intel_lpe_audio.c

  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/drm_print.h>
 72#include <drm/intel/intel_lpe_audio.h>
 73
 74#include "i915_irq.h"
 75#include "intel_audio_regs.h"
 76#include "intel_de.h"
 77#include "intel_lpe_audio.h"
 78#include "intel_pci_config.h"
 79
 80#define HAS_LPE_AUDIO(display) ((display)->audio.lpe.platdev)
 81
 82static struct platform_device *
 83lpe_audio_platdev_create(struct intel_display *display)
 84{
 85	struct pci_dev *pdev = to_pci_dev(display->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    = display->audio.lpe.irq;
102	rsc[0].end      = display->audio.lpe.irq;
103	rsc[0].flags    = IORESOURCE_IRQ;
104	rsc[0].name     = "hdmi-lpe-audio-irq";
105
106	rsc[1].start    = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) +
107		I915_HDMI_LPE_AUDIO_BASE;
108	rsc[1].end      = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) +
109		I915_HDMI_LPE_AUDIO_BASE + I915_HDMI_LPE_AUDIO_SIZE - 1;
110	rsc[1].flags    = IORESOURCE_MEM;
111	rsc[1].name     = "hdmi-lpe-audio-mmio";
112
113	pinfo.parent = display->drm->dev;
114	pinfo.name = "hdmi-lpe-audio";
115	pinfo.id = -1;
116	pinfo.res = rsc;
117	pinfo.num_res = 2;
118	pinfo.data = pdata;
119	pinfo.size_data = sizeof(*pdata);
120	pinfo.dma_mask = DMA_BIT_MASK(32);
121
122	pdata->num_pipes = INTEL_NUM_PIPES(display);
123	pdata->num_ports = display->platform.cherryview ? 3 : 2; /* B,C,D or B,C */
124	pdata->port[0].pipe = -1;
125	pdata->port[1].pipe = -1;
126	pdata->port[2].pipe = -1;
127	spin_lock_init(&pdata->lpe_audio_slock);
128
129	platdev = platform_device_register_full(&pinfo);
130	kfree(rsc);
131	kfree(pdata);
132
133	if (IS_ERR(platdev)) {
134		drm_err(display->drm,
135			"Failed to allocate LPE audio platform device\n");
136		return platdev;
137	}
138
139	pm_runtime_no_callbacks(&platdev->dev);
140
141	return platdev;
142}
143
144static void lpe_audio_platdev_destroy(struct intel_display *display)
145{
146	/* XXX Note that platform_device_register_full() allocates a dma_mask
147	 * and never frees it. We can't free it here as we cannot guarantee
148	 * this is the last reference (i.e. that the dma_mask will not be
149	 * used after our unregister). So ee choose to leak the sizeof(u64)
150	 * allocation here - it should be fixed in the platform_device rather
151	 * than us fiddle with its internals.
152	 */
153
154	platform_device_unregister(display->audio.lpe.platdev);
155}
156
157static void lpe_audio_irq_unmask(struct irq_data *d)
158{
159}
160
161static void lpe_audio_irq_mask(struct irq_data *d)
162{
163}
164
165static struct irq_chip lpe_audio_irqchip = {
166	.name = "hdmi_lpe_audio_irqchip",
167	.irq_mask = lpe_audio_irq_mask,
168	.irq_unmask = lpe_audio_irq_unmask,
169};
170
171static int lpe_audio_irq_init(struct intel_display *display)
172{
173	int irq = display->audio.lpe.irq;
174
175	irq_set_chip_and_handler_name(irq, &lpe_audio_irqchip,
176				      handle_simple_irq,
177				      "hdmi_lpe_audio_irq_handler");
178
179	return 0;
180}
181
182static bool lpe_audio_detect(struct intel_display *display)
183{
184	int lpe_present = false;
185
186	if (display->platform.valleyview || display->platform.cherryview) {
187		static const struct pci_device_id atom_hdaudio_ids[] = {
188			/* Baytrail */
189			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x0f04)},
190			/* Braswell */
191			{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2284)},
192			{}
193		};
194
195		if (!pci_dev_present(atom_hdaudio_ids)) {
196			drm_info(display->drm,
197				 "HDaudio controller not detected, using LPE audio instead\n");
198			lpe_present = true;
199		}
200	}
201	return lpe_present;
202}
203
204static int lpe_audio_setup(struct intel_display *display)
205{
206	int ret;
207
208	display->audio.lpe.irq = irq_alloc_desc(0);
209	if (display->audio.lpe.irq < 0) {
210		drm_err(display->drm, "Failed to allocate IRQ desc: %d\n",
211			display->audio.lpe.irq);
212		ret = display->audio.lpe.irq;
213		goto err;
214	}
215
216	drm_dbg(display->drm, "irq = %d\n", display->audio.lpe.irq);
217
218	ret = lpe_audio_irq_init(display);
219
220	if (ret) {
221		drm_err(display->drm,
222			"Failed to initialize irqchip for lpe audio: %d\n",
223			ret);
224		goto err_free_irq;
225	}
226
227	display->audio.lpe.platdev = lpe_audio_platdev_create(display);
228
229	if (IS_ERR(display->audio.lpe.platdev)) {
230		ret = PTR_ERR(display->audio.lpe.platdev);
231		drm_err(display->drm,
232			"Failed to create lpe audio platform device: %d\n",
233			ret);
234		goto err_free_irq;
235	}
236
237	/* enable chicken bit; at least this is required for Dell Wyse 3040
238	 * with DP outputs (but only sometimes by some reason!)
239	 */
240	intel_de_write(display, VLV_AUD_CHICKEN_BIT_REG,
241		       VLV_CHICKEN_BIT_DBG_ENABLE);
242
243	return 0;
244err_free_irq:
245	irq_free_desc(display->audio.lpe.irq);
246err:
247	display->audio.lpe.irq = -1;
248	display->audio.lpe.platdev = NULL;
249	return ret;
250}
251
252/**
253 * intel_lpe_audio_irq_handler() - forwards the LPE audio irq
254 * @display: display device
255 *
256 * the LPE Audio irq is forwarded to the irq handler registered by LPE audio
257 * driver.
258 */
259void intel_lpe_audio_irq_handler(struct intel_display *display)
260{
261	int ret;
262
263	if (!HAS_LPE_AUDIO(display))
264		return;
265
266	ret = generic_handle_irq(display->audio.lpe.irq);
267	if (ret)
268		drm_err_ratelimited(display->drm,
269				    "error handling LPE audio irq: %d\n", ret);
270}
271
272/**
273 * intel_lpe_audio_init() - detect and setup the bridge between HDMI LPE Audio
274 * driver and i915
275 * @display: display device
276 *
277 * Return: 0 if successful. non-zero if detection or
278 * llocation/initialization fails
279 */
280int intel_lpe_audio_init(struct intel_display *display)
281{
282	int ret = -ENODEV;
283
284	if (lpe_audio_detect(display)) {
285		ret = lpe_audio_setup(display);
286		if (ret < 0)
287			drm_err(display->drm,
288				"failed to setup LPE Audio bridge\n");
289	}
290	return ret;
291}
292
293/**
294 * intel_lpe_audio_teardown() - destroy the bridge between HDMI LPE
295 * audio driver and i915
296 * @display: display device
297 *
298 * release all the resources for LPE audio <-> i915 bridge.
299 */
300void intel_lpe_audio_teardown(struct intel_display *display)
301{
302	if (!HAS_LPE_AUDIO(display))
303		return;
304
305	lpe_audio_platdev_destroy(display);
306
307	irq_free_desc(display->audio.lpe.irq);
308
309	display->audio.lpe.irq = -1;
310	display->audio.lpe.platdev = NULL;
311}
312
313/**
314 * intel_lpe_audio_notify() - notify lpe audio event
315 * audio driver and i915
316 * @display: display device
317 * @cpu_transcoder: CPU transcoder
318 * @port: port
319 * @eld : ELD data
320 * @ls_clock: Link symbol clock in kHz
321 * @dp_output: Driving a DP output?
322 *
323 * Notify lpe audio driver of eld change.
324 */
325void intel_lpe_audio_notify(struct intel_display *display,
326			    enum transcoder cpu_transcoder, enum port port,
327			    const void *eld, int ls_clock, bool dp_output)
328{
329	unsigned long irqflags;
330	struct intel_hdmi_lpe_audio_pdata *pdata;
331	struct intel_hdmi_lpe_audio_port_pdata *ppdata;
332	u32 audio_enable;
333
334	if (!HAS_LPE_AUDIO(display))
335		return;
336
337	pdata = dev_get_platdata(&display->audio.lpe.platdev->dev);
338	ppdata = &pdata->port[port - PORT_B];
339
340	spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
341
342	audio_enable = intel_de_read(display, VLV_AUD_PORT_EN_DBG(port));
343
344	if (eld != NULL) {
345		memcpy(ppdata->eld, eld, HDMI_MAX_ELD_BYTES);
346		ppdata->pipe = cpu_transcoder;
347		ppdata->ls_clock = ls_clock;
348		ppdata->dp_output = dp_output;
349
350		/* Unmute the amp for both DP and HDMI */
351		intel_de_write(display, VLV_AUD_PORT_EN_DBG(port),
352			       audio_enable & ~VLV_AMP_MUTE);
353	} else {
354		memset(ppdata->eld, 0, HDMI_MAX_ELD_BYTES);
355		ppdata->pipe = -1;
356		ppdata->ls_clock = 0;
357		ppdata->dp_output = false;
358
359		/* Mute the amp for both DP and HDMI */
360		intel_de_write(display, VLV_AUD_PORT_EN_DBG(port),
361			       audio_enable | VLV_AMP_MUTE);
362	}
363
364	if (pdata->notify_audio_lpe)
365		pdata->notify_audio_lpe(display->audio.lpe.platdev, port - PORT_B);
366
367	spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
368}