Messages in this thread | | | From | Prabhakar Lad <> | Date | Mon, 1 Apr 2013 13:53:01 +0530 | Subject | Re: [PATCH v2] davinci: vpif: add pm_runtime support |
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On Mon, Apr 1, 2013 at 12:47 PM, Rajagopal Venkat <rajagopal.venkat@linaro.org> wrote: > On 1 April 2013 12:06, Prabhakar lad <prabhakar.csengg@gmail.com> wrote: >> From: Lad, Prabhakar <prabhakar.csengg@gmail.com> >> >> Add pm_runtime support to the TI Davinci VPIF driver. >> >> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> >> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> >> Cc: Hans Verkuil <hans.verkuil@cisco.com> >> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> >> Cc: Sakari Ailus <sakari.ailus@iki.fi> >> Cc: Sekhar Nori <nsekhar@ti.com> >> --- >> Changes for v2: >> 1: Removed use of clk API as pointed by Laurent and Sekhar. >> >> drivers/media/platform/davinci/vpif.c | 24 +++++++----------------- >> 1 files changed, 7 insertions(+), 17 deletions(-) >> >> diff --git a/drivers/media/platform/davinci/vpif.c b/drivers/media/platform/davinci/vpif.c >> index 28638a8..599cabb 100644 >> --- a/drivers/media/platform/davinci/vpif.c >> +++ b/drivers/media/platform/davinci/vpif.c >> @@ -23,8 +23,8 @@ >> #include <linux/spinlock.h> >> #include <linux/kernel.h> >> #include <linux/io.h> >> -#include <linux/clk.h> >> #include <linux/err.h> >> +#include <linux/pm_runtime.h> >> #include <linux/v4l2-dv-timings.h> >> >> #include <mach/hardware.h> >> @@ -44,7 +44,6 @@ static struct resource *res; >> spinlock_t vpif_lock; >> >> void __iomem *vpif_base; >> -struct clk *vpif_clk; >> >> /** >> * ch_params: video standard configuration parameters for vpif >> @@ -439,19 +438,15 @@ static int vpif_probe(struct platform_device *pdev) >> goto fail; >> } >> >> - vpif_clk = clk_get(&pdev->dev, "vpif"); >> - if (IS_ERR(vpif_clk)) { >> - status = PTR_ERR(vpif_clk); >> - goto clk_fail; >> - } >> - clk_prepare_enable(vpif_clk); >> + pm_runtime_enable(&pdev->dev); >> + pm_runtime_resume(&pdev->dev); >> + >> + pm_runtime_get(&pdev->dev); > > I don't see runtime-pm ops being registered. Can you explain how clock > prepare/unprepare is taken care by runtime-pm? > The pm_runtime API handles the clock management for you. For Davinci platform runtime PM support for clock management has been added (You can find it in arch/arm/mach-davinci/pm_domain.c) When runtime PM is enabled, the davinci runtime PM implementation will use the pm_clk layer to enable/disable clocks on demand.
For more/detailed understanding you can go through the pm_runtime framework.
Regards, --Prabhakar
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