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.
The two RTCs supported by that driver (MCP7940M and EOZ9) use slightly
different register order. Add support for a different order to the
i2c-rtc driver.
The EOZ9 RTC has a similar register interface like the MCP7940M (and
quite some other I2C RTCs). This commit:
* Extracts the generic parts from MCP7940M and moves it into a generic
i2c-rtc driver.
* Uses the new i2c-rtc for the MCP7940M.
* Uses the new i2c-rtc for the new Abracom EOZ9.
Fixes the following Coverity warning:
** CID 1539495: Integer handling issues (CONSTANT_EXPRESSION_RESULT)
/bsps/shared/dev/rtc/mcp7940m.c: 317 in mcp7940m_set_time()
Basically coverity warns that (buf[...] & 0x7) can't be bigger than 7.
Just remove the unnecessary comparison.
The MCP7940M is a I2C RTC chip. The new driver uses the dev/i2c API to
support the RTC. It is written with the intention, that the driver can
be adapted to other RTCs with a similar register layout by just
replacing the initialization function.
Add a parameter to _TOD_Validate() to disable the validation of the
ticks member.
There are two reasons for this change. Firstly, in
rtems_task_wake_when() was a double check for time_buffer == NULL (one
in rtems_task_wake_when() and one in _TOD_Validate()). Secondly, the
ticks member is ignored by rtems_task_wake_when(). This was done with a
write of zero to the ticks member and thus a modification of the
user-provided structure. Now the structure is no longer modified.
Using a mask parameter is quite efficient. You just have to load an
immediate value and there are no additional branches in _TOD_Validate().
Close#4406.
This patch fixes bug #4403. Directives
* rtems_timer_fire_when()
* rtems_timer_server_fire_when()
* rtems_task_wake_when()
are documented to return RTEMS_INVALID_ADDRESS when their time-of-day
argument is NULL. But actually they return RTEMS_INVALID_CLOCK. To fix
the issue this patch changes _TOD_Validate() to return a
status code instead of just true/false.
Close#4403
