path: root/drivers/gpu/drm/msm/dp/dp_link.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
 */

#define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__

#include <drm/drm_print.h>

#include "dp_reg.h"
#include "dp_link.h"
#include "dp_panel.h"

#define DP_TEST_REQUEST_MASK		0x7F

enum audio_sample_rate {
	AUDIO_SAMPLE_RATE_32_KHZ	= 0x00,
	AUDIO_SAMPLE_RATE_44_1_KHZ	= 0x01,
	AUDIO_SAMPLE_RATE_48_KHZ	= 0x02,
	AUDIO_SAMPLE_RATE_88_2_KHZ	= 0x03,
	AUDIO_SAMPLE_RATE_96_KHZ	= 0x04,
	AUDIO_SAMPLE_RATE_176_4_KHZ	= 0x05,
	AUDIO_SAMPLE_RATE_192_KHZ	= 0x06,
};

enum audio_pattern_type {
	AUDIO_TEST_PATTERN_OPERATOR_DEFINED	= 0x00,
	AUDIO_TEST_PATTERN_SAWTOOTH		= 0x01,
};

struct dp_link_request {
	u32 test_requested;
	u32 test_link_rate;
	u32 test_lane_count;
};

struct dp_link_private {
	u32 prev_sink_count;
	struct drm_device *drm_dev;
	struct drm_dp_aux *aux;
	struct dp_link dp_link;

	struct dp_link_request request;
	struct mutex psm_mutex;
	u8 link_status[DP_LINK_STATUS_SIZE];
};

static int dp_aux_link_power_up(struct drm_dp_aux *aux,
					struct dp_link_info *link)
{
	u8 value;
	ssize_t len;
	int i;

	if (link->revision < 0x11)
		return 0;

	len = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
	if (len < 0)
		return len;

	value &= ~DP_SET_POWER_MASK;
	value |= DP_SET_POWER_D0;

	/* retry for 1ms to give the sink time to wake up */
	for (i = 0; i < 3; i++) {
		len = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
		usleep_range(1000, 2000);
		if (len == 1)
			break;
	}

	return 0;
}

static int dp_aux_link_power_down(struct drm_dp_aux *aux,
					struct dp_link_info *link)
{
	u8 value;
	int err;

	if (link->revision < 0x11)
		return 0;

	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
	if (err < 0)
		return err;

	value &= ~DP_SET_POWER_MASK;
	value |= DP_SET_POWER_D3;

	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
	if (err < 0)
		return err;

	return 0;
}

static int dp_link_get_period(struct dp_link_private *link, int const addr)
{
	int ret = 0;
	u8 data;
	u32 const max_audio_period = 0xA;

	/* TEST_AUDIO_PERIOD_CH_XX */
	if (drm_dp_dpcd_readb(link->aux, addr, &data) < 0) {
		DRM_ERROR("failed to read test_audio_period (0x%x)\n", addr);
		ret = -EINVAL;
		goto exit;
	}

	/* Period - Bits 3:0 */
	data = data & 0xF;
	if ((int)data > max_audio_period) {
		DRM_ERROR("invalid test_audio_period_ch_1 = 0x%x\n", data);
		ret = -EINVAL;
		goto exit;
	}

	ret = data;
exit:
	return ret;
}

static int dp_link_parse_audio_channel_period(struct dp_link_private *link)
{
	int ret = 0;
	struct dp_link_test_audio *req = &link->dp_link.test_audio;

	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH1);
	if (ret == -EINVAL)
		goto exit;

	req->test_audio_period_ch_1 = ret;
	drm_dbg_dp(link->drm_dev, "test_audio_period_ch_1 = 0x%x\n", ret);

	ret = dp_link_get_period(link, DP_TEST_AUDIO_PERIOD_CH2);
	if (ret == -EINVAL)
		goto exit;

	req->test_audio_period_ch_2 = ret;
	drm_dbg_dp(link<