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_lpe_audio.h"
 75
 76#define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
 77
 78static struct platform_device *
 79lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
 80{
 81	struct drm_device *dev = &dev_priv->drm;
 82	struct platform_device_info pinfo = {};
 83	struct resource *rsc;
 84	struct platform_device *platdev;
 85	struct intel_hdmi_lpe_audio_pdata *pdata;
 86
 87	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 88	if (!pdata)
 89		return ERR_PTR(-ENOMEM);
 90
 91	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
 92	if (!rsc) {
 93		kfree(pdata);
 94		return ERR_PTR(-ENOMEM);
 95	}
 96
 97	rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
 98	rsc[0].flags    = IORESOURCE_IRQ;
 99	rsc[0].name     = "hdmi-lpe-audio-irq";
100
101	rsc[1].start    = pci_resource_start(dev->pdev, 0) +
102		I915_HDMI_LPE_AUDIO_BASE;
103	rsc[1].end      = pci_resource_start(dev->pdev, 0) +
104		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
105	rsc[1].flags    = IORESOURCE_MEM;
106	rsc[1].name     = "hdmi-lpe-audio-mmio";
107
108	pinfo.parent = dev->dev;
109	pinfo.name = "hdmi-lpe-audio";
110	pinfo.id = -1;
111	pinfo.res = rsc;
112	pinfo.num_res = 2;
113	pinfo.data = pdata;
114	pinfo.size_data = sizeof(*pdata);
115	pinfo.dma_mask = DMA_BIT_MASK(32);
116
117	pdata->num_pipes = INTEL_INFO(dev_priv)->num_pipes;
118	pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
119	pdata->port[0].pipe = -1;
120	pdata->port[1].pipe = -1;
121	pdata->port[2].pipe = -1;
122	spin_lock_init(&pdata->lpe_audio_slock);
123
124	platdev = platform_device_register_full(&pinfo);
125	kfree(rsc);
126	kfree(pdata);
127
128	if (IS_ERR(platdev)) {
129		DRM_ERROR("Failed to allocate LPE audio platform device\n");
130		return platdev;
131	}
132
133	pm_runtime_no_callbacks(&platdev->dev);
134
135	return platdev;
136}
137
138static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
139{
140	/* XXX Note that platform_device_register_full() allocates a dma_mask
141	 * and never frees it. We can't free it here as we cannot guarantee
142	 * this is the last reference (i.e. that the dma_mask will not be
143	 * used after our unregister). So ee choose to leak the sizeof(u64)
144	 * allocation here - it should be fixed in the platform_device rather
145	 * than us fiddle with its internals.
146	 */
147
148	platform_device_unregister(dev_priv->lpe_audio.platdev);
149}
150
151static void lpe_audio_irq_unmask(struct irq_data *d)
152{
153}
154
155static void lpe_audio_irq_mask(struct irq_data *d)
156{
157}
158
159static struct irq_chip lpe_audio_irqchip = {
160	.name = "hdmi_lpe_audio_irqchip",
161	.irq_mask = lpe_audio_irq_mask,
162	.irq_unmask = lpe_audio_irq_unmask,
163};
164
165static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
166{
167	int irq = dev_priv->lpe_audio.irq;
168
169	WARN_ON(!intel_irqs_enabled(dev_priv));
170	irq_set_chip_and_handler_name(irq,
171				&lpe_audio_irqchip,
172				handle_simple_irq,
173				"hdmi_lpe_audio_irq_handler");
174
175	return irq_set_chip_data(irq, dev_priv);
176}
177
178static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
179{
180	int lpe_present = false;
181
182	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
183		static const struct pci_device_id atom_hdaudio_ids[] = {
184			/* Baytrail */
185			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
186			/* Braswell */
187			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
188			{}
189		};
190
191		if (!pci_dev_present(atom_hdaudio_ids)) {
192			DRM_INFO("HDaudio controller not detected, using LPE audio instead\n");
193			lpe_present = true;
194		}
195	}
196	return lpe_present;
197}
198
199static int lpe_audio_setup(struct drm_i915_private *dev_priv)
200{
201	int ret;
202
203	dev_priv->lpe_audio.irq = irq_alloc_desc(0);
204	if (dev_priv->lpe_audio.irq < 0) {
205		DRM_ERROR("Failed to allocate IRQ desc: %d\n",
206			dev_priv->lpe_audio.irq);
207		ret = dev_priv->lpe_audio.irq;
208		goto err;
209	}
210
211	DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);
212
213	ret = lpe_audio_irq_init(dev_priv);
214
215	if (ret) {
216		DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
217			ret);
218		goto err_free_irq;
219	}
220
221	dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
222
223	if (IS_ERR(dev_priv->lpe_audio.platdev)) {
224		ret = PTR_ERR(dev_priv->lpe_audio.platdev);
225		DRM_ERROR("Failed to create lpe audio platform device: %d\n",
226			ret);
227		goto err_free_irq;
228	}
229
230	/* enable chicken bit; at least this is required for Dell Wyse 3040
231	 * with DP outputs (but only sometimes by some reason!)
232	 */
233	I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);
234
235	return 0;
236err_free_irq:
237	irq_free_desc(dev_priv->lpe_audio.irq);
238err:
239	dev_priv->lpe_audio.irq = -1;
240	dev_priv->lpe_audio.platdev = NULL;
241	return ret;
242}
243
244/**
245 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
246 * @dev_priv: the i915 drm device private data
247 *
248 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
249 * driver.
250 */
251void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
252{
253	int ret;
254
255	if (!HAS_LPE_AUDIO(dev_priv))
256		return;
257
258	ret = generic_handle_irq(dev_priv->lpe_audio.irq);
259	if (ret)
260		DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
261				ret);
262}
263
264/**
265 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
266 * driver and i915
267 * @dev_priv: the i915 drm device private data
268 *
269 * Return: 0 if successful. non-zero if detection or
270 * llocation/initialization fails
271 */
272int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
273{
274	int ret = -ENODEV;
275
276	if (lpe_audio_detect(dev_priv)) {
277		ret = lpe_audio_setup(dev_priv);
278		if (ret < 0)
279			DRM_ERROR("failed to setup LPE Audio bridge\n");
280	}
281	return ret;
282}
283
284/**
285 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
286 * audio driver and i915
287 * @dev_priv: the i915 drm device private data
288 *
289 * release all the resources for LPE audio <-> i915 bridge.
290 */
291void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
292{
293	struct irq_desc *desc;
294
295	if (!HAS_LPE_AUDIO(dev_priv))
296		return;
297
298	desc = irq_to_desc(dev_priv->lpe_audio.irq);
299
300	lpe_audio_platdev_destroy(dev_priv);
301
302	irq_free_desc(dev_priv->lpe_audio.irq);
303
304	dev_priv->lpe_audio.irq = -1;
305	dev_priv->lpe_audio.platdev = NULL;
306}
307
308/**
309 * intel_lpe_audio_notify() - notify lpe audio event
310 * audio driver and i915
311 * @dev_priv: the i915 drm device private data
312 * @pipe: pipe
313 * @port: port
314 * @eld : ELD data
315 * @ls_clock: Link symbol clock in kHz
316 * @dp_output: Driving a DP output?
317 *
318 * Notify lpe audio driver of eld change.
319 */
320void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
321			    enum pipe pipe, enum port port,
322			    const void *eld, int ls_clock, bool dp_output)
323{
324	unsigned long irqflags;
325	struct intel_hdmi_lpe_audio_pdata *pdata;
326	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
327	u32 audio_enable;
328
329	if (!HAS_LPE_AUDIO(dev_priv))
330		return;
331
332	pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
333	ppdata = &pdata->port[port - PORT_B];
334
335	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
336
337	audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
338
339	if (eld != NULL) {
340		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
341		ppdata->pipe = pipe;
342		ppdata->ls_clock = ls_clock;
343		ppdata->dp_output = dp_output;
344
345		/* Unmute the amp for both DP and HDMI */
346		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
347			   audio_enable & ~VLV_AMP_MUTE);
348	} else {
349		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
350		ppdata->pipe = -1;
351		ppdata->ls_clock = 0;
352		ppdata->dp_output = false;
353
354		/* Mute the amp for both DP and HDMI */
355		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
356			   audio_enable | VLV_AMP_MUTE);
357	}
358
359	if (pdata->notify_audio_lpe)
360		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
361
362	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
363}