lkml.org 
[lkml]   [2015]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] rtc: ds1307: Fix alarm programming for mcp794xx
From
Date
On 10/23/2015 01:29 AM, Tero Kristo wrote:
> mcp794xx alarm registers must be written in BCD format. However, the
> alarm programming logic neglected this by adding one to the value
> after bin2bcd conversion has been already done, writing bad values
> to month register in case the alarm being set is in October. In this
> case, the alarm month value becomes 0x0a instead of the expected 0x10.
>
> Fix by moving the +1 addition within the bin2bcd call also.
>
> Fixes: 1d1945d261a2 ("drivers/rtc/rtc-ds1307.c: add alarm support for mcp7941x chips")
>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>

Nice catch.
Acked-by: Nishanth Menon <nm@ti.com>
> ---
> drivers/rtc/rtc-ds1307.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> index a705e64..188006c 100644
> --- a/drivers/rtc/rtc-ds1307.c
> +++ b/drivers/rtc/rtc-ds1307.c
> @@ -718,9 +718,9 @@ static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
> regs[3] = bin2bcd(t->time.tm_sec);
> regs[4] = bin2bcd(t->time.tm_min);
> regs[5] = bin2bcd(t->time.tm_hour);
> - regs[6] = bin2bcd(t->time.tm_wday) + 1;
> + regs[6] = bin2bcd(t->time.tm_wday + 1);
> regs[7] = bin2bcd(t->time.tm_mday);
> - regs[8] = bin2bcd(t->time.tm_mon) + 1;
> + regs[8] = bin2bcd(t->time.tm_mon + 1);
>
> /* Clear the alarm 0 interrupt flag. */
> regs[6] &= ~MCP794XX_BIT_ALMX_IF;
>


--
Regards,
Nishanth Menon


\
 
 \ /
  Last update: 2015-10-24 17:01    [W:0.250 / U:0.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site