arch/arm/mach-omap2/prm2xxx_3xxx.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-omap2/prm2xxx_3xxx.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-omap2/prm2xxx_3xxx.c
Extension
.c
Size
6919 bytes
Lines
238
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-only
/*
 * OMAP2/3 PRM module functions
 *
 * Copyright (C) 2010-2011 Texas Instruments, Inc.
 * Copyright (C) 2010 Nokia Corporation
 * Benoît Cousson
 * Paul Walmsley
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>

#include "powerdomain.h"
#include "prm2xxx_3xxx.h"
#include "prm-regbits-24xx.h"
#include "clockdomain.h"

/**
 * omap2_prm_is_hardreset_asserted - read the HW reset line state of
 * submodules contained in the hwmod module
 * @shift: register bit shift corresponding to the reset line to check
 * @part: PRM partition, ignored for OMAP2
 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
 * @offset: register offset, ignored for OMAP2
 *
 * Returns 1 if the (sub)module hardreset line is currently asserted,
 * 0 if the (sub)module hardreset line is not currently asserted, or
 * -EINVAL if called while running on a non-OMAP2/3 chip.
 */
int omap2_prm_is_hardreset_asserted(u8 shift, u8 part, s16 prm_mod, u16 offset)
{
	return omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
				       (1 << shift));
}

/**
 * omap2_prm_assert_hardreset - assert the HW reset line of a submodule
 * @shift: register bit shift corresponding to the reset line to assert
 * @part: PRM partition, ignored for OMAP2
 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
 * @offset: register offset, ignored for OMAP2
 *
 * Some IPs like dsp or iva contain processors that require an HW
 * reset line to be asserted / deasserted in order to fully enable the
 * IP.  These modules may have multiple hard-reset lines that reset
 * different 'submodules' inside the IP block.  This function will
 * place the submodule into reset.  Returns 0 upon success or -EINVAL
 * upon an argument error.
 */
int omap2_prm_assert_hardreset(u8 shift, u8 part, s16 prm_mod, u16 offset)
{
	u32 mask;

	mask = 1 << shift;
	omap2_prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);

	return 0;
}

/**
 * omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
 * @rst_shift: register bit shift corresponding to the reset line to deassert
 * @st_shift: register bit shift for the status of the deasserted submodule
 * @part: PRM partition, not used for OMAP2
 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
 * @rst_offset: reset register offset, not used for OMAP2
 * @st_offset: reset status register offset, not used for OMAP2
 *
 * Some IPs like dsp or iva contain processors that require an HW
 * reset line to be asserted / deasserted in order to fully enable the
 * IP.  These modules may have multiple hard-reset lines that reset
 * different 'submodules' inside the IP block.  This function will
 * take the submodule out of reset and wait until the PRCM indicates
 * that the reset has completed before returning.  Returns 0 upon success or
 * -EINVAL upon an argument error, -EEXIST if the submodule was already out
 * of reset, or -EBUSY if the submodule did not exit reset promptly.
 */
int omap2_prm_deassert_hardreset(u8 rst_shift, u8 st_shift, u8 part,
				 s16 prm_mod, u16 rst_offset, u16 st_offset)
{
	u32 rst, st;
	int c;

	rst = 1 << rst_shift;
	st = 1 << st_shift;

Annotation

Implementation Notes