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/device.h>
 65#include <linux/pci.h>
 66#include <linux/pm_runtime.h>
 67
 68#include "i915_drv.h"
 69#include <linux/delay.h>
 70#include <drm/intel_lpe_audio.h>
 71
 72#define HAS_LPE_AUDIO(dev_priv) ((dev_priv)->lpe_audio.platdev != NULL)
 73
 74static struct platform_device *
 75lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
 76{
 77	struct drm_device *dev = &dev_priv->drm;
 78	struct platform_device_info pinfo = {};
 79	struct resource *rsc;
 80	struct platform_device *platdev;
 81	struct intel_hdmi_lpe_audio_pdata *pdata;
 82
 83	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 84	if (!pdata)
 85		return ERR_PTR(-ENOMEM);
 86
 87	rsc = kcalloc(2, sizeof(*rsc), GFP_KERNEL);
 88	if (!rsc) {
 89		kfree(pdata);
 90		return ERR_PTR(-ENOMEM);
 91	}
 92
 93	rsc[0].start    = rsc[0].end = dev_priv->lpe_audio.irq;
 94	rsc[0].flags    = IORESOURCE_IRQ;
 95	rsc[0].name     = "hdmi-lpe-audio-irq";
 96
 97	rsc[1].start    = pci_resource_start(dev->pdev, 0) +
 98		I915_HDMI_LPE_AUDIO_BASE;
 99	rsc[1].end      = pci_resource_start(dev->pdev, 0) +
100		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
101	rsc[1].flags    = IORESOURCE_MEM;
102	rsc[1].name     = "hdmi-lpe-audio-mmio";
103
104	pinfo.parent = dev->dev;
105	pinfo.name = "hdmi-lpe-audio";
106	pinfo.id = -1;
107	pinfo.res = rsc;
108	pinfo.num_res = 2;
109	pinfo.data = pdata;
110	pinfo.size_data = sizeof(*pdata);
111	pinfo.dma_mask = DMA_BIT_MASK(32);
112
113	pdata->num_pipes = INTEL_INFO(dev_priv)->num_pipes;
114	pdata->num_ports = IS_CHERRYVIEW(dev_priv) ? 3 : 2; /* B,C,D or B,C */
115	pdata->port[0].pipe = -1;
116	pdata->port[1].pipe = -1;
117	pdata->port[2].pipe = -1;
118	spin_lock_init(&pdata->lpe_audio_slock);
119
120	platdev = platform_device_register_full(&pinfo);
121	kfree(rsc);
122	kfree(pdata);
123
124	if (IS_ERR(platdev)) {
125		DRM_ERROR("Failed to allocate LPE audio platform device\n");
126		return platdev;
127	}
128
129	pm_runtime_forbid(&platdev->dev);
130	pm_runtime_set_active(&platdev->dev);
131	pm_runtime_enable(&platdev->dev);
132
133	return platdev;
134}
135
136static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)
137{
138	/* XXX Note that platform_device_register_full() allocates a dma_mask
139	 * and never frees it. We can't free it here as we cannot guarantee
140	 * this is the last reference (i.e. that the dma_mask will not be
141	 * used after our unregister). So ee choose to leak the sizeof(u64)
142	 * allocation here - it should be fixed in the platform_device rather
143	 * than us fiddle with its internals.
144	 */
145
146	platform_device_unregister(dev_priv->lpe_audio.platdev);
147}
148
149static void lpe_audio_irq_unmask(struct irq_data *d)
150{
151}
152
153static void lpe_audio_irq_mask(struct irq_data *d)
154{
155}
156
157static struct irq_chip lpe_audio_irqchip = {
158	.name = "hdmi_lpe_audio_irqchip",
159	.irq_mask = lpe_audio_irq_mask,
160	.irq_unmask = lpe_audio_irq_unmask,
161};
162
163static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
164{
165	int irq = dev_priv->lpe_audio.irq;
166
167	WARN_ON(!intel_irqs_enabled(dev_priv));
168	irq_set_chip_and_handler_name(irq,
169				&lpe_audio_irqchip,
170				handle_simple_irq,
171				"hdmi_lpe_audio_irq_handler");
172
173	return irq_set_chip_data(irq, dev_priv);
174}
175
176static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
177{
178	int lpe_present = false;
179
180	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
181		static const struct pci_device_id atom_hdaudio_ids[] = {
182			/* Baytrail */
183			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
184			/* Braswell */
185			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
186			{}
187		};
188
189		if (!pci_dev_present(atom_hdaudio_ids)) {
190			DRM_INFO("HDaudio controller not detected, using LPE audio instead\n");
191			lpe_present = true;
192		}
193	}
194	return lpe_present;
195}
196
197static int lpe_audio_setup(struct drm_i915_private *dev_priv)
198{
199	int ret;
200
201	dev_priv->lpe_audio.irq = irq_alloc_desc(0);
202	if (dev_priv->lpe_audio.irq < 0) {
203		DRM_ERROR("Failed to allocate IRQ desc: %d\n",
204			dev_priv->lpe_audio.irq);
205		ret = dev_priv->lpe_audio.irq;
206		goto err;
207	}
208
209	DRM_DEBUG("irq = %d\n", dev_priv->lpe_audio.irq);
210
211	ret = lpe_audio_irq_init(dev_priv);
212
213	if (ret) {
214		DRM_ERROR("Failed to initialize irqchip for lpe audio: %d\n",
215			ret);
216		goto err_free_irq;
217	}
218
219	dev_priv->lpe_audio.platdev = lpe_audio_platdev_create(dev_priv);
220
221	if (IS_ERR(dev_priv->lpe_audio.platdev)) {
222		ret = PTR_ERR(dev_priv->lpe_audio.platdev);
223		DRM_ERROR("Failed to create lpe audio platform device: %d\n",
224			ret);
225		goto err_free_irq;
226	}
227
228	/* enable chicken bit; at least this is required for Dell Wyse 3040
229	 * with DP outputs (but only sometimes by some reason!)
230	 */
231	I915_WRITE(VLV_AUD_CHICKEN_BIT_REG, VLV_CHICKEN_BIT_DBG_ENABLE);
232
233	return 0;
234err_free_irq:
235	irq_free_desc(dev_priv->lpe_audio.irq);
236err:
237	dev_priv->lpe_audio.irq = -1;
238	dev_priv->lpe_audio.platdev = NULL;
239	return ret;
240}
241
242/**
243 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
244 * @dev_priv: the i915 drm device private data
245 *
246 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
247 * driver.
248 */
249void intel_lpe_audio_irq_handler(struct drm_i915_private *dev_priv)
250{
251	int ret;
252
253	if (!HAS_LPE_AUDIO(dev_priv))
254		return;
255
256	ret = generic_handle_irq(dev_priv->lpe_audio.irq);
257	if (ret)
258		DRM_ERROR_RATELIMITED("error handling LPE audio irq: %d\n",
259				ret);
260}
261
262/**
263 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
264 * driver and i915
265 * @dev_priv: the i915 drm device private data
266 *
267 * Return: 0 if successful. non-zero if detection or
268 * llocation/initialization fails
269 */
270int intel_lpe_audio_init(struct drm_i915_private *dev_priv)
271{
272	int ret = -ENODEV;
273
274	if (lpe_audio_detect(dev_priv)) {
275		ret = lpe_audio_setup(dev_priv);
276		if (ret < 0)
277			DRM_ERROR("failed to setup LPE Audio bridge\n");
278	}
279	return ret;
280}
281
282/**
283 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
284 * audio driver and i915
285 * @dev_priv: the i915 drm device private data
286 *
287 * release all the resources for LPE audio <-> i915 bridge.
288 */
289void intel_lpe_audio_teardown(struct drm_i915_private *dev_priv)
290{
291	struct irq_desc *desc;
292
293	if (!HAS_LPE_AUDIO(dev_priv))
294		return;
295
296	desc = irq_to_desc(dev_priv->lpe_audio.irq);
297
298	lpe_audio_platdev_destroy(dev_priv);
299
300	irq_free_desc(dev_priv->lpe_audio.irq);
301}
302
303
304/**
305 * intel_lpe_audio_notify() - notify lpe audio event
306 * audio driver and i915
307 * @dev_priv: the i915 drm device private data
308 * @pipe: pipe
309 * @port: port
310 * @eld : ELD data
311 * @ls_clock: Link symbol clock in kHz
312 * @dp_output: Driving a DP output?
313 *
314 * Notify lpe audio driver of eld change.
315 */
316void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
317			    enum pipe pipe, enum port port,
318			    const void *eld, int ls_clock, bool dp_output)
319{
320	unsigned long irqflags;
321	struct intel_hdmi_lpe_audio_pdata *pdata;
322	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
323	u32 audio_enable;
324
325	if (!HAS_LPE_AUDIO(dev_priv))
326		return;
327
328	pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
329	ppdata = &pdata->port[port - PORT_B];
330
331	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
332
333	audio_enable = I915_READ(VLV_AUD_PORT_EN_DBG(port));
334
335	if (eld != NULL) {
336		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
337		ppdata->pipe = pipe;
338		ppdata->ls_clock = ls_clock;
339		ppdata->dp_output = dp_output;
340
341		/* Unmute the amp for both DP and HDMI */
342		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
343			   audio_enable & ~VLV_AMP_MUTE);
344	} else {
345		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
346		ppdata->pipe = -1;
347		ppdata->ls_clock = 0;
348		ppdata->dp_output = false;
349
350		/* Mute the amp for both DP and HDMI */
351		I915_WRITE(VLV_AUD_PORT_EN_DBG(port),
352			   audio_enable | VLV_AMP_MUTE);
353	}
354
355	if (pdata->notify_audio_lpe)
356		pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
357
358	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
359}