mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
b65769fc01
This fixes a bug in read_persistent_clock() which causes the system clock to lag the Real Time Clock by one month. The problem was noticed on a Mac, but theoretically it must also affect Atari, BVME6000 and Q40. The tm_mon value in the struct rtc_time passed to mach_hwclk() is zero-based, and atari_mste_hwclk(), atari_tt_hwclk(), bvme6000_hwclk(), mac_hwclk() and q40_hwclk() all make this adjustment. Unfortunately, dn_dummy_hwclk(), mvme147_hwclk(), mvme16x_hwclk(), sun3_hwclk() and sun3x_hwclk() fail to decrement tm_mon. Also m68328_hwclk() assumes a one-based tm_mon. Bring these platforms into line and fix read_persistent_clock() so it works correctly on all m68k platforms. The datasheets for the RTC devices found on the affected platforms all confirm that the year is stored as a value in the range 0-99 and the month is stored as a value in the range 1-12. Please refer to the datasheets for MC146818 (Apollo), DS1643 (MVME), ICM7170 (Sun 3) and M48T02 (Sun 3x). Reported-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
140 lines
3.4 KiB
C
140 lines
3.4 KiB
C
/***************************************************************************/
|
|
|
|
/*
|
|
* timers.c - Generic hardware timer support.
|
|
*
|
|
* Copyright (C) 1993 Hamish Macdonald
|
|
* Copyright (C) 1999 D. Jeff Dionne
|
|
* Copyright (C) 2001 Georges Menie, Ken Desmet
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file COPYING in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
|
|
/***************************************************************************/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/rtc.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/MC68VZ328.h>
|
|
|
|
/***************************************************************************/
|
|
|
|
#if defined(CONFIG_DRAGEN2)
|
|
/* with a 33.16 MHz clock, this will give usec resolution to the time functions */
|
|
#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
|
|
#define CLOCK_PRE 7
|
|
#define TICKS_PER_JIFFY 41450
|
|
|
|
#elif defined(CONFIG_XCOPILOT_BUGS)
|
|
/*
|
|
* The only thing I know is that CLK32 is not available on Xcopilot
|
|
* I have little idea about what frequency SYSCLK has on Xcopilot.
|
|
* The values for prescaler and compare registers were simply
|
|
* taken from the original source
|
|
*/
|
|
#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
|
|
#define CLOCK_PRE 2
|
|
#define TICKS_PER_JIFFY 0xd7e4
|
|
|
|
#else
|
|
/* default to using the 32Khz clock */
|
|
#define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ
|
|
#define CLOCK_PRE 31
|
|
#define TICKS_PER_JIFFY 10
|
|
#endif
|
|
|
|
static u32 m68328_tick_cnt;
|
|
static irq_handler_t timer_interrupt;
|
|
|
|
/***************************************************************************/
|
|
|
|
static irqreturn_t hw_tick(int irq, void *dummy)
|
|
{
|
|
/* Reset Timer1 */
|
|
TSTAT &= 0;
|
|
|
|
m68328_tick_cnt += TICKS_PER_JIFFY;
|
|
return timer_interrupt(irq, dummy);
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static struct irqaction m68328_timer_irq = {
|
|
.name = "timer",
|
|
.flags = IRQF_TIMER,
|
|
.handler = hw_tick,
|
|
};
|
|
|
|
/***************************************************************************/
|
|
|
|
static u64 m68328_read_clk(struct clocksource *cs)
|
|
{
|
|
unsigned long flags;
|
|
u32 cycles;
|
|
|
|
local_irq_save(flags);
|
|
cycles = m68328_tick_cnt + TCN;
|
|
local_irq_restore(flags);
|
|
|
|
return cycles;
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
static struct clocksource m68328_clk = {
|
|
.name = "timer",
|
|
.rating = 250,
|
|
.read = m68328_read_clk,
|
|
.mask = CLOCKSOURCE_MASK(32),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
/***************************************************************************/
|
|
|
|
void hw_timer_init(irq_handler_t handler)
|
|
{
|
|
/* disable timer 1 */
|
|
TCTL = 0;
|
|
|
|
/* set ISR */
|
|
setup_irq(TMR_IRQ_NUM, &m68328_timer_irq);
|
|
|
|
/* Restart mode, Enable int, Set clock source */
|
|
TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
|
|
TPRER = CLOCK_PRE;
|
|
TCMP = TICKS_PER_JIFFY;
|
|
|
|
/* Enable timer 1 */
|
|
TCTL |= TCTL_TEN;
|
|
clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
|
|
timer_interrupt = handler;
|
|
}
|
|
|
|
/***************************************************************************/
|
|
|
|
int m68328_hwclk(int set, struct rtc_time *t)
|
|
{
|
|
if (!set) {
|
|
long now = RTCTIME;
|
|
t->tm_year = 1;
|
|
t->tm_mon = 0;
|
|
t->tm_mday = 1;
|
|
t->tm_hour = (now >> 24) % 24;
|
|
t->tm_min = (now >> 16) % 60;
|
|
t->tm_sec = now % 60;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/***************************************************************************/
|