Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / drivers / char / rtc.c
index 1b3b258..7cac6d0 100644 (file)
  *      1.11a   Daniele Bellucci: Audit create_proc_read_entry in rtc_init
  *     1.12    Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
  *             CONFIG_HPET_EMULATE_RTC
- *
+ *     1.12ac  Alan Cox: Allow read access to the day of week register
  */
 
-#define RTC_VERSION            "1.12"
+#define RTC_VERSION            "1.12ac"
 
 #define RTC_IO_EXTENT  0x8
 
 #include <linux/init.h>
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/sysctl.h>
 #include <linux/wait.h>
 #include <linux/bcd.h>
+#include <linux/delay.h>
 
 #include <asm/current.h>
 #include <asm/uaccess.h>
@@ -147,12 +149,25 @@ static void get_rtc_alm_time (struct rtc_time *alm_tm);
 #ifdef RTC_IRQ
 static void rtc_dropped_irq(unsigned long data);
 
-static void set_rtc_irq_bit(unsigned char bit);
-static void mask_rtc_irq_bit(unsigned char bit);
+static void set_rtc_irq_bit_locked(unsigned char bit);
+static void mask_rtc_irq_bit_locked(unsigned char bit);
+
+static inline void set_rtc_irq_bit(unsigned char bit)
+{
+       spin_lock_irq(&rtc_lock);
+       set_rtc_irq_bit_locked(bit);
+       spin_unlock_irq(&rtc_lock);
+}
+
+static void mask_rtc_irq_bit(unsigned char bit)
+{
+       spin_lock_irq(&rtc_lock);
+       mask_rtc_irq_bit_locked(bit);
+       spin_unlock_irq(&rtc_lock);
+}
 #endif
 
-static int rtc_read_proc(char *page, char **start, off_t off,
-                         int count, int *eof, void *data);
+static int rtc_proc_open(struct inode *inode, struct file *file);
 
 /*
  *     Bits in rtc_status. (6 bits of room for future expansion)
@@ -177,7 +192,7 @@ static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
 /*
  * rtc_task_lock nests inside rtc_lock.
  */
-static spinlock_t rtc_task_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(rtc_task_lock);
 static rtc_task_t *rtc_callback = NULL;
 #endif
 
@@ -400,18 +415,19 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
        }
        case RTC_PIE_OFF:       /* Mask periodic int. enab. bit */
        {
-               mask_rtc_irq_bit(RTC_PIE);
+               unsigned long flags; /* can be called from isr via rtc_control() */
+               spin_lock_irqsave (&rtc_lock, flags);
+               mask_rtc_irq_bit_locked(RTC_PIE);
                if (rtc_status & RTC_TIMER_ON) {
-                       spin_lock_irq (&rtc_lock);
                        rtc_status &= ~RTC_TIMER_ON;
                        del_timer(&rtc_irq_timer);
-                       spin_unlock_irq (&rtc_lock);
                }
+               spin_unlock_irqrestore (&rtc_lock, flags);
                return 0;
        }
        case RTC_PIE_ON:        /* Allow periodic ints          */
        {
-
+               unsigned long flags; /* can be called from isr via rtc_control() */
                /*
                 * We don't really want Joe User enabling more
                 * than 64Hz of interrupts on a multi-user machine.
@@ -420,14 +436,14 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
                        (!capable(CAP_SYS_RESOURCE)))
                        return -EACCES;
 
+               spin_lock_irqsave (&rtc_lock, flags);
                if (!(rtc_status & RTC_TIMER_ON)) {
-                       spin_lock_irq (&rtc_lock);
                        rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100;
                        add_timer(&rtc_irq_timer);
                        rtc_status |= RTC_TIMER_ON;
-                       spin_unlock_irq (&rtc_lock);
                }
-               set_rtc_irq_bit(RTC_PIE);
+               set_rtc_irq_bit_locked(RTC_PIE);
+               spin_unlock_irqrestore (&rtc_lock, flags);
                return 0;
        }
        case RTC_UIE_OFF:       /* Mask ints from RTC updates.  */
@@ -608,6 +624,7 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
        {
                int tmp = 0;
                unsigned char val;
+               unsigned long flags; /* can be called from isr via rtc_control() */
 
                /* 
                 * The max we can do is 8192Hz.
@@ -630,9 +647,9 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
                if (arg != (1<<tmp))
                        return -EINVAL;
 
-               spin_lock_irq(&rtc_lock);
+               spin_lock_irqsave(&rtc_lock, flags);
                if (hpet_set_periodic_freq(arg)) {
-                       spin_unlock_irq(&rtc_lock);
+                       spin_unlock_irqrestore(&rtc_lock, flags);
                        return 0;
                }
                rtc_freq = arg;
@@ -640,7 +657,7 @@ static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
                val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
                val |= (16 - tmp);
                CMOS_WRITE(val, RTC_FREQ_SELECT);
-               spin_unlock_irq(&rtc_lock);
+               spin_unlock_irqrestore(&rtc_lock, flags);
                return 0;
        }
 #endif
@@ -843,12 +860,15 @@ int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
 #ifndef RTC_IRQ
        return -EIO;
 #else
-       spin_lock_irq(&rtc_task_lock);
+       unsigned long flags;
+       if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
+               return -EINVAL;
+       spin_lock_irqsave(&rtc_task_lock, flags);
        if (rtc_callback != task) {
-               spin_unlock_irq(&rtc_task_lock);
+               spin_unlock_irqrestore(&rtc_task_lock, flags);
                return -ENXIO;
        }
-       spin_unlock_irq(&rtc_task_lock);
+       spin_unlock_irqrestore(&rtc_task_lock, flags);
        return rtc_do_ioctl(cmd, arg, 1);
 #endif
 }
@@ -871,22 +891,29 @@ static struct file_operations rtc_fops = {
        .fasync         = rtc_fasync,
 };
 
-static struct miscdevice rtc_dev=
-{
-       RTC_MINOR,
-       "rtc",
-       &rtc_fops
+static struct miscdevice rtc_dev = {
+       .minor          = RTC_MINOR,
+       .name           = "rtc",
+       .fops           = &rtc_fops,
 };
 
-#ifdef RTC_IRQ
+static struct file_operations rtc_proc_fops = {
+       .owner = THIS_MODULE,
+       .open = rtc_proc_open,
+       .read  = seq_read,
+       .llseek = seq_lseek,
+       .release = single_release,
+};
+
+#if defined(RTC_IRQ) && !defined(__sparc__)
 static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs);
 #endif
 
 static int __init rtc_init(void)
 {
+       struct proc_dir_entry *ent;
 #if defined(__alpha__) || defined(__mips__)
        unsigned int year, ctrl;
-       unsigned long uip_watchdog;
        char *guess = NULL;
 #endif
 #ifdef __sparc__
@@ -930,10 +957,9 @@ found:
 
        /*
         * XXX Interrupt pin #7 in Espresso is shared between RTC and
-        * PCI Slot 2 INTA# (and some INTx# in Slot 1). SA_INTERRUPT here
-        * is asking for trouble with add-on boards. Change to SA_SHIRQ.
+        * PCI Slot 2 INTA# (and some INTx# in Slot 1).
         */
-       if (request_irq(rtc_irq, rtc_interrupt, SA_INTERRUPT, "rtc", (void *)&rtc_port)) {
+       if (request_irq(rtc_irq, rtc_interrupt, SA_SHIRQ, "rtc", (void *)&rtc_port)) {
                /*
                 * Standard way for sparc to print irq's is to use
                 * __irq_itoa(). I think for EBus it's ok to use %d.
@@ -974,7 +1000,9 @@ no_irq:
                release_region(RTC_PORT(0), RTC_IO_EXTENT);
                return -ENODEV;
        }
-       if (!create_proc_read_entry ("driver/rtc", 0, NULL, rtc_read_proc, NULL)) {
+
+       ent = create_proc_entry("driver/rtc", 0, NULL);
+       if (!ent) {
 #ifdef RTC_IRQ
                free_irq(RTC_IRQ, NULL);
 #endif
@@ -982,6 +1010,7 @@ no_irq:
                misc_deregister(&rtc_dev);
                return -ENOMEM;
        }
+       ent->proc_fops = &rtc_proc_fops;
 
 #if defined(__alpha__) || defined(__mips__)
        rtc_freq = HZ;
@@ -989,12 +1018,8 @@ no_irq:
        /* Each operating system on an Alpha uses its own epoch.
           Let's try to guess which one we are using now. */
        
-       uip_watchdog = jiffies;
        if (rtc_is_updating() != 0)
-               while (jiffies - uip_watchdog < 2*HZ/100) { 
-                       barrier();
-                       cpu_relax();
-               }
+               msleep(20);
        
        spin_lock_irq(&rtc_lock);
        year = CMOS_READ(RTC_YEAR);
@@ -1119,11 +1144,10 @@ static void rtc_dropped_irq(unsigned long data)
  *     Info exported via "/proc/driver/rtc".
  */
 
-static int rtc_proc_output (char *buf)
+static int rtc_proc_show(struct seq_file *seq, void *v)
 {
 #define YN(bit) ((ctrl & bit) ? "yes" : "no")
 #define NY(bit) ((ctrl & bit) ? "no" : "yes")
-       char *p;
        struct rtc_time tm;
        unsigned char batt, ctrl;
        unsigned long freq;
@@ -1134,7 +1158,6 @@ static int rtc_proc_output (char *buf)
        freq = rtc_freq;
        spin_unlock_irq(&rtc_lock);
 
-       p = buf;
 
        rtc_get_rtc_time(&tm);
 
@@ -1142,12 +1165,12 @@ static int rtc_proc_output (char *buf)
         * 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);
+       seq_printf(seq,
+                  "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);
 
@@ -1156,57 +1179,50 @@ static int rtc_proc_output (char *buf)
         * 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\t\t: ");
+       seq_puts(seq, "alarm\t\t: ");
        if (tm.tm_hour <= 24)
-               p += sprintf(p, "%02d:", tm.tm_hour);
+               seq_printf(seq, "%02d:", tm.tm_hour);
        else
-               p += sprintf(p, "**:");
+               seq_puts(seq, "**:");
 
        if (tm.tm_min <= 59)
-               p += sprintf(p, "%02d:", tm.tm_min);
+               seq_printf(seq, "%02d:", tm.tm_min);
        else
-               p += sprintf(p, "**:");
+               seq_puts(seq, "**:");
 
        if (tm.tm_sec <= 59)
-               p += sprintf(p, "%02d\n", tm.tm_sec);
+               seq_printf(seq, "%02d\n", tm.tm_sec);
        else
-               p += sprintf(p, "**\n");
-
-       p += sprintf(p,
-                    "DST_enable\t: %s\n"
-                    "BCD\t\t: %s\n"
-                    "24hr\t\t: %s\n"
-                    "square_wave\t: %s\n"
-                    "alarm_IRQ\t: %s\n"
-                    "update_IRQ\t: %s\n"
-                    "periodic_IRQ\t: %s\n"
-                    "periodic_freq\t: %ld\n"
-                    "batt_status\t: %s\n",
-                    YN(RTC_DST_EN),
-                    NY(RTC_DM_BINARY),
-                    YN(RTC_24H),
-                    YN(RTC_SQWE),
-                    YN(RTC_AIE),
-                    YN(RTC_UIE),
-                    YN(RTC_PIE),
-                    freq,
-                    batt ? "okay" : "dead");
-
-       return  p - buf;
+               seq_puts(seq, "**\n");
+
+       seq_printf(seq,
+                  "DST_enable\t: %s\n"
+                  "BCD\t\t: %s\n"
+                  "24hr\t\t: %s\n"
+                  "square_wave\t: %s\n"
+                  "alarm_IRQ\t: %s\n"
+                  "update_IRQ\t: %s\n"
+                  "periodic_IRQ\t: %s\n"
+                  "periodic_freq\t: %ld\n"
+                  "batt_status\t: %s\n",
+                  YN(RTC_DST_EN),
+                  NY(RTC_DM_BINARY),
+                  YN(RTC_24H),
+                  YN(RTC_SQWE),
+                  YN(RTC_AIE),
+                  YN(RTC_UIE),
+                  YN(RTC_PIE),
+                  freq,
+                  batt ? "okay" : "dead");
+
+       return  0;
 #undef YN
 #undef NY
 }
 
-static int rtc_read_proc(char *page, char **start, off_t off,
-                         int count, int *eof, void *data)
+static int rtc_proc_open(struct inode *inode, struct file *file)
 {
-        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;
+       return single_open(file, rtc_proc_show, NULL);
 }
 
 void rtc_get_rtc_time(struct rtc_time *rtc_tm)
@@ -1219,7 +1235,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm)
 
        /*
         * 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
+        * can take just over 2ms. We wait 20ms. There is no need to
         * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
         * If you need to know *exactly* when a second has started, enable
         * periodic update complete interrupts, (via ioctl) and then 
@@ -1227,17 +1243,16 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm)
         * Once the read clears, read the RTC time (again via ioctl). Easy.
         */
 
-       if (rtc_is_updating() != 0)
-               while (jiffies - uip_watchdog < 2*HZ/100) {
-                       barrier();
-                       cpu_relax();
-               }
+       while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100) {
+               barrier();
+               cpu_relax();
+       }
 
        /*
         * 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.
+        * tm_wday, tm_yday and tm_isdst untouched. Note that while the
+        * RTC has RTC_DAY_OF_WEEK, we should usually 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(RTC_SECONDS);
@@ -1246,6 +1261,9 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm)
        rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
        rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
        rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
+       /* Only set from 2.6.16 onwards */
+       rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
+
 #ifdef CONFIG_MACH_DECSTATION
        real_year = CMOS_READ(RTC_DEC_YEAR);
 #endif
@@ -1260,6 +1278,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm)
                BCD_TO_BIN(rtc_tm->tm_mday);
                BCD_TO_BIN(rtc_tm->tm_mon);
                BCD_TO_BIN(rtc_tm->tm_year);
+               BCD_TO_BIN(rtc_tm->tm_wday);
        }
 
 #ifdef CONFIG_MACH_DECSTATION
@@ -1310,40 +1329,32 @@ static void get_rtc_alm_time(struct rtc_time *alm_tm)
  * meddles with the interrupt enable/disable bits.
  */
 
-static void mask_rtc_irq_bit(unsigned char bit)
+static void mask_rtc_irq_bit_locked(unsigned char bit)
 {
        unsigned char val;
 
-       spin_lock_irq(&rtc_lock);
-       if (hpet_mask_rtc_irq_bit(bit)) {
-               spin_unlock_irq(&rtc_lock);
+       if (hpet_mask_rtc_irq_bit(bit))
                return;
-       }
        val = CMOS_READ(RTC_CONTROL);
        val &=  ~bit;
        CMOS_WRITE(val, RTC_CONTROL);
        CMOS_READ(RTC_INTR_FLAGS);
 
        rtc_irq_data = 0;
-       spin_unlock_irq(&rtc_lock);
 }
 
-static void set_rtc_irq_bit(unsigned char bit)
+static void set_rtc_irq_bit_locked(unsigned char bit)
 {
        unsigned char val;
 
-       spin_lock_irq(&rtc_lock);
-       if (hpet_set_rtc_irq_bit(bit)) {
-               spin_unlock_irq(&rtc_lock);
+       if (hpet_set_rtc_irq_bit(bit))
                return;
-       }
        val = CMOS_READ(RTC_CONTROL);
        val |= bit;
        CMOS_WRITE(val, RTC_CONTROL);
        CMOS_READ(RTC_INTR_FLAGS);
 
        rtc_irq_data = 0;
-       spin_unlock_irq(&rtc_lock);
 }
 #endif