diff options
Diffstat (limited to 'kernel/drivers/rtc/rtc-at91rm9200.c')
| -rw-r--r-- | kernel/drivers/rtc/rtc-at91rm9200.c | 538 |
1 files changed, 538 insertions, 0 deletions
diff --git a/kernel/drivers/rtc/rtc-at91rm9200.c b/kernel/drivers/rtc/rtc-at91rm9200.c new file mode 100644 index 000000000..35efd3f75 --- /dev/null +++ b/kernel/drivers/rtc/rtc-at91rm9200.c @@ -0,0 +1,538 @@ +/* + * Real Time Clock interface for Linux on Atmel AT91RM9200 + * + * Copyright (C) 2002 Rick Bronson + * + * Converted to RTC class model by Andrew Victor + * + * Ported to Linux 2.6 by Steven Scholz + * Based on s3c2410-rtc.c Simtec Electronics + * + * Based on sa1100-rtc.c by Nils Faerber + * Based on rtc.c by Paul Gortmaker + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/time.h> +#include <linux/rtc.h> +#include <linux/bcd.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/ioctl.h> +#include <linux/completion.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/suspend.h> +#include <linux/uaccess.h> + +#include "rtc-at91rm9200.h" + +#define at91_rtc_read(field) \ + readl_relaxed(at91_rtc_regs + field) +#define at91_rtc_write(field, val) \ + writel_relaxed((val), at91_rtc_regs + field) + +#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ + +struct at91_rtc_config { + bool use_shadow_imr; +}; + +static const struct at91_rtc_config *at91_rtc_config; +static DECLARE_COMPLETION(at91_rtc_updated); +static DECLARE_COMPLETION(at91_rtc_upd_rdy); +static unsigned int at91_alarm_year = AT91_RTC_EPOCH; +static void __iomem *at91_rtc_regs; +static int irq; +static DEFINE_SPINLOCK(at91_rtc_lock); +static u32 at91_rtc_shadow_imr; +static bool suspended; +static DEFINE_SPINLOCK(suspended_lock); +static unsigned long cached_events; +static u32 at91_rtc_imr; + +static void at91_rtc_write_ier(u32 mask) +{ + unsigned long flags; + + spin_lock_irqsave(&at91_rtc_lock, flags); + at91_rtc_shadow_imr |= mask; + at91_rtc_write(AT91_RTC_IER, mask); + spin_unlock_irqrestore(&at91_rtc_lock, flags); +} + +static void at91_rtc_write_idr(u32 mask) +{ + unsigned long flags; + + spin_lock_irqsave(&at91_rtc_lock, flags); + at91_rtc_write(AT91_RTC_IDR, mask); + /* + * Register read back (of any RTC-register) needed to make sure + * IDR-register write has reached the peripheral before updating + * shadow mask. + * + * Note that there is still a possibility that the mask is updated + * before interrupts have actually been disabled in hardware. The only + * way to be certain would be to poll the IMR-register, which is is + * the very register we are trying to emulate. The register read back + * is a reasonable heuristic. + */ + at91_rtc_read(AT91_RTC_SR); + at91_rtc_shadow_imr &= ~mask; + spin_unlock_irqrestore(&at91_rtc_lock, flags); +} + +static u32 at91_rtc_read_imr(void) +{ + unsigned long flags; + u32 mask; + + if (at91_rtc_config->use_shadow_imr) { + spin_lock_irqsave(&at91_rtc_lock, flags); + mask = at91_rtc_shadow_imr; + spin_unlock_irqrestore(&at91_rtc_lock, flags); + } else { + mask = at91_rtc_read(AT91_RTC_IMR); + } + + return mask; +} + +/* + * Decode time/date into rtc_time structure + */ +static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, + struct rtc_time *tm) +{ + unsigned int time, date; + + /* must read twice in case it changes */ + do { + time = at91_rtc_read(timereg); + date = at91_rtc_read(calreg); + } while ((time != at91_rtc_read(timereg)) || + (date != at91_rtc_read(calreg))); + + tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); + tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); + tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); + + /* + * The Calendar Alarm register does not have a field for + * the year - so these will return an invalid value. When an + * alarm is set, at91_alarm_year will store the current year. + */ + tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ + tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ + + tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ + tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; + tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); +} + +/* + * Read current time and date in RTC + */ +static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) +{ + at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); + tm->tm_year = tm->tm_year - 1900; + + dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, + 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + + return 0; +} + +/* + * Set current time and date in RTC + */ +static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) +{ + unsigned long cr; + + dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, + 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + + wait_for_completion(&at91_rtc_upd_rdy); + + /* Stop Time/Calendar from counting */ + cr = at91_rtc_read(AT91_RTC_CR); + at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); + + at91_rtc_write_ier(AT91_RTC_ACKUPD); + wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ + at91_rtc_write_idr(AT91_RTC_ACKUPD); + + at91_rtc_write(AT91_RTC_TIMR, + bin2bcd(tm->tm_sec) << 0 + | bin2bcd(tm->tm_min) << 8 + | bin2bcd(tm->tm_hour) << 16); + + at91_rtc_write(AT91_RTC_CALR, + bin2bcd((tm->tm_year + 1900) / 100) /* century */ + | bin2bcd(tm->tm_year % 100) << 8 /* year */ + | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ + | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ + | bin2bcd(tm->tm_mday) << 24); + + /* Restart Time/Calendar */ + cr = at91_rtc_read(AT91_RTC_CR); + at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV); + at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); + at91_rtc_write_ier(AT91_RTC_SECEV); + + return 0; +} + +/* + * Read alarm time and date in RTC + */ +static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rtc_time *tm = &alrm->time; + + at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); + tm->tm_year = at91_alarm_year - 1900; + + alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM) + ? 1 : 0; + + dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, + 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + + return 0; +} + +/* + * Set alarm time and date in RTC + */ +static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rtc_time tm; + + at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); + + at91_alarm_year = tm.tm_year; + + tm.tm_mon = alrm->time.tm_mon; + tm.tm_mday = alrm->time.tm_mday; + tm.tm_hour = alrm->time.tm_hour; + tm.tm_min = alrm->time.tm_min; + tm.tm_sec = alrm->time.tm_sec; + + at91_rtc_write_idr(AT91_RTC_ALARM); + at91_rtc_write(AT91_RTC_TIMALR, + bin2bcd(tm.tm_sec) << 0 + | bin2bcd(tm.tm_min) << 8 + | bin2bcd(tm.tm_hour) << 16 + | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); + at91_rtc_write(AT91_RTC_CALALR, + bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ + | bin2bcd(tm.tm_mday) << 24 + | AT91_RTC_DATEEN | AT91_RTC_MTHEN); + + if (alrm->enabled) { + at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); + at91_rtc_write_ier(AT91_RTC_ALARM); + } + + dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, + at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, + tm.tm_min, tm.tm_sec); + + return 0; +} + +static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled); + + if (enabled) { + at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); + at91_rtc_write_ier(AT91_RTC_ALARM); + } else + at91_rtc_write_idr(AT91_RTC_ALARM); + + return 0; +} +/* + * Provide additional RTC information in /proc/driver/rtc + */ +static int at91_rtc_proc(struct device *dev, struct seq_file *seq) +{ + unsigned long imr = at91_rtc_read_imr(); + + seq_printf(seq, "update_IRQ\t: %s\n", + (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); + seq_printf(seq, "periodic_IRQ\t: %s\n", + (imr & AT91_RTC_SECEV) ? "yes" : "no"); + + return 0; +} + +/* + * IRQ handler for the RTC + */ +static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) +{ + struct platform_device *pdev = dev_id; + struct rtc_device *rtc = platform_get_drvdata(pdev); + unsigned int rtsr; + unsigned long events = 0; + int ret = IRQ_NONE; + + spin_lock(&suspended_lock); + rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr(); + if (rtsr) { /* this interrupt is shared! Is it ours? */ + if (rtsr & AT91_RTC_ALARM) + events |= (RTC_AF | RTC_IRQF); + if (rtsr & AT91_RTC_SECEV) { + complete(&at91_rtc_upd_rdy); + at91_rtc_write_idr(AT91_RTC_SECEV); + } + if (rtsr & AT91_RTC_ACKUPD) + complete(&at91_rtc_updated); + + at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ + + if (!suspended) { + rtc_update_irq(rtc, 1, events); + + dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", + __func__, events >> 8, events & 0x000000FF); + } else { + cached_events |= events; + at91_rtc_write_idr(at91_rtc_imr); + pm_system_wakeup(); + } + + ret = IRQ_HANDLED; + } + spin_unlock(&suspended_lock); + + return ret; +} + +static const struct at91_rtc_config at91rm9200_config = { +}; + +static const struct at91_rtc_config at91sam9x5_config = { + .use_shadow_imr = true, +}; + +#ifdef CONFIG_OF +static const struct of_device_id at91_rtc_dt_ids[] = { + { + .compatible = "atmel,at91rm9200-rtc", + .data = &at91rm9200_config, + }, { + .compatible = "atmel,at91sam9x5-rtc", + .data = &at91sam9x5_config, + }, { + /* sentinel */ + } +}; +MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); +#endif + +static const struct at91_rtc_config * +at91_rtc_get_config(struct platform_device *pdev) +{ + const struct of_device_id *match; + + if (pdev->dev.of_node) { + match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node); + if (!match) + return NULL; + return (const struct at91_rtc_config *)match->data; + } + + return &at91rm9200_config; +} + +static const struct rtc_class_ops at91_rtc_ops = { + .read_time = at91_rtc_readtime, + .set_time = at91_rtc_settime, + .read_alarm = at91_rtc_readalarm, + .set_alarm = at91_rtc_setalarm, + .proc = at91_rtc_proc, + .alarm_irq_enable = at91_rtc_alarm_irq_enable, +}; + +/* + * Initialize and install RTC driver + */ +static int __init at91_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + struct resource *regs; + int ret = 0; + + at91_rtc_config = at91_rtc_get_config(pdev); + if (!at91_rtc_config) + return -ENODEV; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) { + dev_err(&pdev->dev, "no mmio resource defined\n"); + return -ENXIO; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no irq resource defined\n"); + return -ENXIO; + } + + at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start, + resource_size(regs)); + if (!at91_rtc_regs) { + dev_err(&pdev->dev, "failed to map registers, aborting.\n"); + return -ENOMEM; + } + + at91_rtc_write(AT91_RTC_CR, 0); + at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ + + /* Disable all interrupts */ + at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | + AT91_RTC_SECEV | AT91_RTC_TIMEV | + AT91_RTC_CALEV); + + ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt, + IRQF_SHARED | IRQF_COND_SUSPEND, + "at91_rtc", pdev); + if (ret) { + dev_err(&pdev->dev, "IRQ %d already in use.\n", irq); + return ret; + } + + /* cpu init code should really have flagged this device as + * being wake-capable; if it didn't, do that here. + */ + if (!device_can_wakeup(&pdev->dev)) + device_init_wakeup(&pdev->dev, 1); + + rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &at91_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + platform_set_drvdata(pdev, rtc); + + /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy + * completion. + */ + at91_rtc_write_ier(AT91_RTC_SECEV); + + dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); + return 0; +} + +/* + * Disable and remove the RTC driver + */ +static int __exit at91_rtc_remove(struct platform_device *pdev) +{ + /* Disable all interrupts */ + at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | + AT91_RTC_SECEV | AT91_RTC_TIMEV | + AT91_RTC_CALEV); + + return 0; +} + +static void at91_rtc_shutdown(struct platform_device *pdev) +{ + /* Disable all interrupts */ + at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | + AT91_RTC_SECEV | AT91_RTC_TIMEV | + AT91_RTC_CALEV); +} + +#ifdef CONFIG_PM_SLEEP + +/* AT91RM9200 RTC Power management control */ + +static int at91_rtc_suspend(struct device *dev) +{ + /* this IRQ is shared with DBGU and other hardware which isn't + * necessarily doing PM like we are... + */ + at91_rtc_imr = at91_rtc_read_imr() + & (AT91_RTC_ALARM|AT91_RTC_SECEV); + if (at91_rtc_imr) { + if (device_may_wakeup(dev)) { + unsigned long flags; + + enable_irq_wake(irq); + + spin_lock_irqsave(&suspended_lock, flags); + suspended = true; + spin_unlock_irqrestore(&suspended_lock, flags); + } else { + at91_rtc_write_idr(at91_rtc_imr); + } + } + return 0; +} + +static int at91_rtc_resume(struct device *dev) +{ + struct rtc_device *rtc = dev_get_drvdata(dev); + + if (at91_rtc_imr) { + if (device_may_wakeup(dev)) { + unsigned long flags; + + spin_lock_irqsave(&suspended_lock, flags); + + if (cached_events) { + rtc_update_irq(rtc, 1, cached_events); + cached_events = 0; + } + + suspended = false; + spin_unlock_irqrestore(&suspended_lock, flags); + + disable_irq_wake(irq); + } + at91_rtc_write_ier(at91_rtc_imr); + } + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume); + +static struct platform_driver at91_rtc_driver = { + .remove = __exit_p(at91_rtc_remove), + .shutdown = at91_rtc_shutdown, + .driver = { + .name = "at91_rtc", + .pm = &at91_rtc_pm_ops, + .of_match_table = of_match_ptr(at91_rtc_dt_ids), + }, +}; + +module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe); + +MODULE_AUTHOR("Rick Bronson"); +MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:at91_rtc"); |