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rtems/bsps/shared/dev/rtc/ds1375.c
Sebastian Huber 9c20b987cd rtems: Add <rtems/rtems/clockimpl.h>
2020-12-02 07:45:53 +01:00

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/* Driver for the Maxim 1375 i2c RTC (TOD only; very simple...) */
/*
* Authorship
* ----------
* This software was created by
*
* Till Straumann <strauman@slac.stanford.edu>, 2005-2007,
* Stanford Linear Accelerator Center, Stanford University.
*
* Acknowledgement of sponsorship
* ------------------------------
* The software was produced by
* the Stanford Linear Accelerator Center, Stanford University,
* under Contract DE-AC03-76SFO0515 with the Department of Energy.
*
* Government disclaimer of liability
* ----------------------------------
* Neither the United States nor the United States Department of Energy,
* nor any of their employees, makes any warranty, express or implied, or
* assumes any legal liability or responsibility for the accuracy,
* completeness, or usefulness of any data, apparatus, product, or process
* disclosed, or represents that its use would not infringe privately owned
* rights.
*
* Stanford disclaimer of liability
* --------------------------------
* Stanford University makes no representations or warranties, express or
* implied, nor assumes any liability for the use of this software.
*
* Stanford disclaimer of copyright
* --------------------------------
* Stanford University, owner of the copyright, hereby disclaims its
* copyright and all other rights in this software. Hence, anyone may
* freely use it for any purpose without restriction.
*
* Maintenance of notices
* ----------------------
* In the interest of clarity regarding the origin and status of this
* SLAC software, this and all the preceding Stanford University notices
* are to remain affixed to any copy or derivative of this software made
* or distributed by the recipient and are to be affixed to any copy of
* software made or distributed by the recipient that contains a copy or
* derivative of this software.
*
* ------------------ SLAC Software Notices, Set 4 OTT.002a, 2004 FEB 03
*/
/* This driver uses the file-system interface to the i2c bus */
#include <unistd.h> /* write, read, close */
#include <rtems.h>
#include <rtems/bspIo.h>
#include <rtems/rtc.h>
#include <rtems/score/sysstate.h>
#include <rtems/rtems/clockimpl.h>
#include <libchip/rtc.h>
#include <libchip/ds1375-rtc.h>
#include <sys/fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#define STATIC static
#undef DEBUG
/* The RTC driver routines are possibly called during
* system initialization -- that would be prior to opening
* the console. At this point it is not safe to use stdio
* (printf, perror etc.).
* Our file descriptors may even be 0..2
*/
#define STDIOSAFE(fmt,args...) \
do { \
if ( _System_state_Is_up( _System_state_Get() ) ) { \
fprintf(stderr,fmt,args); \
} else { \
printk(fmt,args); \
} \
} while (0)
STATIC uint8_t ds1375_bcd2bin(uint8_t x)
{
uint8_t h = x & 0xf0;
/* 8*hi + 2*hi + lo */
return ( h >> 1 ) + ( h >> 3 ) + ( x & 0xf );
}
STATIC uint8_t ds1375_bin2bcd(uint8_t x)
{
uint8_t h = x/10;
return ( h << 4 ) + ( x - ( ( h << 3 ) + ( h << 1 ) ) );
}
/*
* Register Definitions and Access Macros
*
* The xxx_REG macros are offsets into the register files
* The xxx_OFF macros are offsets into a in-memory buffer
* starting at the seconds (for the 1375 both,
* _REG and _OFF happen to be identical).
*/
#define DS1375_SEC_REG 0x0
#define DS1375_SEC_OFF (DS1375_SEC_REG-DS1375_SEC_REG)
/* Extract seconds and convert to binary */
#define DS1375_SEC(x) ds1375_bcd2bin( ((x)[DS1375_SEC_OFF]) & 0x7f )
#define DS1375_MIN_REG 0x1
#define DS1375_MIN_OFF (DS1375_MIN_REG-DS1375_SEC_REG)
/* Extract minutes and convert to binary */
#define DS1375_MIN(x) ds1375_bcd2bin( ((x)[DS1375_MIN_OFF]) & 0x7f )
#define DS1375_HR_REG 0x2
#define DS1375_HR_OFF (DS1375_HR_REG-DS1375_SEC_REG)
#define DS1375_HR_1224 (1<<6)
#define DS1375_HR_AMPM (1<<5)
/* Are hours in AM/PM representation ? */
#define DS1375_IS_AMPM(x) (DS1375_HR_1224 & ((x)[DS1375_HR_OFF]))
/* Are we PM ? */
#define DS1375_IS_PM(x) (DS1375_HR_AMPM & ((x)[DS1375_HR_OFF]))
/* Extract hours (12h mode) and convert to binary */
#define DS1375_HR_12(x) ds1375_bcd2bin( ((x)[DS1375_HR_OFF]) & 0x1f )
/* Extract hours (24h mode) and convert to binary */
#define DS1375_HR_24(x) ds1375_bcd2bin( ((x)[DS1375_HR_OFF]) & 0x3f )
#define DS1375_DAY_REG 0x3
#define DS1375_DAY_OFF (DS1375_DAY_REG-DS1375_SEC_REG)
#define DS1375_DAT_REG 0x4
#define DS1375_DAT_OFF (DS1375_DAT_REG-DS1375_SEC_REG)
/* Extract date and convert to binary */
#define DS1375_DAT(x) ds1375_bcd2bin( ((x)[DS1375_DAT_OFF]) & 0x3f )
#define DS1375_MON_REG 0x5
#define DS1375_MON_OFF (DS1375_MON_REG-DS1375_SEC_REG)
#define DS1375_MON_CTRY (1<<7)
/* Is century bit set ? */
#define DS1375_IS_CTRY(x) (((x)[DS1375_MON_OFF]) & DS1375_MON_CTRY)
/* Extract month and convert to binary */
#define DS1375_MON(x) ds1375_bcd2bin( ((x)[DS1375_MON_OFF]) & 0x1f )
#define DS1375_YR_REG 0x6
#define DS1375_YR_OFF (DS1375_YR_REG-DS1375_SEC_REG)
/* Extract year and convert to binary */
#define DS1375_YR(x) ds1375_bcd2bin( ((x)[DS1375_YR_OFF]) & 0xff )
/* CR Register and bit definitions */
#define DS1375_CR_REG 0xe
#define DS1375_CR_ECLK (1<<7)
#define DS1375_CR_CLKSEL1 (1<<6)
#define DS1375_CR_CLKSEL0 (1<<5)
#define DS1375_CR_RS2 (1<<4)
#define DS1375_CR_RS1 (1<<3)
#define DS1375_CR_INTCN (1<<2)
#define DS1375_CR_A2IE (1<<1)
#define DS1375_CR_A1IE (1<<0)
#define DS1375_CSR_REG 0xf
/* User SRAM (8 bytes) */
#define DS1375_RAM 0x10 /* start of 8 bytes user ram */
/* Access Primitives */
STATIC int rd_bytes(
int fd,
uint32_t off,
uint8_t *buf,
int len
)
{
uint8_t ptr = off;
return 1 == write( fd, &ptr, 1 ) && len == read( fd, buf, len ) ? 0 : -1;
}
STATIC int wr_bytes(
int fd,
uint32_t off,
uint8_t *buf,
int len
)
{
uint8_t d[ len + 1 ];
/* Must not break up writing of the register pointer and
* the data to-be-written into multiple write() calls
* because every 'write()' operation sends START and
* the chip interprets the first byte after START as
* the register pointer.
*/
d[0] = off;
memcpy( d + 1, buf, len );
return len + 1 == write( fd, d, len + 1 ) ? 0 : -1;
}
/* Helpers */
static int getfd(
int minor
)
{
return open( (const char *)RTC_Table[minor].ulCtrlPort1, O_RDWR );
}
/* Driver Access Functions */
STATIC void ds1375_initialize(
int minor
)
{
int fd;
uint8_t cr;
if ( ( fd = getfd( minor ) ) >= 0 ) {
if ( 0 == rd_bytes( fd, DS1375_CR_REG, &cr, 1 ) ) {
/* make sure clock is enabled */
if ( ! ( DS1375_CR_ECLK & cr ) ) {
cr |= DS1375_CR_ECLK;
wr_bytes( fd, DS1375_CR_REG, &cr, 1 );
}
}
close( fd );
}
}
STATIC int ds1375_get_time(
int minor,
rtems_time_of_day *time
)
{
int rval = -1;
int fd;
uint8_t buf[DS1375_YR_REG + 1 - DS1375_SEC_REG];
if ( time && ( ( fd = getfd( minor ) ) >= 0 ) ) {
if ( 0 == rd_bytes( fd, DS1375_SEC_REG, buf, sizeof(buf) ) ) {
time->year = DS1375_IS_CTRY( buf ) ? 2000 : 1900;
time->year += DS1375_YR ( buf );
time->month = DS1375_MON( buf );
time->day = DS1375_DAT( buf ); /* DAY is weekday */
if ( DS1375_IS_AMPM( buf ) ) {
time->hour = DS1375_HR_12 ( buf );
if ( DS1375_IS_PM( buf ) )
time->hour += 12;
} else {
time->hour = DS1375_HR_24 ( buf );
}
time->minute = DS1375_MIN( buf );
time->second = DS1375_SEC( buf );
time->ticks = 0;
rval = 0;
}
close( fd );
}
return rval;
}
STATIC int ds1375_set_time(
int minor,
const rtems_time_of_day *time
)
{
int rval = -1;
int fd = -1;
time_t secs;
struct tm tm;
uint8_t buf[DS1375_YR_REG + 1 - DS1375_SEC_REG];
uint8_t cr = 0xff;
/*
* The clock hardware maintains the day-of-week as a separate counter
* so we must compute it ourselves (rtems_time_of_day doesn't come
* with a day of week).
*/
secs = _TOD_To_seconds( time );
/* we're only interested in tm_wday... */
gmtime_r( &secs, &tm );
buf[DS1375_SEC_OFF] = ds1375_bin2bcd( time->second );
buf[DS1375_MIN_OFF] = ds1375_bin2bcd( time->minute );
/* bin2bcd(hour) implicitly selects 24h mode since ms-bit is clear */
buf[DS1375_HR_OFF] = ds1375_bin2bcd( time->hour );
buf[DS1375_DAY_OFF] = tm.tm_wday + 1;
buf[DS1375_DAT_OFF] = ds1375_bin2bcd( time->day );
buf[DS1375_MON_OFF] = ds1375_bin2bcd( time->month );
if ( time->year >= 2000 ) {
buf[DS1375_YR_OFF] = ds1375_bin2bcd( time->year - 2000 );
buf[DS1375_MON_OFF] |= DS1375_MON_CTRY;
} else {
buf[DS1375_YR_OFF] = ds1375_bin2bcd( time->year - 1900 );
}
/*
* Stop clock; update registers and restart. This is slightly
* slower than just writing everyting but if we did that we
* could get inconsistent registers if this routine would not
* complete in less than 1s (says the datasheet) and we don't
* know if we are going to be pre-empted for some time...
*/
if ( ( fd = getfd( minor ) ) < 0 ) {
goto cleanup;
}
if ( rd_bytes( fd, DS1375_CR_REG, &cr, 1 ) )
goto cleanup;
cr &= ~DS1375_CR_ECLK;
/* This stops the clock */
if ( wr_bytes( fd, DS1375_CR_REG, &cr, 1 ) )
goto cleanup;
/* write new contents */
if ( wr_bytes( fd, DS1375_SEC_REG, buf, sizeof(buf) ) )
goto cleanup;
rval = 0;
cleanup:
if ( fd >= 0 ) {
if ( ! ( DS1375_CR_ECLK & cr ) ) {
/* start clock; this handles some cases of failure
* after stopping the clock by restarting it again
*/
cr |= DS1375_CR_ECLK;
if ( wr_bytes( fd, DS1375_CR_REG, &cr, 1 ) )
rval = -1;
}
close( fd );
}
return rval;
}
/* Debugging / Testing */
#ifdef DEBUG
/* Don't forget to set "TZ" when using these test routines */
/* What is rtems_time_of_day good for ? Why not use std types ? */
uint32_t
ds1375_get_time_tst()
{
rtems_time_of_day rtod;
time_t secs;
ds1375_get_time( 0, &rtod );
secs = _TOD_To_seconds( &rtod );
printf( "%s\n", ctime( &secs ) );
return secs;
}
int
ds1375_set_time_tst( const char *datstr, rtems_time_of_day *prt )
{
struct tm tm;
time_t secs;
rtems_time_of_day rt;
if ( !datstr )
return -1;
if ( ! strptime( datstr, "%Y-%m-%d/%T", &tm ) )
return -2;
if ( ! prt )
prt = &rt;
secs = mktime( &tm );
/* convert to UTC */
gmtime_r( &secs, &tm );
printf("Y: %"PRIu32" ", (prt->year = tm.tm_year + 1900) );
printf("M: %"PRIu32" ", (prt->month = tm.tm_mon + 1) );
printf("D: %"PRIu32" ", (prt->day = tm.tm_mday ) );
printf("h: %"PRIu32" ", (prt->hour = tm.tm_hour ) );
printf("m: %"PRIu32" ", (prt->minute = tm.tm_min ) );
printf("s: %"PRIu32"\n", (prt->second = tm.tm_sec ) );
prt->ticks = 0;
return ( prt == &rt ) ? ds1375_set_time( 0, &rt ) : 0;
}
#endif
uint32_t
rtc_ds1375_get_register( uintptr_t port, uint8_t reg )
{
int fd;
uint8_t v;
uint32_t rval = -1;
if ( ( fd = open( (const char*)port, O_RDWR ) ) >= 0 ) {
if ( 0 == rd_bytes( fd, reg, &v, 1 ) ) {
rval = v;
}
close( fd );
}
return rval;
}
void
rtc_ds1375_set_register( uintptr_t port, uint8_t reg, uint32_t value )
{
int fd;
uint8_t v = value;
if ( ( fd = open( (const char*)port, O_RDWR ) ) >= 0 ) {
wr_bytes( fd, reg, &v, 1 );
close( fd );
}
}
bool rtc_ds1375_device_probe(
int minor
)
{
int fd;
if ( ( fd = getfd( minor ) ) < 0 ) {
STDIOSAFE( "ds1375_probe (open): %s\n", strerror( errno ) );
return false;
}
/* Try to set file pointer */
if ( 0 != wr_bytes( fd, DS1375_SEC_REG, 0, 0 ) ) {
STDIOSAFE( "ds1375_probe (wr_bytes): %s\n", strerror( errno ) );
close( fd );
return false;
}
if ( close( fd ) ) {
STDIOSAFE( "ds1375_probe (close): %s\n", strerror( errno ) );
return false;
}
return true;
}
rtc_fns rtc_ds1375_fns = {
.deviceInitialize = ds1375_initialize,
.deviceGetTime = ds1375_get_time,
.deviceSetTime = ds1375_set_time,
};
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