desc: %d\n",
			dev_priv->lpe_audio.irq);
		ret = dev_priv->lpe_audio.irq;
		goto err;
	}

	DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);

	ret = lpe_audio_irq_init(dev_priv);

	if (ret) {
		DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
			ret);
		goto err_free_irq;
	}

	dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);

	if (IS_ERR(dev_priv->lpe_audio.platdev)) {
		ret = PTR_ERR(dev_priv->lpe_audio.platdev);
		DRM_ERROR("Failed to create lpe audio platform device: %d\n",
			ret);
		goto err_free_irq;
	}

	/* enable chicken bit; at least this is required for Dell Wyse 3040
	 * with DP outputs (but only sometimes by some reason!)
	 */
	I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);

	return 0;
err_free_irq:
	irq_free_desc(dev_priv->lpe_audio.irq);
err:
	dev_priv->lpe_audio.irq = -1;
	dev_priv->lpe_audio.platdev = NULL;
	return ret;
}

/**
 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
 * @dev_priv: the i915 drm device private data
 *
 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
 * driver.
 */
void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
{
	int ret;

	if (!HAS_LPE_AUDIO(dev_priv))
		return;

	ret = generic_handle_irq(dev_priv->lpe_audio.irq);
	if (ret)
		DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
				ret);
}

/**
 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
 * driver and i915
 * @dev_priv: the i915 drm device private data
 *
 * Return: 0 if successful. non-zero if detection or
 * llocation/initialization fails
 */
int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
{
	int ret = -ENODEV;

	if (lpe_audio_detect(dev_priv)) {
		ret = lpe_audio_setup(dev_priv);
		if (ret < 0)
			DRM_ERROR("failed to setup LPE Audio bridge\n");
	}
	return ret;
}

/**
 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
 * audio driver and i915
 * @dev_priv: the i915 drm device private data
 *
 * release all the resources for LPE audio <-> i915 bridge.
 */
void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
{
	struct irq_desc *desc;

	if (!HAS_LPE_AUDIO(dev_priv))
		return;

	desc = irq_to_desc(dev_priv->lpe_audio.irq);

	lpe_audio_irq_mask(&desc->irq_data);

	lpe_audio_platdev_destroy(dev_priv);

	irq_free_desc(dev_priv->lpe_audio.irq);
}


/**
 * intel_lpe_audio_notify() - notify lpe audio event
 * audio driver and i915
 * @dev_priv: the i915 drm device private data
 * @eld : ELD data
 * @pipe: pipe id
 * @port: port id
 * @tmds_clk_speed: tmds clock frequency in Hz
 *
 * Notify lpe audio driver of eld change.
 */
void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
			    void *eld, int port, int pipe, int tmds_clk_speed,
			    bool dp_output, int link_rate)
{
	unsigned long irq_flags;
	struct intel_hdmi_lpe_audio_pdata *pdata = NULL;
	u32 audio_enable;

	if (!HAS_LPE_AUDIO(dev_priv))
		return;

	pdata = dev_get_platdata(
		&(dev_priv->lpe_audio.platdev->dev));

	spin_lock_irqsave(&pdata->lpe_audio_slock, irq_flags);

	audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));

	if (eld != NULL) {
		memcpy(pdata->eld.eld_data, eld,
			HDMI_MAX_ELD_BYTES);
		pdata->eld.port_id = port;
		pdata->eld.pipe_id = pipe;
		pdata->hdmi_connected = true;

		pdata->dp_output = dp_output;
		if (tmds_clk_speed)
			pdata->tmds_clock_speed = tmds_clk_speed;
		if (link_rate)
			pdata->link_rate = link_rate;

		/* Unmute the amp for both DP and HDMI */
		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
			   audio_enable & ~VLV_AMP_MUTE);

	} else {
		memset(pdata->eld.eld_data, 0,
			HDMI_MAX_ELD_BYTES);
		pdata->hdmi_connected = false;
		pdata->dp_output = false;

		/* Mute the amp for both DP and HDMI */
		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
			   audio_enable | VLV_AMP_MUTE);
	}

	if (pdata->notify_audio_lpe)
		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev);
	else
		pdata->notify_pending = true;

	spin_unlock_irqrestore(&pdata->lpe_audio_slock,
			irq_flags);
}