mirror of
https://gitlab.rtems.org/rtems/rtos/rtems.git
synced 2025-12-07 08:03:12 +00:00
897a8d3094
Previously this RTC was using the file system-based i2c interface in /dev. Since the RTC is initialized pretty early on during system init, we call open() before stdin/stdout/stderr have been opened. RTEMS assumes that stdin == 0, stdout == 1, etc., and fails when that isn't the case. In particular, when stdin != 0, RTEMS assumes that it wasn't configured with a console driver and skips opening stdout/stderr, leading to confusing issues with the standard I/O streams.
106 lines
3.3 KiB
C
106 lines
3.3 KiB
C
/* 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
|
|
*/
|
|
|
|
/**
|
|
* Modified to use i2c-rtc driver by J. Lorelli <lorelli@slac.stanford.edu>
|
|
*/
|
|
|
|
#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 <stdint.h>
|
|
|
|
/*
|
|
* 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).
|
|
*/
|
|
|
|
/* 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
|
|
|
|
/* Initialize the hardware */
|
|
int
|
|
rtc_ds1375_hw_init(struct i2c_rtc_base *base)
|
|
{
|
|
uint8_t cr;
|
|
int r = i2c_rtc_read(base, DS1375_CR_REG, &cr, 1);
|
|
if (r != 0)
|
|
return r;
|
|
|
|
/* make sure clock is enabled */
|
|
if (!(cr & DS1375_CR_ECLK)) {
|
|
cr |= DS1375_CR_ECLK;
|
|
r = i2c_rtc_write(base, DS1375_CR_REG, &cr, 1);
|
|
if (r != 0)
|
|
return r;
|
|
}
|
|
return 0;
|
|
}
|