cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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rtc-pl030.c (3569B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  linux/drivers/rtc/rtc-pl030.c
      4 *
      5 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
      6 */
      7#include <linux/module.h>
      8#include <linux/rtc.h>
      9#include <linux/init.h>
     10#include <linux/interrupt.h>
     11#include <linux/amba/bus.h>
     12#include <linux/io.h>
     13#include <linux/slab.h>
     14
     15#define RTC_DR		(0)
     16#define RTC_MR		(4)
     17#define RTC_STAT	(8)
     18#define RTC_EOI		(8)
     19#define RTC_LR		(12)
     20#define RTC_CR		(16)
     21#define RTC_CR_MIE	(1 << 0)
     22
     23struct pl030_rtc {
     24	struct rtc_device	*rtc;
     25	void __iomem		*base;
     26};
     27
     28static irqreturn_t pl030_interrupt(int irq, void *dev_id)
     29{
     30	struct pl030_rtc *rtc = dev_id;
     31	writel(0, rtc->base + RTC_EOI);
     32	return IRQ_HANDLED;
     33}
     34
     35static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
     36{
     37	struct pl030_rtc *rtc = dev_get_drvdata(dev);
     38
     39	rtc_time64_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
     40	return 0;
     41}
     42
     43static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
     44{
     45	struct pl030_rtc *rtc = dev_get_drvdata(dev);
     46
     47	writel(rtc_tm_to_time64(&alrm->time), rtc->base + RTC_MR);
     48
     49	return 0;
     50}
     51
     52static int pl030_read_time(struct device *dev, struct rtc_time *tm)
     53{
     54	struct pl030_rtc *rtc = dev_get_drvdata(dev);
     55
     56	rtc_time64_to_tm(readl(rtc->base + RTC_DR), tm);
     57
     58	return 0;
     59}
     60
     61/*
     62 * Set the RTC time.  Unfortunately, we can't accurately set
     63 * the point at which the counter updates.
     64 *
     65 * Also, since RTC_LR is transferred to RTC_CR on next rising
     66 * edge of the 1Hz clock, we must write the time one second
     67 * in advance.
     68 */
     69static int pl030_set_time(struct device *dev, struct rtc_time *tm)
     70{
     71	struct pl030_rtc *rtc = dev_get_drvdata(dev);
     72
     73	writel(rtc_tm_to_time64(tm) + 1, rtc->base + RTC_LR);
     74
     75	return 0;
     76}
     77
     78static const struct rtc_class_ops pl030_ops = {
     79	.read_time	= pl030_read_time,
     80	.set_time	= pl030_set_time,
     81	.read_alarm	= pl030_read_alarm,
     82	.set_alarm	= pl030_set_alarm,
     83};
     84
     85static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
     86{
     87	struct pl030_rtc *rtc;
     88	int ret;
     89
     90	ret = amba_request_regions(dev, NULL);
     91	if (ret)
     92		goto err_req;
     93
     94	rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
     95	if (!rtc) {
     96		ret = -ENOMEM;
     97		goto err_rtc;
     98	}
     99
    100	rtc->rtc = devm_rtc_allocate_device(&dev->dev);
    101	if (IS_ERR(rtc->rtc)) {
    102		ret = PTR_ERR(rtc->rtc);
    103		goto err_rtc;
    104	}
    105
    106	rtc->rtc->ops = &pl030_ops;
    107	rtc->rtc->range_max = U32_MAX;
    108	rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
    109	if (!rtc->base) {
    110		ret = -ENOMEM;
    111		goto err_rtc;
    112	}
    113
    114	__raw_writel(0, rtc->base + RTC_CR);
    115	__raw_writel(0, rtc->base + RTC_EOI);
    116
    117	amba_set_drvdata(dev, rtc);
    118
    119	ret = request_irq(dev->irq[0], pl030_interrupt, 0,
    120			  "rtc-pl030", rtc);
    121	if (ret)
    122		goto err_irq;
    123
    124	ret = devm_rtc_register_device(rtc->rtc);
    125	if (ret)
    126		goto err_reg;
    127
    128	return 0;
    129
    130 err_reg:
    131	free_irq(dev->irq[0], rtc);
    132 err_irq:
    133	iounmap(rtc->base);
    134 err_rtc:
    135	amba_release_regions(dev);
    136 err_req:
    137	return ret;
    138}
    139
    140static void pl030_remove(struct amba_device *dev)
    141{
    142	struct pl030_rtc *rtc = amba_get_drvdata(dev);
    143
    144	writel(0, rtc->base + RTC_CR);
    145
    146	free_irq(dev->irq[0], rtc);
    147	iounmap(rtc->base);
    148	amba_release_regions(dev);
    149}
    150
    151static struct amba_id pl030_ids[] = {
    152	{
    153		.id	= 0x00041030,
    154		.mask	= 0x000fffff,
    155	},
    156	{ 0, 0 },
    157};
    158
    159MODULE_DEVICE_TABLE(amba, pl030_ids);
    160
    161static struct amba_driver pl030_driver = {
    162	.drv		= {
    163		.name	= "rtc-pl030",
    164	},
    165	.probe		= pl030_probe,
    166	.remove		= pl030_remove,
    167	.id_table	= pl030_ids,
    168};
    169
    170module_amba_driver(pl030_driver);
    171
    172MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
    173MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
    174MODULE_LICENSE("GPL");