/*
 * Machine dependent access functions for RTC registers.
 */
#ifndef _ASM_MC146818RTC_H
#define _ASM_MC146818RTC_H

#include <asm/io.h>
#include <xen/spinlock.h>

extern spinlock_t rtc_lock;             /* serialize CMOS RAM access */

/**********************************************************************
 * register summary
 **********************************************************************/
#define RTC_SECONDS             0
#define RTC_SECONDS_ALARM       1
#define RTC_MINUTES             2
#define RTC_MINUTES_ALARM       3
#define RTC_HOURS               4
#define RTC_HOURS_ALARM         5
/* RTC_*_alarm is always true if 2 MSBs are set */
# define RTC_ALARM_DONT_CARE    0xC0

#define RTC_DAY_OF_WEEK         6
#define RTC_DAY_OF_MONTH        7
#define RTC_MONTH               8
#define RTC_YEAR                9

/* control registers - Moto names
 */
#define RTC_REG_A               10
#define RTC_REG_B               11
#define RTC_REG_C               12
#define RTC_REG_D               13

/**********************************************************************
 * register details
 **********************************************************************/
#define RTC_FREQ_SELECT RTC_REG_A

/* update-in-progress  - set to "1" 244 microsecs before RTC goes off the bus,
 * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
 * totalling to a max high interval of 2.228 ms.
 */
# define RTC_UIP                0x80
# define RTC_DIV_CTL            0x70
   /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
#  define RTC_REF_CLCK_4MHZ     0x00
#  define RTC_REF_CLCK_1MHZ     0x10
#  define RTC_REF_CLCK_32KHZ    0x20
   /* 2 values for divider stage reset, others for "testing purposes only" */
#  define RTC_DIV_RESET1        0x60
#  define RTC_DIV_RESET2        0x70
  /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
# define RTC_RATE_SELECT        0x0F

/**********************************************************************/
#define RTC_CONTROL     RTC_REG_B
# define RTC_SET 0x80           /* disable updates for clock setting */
# define RTC_PIE 0x40           /* periodic interrupt enable */
# define RTC_AIE 0x20           /* alarm interrupt enable */
# define RTC_UIE 0x10           /* update-finished interrupt enable */
# define RTC_SQWE 0x08          /* enable square-wave output */
# define RTC_DM_BINARY 0x04     /* all time/date values are BCD if clear */
# define RTC_24H 0x02           /* 24 hour mode - else hours bit 7 means pm */
# define RTC_DST_EN 0x01        /* auto switch DST - works f. USA only */

/**********************************************************************/
#define RTC_INTR_FLAGS  RTC_REG_C
/* caution - cleared by read */
# define RTC_IRQF 0x80          /* any of the following 3 is active */
# define RTC_PF 0x40
# define RTC_AF 0x20
# define RTC_UF 0x10

/**********************************************************************/
#define RTC_VALID       RTC_REG_D
# define RTC_VRT 0x80           /* valid RAM and time */
/**********************************************************************/

/* example: !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 
 * determines if the following two #defines are needed
 */
#ifndef BCD_TO_BIN
#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
#endif

#ifndef BIN_TO_BCD
#define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
#endif


#ifndef RTC_PORT
#define RTC_PORT(x)	(0x70 + (x))
#define RTC_ALWAYS_BCD	1	/* RTC operates in binary mode */
#endif

/*
 * The yet supported machines all access the RTC index register via
 * an ISA port access but the way to access the date register differs ...
 */
#define CMOS_READ(addr) ({ \
outb_p((addr),RTC_PORT(0)); \
inb_p(RTC_PORT(1)); \
})
#define CMOS_WRITE(val, addr) ({ \
outb_p((addr),RTC_PORT(0)); \
outb_p((val),RTC_PORT(1)); \
})

#define RTC_IRQ 8

#endif /* _ASM_MC146818RTC_H */
