linux_dsm_epyc7002/drivers/gpu/drm/tegra/dp.h
Thierry Reding 078c445733 drm/tegra: dp: Add DisplayPort link training helper
Add a helper that will perform link training as described in the
DisplayPort specification.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-10-28 11:18:53 +01:00

178 lines
4.3 KiB
C

/* SPDX-License-Identifier: MIT */
/*
* Copyright (C) 2013-2019 NVIDIA Corporation.
* Copyright (C) 2015 Rob Clark
*/
#ifndef DRM_TEGRA_DP_H
#define DRM_TEGRA_DP_H 1
#include <linux/types.h>
struct drm_display_info;
struct drm_display_mode;
struct drm_dp_aux;
struct drm_dp_link;
/**
* struct drm_dp_link_caps - DP link capabilities
*/
struct drm_dp_link_caps {
/**
* @enhanced_framing:
*
* enhanced framing capability (mandatory as of DP 1.2)
*/
bool enhanced_framing;
/**
* tps3_supported:
*
* training pattern sequence 3 supported for equalization
*/
bool tps3_supported;
/**
* @fast_training:
*
* AUX CH handshake not required for link training
*/
bool fast_training;
/**
* @channel_coding:
*
* ANSI 8B/10B channel coding capability
*/
bool channel_coding;
/**
* @alternate_scrambler_reset:
*
* eDP alternate scrambler reset capability
*/
bool alternate_scrambler_reset;
};
void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
const struct drm_dp_link_caps *src);
/**
* struct drm_dp_link_ops - DP link operations
*/
struct drm_dp_link_ops {
/**
* @apply_training:
*/
int (*apply_training)(struct drm_dp_link *link);
/**
* @configure:
*/
int (*configure)(struct drm_dp_link *link);
};
#define DP_TRAIN_VOLTAGE_SWING_LEVEL(x) ((x) << 0)
#define DP_TRAIN_PRE_EMPHASIS_LEVEL(x) ((x) << 3)
#define DP_LANE_POST_CURSOR(i, x) (((x) & 0x3) << (((i) & 1) << 2))
/**
* struct drm_dp_link_train_set - link training settings
* @voltage_swing: per-lane voltage swing
* @pre_emphasis: per-lane pre-emphasis
* @post_cursor: per-lane post-cursor
*/
struct drm_dp_link_train_set {
unsigned int voltage_swing[4];
unsigned int pre_emphasis[4];
unsigned int post_cursor[4];
};
/**
* struct drm_dp_link_train - link training state information
* @request: currently requested settings
* @adjust: adjustments requested by sink
* @pattern: currently requested training pattern
* @clock_recovered: flag to track if clock recovery has completed
* @channel_equalized: flag to track if channel equalization has completed
*/
struct drm_dp_link_train {
struct drm_dp_link_train_set request;
struct drm_dp_link_train_set adjust;
unsigned int pattern;
bool clock_recovered;
bool channel_equalized;
};
/**
* struct drm_dp_link - DP link capabilities and configuration
* @revision: DP specification revision supported on the link
* @max_rate: maximum clock rate supported on the link
* @max_lanes: maximum number of lanes supported on the link
* @caps: capabilities supported on the link (see &drm_dp_link_caps)
* @aux_rd_interval: AUX read interval to use for training (in microseconds)
* @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)
* @rate: currently configured link rate
* @lanes: currently configured number of lanes
* @rates: additional supported link rates in kHz (eDP 1.4)
* @num_rates: number of additional supported link rates (eDP 1.4)
*/
struct drm_dp_link {
unsigned char revision;
unsigned int max_rate;
unsigned int max_lanes;
struct drm_dp_link_caps caps;
/**
* @cr: clock recovery read interval
* @ce: channel equalization read interval
*/
struct {
unsigned int cr;
unsigned int ce;
} aux_rd_interval;
unsigned char edp;
unsigned int rate;
unsigned int lanes;
unsigned long rates[DP_MAX_SUPPORTED_RATES];
unsigned int num_rates;
/**
* @ops: DP link operations
*/
const struct drm_dp_link_ops *ops;
/**
* @aux: DP AUX channel
*/
struct drm_dp_aux *aux;
/**
* @train: DP link training state
*/
struct drm_dp_link_train train;
};
int drm_dp_link_add_rate(struct drm_dp_link *link, unsigned long rate);
int drm_dp_link_remove_rate(struct drm_dp_link *link, unsigned long rate);
void drm_dp_link_update_rates(struct drm_dp_link *link);
int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_choose(struct drm_dp_link *link,
const struct drm_display_mode *mode,
const struct drm_display_info *info);
void drm_dp_link_train_init(struct drm_dp_link_train *train);
int drm_dp_link_train(struct drm_dp_link *link);
#endif