Re: [PATCH for-7.0] rtc: Move RTC function prototypes to their own header

[Philippe Mathieu-Daudé]

On 11/29/21 21:55, Peter Maydell wrote:
> softmmu/rtc.c defines two public functions: qemu_get_timedate() and
> qemu_timedate_diff().  Currently we keep the prototypes for these in
> qemu-common.h, but most files don't need them.  Move them to their
> own header, a new include/sysemu/rtc.h.
> 
> Since the C files using these two functions did not need to include
> qemu-common.h for any other reason, we can remove those include lines
> when we add the include of the new rtc.h.
> 
> The license for the .h file follows that of the softmmu/rtc.c
> where both the functions are defined.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> I have added documentation comments for the two functions, but
> since my understanding of them and their purpose is little shaky
> review would be welcome.
> ---
>  include/qemu-common.h    |  3 ---
>  include/sysemu/rtc.h     | 58 ++++++++++++++++++++++++++++++++++++++++
>  hw/arm/omap1.c           |  2 +-
>  hw/arm/pxa2xx.c          |  2 +-
>  hw/arm/strongarm.c       |  2 +-
>  hw/misc/mac_via.c        |  2 +-
>  hw/misc/macio/cuda.c     |  2 +-
>  hw/misc/macio/pmu.c      |  2 +-
>  hw/ppc/spapr_rtc.c       |  2 +-
>  hw/rtc/allwinner-rtc.c   |  2 +-
>  hw/rtc/aspeed_rtc.c      |  2 +-
>  hw/rtc/ds1338.c          |  2 +-
>  hw/rtc/exynos4210_rtc.c  |  2 +-
>  hw/rtc/goldfish_rtc.c    |  2 +-
>  hw/rtc/m41t80.c          |  2 +-
>  hw/rtc/m48t59.c          |  2 +-
>  hw/rtc/mc146818rtc.c     |  2 +-
>  hw/rtc/pl031.c           |  2 +-
>  hw/rtc/twl92230.c        |  2 +-
>  hw/rtc/xlnx-zynqmp-rtc.c |  2 +-
>  hw/s390x/tod-tcg.c       |  2 +-
>  hw/scsi/megasas.c        |  2 +-
>  net/dump.c               |  2 +-
>  softmmu/rtc.c            |  2 +-
>  24 files changed, 80 insertions(+), 25 deletions(-)
>  create mode 100644 include/sysemu/rtc.h
> 
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index 73bcf763ed8..bed0b06a3d2 100644
> --- a/include/qemu-common.h
> +++ b/include/qemu-common.h
> @@ -26,9 +26,6 @@
>  int qemu_main(int argc, char **argv, char **envp);
>  #endif
>  
> -void qemu_get_timedate(struct tm *tm, int offset);
> -int qemu_timedate_diff(struct tm *tm);
> -
>  void *qemu_oom_check(void *ptr);
>  
>  ssize_t qemu_write_full(int fd, const void *buf, size_t count)
> diff --git a/include/sysemu/rtc.h b/include/sysemu/rtc.h
> new file mode 100644
> index 00000000000..159702b45b5
> --- /dev/null
> +++ b/include/sysemu/rtc.h
> @@ -0,0 +1,58 @@
> +/*
> + * RTC configuration and clock read
> + *
> + * Copyright (c) 2003-2021 QEMU contributors
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef SYSEMU_RTC_H
> +#define SYSEMU_RTC_H
> +
> +/**
> + * qemu_get_timedate: Get the current RTC time
> + * @tm: struct tm to fill in with RTC time
> + * @offset: offset in seconds to adjust the RTC time by before
> + *          converting to struct tm format.
> + *
> + * This function fills in @tm with the current RTC time, as adjusted
> + * by @offset (for example, if @offset is 3600 then the returned time/date
> + * will be one hour further ahead than the current RTC time).
> + *
> + * The usual use is by RTC device models, which should call this function
> + * to find the time/date value that they should return to the guest
> + * when it reads the RTC registers.
> + *
> + * The behaviour of the clock whose value this function returns will
> + * depend on the -rtc command line option passed by the user.
> + */
> +void qemu_get_timedate(struct tm *tm, int offset);
> +
> +/**
> + * qemu_timedate_diff: Return difference between a struct tm and the RTC
> + * @tm: struct tm containing the date/time to compare against
> + *
> + * Returns the difference in seconds between the RTC clock time
> + * and the date/time specified in @tm. For example, if @tm specifies
> + * a timestamp one hour further ahead than the current RTC time
> + * then this function will return 3600.
> + */
> +int qemu_timedate_diff(struct tm *tm);

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>