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-msm6242.c (6769B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  Oki MSM6242 RTC Driver
      4 *
      5 *  Copyright 2009 Geert Uytterhoeven
      6 *
      7 *  Based on the A2000 TOD code in arch/m68k/amiga/config.c
      8 *  Copyright (C) 1993 Hamish Macdonald
      9 */
     10
     11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
     12
     13#include <linux/delay.h>
     14#include <linux/io.h>
     15#include <linux/kernel.h>
     16#include <linux/module.h>
     17#include <linux/platform_device.h>
     18#include <linux/rtc.h>
     19#include <linux/slab.h>
     20
     21
     22enum {
     23	MSM6242_SECOND1		= 0x0,	/* 1-second digit register */
     24	MSM6242_SECOND10	= 0x1,	/* 10-second digit register */
     25	MSM6242_MINUTE1		= 0x2,	/* 1-minute digit register */
     26	MSM6242_MINUTE10	= 0x3,	/* 10-minute digit register */
     27	MSM6242_HOUR1		= 0x4,	/* 1-hour digit register */
     28	MSM6242_HOUR10		= 0x5,	/* PM/AM, 10-hour digit register */
     29	MSM6242_DAY1		= 0x6,	/* 1-day digit register */
     30	MSM6242_DAY10		= 0x7,	/* 10-day digit register */
     31	MSM6242_MONTH1		= 0x8,	/* 1-month digit register */
     32	MSM6242_MONTH10		= 0x9,	/* 10-month digit register */
     33	MSM6242_YEAR1		= 0xa,	/* 1-year digit register */
     34	MSM6242_YEAR10		= 0xb,	/* 10-year digit register */
     35	MSM6242_WEEK		= 0xc,	/* Week register */
     36	MSM6242_CD		= 0xd,	/* Control Register D */
     37	MSM6242_CE		= 0xe,	/* Control Register E */
     38	MSM6242_CF		= 0xf,	/* Control Register F */
     39};
     40
     41#define MSM6242_HOUR10_AM	(0 << 2)
     42#define MSM6242_HOUR10_PM	(1 << 2)
     43#define MSM6242_HOUR10_HR_MASK	(3 << 0)
     44
     45#define MSM6242_WEEK_SUNDAY	0
     46#define MSM6242_WEEK_MONDAY	1
     47#define MSM6242_WEEK_TUESDAY	2
     48#define MSM6242_WEEK_WEDNESDAY	3
     49#define MSM6242_WEEK_THURSDAY	4
     50#define MSM6242_WEEK_FRIDAY	5
     51#define MSM6242_WEEK_SATURDAY	6
     52
     53#define MSM6242_CD_30_S_ADJ	(1 << 3)	/* 30-second adjustment */
     54#define MSM6242_CD_IRQ_FLAG	(1 << 2)
     55#define MSM6242_CD_BUSY		(1 << 1)
     56#define MSM6242_CD_HOLD		(1 << 0)
     57
     58#define MSM6242_CE_T_MASK	(3 << 2)
     59#define MSM6242_CE_T_64HZ	(0 << 2)	/* period 1/64 second */
     60#define MSM6242_CE_T_1HZ	(1 << 2)	/* period 1 second */
     61#define MSM6242_CE_T_1MINUTE	(2 << 2)	/* period 1 minute */
     62#define MSM6242_CE_T_1HOUR	(3 << 2)	/* period 1 hour */
     63
     64#define MSM6242_CE_ITRPT_STND	(1 << 1)
     65#define MSM6242_CE_MASK		(1 << 0)	/* STD.P output control */
     66
     67#define MSM6242_CF_TEST		(1 << 3)
     68#define MSM6242_CF_12H		(0 << 2)
     69#define MSM6242_CF_24H		(1 << 2)
     70#define MSM6242_CF_STOP		(1 << 1)
     71#define MSM6242_CF_REST		(1 << 0)	/* reset */
     72
     73
     74struct msm6242_priv {
     75	u32 __iomem *regs;
     76	struct rtc_device *rtc;
     77};
     78
     79static inline unsigned int msm6242_read(struct msm6242_priv *priv,
     80				       unsigned int reg)
     81{
     82	return __raw_readl(&priv->regs[reg]) & 0xf;
     83}
     84
     85static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
     86				unsigned int reg)
     87{
     88	__raw_writel(val, &priv->regs[reg]);
     89}
     90
     91static void msm6242_lock(struct msm6242_priv *priv)
     92{
     93	int cnt = 5;
     94
     95	msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, MSM6242_CD);
     96
     97	while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
     98		msm6242_write(priv, MSM6242_CD_IRQ_FLAG, MSM6242_CD);
     99		udelay(70);
    100		msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, MSM6242_CD);
    101		cnt--;
    102	}
    103
    104	if (!cnt)
    105		pr_warn("timed out waiting for RTC (0x%x)\n",
    106			msm6242_read(priv, MSM6242_CD));
    107}
    108
    109static void msm6242_unlock(struct msm6242_priv *priv)
    110{
    111	msm6242_write(priv, MSM6242_CD_IRQ_FLAG, MSM6242_CD);
    112}
    113
    114static int msm6242_read_time(struct device *dev, struct rtc_time *tm)
    115{
    116	struct msm6242_priv *priv = dev_get_drvdata(dev);
    117
    118	msm6242_lock(priv);
    119
    120	tm->tm_sec  = msm6242_read(priv, MSM6242_SECOND10) * 10 +
    121		      msm6242_read(priv, MSM6242_SECOND1);
    122	tm->tm_min  = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
    123		      msm6242_read(priv, MSM6242_MINUTE1);
    124	tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10) &
    125		       MSM6242_HOUR10_HR_MASK) * 10 +
    126		      msm6242_read(priv, MSM6242_HOUR1);
    127	tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
    128		      msm6242_read(priv, MSM6242_DAY1);
    129	tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
    130	tm->tm_mon  = msm6242_read(priv, MSM6242_MONTH10) * 10 +
    131		      msm6242_read(priv, MSM6242_MONTH1) - 1;
    132	tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
    133		      msm6242_read(priv, MSM6242_YEAR1);
    134	if (tm->tm_year <= 69)
    135		tm->tm_year += 100;
    136
    137	if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
    138		unsigned int pm = msm6242_read(priv, MSM6242_HOUR10) &
    139				  MSM6242_HOUR10_PM;
    140		if (!pm && tm->tm_hour == 12)
    141			tm->tm_hour = 0;
    142		else if (pm && tm->tm_hour != 12)
    143			tm->tm_hour += 12;
    144	}
    145
    146	msm6242_unlock(priv);
    147
    148	return 0;
    149}
    150
    151static int msm6242_set_time(struct device *dev, struct rtc_time *tm)
    152{
    153	struct msm6242_priv *priv = dev_get_drvdata(dev);
    154
    155	msm6242_lock(priv);
    156
    157	msm6242_write(priv, tm->tm_sec / 10, MSM6242_SECOND10);
    158	msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
    159	msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
    160	msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
    161	if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
    162		msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
    163	else if (tm->tm_hour >= 12)
    164		msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
    165			      MSM6242_HOUR10);
    166	else
    167		msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
    168	msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
    169	msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
    170	msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
    171	if (tm->tm_wday != -1)
    172		msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
    173	msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
    174	msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
    175	if (tm->tm_year >= 100)
    176		tm->tm_year -= 100;
    177	msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
    178	msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
    179
    180	msm6242_unlock(priv);
    181	return 0;
    182}
    183
    184static const struct rtc_class_ops msm6242_rtc_ops = {
    185	.read_time	= msm6242_read_time,
    186	.set_time	= msm6242_set_time,
    187};
    188
    189static int __init msm6242_rtc_probe(struct platform_device *pdev)
    190{
    191	struct resource *res;
    192	struct msm6242_priv *priv;
    193	struct rtc_device *rtc;
    194
    195	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    196	if (!res)
    197		return -ENODEV;
    198
    199	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
    200	if (!priv)
    201		return -ENOMEM;
    202
    203	priv->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
    204	if (!priv->regs)
    205		return -ENOMEM;
    206	platform_set_drvdata(pdev, priv);
    207
    208	rtc = devm_rtc_device_register(&pdev->dev, "rtc-msm6242",
    209				&msm6242_rtc_ops, THIS_MODULE);
    210	if (IS_ERR(rtc))
    211		return PTR_ERR(rtc);
    212
    213	priv->rtc = rtc;
    214	return 0;
    215}
    216
    217static struct platform_driver msm6242_rtc_driver = {
    218	.driver	= {
    219		.name	= "rtc-msm6242",
    220	},
    221};
    222
    223module_platform_driver_probe(msm6242_rtc_driver, msm6242_rtc_probe);
    224
    225MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
    226MODULE_LICENSE("GPL");
    227MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
    228MODULE_ALIAS("platform:rtc-msm6242");