path: root/drivers/gpu/drm/i915/display/intel_audio.c

/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <linux/component.h>
#include <linux/kernel.h>

#include <drm/drm_edid.h>
#include <drm/i915_component.h>

#include "i915_drv.h"
#include "intel_atomic.h"
#include "intel_audio.h"
#include "intel_cdclk.h"
#include "intel_de.h"
#include "intel_display_types.h"
#include "intel_lpe_audio.h"

/**
 * DOC: High Definition Audio over HDMI and Display Port
 *
 * The graphics and audio drivers together support High Definition Audio over
 * HDMI and Display Port. The audio programming sequences are divided into audio
 * codec and controller enable and disable sequences. The graphics driver
 * handles the audio codec sequences, while the audio driver handles the audio
 * controller sequences.
 *
 * The disable sequences must be performed before disabling the transcoder or
 * port. The enable sequences may only be performed after enabling the
 * transcoder and port, and after completed link training. Therefore the audio
 * enable/disable sequences are part of the modeset sequence.
 *
 * The codec and controller sequences could be done either parallel or serial,
 * but generally the ELDV/PD change in the codec sequence indicates to the audio
 * driver that the controller sequence should start. Indeed, most of the
 * co-operation between the graphics and audio drivers is handled via audio
 * related registers. (The notable exception is the power management, not
 * covered here.)
 *
 * The struct &i915_audio_component is used to interact between the graphics
 * and audio drivers. The struct &i915_audio_component_ops @ops in it is
 * defined in graphics driver and called in audio driver. The
 * struct &i915_audio_component_audio_ops @audio_ops is called from i915 driver.
 */

/* DP N/M table */
#define LC_810M	810000
#define LC_540M	540000
#define LC_270M	270000
#define LC_162M	162000

struct dp_aud_n_m {
	int sample_rate;
	int clock;
	u16 m;
	u16 n;
};

struct hdmi_aud_ncts {
	int sample_rate;
	int clock;
	int n;
	int cts;
};

/* Values according to DP 1.4 Table 2-104 */
static const struct dp_aud_n_m dp_aud_n_m[] = {
	{ 32000, LC_162M, 1024, 10125 },
	{ 44100, LC_162M, 784, 5625 },
	{ 48000, LC_162M, 512, 3375 },
	{ 64000, LC_162M, 2048, 10125 },
	{ 88200, LC_162M, 1568, 5625 },
	{ 96000, LC_162M, 1024, 3375 },
	{ 128000, LC_162M, 4096, 10125 },
	{ 176400, LC_162M, 3136, 5625 },
	{ 192000, LC_162M, 2048, 3375 },
	{ 32000, LC_270M, 1024, 16875 },
	{ 441