On Thu, Nov 06, 2014 at 03:51:02PM +0200, Grygorii Strashko wrote:
> Device's clocks need to be enabled always at probing time
> if !CONFIG_PM_RUNTIME - in that way, device will become accesible
> and, later, its clocks can be disabled/enabled during system
> suspend/resume by using pm_clk_suspend/pm_clk_resume APIs.
>
> But now, the clocks management code doesn't enable clocks when
> clocks are being registered per-device by using pm_clk_add/_clk().
> So, update pm_clk_acquire(), which is called from pm_clk_add/_clk(),
> to enable clock always if !CONFIG_PM_RUNTIME.
>
> Also, Platform PM domains drivers will not have to add code like below
> each time they need to handle the case when !CONFIG_PM_RUNTIME [1 - 3]:
>
> if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {
> ret = pm_clk_resume(dev);
> if (ret) {
> dev_err(dev, "pm_clk_resume failed %d\n", ret);
> goto clk_err;
> };
> }
>
> [1] https://lkml.org/lkml/2014/10/3/306
> [2] https://lkml.org/lkml/2014/10/16/305
> [3] https://lkml.org/lkml/2014/10/20/249
>
> CC: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
> CC: Kevin Hilman <khilman@xxxxxxxxxx>
> CC: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> CC: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> CC: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> CC: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> CC: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx>
>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> ---
> Hi,
>
> I marked it as RFC, because:
> Generic clock manipulation PM callbacks can be used for any device
> for which list of clocks need to be maintained - and it doesn't mean
> that this framework need to be always connected to GPD/Runtime PM or
> used during suspend resume. Also, for DT-use case - it doesn't perform
> any actions (except clk_prepare) on clocks by itself and only
> by request from framework's consumer.
>
> For example, it can be reused by Power domain/controller drivers like:
> - Rockchip RK3288 PM Domain (https://lkml.org/lkml/2014/11/6/30)
> - IMX.6 PU power domain (http://www.spinics.net/lists/arm-kernel/msg360709.html)
>
> to maintain list of clocks for GPD itself and these clocks should not
> be enabled by default, because they are used to power on/off Power domain
> in a specific way:
> - enable all clocks assigned to PD
> - power on/off PD
> - disable all clocks assigned to PD.
> After this patch it will be impossible to reuse Generic clock manipulation PM
> callbacks in cases described above.
I'd rather keep it separate and concentrate on making pm_clk* code
working with the power management core. Individual drivers can easily
keep list of their clocks for whatever additional purpose they need
without involving pm_clk* API.
Thanks.
--
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
