linux/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) …

#include <drm/drm_print.h>

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

#define DP_TEST_REQUEST_MASK …

enum audio_sample_rate { … };

enum audio_pattern_type { … };

struct dp_link_request { … };

struct dp_link_private { … };

static int dp_aux_link_power_up(struct drm_dp_aux *aux,
					struct dp_link_info *link)
{ … }

static int dp_aux_link_power_down(struct drm_dp_aux *aux,
					struct dp_link_info *link)
{ … }

static int dp_link_get_period(struct dp_link_private *link, int const addr)
{ … }

static int dp_link_parse_audio_channel_period(struct dp_link_private *link)
{ … }

static int dp_link_parse_audio_pattern_type(struct dp_link_private *link)
{ … }

static int dp_link_parse_audio_mode(struct dp_link_private *link)
{ … }

static int dp_link_parse_audio_pattern_params(struct dp_link_private *link)
{ … }

static bool dp_link_is_video_pattern_valid(u32 pattern)
{ … }

/**
 * dp_link_is_bit_depth_valid() - validates the bit depth requested
 * @tbd: bit depth requested by the sink
 *
 * Returns true if the requested bit depth is supported.
 */
static bool dp_link_is_bit_depth_valid(u32 tbd)
{ … }

static int dp_link_parse_timing_params1(struct dp_link_private *link,
					int addr, int len, u32 *val)
{ … }

static int dp_link_parse_timing_params2(struct dp_link_private *link,
					int addr, int len,
					u32 *val1, u32 *val2)
{ … }

static int dp_link_parse_timing_params3(struct dp_link_private *link,
					int addr, u32 *val)
{ … }

/**
 * dp_link_parse_video_pattern_params() - parses video pattern parameters from DPCD
 * @link: Display Port Driver data
 *
 * Returns 0 if it successfully parses the video link pattern and the link
 * bit depth requested by the sink and, and if the values parsed are valid.
 */
static int dp_link_parse_video_pattern_params(struct dp_link_private *link)
{ … }

/**
 * dp_link_parse_link_training_params() - parses link training parameters from
 * DPCD
 * @link: Display Port Driver data
 *
 * Returns 0 if it successfully parses the link rate (Byte 0x219) and lane
 * count (Byte 0x220), and if these values parse are valid.
 */
static int dp_link_parse_link_training_params(struct dp_link_private *link)
{ … }

/**
 * dp_link_parse_phy_test_params() - parses the phy link parameters
 * @link: Display Port Driver data
 *
 * Parses the DPCD (Byte 0x248) for the DP PHY link pattern that is being
 * requested.
 */
static int dp_link_parse_phy_test_params(struct dp_link_private *link)
{ … }

/**
 * dp_link_is_video_audio_test_requested() - checks for audio/video link request
 * @link: link requested by the sink
 *
 * Returns true if the requested link is a permitted audio/video link.
 */
static bool dp_link_is_video_audio_test_requested(u32 link)
{ … }

/**
 * dp_link_parse_request() - parses link request parameters from sink
 * @link: Display Port Driver data
 *
 * Parses the DPCD to check if an automated link is requested (Byte 0x201),
 * and what type of link automation is being requested (Byte 0x218).
 */
static int dp_link_parse_request(struct dp_link_private *link)
{ … }

static int dp_link_parse_sink_status_field(struct dp_link_private *link)
{ … }

/**
 * dp_link_process_link_training_request() - processes new training requests
 * @link: Display Port link data
 *
 * This function will handle new link training requests that are initiated by
 * the sink. In particular, it will update the requested lane count and link
 * rate, and then trigger the link retraining procedure.
 *
 * The function will return 0 if a link training request has been processed,
 * otherwise it will return -EINVAL.
 */
static int dp_link_process_link_training_request(struct dp_link_private *link)
{ … }

bool dp_link_send_test_response(struct dp_link *dp_link)
{ … }

int dp_link_psm_config(struct dp_link *dp_link,
			      struct dp_link_info *link_info, bool enable)
{ … }

bool dp_link_send_edid_checksum(struct dp_link *dp_link, u8 checksum)
{ … }

static void dp_link_parse_vx_px(struct dp_link_private *link)
{ … }

/**
 * dp_link_process_phy_test_pattern_request() - process new phy link requests
 * @link: Display Port Driver data
 *
 * This function will handle new phy link pattern requests that are initiated
 * by the sink. The function will return 0 if a phy link pattern has been
 * processed, otherwise it will return -EINVAL.
 */
static int dp_link_process_phy_test_pattern_request(
		struct dp_link_private *link)
{ … }

static bool dp_link_read_psr_error_status(struct dp_link_private *link)
{ … }

static bool dp_link_psr_capability_changed(struct dp_link_private *link)
{ … }

static u8 get_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
{ … }

/**
 * dp_link_process_link_status_update() - processes link status updates
 * @link: Display Port link module data
 *
 * This function will check for changes in the link status, e.g. clock
 * recovery done on all lanes, and trigger link training if there is a
 * failure/error on the link.
 *
 * The function will return 0 if the a link status update has been processed,
 * otherwise it will return -EINVAL.
 */
static int dp_link_process_link_status_update(struct dp_link_private *link)
{ … }

/**
 * dp_link_process_ds_port_status_change() - process port status changes
 * @link: Display Port Driver data
 *
 * This function will handle downstream port updates that are initiated by
 * the sink. If the downstream port status has changed, the EDID is read via
 * AUX.
 *
 * The function will return 0 if a downstream port update has been
 * processed, otherwise it will return -EINVAL.
 */
static int dp_link_process_ds_port_status_change(struct dp_link_private *link)
{ … }

static bool dp_link_is_video_pattern_requested(struct dp_link_private *link)
{ … }

static bool dp_link_is_audio_pattern_requested(struct dp_link_private *link)
{ … }

static void dp_link_reset_data(struct dp_link_private *link)
{ … }

/**
 * dp_link_process_request() - handle HPD IRQ transition to HIGH
 * @dp_link: pointer to link module data
 *
 * This function will handle the HPD IRQ state transitions from LOW to HIGH
 * (including cases when there are back to back HPD IRQ HIGH) indicating
 * the start of a new link training request or sink status update.
 */
int dp_link_process_request(struct dp_link *dp_link)
{ … }

int dp_link_get_colorimetry_config(struct dp_link *dp_link)
{ … }

int dp_link_adjust_levels(struct dp_link *dp_link, u8 *link_status)
{ … }

void dp_link_reset_phy_params_vx_px(struct dp_link *dp_link)
{ … }

u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp)
{ … }

struct dp_link *dp_link_get(struct device *dev, struct drm_dp_aux *aux)
{ … }