Hello,
On 07/02/2022 09:01:56+0200, Hanna Hawa wrote:
> tm_year filed hold the number of years since 1900, in case the century
> was changed the driver will return invalid year, as it will not
> increment the years field by 200.
>
> This change update the years calculation in bq32k_rtc_read_time() and
> bq32k_rtc_write_time(). By increasing the years by 100 always, and only
> if the century enable bit (BQ32K_CENT_EN) is set and century bit
> (BQ32K_CENT) is cleared will increase again by 100 to represent the next
> century.
>
I'm not sure I get the issue, currently, the driver considers that
BQ32K_CENT not set is 19YY and BQ32K_CENT set is 20YY and what is done
seems fine to me. Can you elaborate on what you are trying to fix?
> Signed-off-by: Hanna Hawa <hhhawa@xxxxxxxxxx>
> ---
> drivers/rtc/rtc-bq32k.c | 29 +++++++++++++++++++++++------
> 1 file changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c
> index 2235c968842d..09795dd2728b 100644
> --- a/drivers/rtc/rtc-bq32k.c
> +++ b/drivers/rtc/rtc-bq32k.c
> @@ -108,8 +108,20 @@ static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
> tm->tm_mday = bcd2bin(regs.date);
> tm->tm_wday = bcd2bin(regs.day) - 1;
> tm->tm_mon = bcd2bin(regs.month) - 1;
> - tm->tm_year = bcd2bin(regs.years) +
> - ((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
> + /*
> + * tm_year is number of years since 1900. Need to increase the years by
> + * 100 always assuming we are on 20YY and not 19YY.
> + */
> + tm->tm_year = bcd2bin(regs.years) + 100;
> +
> + /*
> + * If the century enable bit (BQ32K_CENT_EN) is set, and century bit
> + * (BQ32K_CENT) is cleared, that means we are on the next century, which
> + * required to increase by 100.
> + */
> + if ((regs.cent_hours & BQ32K_CENT_EN) &&
> + !(regs.cent_hours & BQ32K_CENT))
> + tm->tm_year += 100;
>
> return 0;
> }
> @@ -117,6 +129,7 @@ static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
> static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
> {
> struct bq32k_regs regs;
> + int year;
>
> regs.seconds = bin2bcd(tm->tm_sec);
> regs.minutes = bin2bcd(tm->tm_min);
> @@ -125,11 +138,15 @@ static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
> regs.date = bin2bcd(tm->tm_mday);
> regs.month = bin2bcd(tm->tm_mon + 1);
>
> - if (tm->tm_year >= 100) {
> + /* Assume we are on 20YY and not 19YY */
> + year = tm->tm_year - 100;
> +
> + if (year < 100) {
> regs.cent_hours |= BQ32K_CENT;
> - regs.years = bin2bcd(tm->tm_year - 100);
> - } else
> - regs.years = bin2bcd(tm->tm_year);
> + regs.years = bin2bcd(year);
> + } else {
> + regs.years = bin2bcd(year - 100);
> + }
>
> return bq32k_write(dev, ®s, 0, sizeof(regs));
> }
> --
> 2.17.1
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
