diff options
Diffstat (limited to 'drivers/rtc/rtc-vt8500.c')
| -rw-r--r-- | drivers/rtc/rtc-vt8500.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-vt8500.c b/drivers/rtc/rtc-vt8500.c new file mode 100644 index 0000000000..ccfa76513a --- /dev/null +++ b/drivers/rtc/rtc-vt8500.c @@ -0,0 +1,266 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/rtc/rtc-vt8500.c + * + * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com> + * + * Based on rtc-pxa.c + */ + +#include <linux/module.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/bcd.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/of.h> + +/* + * Register definitions + */ +#define VT8500_RTC_TS 0x00 /* Time set */ +#define VT8500_RTC_DS 0x04 /* Date set */ +#define VT8500_RTC_AS 0x08 /* Alarm set */ +#define VT8500_RTC_CR 0x0c /* Control */ +#define VT8500_RTC_TR 0x10 /* Time read */ +#define VT8500_RTC_DR 0x14 /* Date read */ +#define VT8500_RTC_WS 0x18 /* Write status */ +#define VT8500_RTC_CL 0x20 /* Calibration */ +#define VT8500_RTC_IS 0x24 /* Interrupt status */ +#define VT8500_RTC_ST 0x28 /* Status */ + +#define INVALID_TIME_BIT (1 << 31) + +#define DATE_CENTURY_S 19 +#define DATE_YEAR_S 11 +#define DATE_YEAR_MASK (0xff << DATE_YEAR_S) +#define DATE_MONTH_S 6 +#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S) +#define DATE_DAY_MASK 0x3f + +#define TIME_DOW_S 20 +#define TIME_DOW_MASK (0x07 << TIME_DOW_S) +#define TIME_HOUR_S 14 +#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S) +#define TIME_MIN_S 7 +#define TIME_MIN_MASK (0x7f << TIME_MIN_S) +#define TIME_SEC_MASK 0x7f + +#define ALARM_DAY_S 20 +#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S) + +#define ALARM_DAY_BIT (1 << 29) +#define ALARM_HOUR_BIT (1 << 28) +#define ALARM_MIN_BIT (1 << 27) +#define ALARM_SEC_BIT (1 << 26) + +#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \ + | ALARM_HOUR_BIT \ + | ALARM_MIN_BIT \ + | ALARM_SEC_BIT) + +#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */ +#define VT8500_RTC_CR_12H (1 << 1) /* 12h time format */ +#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */ +#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */ +#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */ + +#define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */ + +struct vt8500_rtc { + void __iomem *regbase; + int irq_alarm; + struct rtc_device *rtc; + spinlock_t lock; /* Protects this structure */ +}; + +static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id) +{ + struct vt8500_rtc *vt8500_rtc = dev_id; + u32 isr; + unsigned long events = 0; + + spin_lock(&vt8500_rtc->lock); + + /* clear interrupt sources */ + isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); + writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS); + + spin_unlock(&vt8500_rtc->lock); + + if (isr & VT8500_RTC_IS_ALARM) + events |= RTC_AF | RTC_IRQF; + + rtc_update_irq(vt8500_rtc->rtc, 1, events); + + return IRQ_HANDLED; +} + +static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); + u32 date, time; + + date = readl(vt8500_rtc->regbase + VT8500_RTC_DR); + time = readl(vt8500_rtc->regbase + VT8500_RTC_TR); + + tm->tm_sec = bcd2bin(time & TIME_SEC_MASK); + tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S); + tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S); + tm->tm_mday = bcd2bin(date & DATE_DAY_MASK); + tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1; + tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S) + + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100); + tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S; + + return 0; +} + +static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); + + writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S) + | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S) + | (bin2bcd(tm->tm_mday)) + | ((tm->tm_year >= 200) << DATE_CENTURY_S), + vt8500_rtc->regbase + VT8500_RTC_DS); + writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) + | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) + | (bin2bcd(tm->tm_min) << TIME_MIN_S) + | (bin2bcd(tm->tm_sec)), + vt8500_rtc->regbase + VT8500_RTC_TS); + + return 0; +} + +static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); + u32 isr, alarm; + + alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); + isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); + + alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); + alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); + alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); + alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); + + alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; + alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0; + + return rtc_valid_tm(&alrm->time); +} + +static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); + + writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) + | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) + | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) + | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) + | (bin2bcd(alrm->time.tm_sec)), + vt8500_rtc->regbase + VT8500_RTC_AS); + + return 0; +} + +static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); + unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); + + if (enabled) + tmp |= ALARM_ENABLE_MASK; + else + tmp &= ~ALARM_ENABLE_MASK; + + writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); + return 0; +} + +static const struct rtc_class_ops vt8500_rtc_ops = { + .read_time = vt8500_rtc_read_time, + .set_time = vt8500_rtc_set_time, + .read_alarm = vt8500_rtc_read_alarm, + .set_alarm = vt8500_rtc_set_alarm, + .alarm_irq_enable = vt8500_alarm_irq_enable, +}; + +static int vt8500_rtc_probe(struct platform_device *pdev) +{ + struct vt8500_rtc *vt8500_rtc; + int ret; + + vt8500_rtc = devm_kzalloc(&pdev->dev, + sizeof(struct vt8500_rtc), GFP_KERNEL); + if (!vt8500_rtc) + return -ENOMEM; + + spin_lock_init(&vt8500_rtc->lock); + platform_set_drvdata(pdev, vt8500_rtc); + + vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); + if (vt8500_rtc->irq_alarm < 0) + return vt8500_rtc->irq_alarm; + + vt8500_rtc->regbase = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(vt8500_rtc->regbase)) + return PTR_ERR(vt8500_rtc->regbase); + + /* Enable RTC and set it to 24-hour mode */ + writel(VT8500_RTC_CR_ENABLE, + vt8500_rtc->regbase + VT8500_RTC_CR); + + vt8500_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(vt8500_rtc->rtc)) + return PTR_ERR(vt8500_rtc->rtc); + + vt8500_rtc->rtc->ops = &vt8500_rtc_ops; + vt8500_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + vt8500_rtc->rtc->range_max = RTC_TIMESTAMP_END_2199; + + ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm, + vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc); + if (ret < 0) { + dev_err(&pdev->dev, "can't get irq %i, err %d\n", + vt8500_rtc->irq_alarm, ret); + return ret; + } + + return devm_rtc_register_device(vt8500_rtc->rtc); +} + +static void vt8500_rtc_remove(struct platform_device *pdev) +{ + struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); + + /* Disable alarm matching */ + writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); +} + +static const struct of_device_id wmt_dt_ids[] = { + { .compatible = "via,vt8500-rtc", }, + {} +}; +MODULE_DEVICE_TABLE(of, wmt_dt_ids); + +static struct platform_driver vt8500_rtc_driver = { + .probe = vt8500_rtc_probe, + .remove_new = vt8500_rtc_remove, + .driver = { + .name = "vt8500-rtc", + .of_match_table = wmt_dt_ids, + }, +}; + +module_platform_driver(vt8500_rtc_driver); + +MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); +MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:vt8500-rtc"); |