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-mt2712.c (11351B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2019 MediaTek Inc.
      4 * Author: Ran Bi <ran.bi@mediatek.com>
      5 */
      6
      7#include <linux/delay.h>
      8#include <linux/init.h>
      9#include <linux/io.h>
     10#include <linux/irqdomain.h>
     11#include <linux/module.h>
     12#include <linux/of_address.h>
     13#include <linux/of_irq.h>
     14#include <linux/platform_device.h>
     15#include <linux/rtc.h>
     16
     17#define MT2712_BBPU		0x0000
     18#define MT2712_BBPU_CLRPKY	BIT(4)
     19#define MT2712_BBPU_RELOAD	BIT(5)
     20#define MT2712_BBPU_CBUSY	BIT(6)
     21#define MT2712_BBPU_KEY		(0x43 << 8)
     22
     23#define MT2712_IRQ_STA		0x0004
     24#define MT2712_IRQ_STA_AL	BIT(0)
     25#define MT2712_IRQ_STA_TC	BIT(1)
     26
     27#define MT2712_IRQ_EN		0x0008
     28#define MT2712_IRQ_EN_AL	BIT(0)
     29#define MT2712_IRQ_EN_TC	BIT(1)
     30#define MT2712_IRQ_EN_ONESHOT	BIT(2)
     31
     32#define MT2712_CII_EN		0x000c
     33
     34#define MT2712_AL_MASK		0x0010
     35#define MT2712_AL_MASK_DOW	BIT(4)
     36
     37#define MT2712_TC_SEC		0x0014
     38#define MT2712_TC_MIN		0x0018
     39#define MT2712_TC_HOU		0x001c
     40#define MT2712_TC_DOM		0x0020
     41#define MT2712_TC_DOW		0x0024
     42#define MT2712_TC_MTH		0x0028
     43#define MT2712_TC_YEA		0x002c
     44
     45#define MT2712_AL_SEC		0x0030
     46#define MT2712_AL_MIN		0x0034
     47#define MT2712_AL_HOU		0x0038
     48#define MT2712_AL_DOM		0x003c
     49#define MT2712_AL_DOW		0x0040
     50#define MT2712_AL_MTH		0x0044
     51#define MT2712_AL_YEA		0x0048
     52
     53#define MT2712_SEC_MASK		0x003f
     54#define MT2712_MIN_MASK		0x003f
     55#define MT2712_HOU_MASK		0x001f
     56#define MT2712_DOM_MASK		0x001f
     57#define MT2712_DOW_MASK		0x0007
     58#define MT2712_MTH_MASK		0x000f
     59#define MT2712_YEA_MASK		0x007f
     60
     61#define MT2712_POWERKEY1	0x004c
     62#define MT2712_POWERKEY2	0x0050
     63#define MT2712_POWERKEY1_KEY	0xa357
     64#define MT2712_POWERKEY2_KEY	0x67d2
     65
     66#define MT2712_CON0		0x005c
     67#define MT2712_CON1		0x0060
     68
     69#define MT2712_PROT		0x0070
     70#define MT2712_PROT_UNLOCK1	0x9136
     71#define MT2712_PROT_UNLOCK2	0x586a
     72
     73#define MT2712_WRTGR		0x0078
     74
     75#define MT2712_RTC_TIMESTAMP_END_2127	4985971199LL
     76
     77struct mt2712_rtc {
     78	struct rtc_device	*rtc;
     79	void __iomem		*base;
     80	int			irq;
     81	u8			irq_wake_enabled;
     82	u8			powerlost;
     83};
     84
     85static inline u32 mt2712_readl(struct mt2712_rtc *mt2712_rtc, u32 reg)
     86{
     87	return readl(mt2712_rtc->base + reg);
     88}
     89
     90static inline void mt2712_writel(struct mt2712_rtc *mt2712_rtc,
     91				 u32 reg, u32 val)
     92{
     93	writel(val, mt2712_rtc->base + reg);
     94}
     95
     96static void mt2712_rtc_write_trigger(struct mt2712_rtc *mt2712_rtc)
     97{
     98	unsigned long timeout = jiffies + HZ / 10;
     99
    100	mt2712_writel(mt2712_rtc, MT2712_WRTGR, 1);
    101	while (1) {
    102		if (!(mt2712_readl(mt2712_rtc, MT2712_BBPU)
    103					& MT2712_BBPU_CBUSY))
    104			break;
    105
    106		if (time_after(jiffies, timeout)) {
    107			dev_err(&mt2712_rtc->rtc->dev,
    108				"%s time out!\n", __func__);
    109			break;
    110		}
    111		cpu_relax();
    112	}
    113}
    114
    115static void mt2712_rtc_writeif_unlock(struct mt2712_rtc *mt2712_rtc)
    116{
    117	mt2712_writel(mt2712_rtc, MT2712_PROT, MT2712_PROT_UNLOCK1);
    118	mt2712_rtc_write_trigger(mt2712_rtc);
    119	mt2712_writel(mt2712_rtc, MT2712_PROT, MT2712_PROT_UNLOCK2);
    120	mt2712_rtc_write_trigger(mt2712_rtc);
    121}
    122
    123static irqreturn_t rtc_irq_handler_thread(int irq, void *data)
    124{
    125	struct mt2712_rtc *mt2712_rtc = data;
    126	u16 irqsta;
    127
    128	/* Clear interrupt */
    129	irqsta = mt2712_readl(mt2712_rtc, MT2712_IRQ_STA);
    130	if (irqsta & MT2712_IRQ_STA_AL) {
    131		rtc_update_irq(mt2712_rtc->rtc, 1, RTC_IRQF | RTC_AF);
    132		return IRQ_HANDLED;
    133	}
    134
    135	return IRQ_NONE;
    136}
    137
    138static void __mt2712_rtc_read_time(struct mt2712_rtc *mt2712_rtc,
    139				   struct rtc_time *tm, int *sec)
    140{
    141	tm->tm_sec  = mt2712_readl(mt2712_rtc, MT2712_TC_SEC)
    142			& MT2712_SEC_MASK;
    143	tm->tm_min  = mt2712_readl(mt2712_rtc, MT2712_TC_MIN)
    144			& MT2712_MIN_MASK;
    145	tm->tm_hour = mt2712_readl(mt2712_rtc, MT2712_TC_HOU)
    146			& MT2712_HOU_MASK;
    147	tm->tm_mday = mt2712_readl(mt2712_rtc, MT2712_TC_DOM)
    148			& MT2712_DOM_MASK;
    149	tm->tm_mon  = (mt2712_readl(mt2712_rtc, MT2712_TC_MTH) - 1)
    150			& MT2712_MTH_MASK;
    151	tm->tm_year = (mt2712_readl(mt2712_rtc, MT2712_TC_YEA) + 100)
    152			& MT2712_YEA_MASK;
    153
    154	*sec = mt2712_readl(mt2712_rtc, MT2712_TC_SEC) & MT2712_SEC_MASK;
    155}
    156
    157static int mt2712_rtc_read_time(struct device *dev, struct rtc_time *tm)
    158{
    159	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    160	int sec;
    161
    162	if (mt2712_rtc->powerlost)
    163		return -EINVAL;
    164
    165	do {
    166		__mt2712_rtc_read_time(mt2712_rtc, tm, &sec);
    167	} while (sec < tm->tm_sec);	/* SEC has carried */
    168
    169	return 0;
    170}
    171
    172static int mt2712_rtc_set_time(struct device *dev, struct rtc_time *tm)
    173{
    174	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    175
    176	mt2712_writel(mt2712_rtc, MT2712_TC_SEC, tm->tm_sec  & MT2712_SEC_MASK);
    177	mt2712_writel(mt2712_rtc, MT2712_TC_MIN, tm->tm_min  & MT2712_MIN_MASK);
    178	mt2712_writel(mt2712_rtc, MT2712_TC_HOU, tm->tm_hour & MT2712_HOU_MASK);
    179	mt2712_writel(mt2712_rtc, MT2712_TC_DOM, tm->tm_mday & MT2712_DOM_MASK);
    180	mt2712_writel(mt2712_rtc, MT2712_TC_MTH,
    181		      (tm->tm_mon + 1) & MT2712_MTH_MASK);
    182	mt2712_writel(mt2712_rtc, MT2712_TC_YEA,
    183		      (tm->tm_year - 100) & MT2712_YEA_MASK);
    184
    185	mt2712_rtc_write_trigger(mt2712_rtc);
    186
    187	if (mt2712_rtc->powerlost)
    188		mt2712_rtc->powerlost = false;
    189
    190	return 0;
    191}
    192
    193static int mt2712_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
    194{
    195	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    196	struct rtc_time *tm = &alm->time;
    197	u16 irqen;
    198
    199	irqen = mt2712_readl(mt2712_rtc, MT2712_IRQ_EN);
    200	alm->enabled = !!(irqen & MT2712_IRQ_EN_AL);
    201
    202	tm->tm_sec  = mt2712_readl(mt2712_rtc, MT2712_AL_SEC) & MT2712_SEC_MASK;
    203	tm->tm_min  = mt2712_readl(mt2712_rtc, MT2712_AL_MIN) & MT2712_MIN_MASK;
    204	tm->tm_hour = mt2712_readl(mt2712_rtc, MT2712_AL_HOU) & MT2712_HOU_MASK;
    205	tm->tm_mday = mt2712_readl(mt2712_rtc, MT2712_AL_DOM) & MT2712_DOM_MASK;
    206	tm->tm_mon  = (mt2712_readl(mt2712_rtc, MT2712_AL_MTH) - 1)
    207		      & MT2712_MTH_MASK;
    208	tm->tm_year = (mt2712_readl(mt2712_rtc, MT2712_AL_YEA) + 100)
    209		      & MT2712_YEA_MASK;
    210
    211	return 0;
    212}
    213
    214static int mt2712_rtc_alarm_irq_enable(struct device *dev,
    215				       unsigned int enabled)
    216{
    217	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    218	u16 irqen;
    219
    220	irqen = mt2712_readl(mt2712_rtc, MT2712_IRQ_EN);
    221	if (enabled)
    222		irqen |= MT2712_IRQ_EN_AL;
    223	else
    224		irqen &= ~MT2712_IRQ_EN_AL;
    225	mt2712_writel(mt2712_rtc, MT2712_IRQ_EN, irqen);
    226	mt2712_rtc_write_trigger(mt2712_rtc);
    227
    228	return 0;
    229}
    230
    231static int mt2712_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
    232{
    233	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    234	struct rtc_time *tm = &alm->time;
    235
    236	dev_dbg(&mt2712_rtc->rtc->dev, "set al time: %ptR, alm en: %d\n",
    237		tm, alm->enabled);
    238
    239	mt2712_writel(mt2712_rtc, MT2712_AL_SEC,
    240		      (mt2712_readl(mt2712_rtc, MT2712_AL_SEC)
    241		       & ~(MT2712_SEC_MASK)) | (tm->tm_sec  & MT2712_SEC_MASK));
    242	mt2712_writel(mt2712_rtc, MT2712_AL_MIN,
    243		      (mt2712_readl(mt2712_rtc, MT2712_AL_MIN)
    244		       & ~(MT2712_MIN_MASK)) | (tm->tm_min  & MT2712_MIN_MASK));
    245	mt2712_writel(mt2712_rtc, MT2712_AL_HOU,
    246		      (mt2712_readl(mt2712_rtc, MT2712_AL_HOU)
    247		       & ~(MT2712_HOU_MASK)) | (tm->tm_hour & MT2712_HOU_MASK));
    248	mt2712_writel(mt2712_rtc, MT2712_AL_DOM,
    249		      (mt2712_readl(mt2712_rtc, MT2712_AL_DOM)
    250		       & ~(MT2712_DOM_MASK)) | (tm->tm_mday & MT2712_DOM_MASK));
    251	mt2712_writel(mt2712_rtc, MT2712_AL_MTH,
    252		      (mt2712_readl(mt2712_rtc, MT2712_AL_MTH)
    253		       & ~(MT2712_MTH_MASK))
    254		      | ((tm->tm_mon + 1) & MT2712_MTH_MASK));
    255	mt2712_writel(mt2712_rtc, MT2712_AL_YEA,
    256		      (mt2712_readl(mt2712_rtc, MT2712_AL_YEA)
    257		       & ~(MT2712_YEA_MASK))
    258		      | ((tm->tm_year - 100) & MT2712_YEA_MASK));
    259
    260	/* mask day of week */
    261	mt2712_writel(mt2712_rtc, MT2712_AL_MASK, MT2712_AL_MASK_DOW);
    262	mt2712_rtc_write_trigger(mt2712_rtc);
    263
    264	mt2712_rtc_alarm_irq_enable(dev, alm->enabled);
    265
    266	return 0;
    267}
    268
    269/* Init RTC register */
    270static void mt2712_rtc_hw_init(struct mt2712_rtc *mt2712_rtc)
    271{
    272	u32 p1, p2;
    273
    274	mt2712_writel(mt2712_rtc, MT2712_BBPU,
    275		      MT2712_BBPU_KEY | MT2712_BBPU_RELOAD);
    276
    277	mt2712_writel(mt2712_rtc, MT2712_CII_EN, 0);
    278	mt2712_writel(mt2712_rtc, MT2712_AL_MASK, 0);
    279	/* necessary before set MT2712_POWERKEY */
    280	mt2712_writel(mt2712_rtc, MT2712_CON0, 0x4848);
    281	mt2712_writel(mt2712_rtc, MT2712_CON1, 0x0048);
    282
    283	mt2712_rtc_write_trigger(mt2712_rtc);
    284
    285	p1 = mt2712_readl(mt2712_rtc, MT2712_POWERKEY1);
    286	p2 = mt2712_readl(mt2712_rtc, MT2712_POWERKEY2);
    287	if (p1 != MT2712_POWERKEY1_KEY || p2 != MT2712_POWERKEY2_KEY) {
    288		mt2712_rtc->powerlost = true;
    289		dev_dbg(&mt2712_rtc->rtc->dev,
    290			"powerkey not set (lost power)\n");
    291	} else {
    292		mt2712_rtc->powerlost = false;
    293	}
    294
    295	/* RTC need POWERKEY1/2 match, then goto normal work mode */
    296	mt2712_writel(mt2712_rtc, MT2712_POWERKEY1, MT2712_POWERKEY1_KEY);
    297	mt2712_writel(mt2712_rtc, MT2712_POWERKEY2, MT2712_POWERKEY2_KEY);
    298	mt2712_rtc_write_trigger(mt2712_rtc);
    299
    300	mt2712_rtc_writeif_unlock(mt2712_rtc);
    301}
    302
    303static const struct rtc_class_ops mt2712_rtc_ops = {
    304	.read_time	= mt2712_rtc_read_time,
    305	.set_time	= mt2712_rtc_set_time,
    306	.read_alarm	= mt2712_rtc_read_alarm,
    307	.set_alarm	= mt2712_rtc_set_alarm,
    308	.alarm_irq_enable = mt2712_rtc_alarm_irq_enable,
    309};
    310
    311static int mt2712_rtc_probe(struct platform_device *pdev)
    312{
    313	struct mt2712_rtc *mt2712_rtc;
    314	int ret;
    315
    316	mt2712_rtc = devm_kzalloc(&pdev->dev,
    317				  sizeof(struct mt2712_rtc), GFP_KERNEL);
    318	if (!mt2712_rtc)
    319		return -ENOMEM;
    320
    321	mt2712_rtc->base = devm_platform_ioremap_resource(pdev, 0);
    322	if (IS_ERR(mt2712_rtc->base))
    323		return PTR_ERR(mt2712_rtc->base);
    324
    325	/* rtc hw init */
    326	mt2712_rtc_hw_init(mt2712_rtc);
    327
    328	mt2712_rtc->irq = platform_get_irq(pdev, 0);
    329	if (mt2712_rtc->irq < 0)
    330		return mt2712_rtc->irq;
    331
    332	platform_set_drvdata(pdev, mt2712_rtc);
    333
    334	mt2712_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
    335	if (IS_ERR(mt2712_rtc->rtc))
    336		return PTR_ERR(mt2712_rtc->rtc);
    337
    338	ret = devm_request_threaded_irq(&pdev->dev, mt2712_rtc->irq, NULL,
    339					rtc_irq_handler_thread,
    340					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
    341					dev_name(&mt2712_rtc->rtc->dev),
    342					mt2712_rtc);
    343	if (ret) {
    344		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
    345			mt2712_rtc->irq, ret);
    346		return ret;
    347	}
    348
    349	device_init_wakeup(&pdev->dev, true);
    350
    351	mt2712_rtc->rtc->ops = &mt2712_rtc_ops;
    352	mt2712_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
    353	mt2712_rtc->rtc->range_max = MT2712_RTC_TIMESTAMP_END_2127;
    354
    355	return devm_rtc_register_device(mt2712_rtc->rtc);
    356}
    357
    358#ifdef CONFIG_PM_SLEEP
    359static int mt2712_rtc_suspend(struct device *dev)
    360{
    361	int wake_status = 0;
    362	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    363
    364	if (device_may_wakeup(dev)) {
    365		wake_status = enable_irq_wake(mt2712_rtc->irq);
    366		if (!wake_status)
    367			mt2712_rtc->irq_wake_enabled = true;
    368	}
    369
    370	return 0;
    371}
    372
    373static int mt2712_rtc_resume(struct device *dev)
    374{
    375	int wake_status = 0;
    376	struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
    377
    378	if (device_may_wakeup(dev) && mt2712_rtc->irq_wake_enabled) {
    379		wake_status = disable_irq_wake(mt2712_rtc->irq);
    380		if (!wake_status)
    381			mt2712_rtc->irq_wake_enabled = false;
    382	}
    383
    384	return 0;
    385}
    386
    387static SIMPLE_DEV_PM_OPS(mt2712_pm_ops, mt2712_rtc_suspend,
    388			 mt2712_rtc_resume);
    389#endif
    390
    391static const struct of_device_id mt2712_rtc_of_match[] = {
    392	{ .compatible = "mediatek,mt2712-rtc", },
    393	{ },
    394};
    395
    396MODULE_DEVICE_TABLE(of, mt2712_rtc_of_match);
    397
    398static struct platform_driver mt2712_rtc_driver = {
    399	.driver = {
    400		.name = "mt2712-rtc",
    401		.of_match_table = mt2712_rtc_of_match,
    402#ifdef CONFIG_PM_SLEEP
    403		.pm = &mt2712_pm_ops,
    404#endif
    405	},
    406	.probe  = mt2712_rtc_probe,
    407};
    408
    409module_platform_driver(mt2712_rtc_driver);
    410
    411MODULE_DESCRIPTION("MediaTek MT2712 SoC based RTC Driver");
    412MODULE_AUTHOR("Ran Bi <ran.bi@mediatek.com>");
    413MODULE_LICENSE("GPL");