]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
Add OMAP RTC driver
authorTony Lindgren <tony@atomide.com>
Mon, 9 May 2005 21:31:33 +0000 (14:31 -0700)
committerTony Lindgren <tony@atomide.com>
Mon, 9 May 2005 21:31:33 +0000 (14:31 -0700)
Adds OMAP RTC driver.

Signed-off-by: Tony Lindgren <tony@atomide.com>
drivers/char/Kconfig
drivers/char/Makefile
drivers/char/omap-rtc.c [new file with mode: 0644]
drivers/char/omap-rtc.h [new file with mode: 0644]

index 5ed6515ae01fe0fee127d23fa18717b688a7eb24..5a93b678fc743940e2441dcceed55dcf44722905 100644 (file)
@@ -761,6 +761,11 @@ config GEN_RTC_X
 config EFI_RTC
        bool "EFI Real Time Clock Services"
        depends on IA64
+config OMAP_RTC
+       bool "TI OMAP Real Time Clock"
+       depends on ARCH_OMAP1510 || ARCH_OMAP16XX || ARCH_OMAP730
+       help
+         Support for TI OMAP RTC
 
 config DS1302
        tristate "DS1302 RTC support"
index e3f5c32aac55d24312054b1a0bc32d8c2d84e4df..b7f15edbdeada2d3093cca6516f01d6f18feb534 100644 (file)
@@ -65,6 +65,7 @@ obj-$(CONFIG_SGI_IP27_RTC) += ip27-rtc.o
 obj-$(CONFIG_DS1302) += ds1302.o
 obj-$(CONFIG_S3C2410_RTC) += s3c2410-rtc.o
 obj-$(CONFIG_RTC_VR41XX) += vr41xx_rtc.o
+obj-$(CONFIG_OMAP_RTC)+= omap-rtc.o
 ifeq ($(CONFIG_GENERIC_NVRAM),y)
   obj-$(CONFIG_NVRAM) += generic_nvram.o
 else
diff --git a/drivers/char/omap-rtc.c b/drivers/char/omap-rtc.c
new file mode 100644 (file)
index 0000000..84cba75
--- /dev/null
@@ -0,0 +1,791 @@
+/*
+ *     TI OMAP Real Time Clock interface for Linux     
+ *
+ *     Copyright (C) 2003 MontaVista Software, Inc.
+ *      Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
+ *
+ *     Initially based on linux-2.4.20/drivers/char/rtc.c
+ *     Copyright (C) 1996 Paul Gortmaker
+ *
+ *     This driver allows use of the real time clock (built into
+ *     nearly all computers) from user space. It exports the /dev/rtc
+ *     interface supporting various ioctl() and also the
+ *     /proc/driver/rtc pseudo-file for status information.
+ *
+ *     The ioctls can be used to set the interrupt behaviour from the
+ *     RTC via IRQs. Then the /dev/rtc interface can be used to make
+ *     use of RTC interrupts, be they time update or alarm based.
+ *
+ *     The /dev/rtc interface will block on reads until an interrupt
+ *     has been received. If a RTC interrupt has already happened,
+ *     it will output an unsigned long and then block. The output value
+ *     contains the interrupt status in the low byte and the number of
+ *     interrupts since the last read in the remaining high bytes. The 
+ *     /dev/rtc interface can also be used with the select(2) call.
+ *
+ *     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.
+ *
+ *     Based on other minimal char device drivers, like Alan's
+ *     watchdog, Ted's random, etc. etc.
+ *
+ * Change Log :
+ *      v1.0    <gdavis@mvista.com> Initial version based on rtc.c v1.10e
+ *              <ramakrishnan@india.ti.com> Added support for 2.6 kernel, 
+ *                  - changed the return value of the interrupt handler
+ */
+
+#define RTC_VERSION            "1.0"
+
+/*
+ *     Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
+ *     interrupts disabled.
+ *     REVISIT: Elaborate on OMAP1510 TRM 15uS BUSY access rule.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+#include <linux/rtc.h>
+
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include "omap-rtc.h"
+
+extern spinlock_t rtc_lock;
+
+
+/* OMAP RTC register access macros: */
+
+#define CMOS_READ(addr)                omap_readb(addr)
+#define CMOS_WRITE(val, addr)  omap_writeb(val, addr)
+
+
+/* Local BCD/BIN conversion macros: */
+#ifdef BCD_TO_BIN
+#undef BCD_TO_BIN
+#endif
+#define BCD_TO_BIN(val)        ((val)=((val)&15) + ((val)>>4)*10)
+#ifdef BIN_TO_BCD
+#undef BIN_TO_BCD
+#endif
+#define BIN_TO_BCD(val)        ((val)=(((val)/10)<<4) + (val)%10)
+
+
+/*
+ *     We sponge a minor off of the misc major. No need slurping
+ *     up another valuable major dev number for this. If you add
+ *     an ioctl, make sure you don't conflict with SPARC's RTC
+ *     ioctls.
+ */
+
+static struct fasync_struct *rtc_async_queue;
+
+static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
+
+static ssize_t rtc_read(struct file *file, char *buf,
+                       size_t count, loff_t *ppos);
+
+static int rtc_ioctl(struct inode *inode, struct file *file,
+                    unsigned int cmd, unsigned long arg);
+
+static unsigned int rtc_poll(struct file *file, poll_table *wait);
+
+static void get_rtc_time (struct rtc_time *rtc_tm);
+static void get_rtc_alm_time (struct rtc_time *alm_tm);
+
+static void set_rtc_irq_bit(unsigned char bit);
+static void mask_rtc_irq_bit(unsigned char bit);
+
+static inline unsigned char rtc_is_updating(void);
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+                         int count, int *eof, void *data);
+
+/*
+ *     Bits in rtc_status. (7 bits of room for future expansion)
+ */
+
+#define RTC_IS_OPEN            0x01    /* means /dev/rtc is in use     */
+
+/*
+ * REVISIT: fix this comment:
+ * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
+ * protected by the big kernel lock.
+ */
+static unsigned long rtc_status = 0;   /* bitmapped status byte.       */
+static unsigned long rtc_irq_data = 0; /* our output to the world      */
+
+/*
+ *     If this driver ever becomes modularised, it will be really nice
+ *     to make the epoch retain its value across module reload...
+ */
+
+static unsigned long epoch = 1900;     /* year corresponding to 0x00   */
+
+static const unsigned char days_in_mo[] = 
+{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+/*
+ *     A very tiny interrupt handler. It runs with SA_INTERRUPT set.
+ */
+
+static irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+       /*
+        *      Either an alarm interrupt or update complete interrupt.
+        *      We store the status in the low byte and the number of
+        *      interrupts received since the last read in the remainder
+        *      of rtc_irq_data.
+        */
+
+       spin_lock (&rtc_lock);
+
+       rtc_irq_data += 0x100;
+       rtc_irq_data &= ~0xff;
+       rtc_irq_data |= CMOS_READ(OMAP_RTC_STATUS_REG);
+
+       if (rtc_irq_data & OMAP_RTC_STATUS_ALARM)
+               CMOS_WRITE(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
+
+       spin_unlock (&rtc_lock);
+
+       /* Now do the rest of the actions */
+       wake_up_interruptible(&rtc_wait);       
+
+       kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
+       return IRQ_HANDLED;
+}
+
+/*
+ *     Now all the various file operations that we export.
+ */
+
+static ssize_t rtc_read(struct file *file, char *buf,
+                       size_t count, loff_t *ppos)
+{
+       DECLARE_WAITQUEUE(wait, current);
+       unsigned long data;
+       ssize_t retval;
+       
+       if (count < sizeof(unsigned long))
+               return -EINVAL;
+
+       add_wait_queue(&rtc_wait, &wait);
+       set_current_state(TASK_INTERRUPTIBLE);
+
+       for (;;) {
+               spin_lock_irq (&rtc_lock);
+               data = rtc_irq_data;
+               if (data != 0) {
+                       rtc_irq_data = 0;
+                       break;
+               }
+               spin_unlock_irq (&rtc_lock);
+
+               if (file->f_flags & O_NONBLOCK) {
+                       retval = -EAGAIN;
+                       goto out;
+               }
+               if (signal_pending(current)) {
+                       retval = -ERESTARTSYS;
+                       goto out;
+               }
+               schedule();
+       }
+
+       spin_unlock_irq (&rtc_lock);
+       retval = put_user(data, (unsigned long *)buf); 
+       if (!retval)
+               retval = sizeof(unsigned long); 
+ out:
+       set_current_state(TASK_RUNNING);
+       remove_wait_queue(&rtc_wait, &wait);
+
+       return retval;
+}
+
+static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+                    unsigned long arg)
+{
+       struct rtc_time wtime; 
+
+       switch (cmd) {
+       case RTC_AIE_OFF:       /* Mask alarm int. enab. bit    */
+       {
+               mask_rtc_irq_bit(OMAP_RTC_INTERRUPTS_IT_ALARM);
+               return 0;
+       }
+       case RTC_AIE_ON:        /* Allow alarm interrupts.      */
+       {
+               set_rtc_irq_bit(OMAP_RTC_INTERRUPTS_IT_ALARM);
+               return 0;
+       }
+       case RTC_UIE_OFF:       /* Mask ints from RTC updates.  */
+       {
+               mask_rtc_irq_bit(OMAP_RTC_INTERRUPTS_IT_TIMER);
+               return 0;
+       }
+       case RTC_UIE_ON:        /* Allow ints for RTC updates.  */
+       {
+               set_rtc_irq_bit(OMAP_RTC_INTERRUPTS_IT_TIMER);
+               return 0;
+       }
+       case RTC_ALM_READ:      /* Read the present alarm time */
+       {
+               /*
+                * This returns a struct rtc_time. Reading >= 0xc0
+                * means "don't care" or "match all". Only the tm_hour,
+                * tm_min, and tm_sec values are filled in.
+                */
+               memset(&wtime, 0, sizeof(struct rtc_time));
+               get_rtc_alm_time(&wtime);
+               break; 
+       }
+       case RTC_ALM_SET:       /* Store a time into the alarm */
+       {
+               struct rtc_time alm_tm;
+               unsigned char mon, day, hrs, min, sec, leap_yr;
+               unsigned int yrs;
+
+               if (copy_from_user(&alm_tm, (struct rtc_time*)arg,
+                                  sizeof(struct rtc_time)))
+                       return -EFAULT;
+
+               yrs = alm_tm.tm_year + 1900;
+               mon = alm_tm.tm_mon + 1;
+               day = alm_tm.tm_mday;
+               hrs = alm_tm.tm_hour;
+               min = alm_tm.tm_min;
+               sec = alm_tm.tm_sec;
+
+               if (yrs < 1970)
+                       return -EINVAL;
+
+               leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
+
+               if ((mon > 12) || (day == 0))
+                       return -EINVAL;
+
+               if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
+                       return -EINVAL;
+                       
+               if ((hrs >= 24) || (min >= 60) || (sec >= 60))
+                       return -EINVAL;
+
+               if ((yrs -= epoch) > 255)    /* They are unsigned */
+                       return -EINVAL;
+
+               if (yrs > 169) {
+                       return -EINVAL;
+               }
+
+               if (yrs >= 100)
+                       yrs -= 100;
+
+               BIN_TO_BCD(sec);
+               BIN_TO_BCD(min);
+               BIN_TO_BCD(hrs);
+               BIN_TO_BCD(day);
+               BIN_TO_BCD(mon);
+               BIN_TO_BCD(yrs);
+
+               spin_lock_irq(&rtc_lock);
+               CMOS_WRITE(yrs, OMAP_RTC_ALARM_YEARS_REG);
+               CMOS_WRITE(mon, OMAP_RTC_ALARM_MONTHS_REG);
+               CMOS_WRITE(day, OMAP_RTC_ALARM_DAYS_REG);
+               CMOS_WRITE(hrs, OMAP_RTC_ALARM_HOURS_REG);
+               CMOS_WRITE(min, OMAP_RTC_ALARM_MINUTES_REG);
+               CMOS_WRITE(sec, OMAP_RTC_ALARM_SECONDS_REG);
+               spin_unlock_irq(&rtc_lock);
+
+               return 0;
+       }
+       case RTC_RD_TIME:       /* Read the time/date from RTC  */
+       {
+               memset(&wtime, 0, sizeof(struct rtc_time));
+               get_rtc_time(&wtime);
+               break;
+       }
+       case RTC_SET_TIME:      /* Set the RTC */
+       {
+               struct rtc_time rtc_tm;
+               unsigned char mon, day, hrs, min, sec, leap_yr;
+               unsigned char save_control;
+               unsigned int yrs;
+
+               if (!capable(CAP_SYS_TIME))
+                       return -EACCES;
+
+               if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
+                                  sizeof(struct rtc_time)))
+                       return -EFAULT;
+
+               yrs = rtc_tm.tm_year + 1900;
+               mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
+               day = rtc_tm.tm_mday;
+               hrs = rtc_tm.tm_hour;
+               min = rtc_tm.tm_min;
+               sec = rtc_tm.tm_sec;
+
+               if (yrs < 1970)
+                       return -EINVAL;
+
+               leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
+
+               if ((mon > 12) || (day == 0))
+                       return -EINVAL;
+
+               if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
+                       return -EINVAL;
+
+               if ((hrs >= 24) || (min >= 60) || (sec >= 60))
+                       return -EINVAL;
+
+               if ((yrs -= epoch) > 255)    /* They are unsigned */
+                       return -EINVAL;
+
+               if (yrs > 169) {
+                       return -EINVAL;
+               }
+
+               if (yrs >= 100)
+                       yrs -= 100;
+
+               BIN_TO_BCD(sec);
+               BIN_TO_BCD(min);
+               BIN_TO_BCD(hrs);
+               BIN_TO_BCD(day);
+               BIN_TO_BCD(mon);
+               BIN_TO_BCD(yrs);
+
+               spin_lock_irq(&rtc_lock);
+               save_control = CMOS_READ(OMAP_RTC_CTRL_REG);
+               CMOS_WRITE((save_control & ~OMAP_RTC_CTRL_STOP),
+                          OMAP_RTC_CTRL_REG);
+               CMOS_WRITE(yrs, OMAP_RTC_YEARS_REG);
+               CMOS_WRITE(mon, OMAP_RTC_MONTHS_REG);
+               CMOS_WRITE(day, OMAP_RTC_DAYS_REG);
+               CMOS_WRITE(hrs, OMAP_RTC_HOURS_REG);
+               CMOS_WRITE(min, OMAP_RTC_MINUTES_REG);
+               CMOS_WRITE(sec, OMAP_RTC_SECONDS_REG);
+               CMOS_WRITE((save_control | OMAP_RTC_CTRL_STOP),
+                          OMAP_RTC_CTRL_REG);
+               spin_unlock_irq(&rtc_lock);
+
+               return 0;
+       }
+       case RTC_EPOCH_READ:    /* Read the epoch.      */
+       {
+               return put_user (epoch, (unsigned long *)arg);
+       }
+       case RTC_EPOCH_SET:     /* Set the epoch.       */
+       {
+               /* 
+                * There were no RTC clocks before 1900.
+                */
+               if (arg < 1900)
+                       return -EINVAL;
+
+               if (!capable(CAP_SYS_TIME))
+                       return -EACCES;
+
+               epoch = arg;
+               return 0;
+       }
+       default:
+#if    !defined(CONFIG_ARCH_OMAP)
+               return -ENOTTY;
+#else
+               return -EINVAL;
+#endif
+       }
+       return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
+}
+
+/*
+ *     We enforce only one user at a time here with the open/close.
+ *     Also clear the previous interrupt data on an open, and clean
+ *     up things on a close.
+ */
+
+/* We use rtc_lock to protect against concurrent opens. So the BKL is not
+ * needed here. Or anywhere else in this driver. */
+static int rtc_open(struct inode *inode, struct file *file)
+{
+       spin_lock_irq (&rtc_lock);
+
+       if(rtc_status & RTC_IS_OPEN)
+               goto out_busy;
+
+       rtc_status |= RTC_IS_OPEN;
+
+       rtc_irq_data = 0;
+       spin_unlock_irq (&rtc_lock);
+       return 0;
+
+out_busy:
+       spin_unlock_irq (&rtc_lock);
+       return -EBUSY;
+}
+
+static int rtc_fasync (int fd, struct file *filp, int on)
+
+{
+       return fasync_helper (fd, filp, on, &rtc_async_queue);
+}
+
+static int rtc_release(struct inode *inode, struct file *file)
+{
+       unsigned char tmp;
+
+       /*
+        * Turn off all interrupts once the device is no longer
+        * in use, and clear the data.
+        */
+
+       spin_lock_irq(&rtc_lock);
+       tmp = CMOS_READ(OMAP_RTC_INTERRUPTS_REG);
+       tmp &=  ~OMAP_RTC_INTERRUPTS_IT_ALARM;
+       tmp &=  ~OMAP_RTC_INTERRUPTS_IT_TIMER;
+       CMOS_WRITE(tmp, OMAP_RTC_INTERRUPTS_REG);
+       spin_unlock_irq(&rtc_lock);
+
+       if (file->f_flags & FASYNC) {
+               rtc_fasync (-1, file, 0);
+       }
+
+       spin_lock_irq (&rtc_lock);
+       rtc_irq_data = 0;
+       spin_unlock_irq (&rtc_lock);
+
+       /* No need for locking -- nobody else can do anything until this rmw
+        * is committed, and we don't implement timer support in omap-rtc.
+        */
+       rtc_status &= ~RTC_IS_OPEN;
+       return 0;
+}
+
+/* Called without the kernel lock - fine */
+static unsigned int rtc_poll(struct file *file, poll_table *wait)
+{
+       unsigned long l;
+
+       poll_wait(file, &rtc_wait, wait);
+
+       spin_lock_irq (&rtc_lock);
+       l = rtc_irq_data;
+       spin_unlock_irq (&rtc_lock);
+
+       if (l != 0)
+               return POLLIN | POLLRDNORM;
+       return 0;
+}
+
+/*
+ *     The various file operations we support.
+ */
+
+static struct file_operations rtc_fops = {
+       owner:          THIS_MODULE,
+       llseek:         no_llseek,
+       read:           rtc_read,
+       poll:           rtc_poll,
+       ioctl:          rtc_ioctl,
+       open:           rtc_open,
+       release:        rtc_release,
+       fasync:         rtc_fasync,
+};
+
+static struct miscdevice rtc_dev=
+{
+       RTC_MINOR,
+       "rtc",
+       &rtc_fops
+};
+
+static int __init rtc_init(void)
+{
+       if (!request_region(OMAP_RTC_VIRT_BASE, OMAP_RTC_SIZE,
+                           rtc_dev.name)) {
+               printk(KERN_ERR "%s: RTC I/O port %d is not free.\n",
+                      rtc_dev.name, OMAP_RTC_VIRT_BASE);
+               return -EIO;
+       }
+
+       if (CMOS_READ(OMAP_RTC_STATUS_REG) & OMAP_RTC_STATUS_POWER_UP) {
+               printk(KERN_WARNING "%s: RTC power up reset detected.\n",
+                      rtc_dev.name);
+               /* Clear OMAP_RTC_STATUS_POWER_UP */
+               CMOS_WRITE(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
+       }
+
+       if (CMOS_READ(OMAP_RTC_STATUS_REG) & OMAP_RTC_STATUS_ALARM) {
+               printk(KERN_WARNING "%s: Clearing RTC ALARM interrupt.\n",
+                      rtc_dev.name);
+               /* Clear OMAP_RTC_STATUS_ALARM */
+               CMOS_WRITE(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
+       }
+
+       if (!(CMOS_READ(OMAP_RTC_CTRL_REG) & OMAP_RTC_CTRL_STOP)) {
+               printk(KERN_INFO "%s: Enabling RTC.\n", rtc_dev.name);
+               CMOS_WRITE(OMAP_RTC_CTRL_STOP, OMAP_RTC_CTRL_REG);
+       }
+
+       if (request_irq(INT_RTC_TIMER, rtc_interrupt, SA_INTERRUPT,
+                       rtc_dev.name, NULL)) {
+               printk(KERN_ERR "%s: RTC timer interrupt IRQ%d is not free.\n",
+                      rtc_dev.name, INT_RTC_TIMER);
+               release_region(OMAP_RTC_VIRT_BASE, OMAP_RTC_SIZE);
+               return -EIO;
+       }
+
+       if (request_irq(INT_RTC_ALARM, rtc_interrupt, SA_INTERRUPT,
+                       "omap-rtc alarm", NULL)) {
+               printk(KERN_ERR "%s: RTC alarm interrupt IRQ%d is not free.\n",
+                      rtc_dev.name, INT_RTC_ALARM);
+               release_region(OMAP_RTC_VIRT_BASE, OMAP_RTC_SIZE);
+               return -EIO;
+       }
+
+       spin_lock_init(&rtc_lock);
+       misc_register(&rtc_dev);
+       create_proc_read_entry ("driver/rtc", 0, 0, rtc_read_proc, NULL);
+
+       printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
+
+       return 0;
+}
+
+static void __exit rtc_exit (void)
+{
+       free_irq (INT_RTC_TIMER, NULL);
+       free_irq (INT_RTC_ALARM, NULL);
+
+       remove_proc_entry ("driver/rtc", NULL);
+       misc_deregister(&rtc_dev);
+
+       release_region (OMAP_RTC_VIRT_BASE, OMAP_RTC_SIZE);
+}
+
+/*
+ *     Info exported via "/proc/driver/rtc".
+ */
+
+static int rtc_proc_output (char *buf)
+{
+#define YN(value) ((value) ? "yes" : "no")
+#define NY(value) ((value) ? "no" : "yes")
+       char *p;
+       struct rtc_time tm;
+
+       p = buf;
+
+       get_rtc_time(&tm);
+
+       /*
+        * There is no way to tell if the luser has the RTC set for local
+        * time or for Universal Standard Time (GMT). Probably local though.
+        */
+       p += sprintf(p,
+                    "rtc_time\t: %02d:%02d:%02d\n"
+                    "rtc_date\t: %04d-%02d-%02d\n"
+                    "rtc_epoch\t: %04lu\n",
+                    tm.tm_hour, tm.tm_min, tm.tm_sec,
+                    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
+
+       get_rtc_alm_time(&tm);
+
+       /*
+        * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
+        * match any value for that particular field. Values that are
+        * greater than a valid time, but less than 0xc0 shouldn't appear.
+        */
+       p += sprintf(p,
+                    "alarm_time\t: %02d:%02d:%02d\n"
+                    "alarm_date\t: %04d-%02d-%02d\n",
+                    tm.tm_hour, tm.tm_min, tm.tm_sec,
+                    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+
+       p += sprintf(p,
+                    "BCD\t\t: %s\n"
+                    "24hr\t\t: %s\n"
+                    "alarm_IRQ\t: %s\n"
+                    "update_IRQ\t: %s\n"
+                    "update_rate\t: %ud\n",
+                    YN(1),
+                    YN(1),
+                    YN(CMOS_READ(OMAP_RTC_INTERRUPTS_REG) &
+                       OMAP_RTC_INTERRUPTS_IT_ALARM),
+                    YN(CMOS_READ(OMAP_RTC_INTERRUPTS_REG) &
+                       OMAP_RTC_INTERRUPTS_IT_TIMER),
+                    CMOS_READ(OMAP_RTC_INTERRUPTS_REG) & 3 /* REVISIT */);
+
+       return  p - buf;
+#undef YN
+#undef NY
+}
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+                         int count, int *eof, void *data)
+{
+        int len = rtc_proc_output (page);
+        if (len <= off+count) *eof = 1;
+        *start = page + off;
+        len -= off;
+        if (len>count) len = count;
+        if (len<0) len = 0;
+        return len;
+}
+
+/*
+ * Returns true if a clock update is in progress
+ */
+/* FIXME shouldn't this be above rtc_init to make it fully inlined? */
+static inline unsigned char rtc_is_updating(void)
+{
+       unsigned char uip;
+
+       spin_lock_irq(&rtc_lock);
+       uip = (CMOS_READ(OMAP_RTC_STATUS_REG) & OMAP_RTC_STATUS_BUSY);
+       spin_unlock_irq(&rtc_lock);
+       return uip;
+}
+
+static void get_rtc_time(struct rtc_time *rtc_tm)
+{
+       unsigned char ctrl;
+
+       /* REVISIT: Fix this comment!!!
+        * read RTC once any update in progress is done. The update
+        * can take just over 2ms. We wait 10 to 20ms. There is no need to
+        * to poll-wait (up to 1s - eeccch) for the falling edge of OMAP_RTC_STATUS_BUSY.
+        * If you need to know *exactly* when a second has started, enable
+        * periodic update complete interrupts, (via ioctl) and then 
+        * immediately read /dev/rtc which will block until you get the IRQ.
+        * Once the read clears, read the RTC time (again via ioctl). Easy.
+        */
+
+#if    0 /* REVISIT: This need to do as the TRM says. */
+       unsigned long uip_watchdog = jiffies;
+       if (rtc_is_updating() != 0)
+               while (jiffies - uip_watchdog < 2*HZ/100) {
+                       barrier();
+                       cpu_relax();
+               }
+#endif
+
+       /*
+        * Only the values that we read from the RTC are set. We leave
+        * tm_wday, tm_yday and tm_isdst untouched. Even though the
+        * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
+        * by the RTC when initially set to a non-zero value.
+        */
+       spin_lock_irq(&rtc_lock);
+       rtc_tm->tm_sec = CMOS_READ(OMAP_RTC_SECONDS_REG);
+       rtc_tm->tm_min = CMOS_READ(OMAP_RTC_MINUTES_REG);
+       rtc_tm->tm_hour = CMOS_READ(OMAP_RTC_HOURS_REG);
+       rtc_tm->tm_mday = CMOS_READ(OMAP_RTC_DAYS_REG);
+       rtc_tm->tm_mon = CMOS_READ(OMAP_RTC_MONTHS_REG);
+       rtc_tm->tm_year = CMOS_READ(OMAP_RTC_YEARS_REG);
+       ctrl = CMOS_READ(OMAP_RTC_CTRL_REG);
+       spin_unlock_irq(&rtc_lock);
+
+       BCD_TO_BIN(rtc_tm->tm_sec);
+       BCD_TO_BIN(rtc_tm->tm_min);
+       BCD_TO_BIN(rtc_tm->tm_hour);
+       BCD_TO_BIN(rtc_tm->tm_mday);
+       BCD_TO_BIN(rtc_tm->tm_mon);
+       BCD_TO_BIN(rtc_tm->tm_year);
+
+       /*
+        * Account for differences between how the RTC uses the values
+        * and how they are defined in a struct rtc_time;
+        */
+       if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
+               rtc_tm->tm_year += 100;
+
+       rtc_tm->tm_mon--;
+}
+
+static void get_rtc_alm_time(struct rtc_time *alm_tm)
+{
+       unsigned char ctrl;
+
+       spin_lock_irq(&rtc_lock);
+       alm_tm->tm_sec = CMOS_READ(OMAP_RTC_ALARM_SECONDS_REG);
+       alm_tm->tm_min = CMOS_READ(OMAP_RTC_ALARM_MINUTES_REG);
+       alm_tm->tm_hour = CMOS_READ(OMAP_RTC_ALARM_HOURS_REG);
+       alm_tm->tm_mday = CMOS_READ(OMAP_RTC_ALARM_DAYS_REG);
+       alm_tm->tm_mon = CMOS_READ(OMAP_RTC_ALARM_MONTHS_REG);
+       alm_tm->tm_year = CMOS_READ(OMAP_RTC_ALARM_YEARS_REG);
+       ctrl = CMOS_READ(OMAP_RTC_CTRL_REG);
+       spin_unlock_irq(&rtc_lock);
+
+       BCD_TO_BIN(alm_tm->tm_sec);
+       BCD_TO_BIN(alm_tm->tm_min);
+       BCD_TO_BIN(alm_tm->tm_hour);
+       BCD_TO_BIN(alm_tm->tm_mday);
+       BCD_TO_BIN(alm_tm->tm_mon);
+       BCD_TO_BIN(alm_tm->tm_year);
+
+       /*
+        * Account for differences between how the RTC uses the values
+        * and how they are defined in a struct rtc_time;
+        */
+       if ((alm_tm->tm_year += (epoch - 1900)) <= 69)
+               alm_tm->tm_year += 100;
+
+       alm_tm->tm_mon--;
+}
+
+/*
+ * Used to disable/enable UIE and AIE interrupts.
+ */
+
+static void mask_rtc_irq_bit(unsigned char bit)
+{
+       unsigned char val;
+
+       spin_lock_irq(&rtc_lock);
+       val = CMOS_READ(OMAP_RTC_INTERRUPTS_REG);
+       val &=  ~bit;
+       CMOS_WRITE(val, OMAP_RTC_INTERRUPTS_REG);
+       rtc_irq_data = 0;
+       spin_unlock_irq(&rtc_lock);
+}
+
+static void set_rtc_irq_bit(unsigned char bit)
+{
+       unsigned char val;
+
+       spin_lock_irq(&rtc_lock);
+       val = CMOS_READ(OMAP_RTC_INTERRUPTS_REG);
+       val |= bit;
+       CMOS_WRITE(val, OMAP_RTC_INTERRUPTS_REG);
+       rtc_irq_data = 0;
+       spin_unlock_irq(&rtc_lock);
+}
+
+MODULE_AUTHOR("George G. Davis");
+MODULE_LICENSE("GPL");
+
+module_init(rtc_init);
+module_exit(rtc_exit);
diff --git a/drivers/char/omap-rtc.h b/drivers/char/omap-rtc.h
new file mode 100644 (file)
index 0000000..d8acb56
--- /dev/null
@@ -0,0 +1,59 @@
+/*
+ *  TI OMAP Real Time Clock header file
+ *
+ *  Copyright (C) 2003 TI
+ *
+ *  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.
+ *
+ */
+
+#define OMAP_RTC_BASE                  0xfffb4800
+#define OMAP_RTC_SIZE                  128
+
+#define OMAP_RTC_VIRT_BASE             IO_ADDRESS(OMAP_RTC_BASE)
+
+/*
+ * Real-Time Clock
+ */
+
+#define OMAP_RTC_SECONDS_REG            (OMAP_RTC_BASE + 0x00)
+#define OMAP_RTC_MINUTES_REG            (OMAP_RTC_BASE + 0x04)
+#define OMAP_RTC_HOURS_REG              (OMAP_RTC_BASE + 0x08)
+#define OMAP_RTC_DAYS_REG               (OMAP_RTC_BASE + 0x0C)
+#define OMAP_RTC_MONTHS_REG             (OMAP_RTC_BASE + 0x10)
+#define OMAP_RTC_YEARS_REG              (OMAP_RTC_BASE + 0x14)
+#define OMAP_RTC_WEEKS_REG              (OMAP_RTC_BASE + 0x18)
+#define OMAP_RTC_ALARM_SECONDS_REG      (OMAP_RTC_BASE + 0x20)
+#define OMAP_RTC_ALARM_MINUTES_REG      (OMAP_RTC_BASE + 0x24)
+#define OMAP_RTC_ALARM_HOURS_REG        (OMAP_RTC_BASE + 0x28)
+#define OMAP_RTC_ALARM_DAYS_REG         (OMAP_RTC_BASE + 0x2c)
+#define OMAP_RTC_ALARM_MONTHS_REG       (OMAP_RTC_BASE + 0x30)
+#define OMAP_RTC_ALARM_YEARS_REG        (OMAP_RTC_BASE + 0x34)
+#define OMAP_RTC_CTRL_REG               (OMAP_RTC_BASE + 0x40)
+#define OMAP_RTC_STATUS_REG             (OMAP_RTC_BASE + 0x44)
+#define OMAP_RTC_INTERRUPTS_REG         (OMAP_RTC_BASE + 0x48)
+#define OMAP_RTC_COMP_LSB_REG           (OMAP_RTC_BASE + 0x4c)
+#define OMAP_RTC_COMP_MSB_REG           (OMAP_RTC_BASE + 0x50)
+
+/* RTC Control Register bit fields: */
+
+#define OMAP_RTC_CTRL_STOP              (1<<0)
+
+/* RTC Status Register 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)
+
+/* RTC Interrupt Register bit fields: */
+
+#define OMAP_RTC_INTERRUPTS_IT_ALARM    (1<<3)
+#define OMAP_RTC_INTERRUPTS_IT_TIMER    (1<<2)