1/*
  2 *  hdac_i915.c - routines for sync between HD-A core and i915 display driver
  3 *
  4 *  This program is free software; you can redistribute it and/or modify it
  5 *  under the terms of the GNU General Public License as published by the Free
  6 *  Software Foundation; either version 2 of the License, or (at your option)
  7 *  any later version.
  8 *
  9 *  This program is distributed in the hope that it will be useful, but
 10 *  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 11 *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12 *  for more details.
 13 */
 14
 15#include <linux/init.h>
 16#include <linux/module.h>
 17#include <linux/pci.h>
 18#include <linux/component.h>
 19#include <drm/i915_component.h>
 20#include <sound/core.h>
 21#include <sound/hdaudio.h>
 22#include <sound/hda_i915.h>
 23#include <sound/hda_register.h>
 24
 25static struct i915_audio_component *hdac_acomp;
 26
 27/**
 28 * snd_hdac_set_codec_wakeup - Enable / disable HDMI/DP codec wakeup
 29 * @bus: HDA core bus
 30 * @enable: enable or disable the wakeup
 31 *
 32 * This function is supposed to be used only by a HD-audio controller
 33 * driver that needs the interaction with i915 graphics.
 34 *
 35 * This function should be called during the chip reset, also called at
 36 * resume for updating STATESTS register read.
 37 *
 38 * Returns zero for success or a negative error code.
 39 */
 40int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
 41{
 42	struct i915_audio_component *acomp = bus->audio_component;
 43
 44	if (!acomp || !acomp->ops)
 45		return -ENODEV;
 46
 47	if (!acomp->ops->codec_wake_override) {
 48		dev_warn(bus->dev,
 49			"Invalid codec wake callback\n");
 50		return 0;
 51	}
 52
 53	dev_dbg(bus->dev, "%s codec wakeup\n",
 54		enable ? "enable" : "disable");
 55
 56	acomp->ops->codec_wake_override(acomp->dev, enable);
 57
 58	return 0;
 59}
 60EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);
 61
 62/**
 63 * snd_hdac_display_power - Power up / down the power refcount
 64 * @bus: HDA core bus
 65 * @enable: power up or down
 66 *
 67 * This function is supposed to be used only by a HD-audio controller
 68 * driver that needs the interaction with i915 graphics.
 69 *
 70 * This function manages a refcount and calls the i915 get_power() and
 71 * put_power() ops accordingly, toggling the codec wakeup, too.
 72 *
 73 * Returns zero for success or a negative error code.
 74 */
 75int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
 76{
 77	struct i915_audio_component *acomp = bus->audio_component;
 78
 79	if (!acomp || !acomp->ops)
 80		return -ENODEV;
 81
 82	dev_dbg(bus->dev, "display power %s\n",
 83		enable ? "enable" : "disable");
 84
 85	if (enable) {
 86		if (!bus->i915_power_refcount++) {
 87			acomp->ops->get_power(acomp->dev);
 88			snd_hdac_set_codec_wakeup(bus, true);
 89			snd_hdac_set_codec_wakeup(bus, false);
 90		}
 91	} else {
 92		WARN_ON(!bus->i915_power_refcount);
 93		if (!--bus->i915_power_refcount)
 94			acomp->ops->put_power(acomp->dev);
 95	}
 96
 97	return 0;
 98}
 99EXPORT_SYMBOL_GPL(snd_hdac_display_power);
100
101#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
102				((pci)->device == 0x0c0c) || \
103				((pci)->device == 0x0d0c) || \
104				((pci)->device == 0x160c))
105
106/**
107 * snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW
108 * @bus: HDA core bus
109 *
110 * Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
111 * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)
112 * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:
113 * BCLK = CDCLK * M / N
114 * The values will be lost when the display power well is disabled and need to
115 * be restored to avoid abnormal playback speed.
116 *
117 * Call this function at initializing and changing power well, as well as
118 * at ELD notifier for the hotplug.
119 */
120void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
121{
122	struct i915_audio_component *acomp = bus->audio_component;
123	struct pci_dev *pci = to_pci_dev(bus->dev);
124	int cdclk_freq;
125	unsigned int bclk_m, bclk_n;
126
127	if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq)
128		return; /* only for i915 binding */
129	if (!CONTROLLER_IN_GPU(pci))
130		return; /* only HSW/BDW */
131
132	cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev);
133	switch (cdclk_freq) {
134	case 337500:
135		bclk_m = 16;
136		bclk_n = 225;
137		break;
138
139	case 450000:
140	default: /* default CDCLK 450MHz */
141		bclk_m = 4;
142		bclk_n = 75;
143		break;
144
145	case 540000:
146		bclk_m = 4;
147		bclk_n = 90;
148		break;
149
150	case 675000:
151		bclk_m = 8;
152		bclk_n = 225;
153		break;
154	}
155
156	snd_hdac_chip_writew(bus, HSW_EM4, bclk_m);
157	snd_hdac_chip_writew(bus, HSW_EM5, bclk_n);
158}
159EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);
160
161/* There is a fixed mapping between audio pin node and display port.
162 * on SNB, IVY, HSW, BSW, SKL, BXT, KBL:
163 * Pin Widget 5 - PORT B (port = 1 in i915 driver)
164 * Pin Widget 6 - PORT C (port = 2 in i915 driver)
165 * Pin Widget 7 - PORT D (port = 3 in i915 driver)
166 *
167 * on VLV, ILK:
168 * Pin Widget 4 - PORT B (port = 1 in i915 driver)
169 * Pin Widget 5 - PORT C (port = 2 in i915 driver)
170 * Pin Widget 6 - PORT D (port = 3 in i915 driver)
171 */
172static int pin2port(struct hdac_device *codec, hda_nid_t pin_nid)
173{
174	int base_nid;
175
176	switch (codec->vendor_id) {
177	case 0x80860054: /* ILK */
178	case 0x80862804: /* ILK */
179	case 0x80862882: /* VLV */
180		base_nid = 3;
181		break;
182	default:
183		base_nid = 4;
184		break;
185	}
186
187	if (WARN_ON(pin_nid <= base_nid || pin_nid > base_nid + 3))
188		return -1;
189	return pin_nid - base_nid;
190}
191
192/**
193 * snd_hdac_sync_audio_rate - Set N/CTS based on the sample rate
194 * @codec: HDA codec
195 * @nid: the pin widget NID
196 * @dev_id: device identifier
197 * @rate: the sample rate to set
198 *
199 * This function is supposed to be used only by a HD-audio controller
200 * driver that needs the interaction with i915 graphics.
201 *
202 * This function sets N/CTS value based on the given sample rate.
203 * Returns zero for success, or a negative error code.
204 */
205int snd_hdac_sync_audio_rate(struct hdac_device *codec, hda_nid_t nid,
206			     int dev_id, int rate)
207{
208	struct hdac_bus *bus = codec->bus;
209	struct i915_audio_component *acomp = bus->audio_component;
210	int port, pipe;
211
212	if (!acomp || !acomp->ops || !acomp->ops->sync_audio_rate)
213		return -ENODEV;
214	port = pin2port(codec, nid);
215	if (port < 0)
216		return -EINVAL;
217	pipe = dev_id;
218	return acomp->ops->sync_audio_rate(acomp->dev, port, pipe, rate);
219}
220EXPORT_SYMBOL_GPL(snd_hdac_sync_audio_rate);
221
222/**
223 * snd_hdac_acomp_get_eld - Get the audio state and ELD via component
224 * @codec: HDA codec
225 * @nid: the pin widget NID
226 * @dev_id: device identifier
227 * @audio_enabled: the pointer to store the current audio state
228 * @buffer: the buffer pointer to store ELD bytes
229 * @max_bytes: the max bytes to be stored on @buffer
230 *
231 * This function is supposed to be used only by a HD-audio controller
232 * driver that needs the interaction with i915 graphics.
233 *
234 * This function queries the current state of the audio on the given
235 * digital port and fetches the ELD bytes onto the given buffer.
236 * It returns the number of bytes for the total ELD data, zero for
237 * invalid ELD, or a negative error code.
238 *
239 * The return size is the total bytes required for the whole ELD bytes,
240 * thus it may be over @max_bytes.  If it's over @max_bytes, it implies
241 * that only a part of ELD bytes have been fetched.
242 */
243int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
244			   bool *audio_enabled, char *buffer, int max_bytes)
245{
246	struct hdac_bus *bus = codec->bus;
247	struct i915_audio_component *acomp = bus->audio_component;
248	int port, pipe;
249
250	if (!acomp || !acomp->ops || !acomp->ops->get_eld)
251		return -ENODEV;
252
253	port = pin2port(codec, nid);
254	if (port < 0)
255		return -EINVAL;
256
257	pipe = dev_id;
258	return acomp->ops->get_eld(acomp->dev, port, pipe, audio_enabled,
259				   buffer, max_bytes);
260}
261EXPORT_SYMBOL_GPL(snd_hdac_acomp_get_eld);
262
263static int hdac_component_master_bind(struct device *dev)
264{
265	struct i915_audio_component *acomp = hdac_acomp;
266	int ret;
267
268	ret = component_bind_all(dev, acomp);
269	if (ret < 0)
270		return ret;
271
272	if (WARN_ON(!(acomp->dev && acomp->ops && acomp->ops->get_power &&
273		      acomp->ops->put_power && acomp->ops->get_cdclk_freq))) {
274		ret = -EINVAL;
275		goto out_unbind;
276	}
277
278	/*
279	 * Atm, we don't support dynamic unbinding initiated by the child
280	 * component, so pin its containing module until we unbind.
281	 */
282	if (!try_module_get(acomp->ops->owner)) {
283		ret = -ENODEV;
284		goto out_unbind;
285	}
286
287	return 0;
288
289out_unbind:
290	component_unbind_all(dev, acomp);
291
292	return ret;
293}
294
295static void hdac_component_master_unbind(struct device *dev)
296{
297	struct i915_audio_component *acomp = hdac_acomp;
298
299	module_put(acomp->ops->owner);
300	component_unbind_all(dev, acomp);
301	WARN_ON(acomp->ops || acomp->dev);
302}
303
304static const struct component_master_ops hdac_component_master_ops = {
305	.bind = hdac_component_master_bind,
306	.unbind = hdac_component_master_unbind,
307};
308
309static int hdac_component_master_match(struct device *dev, void *data)
310{
311	/* i915 is the only supported component */
312	return !strcmp(dev->driver->name, "i915");
313}
314
315/**
316 * snd_hdac_i915_register_notifier - Register i915 audio component ops
317 * @aops: i915 audio component ops
318 *
319 * This function is supposed to be used only by a HD-audio controller
320 * driver that needs the interaction with i915 graphics.
321 *
322 * This function sets the given ops to be called by the i915 graphics driver.
323 *
324 * Returns zero for success or a negative error code.
325 */
326int snd_hdac_i915_register_notifier(const struct i915_audio_component_audio_ops *aops)
327{
328	if (!hdac_acomp)
329		return -ENODEV;
330
331	hdac_acomp->audio_ops = aops;
332	return 0;
333}
334EXPORT_SYMBOL_GPL(snd_hdac_i915_register_notifier);
335
336/* check whether intel graphics is present */
337static bool i915_gfx_present(void)
338{
339	static const struct pci_device_id ids[] = {
340		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_ANY_ID),
341		  .class = PCI_BASE_CLASS_DISPLAY << 16,
342		  .class_mask = 0xff << 16 },
343		{}
344	};
345	return pci_dev_present(ids);
346}
347
348/**
349 * snd_hdac_i915_init - Initialize i915 audio component
350 * @bus: HDA core bus
351 *
352 * This function is supposed to be used only by a HD-audio controller
353 * driver that needs the interaction with i915 graphics.
354 *
355 * This function initializes and sets up the audio component to communicate
356 * with i915 graphics driver.
357 *
358 * Returns zero for success or a negative error code.
359 */
360int snd_hdac_i915_init(struct hdac_bus *bus)
361{
362	struct component_match *match = NULL;
363	struct device *dev = bus->dev;
364	struct i915_audio_component *acomp;
365	int ret;
366
367	if (WARN_ON(hdac_acomp))
368		return -EBUSY;
369
370	if (!i915_gfx_present())
371		return -ENODEV;
372
373	acomp = kzalloc(sizeof(*acomp), GFP_KERNEL);
374	if (!acomp)
375		return -ENOMEM;
376	bus->audio_component = acomp;
377	hdac_acomp = acomp;
378
379	component_match_add(dev, &match, hdac_component_master_match, bus);
380	ret = component_master_add_with_match(dev, &hdac_component_master_ops,
381					      match);
382	if (ret < 0)
383		goto out_err;
384
385	/*
386	 * Atm, we don't support deferring the component binding, so make sure
387	 * i915 is loaded and that the binding successfully completes.
388	 */
389	request_module("i915");
390
391	if (!acomp->ops) {
392		ret = -ENODEV;
393		goto out_master_del;
394	}
395	dev_dbg(dev, "bound to i915 component master\n");
396
397	return 0;
398out_master_del:
399	component_master_del(dev, &hdac_component_master_ops);
400out_err:
401	kfree(acomp);
402	bus->audio_component = NULL;
403	hdac_acomp = NULL;
404	dev_info(dev, "failed to add i915 component master (%d)\n", ret);
405
406	return ret;
407}
408EXPORT_SYMBOL_GPL(snd_hdac_i915_init);
409
410/**
411 * snd_hdac_i915_exit - Finalize i915 audio component
412 * @bus: HDA core bus
413 *
414 * This function is supposed to be used only by a HD-audio controller
415 * driver that needs the interaction with i915 graphics.
416 *
417 * This function releases the i915 audio component that has been used.
418 *
419 * Returns zero for success or a negative error code.
420 */
421int snd_hdac_i915_exit(struct hdac_bus *bus)
422{
423	struct device *dev = bus->dev;
424	struct i915_audio_component *acomp = bus->audio_component;
425
426	if (!acomp)
427		return 0;
428
429	WARN_ON(bus->i915_power_refcount);
430	if (bus->i915_power_refcount > 0 && acomp->ops)
431		acomp->ops->put_power(acomp->dev);
432
433	component_master_del(dev, &hdac_component_master_ops);
434
435	kfree(acomp);
436	bus->audio_component = NULL;
437	hdac_acomp = NULL;
438
439	return 0;
440}
441EXPORT_SYMBOL_GPL(snd_hdac_i915_exit);