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
 79static struct platform_device *
 80lpe_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
140static 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
153static void lpe_audio_irq_unmask(struct irq_data *d)
154{
155}
156
157static void lpe_audio_irq_mask(struct irq_data *d)
158{
159}
160
161static 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
167static 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
180static 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
202static 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;
242err_free_irq:
243	irq_free_desc(dev_priv->lpe_audio.irq);
244err:
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 */
257void 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 */
278int 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 */
298void 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 */
327void 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}