drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c
Extension
.c
Size
4860 bytes
Lines
162
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
 */

#include <drm/drm_crtc.h>
#include <drm/drm_probe_helper.h>

#include "mdp5_kms.h"

#ifdef CONFIG_DRM_MSM_DSI

static struct mdp5_kms *get_kms(struct drm_encoder *encoder)
{
	struct msm_drm_private *priv = encoder->dev->dev_private;
	return to_mdp5_kms(to_mdp_kms(priv->kms));
}

#define VSYNC_CLK_RATE 19200000
static int pingpong_tearcheck_setup(struct drm_encoder *encoder,
				    struct drm_display_mode *mode)
{
	struct mdp5_kms *mdp5_kms = get_kms(encoder);
	struct device *dev = encoder->dev->dev;
	u32 total_lines, vclks_line, cfg;
	long vsync_clk_speed;
	struct mdp5_hw_mixer *mixer = mdp5_crtc_get_mixer(encoder->crtc);
	int pp_id = mixer->pp;

	if (IS_ERR_OR_NULL(mdp5_kms->vsync_clk)) {
		DRM_DEV_ERROR(dev, "vsync_clk is not initialized\n");
		return -EINVAL;
	}

	total_lines = mode->vtotal * drm_mode_vrefresh(mode);
	if (!total_lines) {
		DRM_DEV_ERROR(dev, "%s: vtotal(%d) or vrefresh(%d) is 0\n",
			      __func__, mode->vtotal, drm_mode_vrefresh(mode));
		return -EINVAL;
	}

	vsync_clk_speed = clk_round_rate(mdp5_kms->vsync_clk, VSYNC_CLK_RATE);
	if (vsync_clk_speed <= 0) {
		DRM_DEV_ERROR(dev, "vsync_clk round rate failed %ld\n",
							vsync_clk_speed);
		return -EINVAL;
	}
	vclks_line = vsync_clk_speed / total_lines;

	cfg = MDP5_PP_SYNC_CONFIG_VSYNC_COUNTER_EN
		| MDP5_PP_SYNC_CONFIG_VSYNC_IN_EN;
	cfg |= MDP5_PP_SYNC_CONFIG_VSYNC_COUNT(vclks_line);

	/*
	 * Tearcheck emits a blanking signal every vclks_line * vtotal * 2 ticks on
	 * the vsync_clk equating to roughly half the desired panel refresh rate.
	 * This is only necessary as stability fallback if interrupts from the
	 * panel arrive too late or not at all, but is currently used by default
	 * because these panel interrupts are not wired up yet.
	 */
	mdp5_write(mdp5_kms, REG_MDP5_PP_SYNC_CONFIG_VSYNC(pp_id), cfg);
	mdp5_write(mdp5_kms,
		REG_MDP5_PP_SYNC_CONFIG_HEIGHT(pp_id), (2 * mode->vtotal));

	mdp5_write(mdp5_kms,
		REG_MDP5_PP_VSYNC_INIT_VAL(pp_id), mode->vdisplay);
	mdp5_write(mdp5_kms, REG_MDP5_PP_RD_PTR_IRQ(pp_id), mode->vdisplay + 1);
	mdp5_write(mdp5_kms, REG_MDP5_PP_START_POS(pp_id), mode->vdisplay);
	mdp5_write(mdp5_kms, REG_MDP5_PP_SYNC_THRESH(pp_id),
			MDP5_PP_SYNC_THRESH_START(4) |
			MDP5_PP_SYNC_THRESH_CONTINUE(4));
	mdp5_write(mdp5_kms, REG_MDP5_PP_AUTOREFRESH_CONFIG(pp_id), 0x0);

	return 0;
}

static int pingpong_tearcheck_enable(struct drm_encoder *encoder)
{
	struct mdp5_kms *mdp5_kms = get_kms(encoder);
	struct mdp5_hw_mixer *mixer = mdp5_crtc_get_mixer(encoder->crtc);
	int pp_id = mixer->pp;
	int ret;

	ret = clk_set_rate(mdp5_kms->vsync_clk,
		clk_round_rate(mdp5_kms->vsync_clk, VSYNC_CLK_RATE));
	if (ret) {
		DRM_DEV_ERROR(encoder->dev->dev,
			"vsync_clk clk_set_rate failed, %d\n", ret);
		return ret;
	}

Annotation

Implementation Notes