--- /dev/null
+/*
+ * TI OMAP1 Real Time Clock interface for Linux
+ *
+ * Copyright (C) 2003 MontaVista Software, Inc.
+ * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
+ *
+ * Copyright (C) 2006 David Brownell (new RTC framework)
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include <asm/mach/time.h>
+
+
+/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
+ * with century-range alarm matching, driven by the 32kHz clock.
+ *
+ * The main user-visible ways it differs from PC RTCs are by omitting
+ * "don't care" alarm fields and sub-second periodic IRQs, and having
+ * an autoadjust mechanism to calibrate to the true oscillator rate.
+ *
+ * Board-specific wiring options include using split power mode with
+ * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
+ * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
+ * low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment.
+ */
+
+#define OMAP_RTC_BASE 0xfffb4800
+
+/* RTC registers */
+#define OMAP_RTC_SECONDS_REG 0x00
+#define OMAP_RTC_MINUTES_REG 0x04
+#define OMAP_RTC_HOURS_REG 0x08
+#define OMAP_RTC_DAYS_REG 0x0C
+#define OMAP_RTC_MONTHS_REG 0x10
+#define OMAP_RTC_YEARS_REG 0x14
+#define OMAP_RTC_WEEKS_REG 0x18
+
+#define OMAP_RTC_ALARM_SECONDS_REG 0x20
+#define OMAP_RTC_ALARM_MINUTES_REG 0x24
+#define OMAP_RTC_ALARM_HOURS_REG 0x28
+#define OMAP_RTC_ALARM_DAYS_REG 0x2c
+#define OMAP_RTC_ALARM_MONTHS_REG 0x30
+#define OMAP_RTC_ALARM_YEARS_REG 0x34
+
+#define OMAP_RTC_CTRL_REG 0x40
+#define OMAP_RTC_STATUS_REG 0x44
+#define OMAP_RTC_INTERRUPTS_REG 0x48
+
+#define OMAP_RTC_COMP_LSB_REG 0x4c
+#define OMAP_RTC_COMP_MSB_REG 0x50
+#define OMAP_RTC_OSC_REG 0x54
+
+/* OMAP_RTC_CTRL_REG bit fields: */
+#define OMAP_RTC_CTRL_SPLIT (1<<7)
+#define OMAP_RTC_CTRL_DISABLE (1<<6)
+#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
+#define OMAP_RTC_CTRL_TEST (1<<4)
+#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
+#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
+#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
+#define OMAP_RTC_CTRL_STOP (1<<0)
+
+/* OMAP_RTC_STATUS_REG bit fields: */
+#define OMAP_RTC_STATUS_POWER_UP (1<<7)
+#define OMAP_RTC_STATUS_ALARM (1<<6)
+#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
+#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
+#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
+#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
+#define OMAP_RTC_STATUS_RUN (1<<1)
+#define OMAP_RTC_STATUS_BUSY (1<<0)
+
+/* OMAP_RTC_INTERRUPTS_REG bit fields: */
+#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
+#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
+
+
+#define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
+#define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
+
+
+/* platform_bus isn't hotpluggable, so for static linkage it'd be safe
+ * to get rid of probe() and remove() code ... too bad the driver struct
+ * remembers probe(), that's about 25% of the runtime footprint!!
+ */
+#ifndef MODULE
+#undef __devexit
+#undef __devexit_p
+#define __devexit __exit
+#define __devexit_p __exit_p
+#endif
+
+
+/* we rely on the rtc framework to handle locking (rtc->ops_lock),
+ * so the only other requirement is that register accesses which
+ * require BUSY to be clear are made with IRQs locally disabled
+ */
+static void rtc_wait_not_busy(void)
+{
+ int count = 0;
+ u8 status;
+
+ /* BUSY may stay active for 1/32768 second (~30 usec) */
+ for (count = 0; count < 50; count++) {
+ status = rtc_read(OMAP_RTC_STATUS_REG);
+ if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
+ break;
+ udelay(1);
+ }
+ /* now we have ~15 usec to read/write various registers */
+}
+
+static irqreturn_t rtc_irq(int irq, void *class_dev)
+{
+ unsigned long events = 0;
+ u8 irq_data;
+
+ irq_data = rtc_read(OMAP_RTC_STATUS_REG);
+
+ /* alarm irq? */
+ if (irq_data & OMAP_RTC_STATUS_ALARM) {
+ rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
+ events |= RTC_IRQF | RTC_AF;
+ }
+
+ /* 1/sec periodic/update irq? */
+ if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
+ events |= RTC_IRQF | RTC_UF;
+
+ rtc_update_irq(class_dev, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_RTC_INTF_DEV
+
+static int
+omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ u8 reg;
+
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ case RTC_AIE_ON:
+ case RTC_UIE_OFF:
+ case RTC_UIE_ON:
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ local_irq_disable();
+ rtc_wait_not_busy();
+ reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
+ switch (cmd) {
+ /* AIE = Alarm Interrupt Enable */
+ case RTC_AIE_OFF:
+ reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
+ break;
+ case RTC_AIE_ON:
+ reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
+ break;
+ /* UIE = Update Interrupt Enable (1/second) */
+ case RTC_UIE_OFF:
+ reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
+ break;
+ case RTC_UIE_ON:
+ reg |= OMAP_RTC_INTERRUPTS_IT_TIMER;
+ break;
+ }
+ rtc_wait_not_busy();
+ rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
+ local_irq_enable();
+
+ return 0;
+}
+
+#else
+#define omap_rtc_ioctl NULL
+#endif
+
+/* this hardware doesn't support "don't care" alarm fields */
+static int tm2bcd(struct rtc_time *tm)
+{
+ if (rtc_valid_tm(tm) != 0)
+ return -EINVAL;
+
+ tm->tm_sec = BIN2BCD(tm->tm_sec);
+ tm->tm_min = BIN2BCD(tm->tm_min);
+ tm->tm_hour = BIN2BCD(tm->tm_hour);
+ tm->tm_mday = BIN2BCD(tm->tm_mday);
+
+ tm->tm_mon = BIN2BCD(tm->tm_mon + 1);
+
+ /* epoch == 1900 */
+ if (tm->tm_year < 100 || tm->tm_year > 199)
+ return -EINVAL;
+ tm->tm_year = BIN2BCD(tm->tm_year - 100);
+
+ return 0;
+}
+
+static void bcd2tm(struct rtc_time *tm)
+{
+ tm->tm_sec = BCD2BIN(tm->tm_sec);
+ tm->tm_min = BCD2BIN(tm->tm_min);
+ tm->tm_hour = BCD2BIN(tm->tm_hour);
+ tm->tm_mday = BCD2BIN(tm->tm_mday);
+ tm->tm_mon = BCD2BIN(tm->tm_mon) - 1;
+ /* epoch == 1900 */
+ tm->tm_year = BCD2BIN(tm->tm_year) + 100;
+}
+
+
+static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ /* we don't report wday/yday/isdst ... */
+ local_irq_disable();
+ rtc_wait_not_busy();
+
+ tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
+ tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
+ tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
+ tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
+ tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
+ tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
+
+ local_irq_enable();
+
+ bcd2tm(tm);
+ return 0;
+}
+
+static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ if (tm2bcd(tm) < 0)
+ return -EINVAL;
+ local_irq_disable();
+ rtc_wait_not_busy();
+
+ rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
+ rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
+ rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
+ rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
+ rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
+ rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
+
+ local_irq_enable();
+
+ return 0;
+}
+
+static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ local_irq_disable();
+ rtc_wait_not_busy();
+
+ alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
+ alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
+ alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
+ alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
+ alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
+ alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
+
+ local_irq_enable();
+
+ bcd2tm(&alm->time);
+ alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
+ & OMAP_RTC_INTERRUPTS_IT_ALARM);
+
+ return 0;
+}
+
+static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ u8 reg;
+
+ /* Much userspace code uses RTC_ALM_SET, thus "don't care" for
+ * day/month/year specifies alarms up to 24 hours in the future.
+ * So we need to handle that ... but let's ignore the "don't care"
+ * values for hours/minutes/seconds.
+ */
+ if (alm->time.tm_mday <= 0
+ && alm->time.tm_mon < 0
+ && alm->time.tm_year < 0) {
+ struct rtc_time tm;
+ unsigned long now, then;
+
+ omap_rtc_read_time(dev, &tm);
+ rtc_tm_to_time(&tm, &now);
+
+ alm->time.tm_mday = tm.tm_mday;
+ alm->time.tm_mon = tm.tm_mon;
+ alm->time.tm_year = tm.tm_year;
+ rtc_tm_to_time(&alm->time, &then);
+
+ /* sometimes the alarm wraps into tomorrow */
+ if (then < now) {
+ rtc_time_to_tm(now + 24 * 60 * 60, &tm);
+ alm->time.tm_mday = tm.tm_mday;
+ alm->time.tm_mon = tm.tm_mon;
+ alm->time.tm_year = tm.tm_year;
+ }
+ }
+
+ if (tm2bcd(&alm->time) < 0)
+ return -EINVAL;
+
+ local_irq_disable();
+ rtc_wait_not_busy();
+
+ rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
+ rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
+ rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
+ rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
+ rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
+ rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
+
+ reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
+ if (alm->enabled)
+ reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
+ else
+ reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
+ rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
+
+ local_irq_enable();
+
+ return 0;
+}
+
+static struct rtc_class_ops omap_rtc_ops = {
+ .ioctl = omap_rtc_ioctl,
+ .read_time = omap_rtc_read_time,
+ .set_time = omap_rtc_set_time,
+ .read_alarm = omap_rtc_read_alarm,
+ .set_alarm = omap_rtc_set_alarm,
+};
+
+static int omap_rtc_alarm;
+static int omap_rtc_timer;
+
+static int __devinit omap_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res, *mem;
+ struct rtc_device *rtc;
+ u8 reg, new_ctrl;
+
+ omap_rtc_timer = platform_get_irq(pdev, 0);
+ if (omap_rtc_timer <= 0) {
+ pr_debug("%s: no update irq?\n", pdev->name);
+ return -ENOENT;
+ }
+
+ omap_rtc_alarm = platform_get_irq(pdev, 1);
+ if (omap_rtc_alarm <= 0) {
+ pr_debug("%s: no alarm irq?\n", pdev->name);
+ return -ENOENT;
+ }
+
+ /* NOTE: using static mapping for RTC registers */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res && res->start != OMAP_RTC_BASE) {
+ pr_debug("%s: RTC registers at %08x, expected %08x\n",
+ pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
+ return -ENOENT;
+ }
+
+ if (res)
+ mem = request_mem_region(res->start,
+ res->end - res->start + 1,
+ pdev->name);
+ else
+ mem = NULL;
+ if (!mem) {
+ pr_debug("%s: RTC registers at %08x are not free\n",
+ pdev->name, OMAP_RTC_BASE);
+ return -EBUSY;
+ }
+
+ rtc = rtc_device_register(pdev->name, &pdev->dev,
+ &omap_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ pr_debug("%s: can't register RTC device, err %ld\n",
+ pdev->name, PTR_ERR(rtc));
+ goto fail;
+ }
+ platform_set_drvdata(pdev, rtc);
+ class_set_devdata(&rtc->class_dev, mem);
+
+ /* clear pending irqs, and set 1/second periodic,
+ * which we'll use instead of update irqs
+ */
+ rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
+
+ /* clear old status */
+ reg = rtc_read(OMAP_RTC_STATUS_REG);
+ if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
+ pr_info("%s: RTC power up reset detected\n",
+ pdev->name);
+ rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
+ }
+ if (reg & (u8) OMAP_RTC_STATUS_ALARM)
+ rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
+
+ /* handle periodic and alarm irqs */
+ if (request_irq(omap_rtc_timer, rtc_irq, SA_INTERRUPT,
+ rtc->class_dev.class_id, &rtc->class_dev)) {
+ pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
+ pdev->name, omap_rtc_timer);
+ goto fail0;
+ }
+ if (request_irq(omap_rtc_alarm, rtc_irq, SA_INTERRUPT,
+ rtc->class_dev.class_id, &rtc->class_dev)) {
+ pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
+ pdev->name, omap_rtc_alarm);
+ goto fail1;
+ }
+
+ /* On boards with split power, RTC_ON_NOFF won't reset the RTC */
+ reg = rtc_read(OMAP_RTC_CTRL_REG);
+ if (reg & (u8) OMAP_RTC_CTRL_STOP)
+ pr_info("%s: already running\n", pdev->name);
+
+ /* force to 24 hour mode */
+ new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
+ new_ctrl |= OMAP_RTC_CTRL_STOP;
+
+ /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
+ *
+ * - Boards wired so that RTC_WAKE_INT does something, and muxed
+ * right (W13_1610_RTC_WAKE_INT is the default after chip reset),
+ * should initialize the device wakeup flag appropriately.
+ *
+ * - Boards wired so RTC_ON_nOFF is used as the reset signal,
+ * rather than nPWRON_RESET, should forcibly enable split
+ * power mode. (Some chip errata report that RTC_CTRL_SPLIT
+ * is write-only, and always reads as zero...)
+ */
+ device_init_wakeup(&pdev->dev, 0);
+
+ if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
+ pr_info("%s: split power mode\n", pdev->name);
+
+ if (reg != new_ctrl)
+ rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
+
+ return 0;
+
+fail1:
+ free_irq(omap_rtc_timer, NULL);
+fail0:
+ rtc_device_unregister(rtc);
+fail:
+ release_resource(mem);
+ return -EIO;
+}
+
+static int __devexit omap_rtc_remove(struct platform_device *pdev)
+{
+ struct rtc_device *rtc = platform_get_drvdata(pdev);;
+
+ device_init_wakeup(&pdev->dev, 0);
+
+ /* leave rtc running, but disable irqs */
+ rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
+
+ free_irq(omap_rtc_timer, rtc);
+ free_irq(omap_rtc_alarm, rtc);
+
+ release_resource(class_get_devdata(&rtc->class_dev));
+ rtc_device_unregister(rtc);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static struct timespec rtc_delta;
+static u8 irqstat;
+
+static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct rtc_time rtc_tm;
+ struct timespec time;
+
+ time.tv_nsec = 0;
+ omap_rtc_read_time(NULL, &rtc_tm);
+ rtc_tm_to_time(&rtc_tm, &time.tv_sec);
+
+ save_time_delta(&rtc_delta, &time);
+ irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
+
+ /* FIXME the RTC alarm is not currently acting as a wakeup event
+ * source, and in fact this enable() call is just saving a flag
+ * that's never used...
+ */
+ if (device_may_wakeup(&pdev->dev))
+ enable_irq_wake(omap_rtc_alarm);
+ else
+ rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
+
+ return 0;
+}
+
+static int omap_rtc_resume(struct platform_device *pdev)
+{
+ struct rtc_time rtc_tm;
+ struct timespec time;
+
+ time.tv_nsec = 0;
+ omap_rtc_read_time(NULL, &rtc_tm);
+ rtc_tm_to_time(&rtc_tm, &time.tv_sec);
+
+ restore_time_delta(&rtc_delta, &time);
+ if (device_may_wakeup(&pdev->dev))
+ disable_irq_wake(omap_rtc_alarm);
+ else
+ rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
+ return 0;
+}
+
+#else
+#define omap_rtc_suspend NULL
+#define omap_rtc_resume NULL
+#endif
+
+static void omap_rtc_shutdown(struct platform_device *pdev)
+{
+ rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
+}
+
+MODULE_ALIAS("omap_rtc");
+static struct platform_driver omap_rtc_driver = {
+ .probe = omap_rtc_probe,
+ .remove = __devexit_p(omap_rtc_remove),
+ .suspend = omap_rtc_suspend,
+ .resume = omap_rtc_resume,
+ .shutdown = omap_rtc_shutdown,
+ .driver = {
+ .name = "omap_rtc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init rtc_init(void)
+{
+ return platform_driver_register(&omap_rtc_driver);
+}
+module_init(rtc_init);
+
+static void __exit rtc_exit(void)
+{
+ platform_driver_unregister(&omap_rtc_driver);
+}
+module_exit(rtc_exit);
+
+MODULE_AUTHOR("George G. Davis (and others)");
+MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff