arch/arm/mach-omap2/omap_phy_internal.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-omap2/omap_phy_internal.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-omap2/omap_phy_internal.c
Extension
.c
Size
1267 bytes
Lines
54
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * This file configures the internal USB PHY in OMAP4430. Used
 * with TWL6030 transceiver and MUSB on OMAP4430.
 *
 * Copyright (C) 2010 Texas Instruments Incorporated - https://www.ti.com
 * Author: Hema HK <hemahk@ti.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/usb.h>
#include <linux/usb/musb.h>

#include "soc.h"
#include "control.h"

#define CONTROL_DEV_CONF		0x300
#define PHY_PD				0x1

/**
 * omap4430_phy_power_down: disable MUSB PHY during early init
 *
 * OMAP4 MUSB PHY module is enabled by default on reset, but this will
 * prevent core retention if not disabled by SW. USB driver will
 * later on enable this, once and if the driver needs it.
 */
static int __init omap4430_phy_power_down(void)
{
	void __iomem *ctrl_base;

	if (!cpu_is_omap44xx())
		return 0;

	ctrl_base = ioremap(OMAP443X_SCM_BASE, SZ_1K);
	if (!ctrl_base) {
		pr_err("control module ioremap failed\n");
		return -ENOMEM;
	}

	/* Power down the phy */
	writel_relaxed(PHY_PD, ctrl_base + CONTROL_DEV_CONF);

	iounmap(ctrl_base);

	return 0;
}
omap_early_initcall(omap4430_phy_power_down);

Annotation

Implementation Notes