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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh/boards/snapgear/rtc.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sh/boards/snapgear/rtc.c')
-rw-r--r--arch/sh/boards/snapgear/rtc.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/arch/sh/boards/snapgear/rtc.c b/arch/sh/boards/snapgear/rtc.c
new file mode 100644
index 00000000000..b71e009da35
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+++ b/arch/sh/boards/snapgear/rtc.c
@@ -0,0 +1,333 @@
+/****************************************************************************/
+/*
+ * linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code
+ *
+ * Copyright (C) 2002 David McCullough <davidm@snapgear.com>
+ * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
+ *
+ * The SecureEdge5410 can have one of 2 real time clocks, the SH
+ * built in version or the preferred external DS1302. Here we work out
+ * each to see what we have and then run with it.
+ */
+/****************************************************************************/
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/mc146818rtc.h>
+
+#include <asm/io.h>
+#include <asm/rtc.h>
+#include <asm/mc146818rtc.h>
+
+/****************************************************************************/
+
+static int use_ds1302 = 0;
+
+/****************************************************************************/
+/*
+ * we need to implement a DS1302 driver here that can operate in
+ * conjunction with the builtin rtc driver which is already quite friendly
+ */
+/*****************************************************************************/
+
+#define RTC_CMD_READ 0x81 /* Read command */
+#define RTC_CMD_WRITE 0x80 /* Write command */
+
+#define RTC_ADDR_YEAR 0x06 /* Address of year register */
+#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
+#define RTC_ADDR_MON 0x04 /* Address of month register */
+#define RTC_ADDR_DATE 0x03 /* Address of day of month register */
+#define RTC_ADDR_HOUR 0x02 /* Address of hour register */
+#define RTC_ADDR_MIN 0x01 /* Address of minute register */
+#define RTC_ADDR_SEC 0x00 /* Address of second register */
+
+#define RTC_RESET 0x1000
+#define RTC_IODATA 0x0800
+#define RTC_SCLK 0x0400
+
+#define set_dirp(x)
+#define get_dirp(x) 0
+#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
+#define get_dp(x) SECUREEDGE_READ_IOPORT()
+
+static void ds1302_sendbits(unsigned int val)
+{
+ int i;
+
+ for (i = 8; (i); i--, val >>= 1) {
+ set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? RTC_IODATA : 0));
+ set_dp(get_dp() | RTC_SCLK); // clock high
+ set_dp(get_dp() & ~RTC_SCLK); // clock low
+ }
+}
+
+static unsigned int ds1302_recvbits(void)
+{
+ unsigned int val;
+ int i;
+
+ for (i = 0, val = 0; (i < 8); i++) {
+ val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
+ set_dp(get_dp() | RTC_SCLK); // clock high
+ set_dp(get_dp() & ~RTC_SCLK); // clock low
+ }
+ return(val);
+}
+
+static unsigned int ds1302_readbyte(unsigned int addr)
+{
+ unsigned int val;
+ unsigned long flags;
+
+#if 0
+ printk("SnapGear RTC: ds1302_readbyte(addr=%x)\n", addr);
+#endif
+
+ local_irq_save(flags);
+ set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+
+ set_dp(get_dp() | RTC_RESET);
+ ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
+ set_dirp(get_dirp() & ~RTC_IODATA);
+ val = ds1302_recvbits();
+ set_dp(get_dp() & ~RTC_RESET);
+ local_irq_restore(flags);
+
+ return(val);
+}
+
+static void ds1302_writebyte(unsigned int addr, unsigned int val)
+{
+ unsigned long flags;
+
+#if 0
+ printk("SnapGear RTC: ds1302_writebyte(addr=%x)\n", addr);
+#endif
+
+ local_irq_save(flags);
+ set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+ set_dp(get_dp() | RTC_RESET);
+ ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
+ ds1302_sendbits(val);
+ set_dp(get_dp() & ~RTC_RESET);
+ local_irq_restore(flags);
+}
+
+static void ds1302_reset(void)
+{
+ unsigned long flags;
+ /* Hardware dependant reset/init */
+ local_irq_save(flags);
+ set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+ local_irq_restore(flags);
+}
+
+/*****************************************************************************/
+
+static inline int bcd2int(int val)
+{
+ return((((val & 0xf0) >> 4) * 10) + (val & 0xf));
+}
+
+static inline int int2bcd(int val)
+{
+ return(((val / 10) << 4) + (val % 10));
+}
+
+/*****************************************************************************/
+/*
+ * Write and Read some RAM in the DS1302, if it works assume it's there
+ * Otherwise use the SH4 internal RTC
+ */
+
+void snapgear_rtc_gettimeofday(struct timespec *);
+int snapgear_rtc_settimeofday(const time_t);
+
+void __init secureedge5410_rtc_init(void)
+{
+ unsigned char *test = "snapgear";
+ int i;
+
+ ds1302_reset();
+
+ use_ds1302 = 1;
+
+ for (i = 0; test[i]; i++)
+ ds1302_writebyte(32 + i, test[i]);
+
+ for (i = 0; test[i]; i++)
+ if (ds1302_readbyte(32 + i) != test[i]) {
+ use_ds1302 = 0;
+ break;
+ }
+
+ if (use_ds1302) {
+ rtc_get_time = snapgear_rtc_gettimeofday;
+ rtc_set_time = snapgear_rtc_settimeofday;
+ } else {
+ rtc_get_time = sh_rtc_gettimeofday;
+ rtc_set_time = sh_rtc_settimeofday;
+ }
+
+ printk("SnapGear RTC: using %s rtc.\n", use_ds1302 ? "ds1302" : "internal");
+}
+
+/****************************************************************************/
+/*
+ * our generic interface that chooses the correct code to use
+ */
+
+void snapgear_rtc_gettimeofday(struct timespec *ts)
+{
+ unsigned int sec, min, hr, day, mon, yr;
+
+ if (!use_ds1302) {
+ sh_rtc_gettimeofday(ts);
+ return;
+ }
+
+ sec = bcd2int(ds1302_readbyte(RTC_ADDR_SEC));
+ min = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
+ hr = bcd2int(ds1302_readbyte(RTC_ADDR_HOUR));
+ day = bcd2int(ds1302_readbyte(RTC_ADDR_DATE));
+ mon = bcd2int(ds1302_readbyte(RTC_ADDR_MON));
+ yr = bcd2int(ds1302_readbyte(RTC_ADDR_YEAR));
+
+bad_time:
+ if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
+ hr > 23 || min > 59 || sec > 59) {
+ printk(KERN_ERR
+ "SnapGear RTC: invalid value, resetting to 1 Jan 2000\n");
+ ds1302_writebyte(RTC_ADDR_MIN, min = 0);
+ ds1302_writebyte(RTC_ADDR_HOUR, hr = 0);
+ ds1302_writebyte(RTC_ADDR_DAY, 7);
+ ds1302_writebyte(RTC_ADDR_DATE, day = 1);
+ ds1302_writebyte(RTC_ADDR_MON, mon = 1);
+ ds1302_writebyte(RTC_ADDR_YEAR, yr = 0);
+ ds1302_writebyte(RTC_ADDR_SEC, sec = 0);
+ }
+
+ ts->tv_sec = mktime(2000 + yr, mon, day, hr, min, sec);
+ if (ts->tv_sec < 0) {
+#if 0
+ printk("BAD TIME %d %d %d %d %d %d\n", yr, mon, day, hr, min, sec);
+#endif
+ yr = 100;
+ goto bad_time;
+ }
+ ts->tv_nsec = 0;
+}
+
+int snapgear_rtc_settimeofday(const time_t secs)
+{
+ int retval = 0;
+ int real_seconds, real_minutes, cmos_minutes;
+ unsigned long nowtime;
+
+ if (!use_ds1302)
+ return sh_rtc_settimeofday(secs);
+
+/*
+ * This is called direct from the kernel timer handling code.
+ * It is supposed to synchronize the kernel clock to the RTC.
+ */
+
+ nowtime = secs;
+
+#if 1
+ printk("SnapGear RTC: snapgear_rtc_settimeofday(nowtime=%ld)\n", nowtime);
+#endif
+
+ /* STOP RTC */
+ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
+
+ cmos_minutes = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
+
+ /*
+ * since we're only adjusting minutes and seconds,
+ * don't interfere with hour overflow. This avoids
+ * messing with unknown time zones but requires your
+ * RTC not to be off by more than 15 minutes
+ */
+ real_seconds = nowtime % 60;
+ real_minutes = nowtime / 60;
+ if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
+ real_minutes += 30; /* correct for half hour time zone */
+ real_minutes %= 60;
+
+ if (abs(real_minutes - cmos_minutes) < 30) {
+ ds1302_writebyte(RTC_ADDR_MIN, int2bcd(real_minutes));
+ ds1302_writebyte(RTC_ADDR_SEC, int2bcd(real_seconds));
+ } else {
+ printk(KERN_WARNING
+ "SnapGear RTC: can't update from %d to %d\n",
+ cmos_minutes, real_minutes);
+ retval = -1;
+ }
+
+ /* START RTC */
+ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
+ return(0);
+}
+
+unsigned char secureedge5410_cmos_read(int addr)
+{
+ unsigned char val = 0;
+
+ if (!use_ds1302)
+ return(__CMOS_READ(addr, w));
+
+ switch(addr) {
+ case RTC_SECONDS: val = ds1302_readbyte(RTC_ADDR_SEC); break;
+ case RTC_SECONDS_ALARM: break;
+ case RTC_MINUTES: val = ds1302_readbyte(RTC_ADDR_MIN); break;
+ case RTC_MINUTES_ALARM: break;
+ case RTC_HOURS: val = ds1302_readbyte(RTC_ADDR_HOUR); break;
+ case RTC_HOURS_ALARM: break;
+ case RTC_DAY_OF_WEEK: val = ds1302_readbyte(RTC_ADDR_DAY); break;
+ case RTC_DAY_OF_MONTH: val = ds1302_readbyte(RTC_ADDR_DATE); break;
+ case RTC_MONTH: val = ds1302_readbyte(RTC_ADDR_MON); break;
+ case RTC_YEAR: val = ds1302_readbyte(RTC_ADDR_YEAR); break;
+ case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
+ case RTC_REG_B: /* RTC_CONTROL */ break;
+ case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
+ case RTC_REG_D: val = RTC_VRT /* RTC_VALID */; break;
+ default: break;
+ }
+
+ return(val);
+}
+
+void secureedge5410_cmos_write(unsigned char val, int addr)
+{
+ if (!use_ds1302) {
+ __CMOS_WRITE(val, addr, w);
+ return;
+ }
+
+ switch(addr) {
+ case RTC_SECONDS: ds1302_writebyte(RTC_ADDR_SEC, val); break;
+ case RTC_SECONDS_ALARM: break;
+ case RTC_MINUTES: ds1302_writebyte(RTC_ADDR_MIN, val); break;
+ case RTC_MINUTES_ALARM: break;
+ case RTC_HOURS: ds1302_writebyte(RTC_ADDR_HOUR, val); break;
+ case RTC_HOURS_ALARM: break;
+ case RTC_DAY_OF_WEEK: ds1302_writebyte(RTC_ADDR_DAY, val); break;
+ case RTC_DAY_OF_MONTH: ds1302_writebyte(RTC_ADDR_DATE, val); break;
+ case RTC_MONTH: ds1302_writebyte(RTC_ADDR_MON, val); break;
+ case RTC_YEAR: ds1302_writebyte(RTC_ADDR_YEAR, val); break;
+ case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
+ case RTC_REG_B: /* RTC_CONTROL */ break;
+ case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
+ case RTC_REG_D: /* RTC_VALID */ break;
+ default: break;
+ }
+}
+
+/****************************************************************************/