drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Copyright (c) 2024 Hisilicon Limited. */

#ifndef DP_COMM_H
#define DP_COMM_H

#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/kernel.h>
#include <linux/bitfield.h>
#include <linux/io.h>
#include <drm/display/drm_dp_helper.h>

#define HIBMC_DP_LANE_NUM_MAX 2

struct hibmc_link_status {
	bool clock_recovered;
	bool channel_equalized;
};

struct hibmc_link_cap {
	u8 link_rate;
	u8 lanes;
};

struct hibmc_dp_link {
	struct hibmc_link_status status;
	u8 train_set[HIBMC_DP_LANE_NUM_MAX];
	struct hibmc_link_cap cap;
};

struct hibmc_dp_dev {
	struct drm_dp_aux aux;
	struct drm_device *dev;
	void __iomem *base;
	struct mutex lock; /* protects concurrent RW in hibmc_dp_reg_write_field() */
	struct hibmc_dp_link link;
	u8 dpcd[DP_RECEIVER_CAP_SIZE];
};

#define dp_field_modify(reg_value, mask, val)				\
	do {								\
		(reg_value) &= ~(mask);					\
		(reg_value) |= FIELD_PREP(mask, val);			\
	} while (0)							\

#define hibmc_dp_reg_write_field(dp, offset, mask, val)			\
	do {								\
		typeof(dp) _dp = dp;					\
		typeof(_dp->base) addr = (_dp->base + (offset));	\
		mutex_lock(&_dp->lock);					\
		u32 reg_value = readl(addr);				\
		dp_field_modify(reg_value, mask, val);			\
		writel(reg_value, addr);				\
		mutex_unlock(&_dp->lock);				\
	} while (0)

void hibmc_dp_aux_init(struct hibmc_dp_dev *dp);
int hibmc_dp_link_training(struct hibmc_dp_dev *dp);

#endif