[RFC][Patchset 16/20] Support for PC-9800 (RTC)

Osamu Tomita (tomita@cinet.co.jp)
Sun, 3 Nov 2002 03:18:17 +0900


This is part 16/20 of patchset for add support NEC PC-9800 architecture,
against 2.5.45.

Summary:
PC-9800 standard real time clock driver.(add new files)

diffstat:
drivers/char/upd4990a.c | 438 ++++++++++++++++++++++++++++++++++++++++++++
include/asm-i386/upd4990a.h | 58 +++++
include/linux/upd4990a.h | 140 ++++++++++++++
3 files changed, 636 insertions(+)

patch:
diff -urN linux/drivers/char/upd4990a.c linux98/drivers/char/upd4990a.c
--- linux/drivers/char/upd4990a.c Thu Jan 1 09:00:00 1970
+++ linux98/drivers/char/upd4990a.c Fri Aug 17 21:50:17 2001
@@ -0,0 +1,438 @@
+/*
+ * NEC PC-9800 Real Time Clock interface for Linux
+ *
+ * Copyright (C) 1997-2001 Linux/98 project,
+ * Kyoto University Microcomputer Club.
+ *
+ * Based on:
+ * drivers/char/rtc.c by Paul Gortmaker
+ *
+ * Changes:
+ * 2001-02-09 Call check_region on rtc_init and do not request I/O 0033h.
+ * Call del_timer and release_region on rtc_exit. -- tak
+ * 2001-07-14 Rewrite <linux/upd4990a.h> and split to <linux/upd4990a.h>
+ * and <asm-i386/upd4990a.h>.
+ * Introduce a lot of spin_lock/unlock (&rtc_lock).
+ */
+
+#define RTC98_VERSION "1.2"
+
+#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/rtc.h>
+#include <linux/upd4990a.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define BCD_TO_BINARY(val) (((val) >> 4) * 10 + ((val) & 0xF))
+#define BINARY_TO_BCD(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 struct timer_list rtc_uie_timer;
+static u8 old_refclk;
+
+static long long rtc_llseek(struct file *file, loff_t offset, int origin);
+
+static int rtc_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg);
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data);
+
+/*
+ * Bits in rtc_status. (5 bits of room for future expansion)
+ */
+
+#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
+#define RTC_TIMER_ON 0x02 /* not used */
+#define RTC_UIE_TIMER_ON 0x04 /* UIE emulation timer is active */
+
+/*
+ * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
+ * protected by the big kernel lock. However, ioctl can still disable the timer
+ * in rtc_status and then with del_timer after the interrupt has read
+ * rtc_status but before mod_timer is called, which would then reenable the
+ * timer (but you would need to have an awful timing before you'd trip on it)
+ */
+static unsigned char rtc_status; /* bitmapped status byte. */
+static unsigned long rtc_irq_data; /* our output to the world */
+
+static const unsigned char days_in_mo[] = +{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+extern spinlock_t rtc_lock; /* defined in arch/i386/kernel/time.c */
+
+static void rtc_uie_intr(unsigned long data)
+{
+ u8 refclk, tmp;
+
+ /* Kernel timer does del_timer internally before calling
+ each timer entry, so this is unnecessary.
+ del_timer(&rtc_uie_timer); */
+ spin_lock(&rtc_lock);
+
+ /* Detect rising edge of 1Hz reference clock. */
+ refclk = UPD4990A_READ_DATA();
+ tmp = old_refclk & refclk;
+ old_refclk = ~refclk;
+ if (!(tmp & 1))
+ rtc_irq_data += 0x100;
+
+ spin_unlock(&rtc_lock);
+
+ if (!(tmp & 1)) {
+ /* Now do the rest of the actions */
+ wake_up_interruptible(&rtc_wait);
+ kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
+ }
+
+ rtc_uie_timer.expires = jiffies + 1;
+ add_timer(&rtc_uie_timer);
+}
+
+/*
+ * Now all the various file operations that we export.
+ */
+
+static long long rtc_llseek(struct file *file, loff_t offset, int origin)
+{
+ return -ESPIPE;
+}
+
+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 = 0;
+
+ if (count < sizeof(unsigned long))
+ return -EINVAL;
+
+ add_wait_queue(&rtc_wait, &wait);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ do {
+ /* First make it right. Then make it fast. Putting this whole
+ * block within the parentheses of a while would be too
+ * confusing. And no, xchg() is not the answer. */
+ spin_lock_irq(&rtc_lock);
+ data = rtc_irq_data;
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_lock);
+
+ if (data != 0)
+ break;
+
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto out;
+ }
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ goto out;
+ }
+ schedule();
+ } while (1);
+
+ 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; + struct upd4990a_raw_data raw;
+
+ switch (cmd) {
+ case RTC_UIE_OFF: /* Mask ints from RTC updates. */
+ spin_lock_irq(&rtc_lock);
+ if (rtc_status & RTC_UIE_TIMER_ON) {
+ rtc_status &= ~RTC_UIE_TIMER_ON;
+ del_timer(&rtc_uie_timer);
+ }
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+
+ case RTC_UIE_ON: /* Allow ints for RTC updates. */
+ spin_lock_irq(&rtc_lock);
+ rtc_irq_data = 0;
+ if (!(rtc_status & RTC_UIE_TIMER_ON)){
+ rtc_status |= RTC_UIE_TIMER_ON;
+ rtc_uie_timer.expires = jiffies + 1;
+ add_timer(&rtc_uie_timer);
+ }
+ /* Just in case... */
+ upd4990a_serial_command(UPD4990A_REGISTER_HOLD);
+ old_refclk = ~UPD4990A_READ_DATA();
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+
+ case RTC_RD_TIME: /* Read the time/date from RTC */
+ spin_lock_irq(&rtc_lock);
+ upd4990a_get_time(&raw, 0);
+ spin_unlock_irq(&rtc_lock);
+
+ wtime.tm_sec = BCD_TO_BINARY(raw.sec);
+ wtime.tm_min = BCD_TO_BINARY(raw.min);
+ wtime.tm_hour = BCD_TO_BINARY(raw.hour);
+ wtime.tm_mday = BCD_TO_BINARY(raw.mday);
+ wtime.tm_mon = raw.mon - 1; /* convert to 0-base */
+ wtime.tm_wday = raw.wday;
+
+ /*
+ * Account for differences between how the RTC uses the values
+ * and how they are defined in a struct rtc_time;
+ */
+ if ((wtime.tm_year = BCD_TO_BINARY(raw.year)) < 95)
+ wtime.tm_year += 100;
+
+ wtime.tm_isdst = 0;
+ break;
+
+ case RTC_SET_TIME: /* Set the RTC */
+ {
+ int leap_yr;
+
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+
+ if (copy_from_user(&wtime, (struct rtc_time *) arg,
+ sizeof (struct rtc_time)))
+ return -EFAULT;
+
+ /* Valid year is 1995 - 2094, inclusive. */
+ if (wtime.tm_year < 95 || wtime.tm_year > 194)
+ return -EINVAL;
+
+ if (wtime.tm_mon > 11 || wtime.tm_mday == 0)
+ return -EINVAL;
+
+ /* For acceptable year domain (1995 - 2094),
+ this IS sufficient. */
+ leap_yr = !(wtime.tm_year % 4);
+
+ if (wtime.tm_mday > (days_in_mo[wtime.tm_mon]
+ + (wtime.tm_mon == 2 && leap_yr)))
+ return -EINVAL;
+
+ if (wtime.tm_hour >= 24
+ || wtime.tm_min >= 60 || wtime.tm_sec >= 60)
+ return -EINVAL;
+
+ if (wtime.tm_wday > 6)
+ return -EINVAL;
+
+ raw.sec = BINARY_TO_BCD(wtime.tm_sec);
+ raw.min = BINARY_TO_BCD(wtime.tm_min);
+ raw.hour = BINARY_TO_BCD(wtime.tm_hour);
+ raw.mday = BINARY_TO_BCD(wtime.tm_mday);
+ raw.mon = wtime.tm_mon + 1;
+ raw.wday = wtime.tm_wday;
+ raw.year = BINARY_TO_BCD(wtime.tm_year % 100);
+
+ spin_lock_irq(&rtc_lock);
+ upd4990a_set_time(&raw, 0);
+ spin_unlock_irq(&rtc_lock);
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+ 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.
+ */
+
+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)
+{
+ del_timer(&rtc_uie_timer);
+
+ if (file->f_flags & FASYNC)
+ rtc_fasync(-1, file, 0);
+
+ rtc_irq_data = 0;
+
+ /* No need for locking -- nobody else can do anything until this rmw is
+ * committed, and no timer is running. */
+ rtc_status &= ~(RTC_IS_OPEN | RTC_UIE_TIMER_ON);
+ return 0;
+}
+
+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: rtc_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(UPD4990A_IO, 1, "rtc")) {
+ printk(KERN_ERR "upd4990a: could not acquire I/O port %#x\n",
+ UPD4990A_IO);
+ return -EBUSY;
+ }
+
+#if 0
+ printk(KERN_INFO "\xB6\xDA\xDD\xC0\xDE \xC4\xDE\xB9\xB2 Driver\n"); /* Calender Clock Driver */
+#else
+ printk(KERN_INFO
+ "Real Time Clock driver for NEC PC-9800 v" RTC98_VERSION "\n");
+#endif
+ misc_register(&rtc_dev);
+ create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL);
+
+ init_timer(&rtc_uie_timer);
+ rtc_uie_timer.function = rtc_uie_intr;
+
+ return 0;
+}
+
+module_init (rtc_init);
+
+#ifdef MODULE
+static void __exit rtc_exit(void)
+{
+ del_timer(&rtc_uie_timer);
+ release_region(UPD4990A_IO, 1);
+ remove_proc_entry("driver/rtc", NULL);
+ misc_deregister(&rtc_dev);
+}
+
+module_exit (rtc_exit);
+#endif
+
+EXPORT_NO_SYMBOLS;
+
+/*
+ * Info exported via "/proc/driver/rtc".
+ */
+
+static inline int rtc_get_status(char *buf)
+{
+ char *p;
+ unsigned int year;
+ struct upd4990a_raw_data data;
+
+ p = buf;
+
+ upd4990a_get_time(&data, 0);
+
+ /*
+ * 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.
+ */
+ if ((year = BCD_TO_BINARY(data.year) + 1900) < 1995)
+ year += 100;
+ p += sprintf(p,
+ "rtc_time\t: %02d:%02d:%02d\n"
+ "rtc_date\t: %04d-%02d-%02d\n",
+ BCD_TO_BINARY(data.hour), BCD_TO_BINARY(data.min),
+ BCD_TO_BINARY(data.sec),
+ year, data.mon, BCD_TO_BINARY(data.mday));
+
+ return p - buf;
+}
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = rtc_get_status(page);
+
+ if (len <= off + count)
+ *eof = 1;
+ *start = page + off;
+ len -= off;
+ if (len > count)
+ len = count;
+ if (len < 0)
+ len = 0;
+ return len;
+}
diff -urN linux/include/asm-i386/upd4990a.h linux98/include/asm-i386/upd4990a.h
--- linux/include/asm-i386/upd4990a.h Thu Jan 1 09:00:00 1970
+++ linux98/include/asm-i386/upd4990a.h Fri Aug 17 22:15:17 2001
@@ -0,0 +1,58 @@
+/*
+ * Architecture dependent definitions
+ * for NEC uPD4990A serial I/O real-time clock.
+ *
+ * Copyright 2001 TAKAI Kousuke <tak@kmc.kyoto-u.ac.jp>
+ * Kyoto University Microcomputer Club (KMC).
+ *
+ * References:
+ * uPD4990A serial I/O real-time clock users' manual (Japanese)
+ * No. S12828JJ4V0UM00 (4th revision), NEC Corporation, 1999.
+ */
+
+#ifndef _ASM_I386_uPD4990A_H
+#define _ASM_I386_uPD4990A_H
+
+#include <linux/config.h>
+
+#ifdef CONFIG_PC9800
+
+#include <asm/io.h>
+
+#define UPD4990A_IO (0x0020)
+#define UPD4990A_IO_DATAOUT (0x0033)
+
+#define UPD4990A_OUTPUT_DATA_CLK(data, clk) \
+ outb((((data) & 1) << 5) | (((clk) & 1) << 4) \
+ | UPD4990A_PAR_SERIAL_MODE, UPD4990A_IO)
+
+#define UPD4990A_OUTPUT_CLK(clk) UPD4990A_OUTPUT_DATA_CLK(0, (clk))
+
+#define UPD4990A_OUTPUT_STROBE(stb) \
+ outb(((stb) << 3) | UPD4990A_PAR_SERIAL_MODE, UPD4990A_IO)
+
+/*
+ * Note: udelay() is *not* usable for UPD4990A_DELAY because
+ * the Linux kernel reads uPD4990A to set up system clock
+ * before calibrating delay...
+ */
+#define UPD4990A_DELAY(usec) \
+ do { \
+ if (__builtin_constant_p((usec)) && (usec) < 5) \
+ __asm__ (".rept %c1\n\toutb %%al,%0\n\t.endr" \
+ : : "N" (0x5F), \
+ "i" (((usec) * 10 + 5) / 6)); \
+ else { \
+ int _count = ((usec) * 10 + 5) / 6; \
+ __asm__ volatile ("1: outb %%al,%1\n\tloop 1b" \
+ : "=c" (_count) \
+ : "N" (0x5F), "0" (_count)); \
+ } \
+ } while (0)
+
+/* Caller should ignore all bits except bit0 */
+#define UPD4990A_READ_DATA() inb(UPD4990A_IO_DATAOUT)
+
+#endif /* CONFIG_PC9800 */
+
+#endif
diff -urN linux/include/linux/upd4990a.h linux98/include/linux/upd4990a.h
--- linux/include/linux/upd4990a.h Thu Jan 1 09:00:00 1970
+++ linux98/include/linux/upd4990a.h Fri Aug 17 22:15:48 2001
@@ -0,0 +1,140 @@
+/*
+ * Constant and architecture independent procedures
+ * for NEC uPD4990A serial I/O real-time clock.
+ *
+ * Copyright 2001 TAKAI Kousuke <tak@kmc.kyoto-u.ac.jp>
+ * Kyoto University Microcomputer Club (KMC).
+ *
+ * References:
+ * uPD4990A serial I/O real-time clock users' manual (Japanese)
+ * No. S12828JJ4V0UM00 (4th revision), NEC Corporation, 1999.
+ */
+
+#ifndef _LINUX_uPD4990A_H
+#define _LINUX_uPD4990A_H
+
+#include <asm/byteorder.h>
+
+#include <asm/upd4990a.h>
+
+/* Serial commands (4 bits) */
+#define UPD4990A_REGISTER_HOLD (0x0)
+#define UPD4990A_REGISTER_SHIFT (0x1)
+#define UPD4990A_TIME_SET_AND_COUNTER_HOLD (0x2)
+#define UPD4990A_TIME_READ (0x3)
+#define UPD4990A_TP_64HZ (0x4)
+#define UPD4990A_TP_256HZ (0x5)
+#define UPD4990A_TP_2048HZ (0x6)
+#define UPD4990A_TP_4096HZ (0x7)
+#define UPD4990A_TP_1S (0x8)
+#define UPD4990A_TP_10S (0x9)
+#define UPD4990A_TP_30S (0xA)
+#define UPD4990A_TP_60S (0xB)
+#define UPD4990A_INTERRUPT_RESET (0xC)
+#define UPD4990A_INTERRUPT_TIMER_START (0xD)
+#define UPD4990A_INTERRUPT_TIMER_STOP (0xE)
+#define UPD4990A_TEST_MODE_SET (0xF)
+
+/* Parallel commands (3 bits)
+ 0-6 are same with serial commands. */
+#define UPD4990A_PAR_SERIAL_MODE 7
+
+#ifndef UPD4990A_DELAY
+# include <linux/delay.h>
+# define UPD4990A_DELAY(usec) udelay((usec))
+#endif
+#ifndef UPD4990A_OUTPUT_DATA
+# define UPD4990A_OUTPUT_DATA(bit) \
+ do { \
+ UPD4990A_OUTPUT_DATA_CLK((bit), 0); \
+ UPD4990A_DELAY(1); /* t-DSU */ \
+ UPD4990A_OUTPUT_DATA_CLK((bit), 1); \
+ UPD4990A_DELAY(1); /* t-DHLD */ \
+ } while (0)
+#endif
+
+static __inline__ void upd4990a_serial_command(int command)
+{
+ UPD4990A_OUTPUT_DATA(command >> 0);
+ UPD4990A_OUTPUT_DATA(command >> 1);
+ UPD4990A_OUTPUT_DATA(command >> 2);
+ UPD4990A_OUTPUT_DATA(command >> 3);
+ UPD4990A_DELAY(1); /* t-HLD */
+ UPD4990A_OUTPUT_STROBE(1);
+ UPD4990A_DELAY(1); /* t-STB & t-d1 */
+ UPD4990A_OUTPUT_STROBE(0);
+ /* 19 microseconds extra delay is needed
+ iff previous mode is TIME READ command */
+}
+
+struct upd4990a_raw_data {
+ u8 sec; /* BCD */
+ u8 min; /* BCD */
+ u8 hour; /* BCD */
+ u8 mday; /* BCD */
+#if defined __LITTLE_ENDIAN_BITFIELD
+ unsigned wday :4; /* 0-6 */
+ unsigned mon :4; /* 1-based */
+#elif defined __BIG_ENDIAN_BITFIELD
+ unsigned mon :4; /* 1-based */
+ unsigned wday :4; /* 0-6 */
+#else
+# error Unknown bitfield endian!
+#endif
+ u8 year; /* BCD */
+};
+
+static __inline__ void upd4990a_get_time(struct upd4990a_raw_data *buf,
+ int leave_register_hold)
+{
+ int byte;
+
+ upd4990a_serial_command(UPD4990A_TIME_READ);
+ upd4990a_serial_command(UPD4990A_REGISTER_SHIFT);
+ UPD4990A_DELAY(19); /* t-d2 - t-d1 */
+
+ for (byte = 0; byte < 6; byte++) {
+ u8 tmp;
+ int bit;
+
+ for (tmp = 0, bit = 0; bit < 8; bit++) {
+ tmp = (tmp | (UPD4990A_READ_DATA() << 8)) >> 1;
+ UPD4990A_OUTPUT_CLK(1);
+ UPD4990A_DELAY(1);
+ UPD4990A_OUTPUT_CLK(0);
+ UPD4990A_DELAY(1);
+ }
+ ((u8 *) buf)[byte] = tmp;
+ }
+
+ /* The uPD4990A users' manual says that we should issue `Register
+ Hold' command after each data retrieval, or next `Time Read'
+ command may not work correctly. */
+ if (!leave_register_hold)
+ upd4990a_serial_command(UPD4990A_REGISTER_HOLD);
+}
+
+static __inline__ void upd4990a_set_time(const struct upd4990a_raw_data *data,
+ int time_set_only)
+{
+ int byte;
+
+ if (!time_set_only)
+ upd4990a_serial_command(UPD4990A_REGISTER_SHIFT);
+
+ for (byte = 0; byte < 6; byte++) {
+ int bit;
+ u8 tmp = ((const u8 *) data)[byte];
+
+ for (bit = 0; bit < 8; bit++, tmp >>= 1)
+ UPD4990A_OUTPUT_DATA(tmp);
+ }
+
+ upd4990a_serial_command(UPD4990A_TIME_SET_AND_COUNTER_HOLD);
+
+ /* Release counter hold and start the clock. */
+ if (!time_set_only)
+ upd4990a_serial_command(UPD4990A_REGISTER_HOLD);
+}
+
+#endif /* _LINUX_uPD4990A_H */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/