drivers/gpu/drm/msm/hdmi/hdmi_hpd.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
Extension
.c
Size
5498 bytes
Lines
216
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) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/pinctrl/consumer.h>

#include "msm_kms.h"
#include "hdmi.h"

static void msm_hdmi_phy_reset(struct hdmi *hdmi)
{
	unsigned int val;

	val = hdmi_read(hdmi, REG_HDMI_PHY_CTRL);

	if (val & HDMI_PHY_CTRL_SW_RESET_LOW) {
		/* pull low */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val & ~HDMI_PHY_CTRL_SW_RESET);
	} else {
		/* pull high */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val | HDMI_PHY_CTRL_SW_RESET);
	}

	if (val & HDMI_PHY_CTRL_SW_RESET_PLL_LOW) {
		/* pull low */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val & ~HDMI_PHY_CTRL_SW_RESET_PLL);
	} else {
		/* pull high */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val | HDMI_PHY_CTRL_SW_RESET_PLL);
	}

	msleep(100);

	if (val & HDMI_PHY_CTRL_SW_RESET_LOW) {
		/* pull high */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val | HDMI_PHY_CTRL_SW_RESET);
	} else {
		/* pull low */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val & ~HDMI_PHY_CTRL_SW_RESET);
	}

	if (val & HDMI_PHY_CTRL_SW_RESET_PLL_LOW) {
		/* pull high */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val | HDMI_PHY_CTRL_SW_RESET_PLL);
	} else {
		/* pull low */
		hdmi_write(hdmi, REG_HDMI_PHY_CTRL,
				val & ~HDMI_PHY_CTRL_SW_RESET_PLL);
	}
}

void msm_hdmi_hpd_enable(struct drm_bridge *bridge)
{
	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
	struct hdmi *hdmi = hdmi_bridge->hdmi;
	struct device *dev = &hdmi->pdev->dev;
	u32 hpd_ctrl;
	int ret;
	unsigned long flags;

	if (hdmi->hpd_gpiod)
		gpiod_set_value_cansleep(hdmi->hpd_gpiod, 1);

	ret = pm_runtime_resume_and_get(dev);
	if (WARN_ON(ret))
		return;

	mutex_lock(&hdmi->state_mutex);
	msm_hdmi_set_mode(hdmi, false);
	msm_hdmi_phy_reset(hdmi);
	msm_hdmi_set_mode(hdmi, true);

	hdmi->hpd_enabled = true;
	mutex_unlock(&hdmi->state_mutex);

	hdmi_write(hdmi, REG_HDMI_USEC_REFTIMER, 0x0001001b);

	/* enable HPD events: */
	hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL,

Annotation

Implementation Notes