lkml.org 
[lkml]   [2013]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] rtc: rtc-twl: ensure IRQ is wakeup enabled
Hi Kevin,

On 06/01/2013 01:37 AM, Kevin Hilman wrote:
> Currently, the RTC IRQ is never wakeup-enabled so is not capable of
> bringing the system out of suspend.
>
> On OMAP platforms, we have gotten by without this because the TWL RTC
> is on an I2C-connected chip which is capable of waking up the OMAP via
> the IO ring when the OMAP is in low-power states.
>
> However, if the OMAP suspends without hitting the low-power states
> (and the IO ring is not enabled), RTC wakeups will not work because
> the IRQ is not wakeup enabled.
As I understand, IRQ wake up capabilities are set/clear simultaneously with
IRQ unmasking/masking on OMAP4+ in omap-wakeupgen.c.
So, it should work without this patch on OMAP4+.
But if TWL is used on non OMAP4+ platform then it is needed.
(OMAP3: I haven't found the place where IRQ wakeup capabilities are
configured,
would be appreciate if you can point me on)
>
> To fix, ensure the RTC IRQ is wakeup enabled whenever the RTC alarm is
> set.
>
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Kevin Hilman <khilman@linaro.org>
> ---
> drivers/rtc/rtc-twl.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
> index 8751a52..bbda0fd 100644
> --- a/drivers/rtc/rtc-twl.c
> +++ b/drivers/rtc/rtc-twl.c
> @@ -213,12 +213,24 @@ static int mask_rtc_irq_bit(unsigned char bit)
>
> static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
> {
> + struct platform_device *pdev = to_platform_device(dev);
> + int irq = platform_get_irq(pdev, 0);
> + static bool twl_rtc_wake_enabled;
> int ret;
>
> - if (enabled)
> + if (enabled) {
> ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
> - else
> + if (device_can_wakeup(dev) && !twl_rtc_wake_enabled) {
> + enable_irq_wake(irq);
> + twl_rtc_wake_enabled = true;
> + }
> + } else {
> ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
> + if (twl_rtc_wake_enabled) {
> + disable_irq_wake(irq);
> + twl_rtc_wake_enabled = false;
> + }
> + }
>
> return ret;
> }
twl-rtc has suspend/resume callbacks implemented, so I think it's the
better place
for this code and twl_rtc_wake_enabled can be dropped.



\
 
 \ /
  Last update: 2013-06-04 14:21    [W:0.116 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site