cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

pmc.c (2098B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* pmc - Driver implementation for power management functions
      3 * of Power Management Controller (PMC) on SPARCstation-Voyager.
      4 *
      5 * Copyright (c) 2002 Eric Brower (ebrower@usa.net)
      6 */
      7
      8#include <linux/kernel.h>
      9#include <linux/fs.h>
     10#include <linux/errno.h>
     11#include <linux/init.h>
     12#include <linux/pm.h>
     13#include <linux/of.h>
     14#include <linux/of_device.h>
     15#include <linux/module.h>
     16
     17#include <asm/io.h>
     18#include <asm/oplib.h>
     19#include <linux/uaccess.h>
     20#include <asm/auxio.h>
     21#include <asm/processor.h>
     22
     23/* Debug
     24 *
     25 * #define PMC_DEBUG_LED
     26 * #define PMC_NO_IDLE
     27 */
     28
     29#define PMC_OBPNAME	"SUNW,pmc"
     30#define PMC_DEVNAME	"pmc"
     31
     32#define PMC_IDLE_REG	0x00
     33#define PMC_IDLE_ON	0x01
     34
     35static u8 __iomem *regs;
     36
     37#define pmc_readb(offs)		(sbus_readb(regs+offs))
     38#define pmc_writeb(val, offs)	(sbus_writeb(val, regs+offs))
     39
     40/*
     41 * CPU idle callback function
     42 * See .../arch/sparc/kernel/process.c
     43 */
     44static void pmc_swift_idle(void)
     45{
     46#ifdef PMC_DEBUG_LED
     47	set_auxio(0x00, AUXIO_LED);
     48#endif
     49
     50	pmc_writeb(pmc_readb(PMC_IDLE_REG) | PMC_IDLE_ON, PMC_IDLE_REG);
     51
     52#ifdef PMC_DEBUG_LED
     53	set_auxio(AUXIO_LED, 0x00);
     54#endif
     55}
     56
     57static int pmc_probe(struct platform_device *op)
     58{
     59	regs = of_ioremap(&op->resource[0], 0,
     60			  resource_size(&op->resource[0]), PMC_OBPNAME);
     61	if (!regs) {
     62		printk(KERN_ERR "%s: unable to map registers\n", PMC_DEVNAME);
     63		return -ENODEV;
     64	}
     65
     66#ifndef PMC_NO_IDLE
     67	/* Assign power management IDLE handler */
     68	sparc_idle = pmc_swift_idle;
     69#endif
     70
     71	printk(KERN_INFO "%s: power management initialized\n", PMC_DEVNAME);
     72	return 0;
     73}
     74
     75static const struct of_device_id pmc_match[] = {
     76	{
     77		.name = PMC_OBPNAME,
     78	},
     79	{},
     80};
     81MODULE_DEVICE_TABLE(of, pmc_match);
     82
     83static struct platform_driver pmc_driver = {
     84	.driver = {
     85		.name = "pmc",
     86		.of_match_table = pmc_match,
     87	},
     88	.probe		= pmc_probe,
     89};
     90
     91static int __init pmc_init(void)
     92{
     93	return platform_driver_register(&pmc_driver);
     94}
     95
     96/* This driver is not critical to the boot process
     97 * and is easiest to ioremap when SBus is already
     98 * initialized, so we install ourselves thusly:
     99 */
    100__initcall(pmc_init);