[PATCH] AT91RM9200 RTC

The new Atmel AT91SAM9261 and AT91SAM9260 processors do not have the
internal RTC peripheral.  This RTC driver is therefore
AT91RM9200-specific.

This patch renames rtc-at91.c to rtc-at91rm9200.c, and changes the name
of the configuration option.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 429 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
new file mode 100644
index 000000000000..5c8addcaf1fb
--- /dev/null
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -0,0 +1,429 @@
+/*
+ *      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/ioctl.h>
+#include <linux/completion.h>
+
+#include <asm/uaccess.h>
+#include <asm/rtc.h>
+
+#include <asm/mach/time.h>
+
+
+#define AT91_RTC_FREQ           1
+#define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
+
+static DECLARE_COMPLETION(at91_rtc_updated);
+static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
+
+/*
+ * 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_sys_read(timereg);
+                date = at91_sys_read(calreg);
+        } while ((time != at91_sys_read(timereg)) ||
+                        (date != at91_sys_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 wille 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;
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                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;
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
+                tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+        /* Stop Time/Calendar from counting */
+        cr = at91_sys_read(AT91_RTC_CR);
+        at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
+
+        at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
+        wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
+        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
+
+        at91_sys_write(AT91_RTC_TIMR,
+                          BIN2BCD(tm->tm_sec) << 0
+                        | BIN2BCD(tm->tm_min) << 8
+                        | BIN2BCD(tm->tm_hour) << 16);
+
+        at91_sys_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_sys_read(AT91_RTC_CR);
+        at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
+
+        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;
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                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_hour = alrm->time.tm_hour;
+        tm.tm_min = alrm->time.tm_min;
+        tm.tm_sec = alrm->time.tm_sec;
+
+        at91_sys_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_sys_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);
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
+                tm.tm_min, tm.tm_sec);
+
+        return 0;
+}
+
+/*
+ * Handle commands from user-space
+ */
+static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
+                        unsigned long arg)
+{
+        int ret = 0;
+
+        pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
+
+        switch (cmd) {
+        case RTC_AIE_OFF:       /* alarm off */
+                at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
+                break;
+        case RTC_AIE_ON:        /* alarm on */
+                at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
+                break;
+        case RTC_UIE_OFF:       /* update off */
+        case RTC_PIE_OFF:       /* periodic off */
+                at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
+                break;
+        case RTC_UIE_ON:        /* update on */
+        case RTC_PIE_ON:        /* periodic on */
+                at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
+                break;
+        case RTC_IRQP_READ:     /* read periodic alarm frequency */
+                ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
+                break;
+        case RTC_IRQP_SET:      /* set periodic alarm frequency */
+                if (arg != AT91_RTC_FREQ)
+                        ret = -EINVAL;
+                break;
+        default:
+                ret = -ENOIOCTLCMD;
+                break;
+        }
+
+        return ret;
+}
+
+/*
+ * Provide additional RTC information in /proc/driver/rtc
+ */
+static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+        unsigned long imr = at91_sys_read(AT91_RTC_IMR);
+
+        seq_printf(seq, "alarm_IRQ\t: %s\n",
+                        (imr & AT91_RTC_ALARM) ? "yes" : "no");
+        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");
+        seq_printf(seq, "periodic_freq\t: %ld\n",
+                        (unsigned long) AT91_RTC_FREQ);
+
+        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;
+
+        rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_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)
+                        events |= (RTC_UF | RTC_IRQF);
+                if (rtsr & AT91_RTC_ACKUPD)
+                        complete(&at91_rtc_updated);
+
+                at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
+
+                rtc_update_irq(&rtc->class_dev, 1, events);
+
+                pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
+                        events >> 8, events & 0x000000FF);
+
+                return IRQ_HANDLED;
+        }
+        return IRQ_NONE;                /* not handled */
+}
+
+static const struct rtc_class_ops at91_rtc_ops = {
+        .ioctl          = at91_rtc_ioctl,
+        .read_time      = at91_rtc_readtime,
+        .set_time       = at91_rtc_settime,
+        .read_alarm     = at91_rtc_readalarm,
+        .set_alarm      = at91_rtc_setalarm,
+        .proc           = at91_rtc_proc,
+};
+
+/*
+ * Initialize and install RTC driver
+ */
+static int __init at91_rtc_probe(struct platform_device *pdev)
+{
+        struct rtc_device *rtc;
+        int ret;
+
+        at91_sys_write(AT91_RTC_CR, 0);
+        at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
+
+        /* Disable all interrupts */
+        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
+                                        AT91_RTC_CALEV);
+
+        ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
+                                IRQF_DISABLED | IRQF_SHARED,
+                                "at91_rtc", pdev);
+        if (ret) {
+                printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
+                                AT91_ID_SYS);
+                return ret;
+        }
+
+        rtc = rtc_device_register(pdev->name, &pdev->dev,
+                                &at91_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc)) {
+                free_irq(AT91_ID_SYS, pdev);
+                return PTR_ERR(rtc);
+        }
+        platform_set_drvdata(pdev, rtc);
+        device_init_wakeup(&pdev->dev, 1);
+
+        printk(KERN_INFO "AT91 Real Time Clock driver.\n");
+        return 0;
+}
+
+/*
+ * Disable and remove the RTC driver
+ */
+static int __devexit at91_rtc_remove(struct platform_device *pdev)
+{
+        struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+        /* Disable all interrupts */
+        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
+                                        AT91_RTC_CALEV);
+        free_irq(AT91_ID_SYS, pdev);
+
+        rtc_device_unregister(rtc);
+        platform_set_drvdata(pdev, NULL);
+        device_init_wakeup(&pdev->dev, 0);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+
+/* AT91RM9200 RTC Power management control */
+
+static struct timespec at91_rtc_delta;
+static u32 at91_rtc_imr;
+
+static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct rtc_time tm;
+        struct timespec time;
+
+        time.tv_nsec = 0;
+
+        /* calculate time delta for suspend */
+        at91_rtc_readtime(&pdev->dev, &tm);
+        rtc_tm_to_time(&tm, &time.tv_sec);
+        save_time_delta(&at91_rtc_delta, &time);
+
+        /* this IRQ is shared with DBGU and other hardware which isn't
+         * necessarily doing PM like we are...
+         */
+        at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
+                        & (AT91_RTC_ALARM|AT91_RTC_SECEV);
+        if (at91_rtc_imr) {
+                if (device_may_wakeup(&pdev->dev))
+                        enable_irq_wake(AT91_ID_SYS);
+                else
+                        at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
+        }
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
+                tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+        return 0;
+}
+
+static int at91_rtc_resume(struct platform_device *pdev)
+{
+        struct rtc_time tm;
+        struct timespec time;
+
+        time.tv_nsec = 0;
+
+        at91_rtc_readtime(&pdev->dev, &tm);
+        rtc_tm_to_time(&tm, &time.tv_sec);
+        restore_time_delta(&at91_rtc_delta, &time);
+
+        if (at91_rtc_imr) {
+                if (device_may_wakeup(&pdev->dev))
+                        disable_irq_wake(AT91_ID_SYS);
+                else
+                        at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
+        }
+
+        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
+                1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
+                tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+        return 0;
+}
+#else
+#define at91_rtc_suspend NULL
+#define at91_rtc_resume  NULL
+#endif
+
+static struct platform_driver at91_rtc_driver = {
+        .probe          = at91_rtc_probe,
+        .remove         = at91_rtc_remove,
+        .suspend        = at91_rtc_suspend,
+        .resume         = at91_rtc_resume,
+        .driver         = {
+                .name   = "at91_rtc",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init at91_rtc_init(void)
+{
+        return platform_driver_register(&at91_rtc_driver);
+}
+
+static void __exit at91_rtc_exit(void)
+{
+        platform_driver_unregister(&at91_rtc_driver);
+}
+
+module_init(at91_rtc_init);
+module_exit(at91_rtc_exit);
+
+MODULE_AUTHOR("Rick Bronson");
+MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
+MODULE_LICENSE("GPL");