lkml.org 
[lkml]   [2012]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v5 4/5] fsl_pmc: Add API to enable device as wakeup event source
Date


> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Tuesday, June 05, 2012 7:03 AM
> To: Zhao Chenhui-B35336
> Cc: linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org;
> galak@kernel.crashing.org; Li Yang-R58472
> Subject: Re: [PATCH v5 4/5] fsl_pmc: Add API to enable device as wakeup
> event source
>
> On 06/04/2012 06:36 AM, Zhao Chenhui wrote:
> > On Fri, Jun 01, 2012 at 05:08:52PM -0500, Scott Wood wrote:
> >> On 05/11/2012 06:53 AM, Zhao Chenhui wrote:
> >>> Add APIs for setting wakeup source and lossless Ethernet in low power
> modes.
> >>> These APIs can be used by wake-on-packet feature.
> >>>
> >>> Signed-off-by: Dave Liu <daveliu@freescale.com>
> >>> Signed-off-by: Li Yang <leoli@freescale.com>
> >>> Signed-off-by: Jin Qing <b24347@freescale.com>
> >>> Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
> >>> ---
> >>> arch/powerpc/sysdev/fsl_pmc.c | 71
> ++++++++++++++++++++++++++++++++++++++++-
> >>> arch/powerpc/sysdev/fsl_soc.h | 9 +++++
> >>> 2 files changed, 79 insertions(+), 1 deletions(-)
> >>>
> >>> diff --git a/arch/powerpc/sysdev/fsl_pmc.c
> b/arch/powerpc/sysdev/fsl_pmc.c
> >>> index 1dc6e9e..c1170f7 100644
> >>> --- a/arch/powerpc/sysdev/fsl_pmc.c
> >>> +++ b/arch/powerpc/sysdev/fsl_pmc.c
> >>> @@ -34,6 +34,7 @@ struct pmc_regs {
> >>> __be32 powmgtcsr;
> >>> #define POWMGTCSR_SLP 0x00020000
> >>> #define POWMGTCSR_DPSLP 0x00100000
> >>> +#define POWMGTCSR_LOSSLESS 0x00400000
> >>> __be32 res3[2];
> >>> __be32 pmcdr;
> >>> };
> >>> @@ -43,6 +44,74 @@ static unsigned int pmc_flag;
> >>>
> >>> #define PMC_SLEEP 0x1
> >>> #define PMC_DEEP_SLEEP 0x2
> >>> +#define PMC_LOSSLESS 0x4
> >>> +
> >>> +/**
> >>> + * mpc85xx_pmc_set_wake - enable devices as wakeup event source
> >>> + * @pdev: platform device affected
> >>> + * @enable: True to enable event generation; false to disable
> >>> + *
> >>> + * This enables the device as a wakeup event source, or disables it.
> >>> + *
> >>> + * RETURN VALUE:
> >>> + * 0 is returned on success
> >>> + * -EINVAL is returned if device is not supposed to wake up the
> system
> >>> + * Error code depending on the platform is returned if both the
> platform and
> >>> + * the native mechanism fail to enable the generation of wake-up
> events
> >>> + */
> >>> +int mpc85xx_pmc_set_wake(struct platform_device *pdev, bool enable)
> >>
> >> Why does it have to be a platform_device? Would a bare device_node
> work
> >> here? If it's for stuff like device_may_wakeup() that could be in a
> >> platform_device wrapper function.
> >
> > It does not have to be a platform_device. I think it can be a struct
> device.
>
> Why does it even need that? The low level mechanism for influencing
> PMCDR should only need a device node, not a Linux device struct.

It does no harm to pass the device structure and makes more sense for object oriented interface design.

>
> >> Where does this get called from? I don't see an example user in this
> >> patchset.
> >
> > It will be used by a gianfar related patch. I plan to submit that patch
> > after these patches accepted.
>
> It would be nice to see how this is used when reviewing this.
>
> >>> +{
> >>> + int ret = 0;
> >>> + struct device_node *clk_np;
> >>> + u32 *prop;
> >>> + u32 pmcdr_mask;
> >>> +
> >>> + if (!pmc_regs) {
> >>> + pr_err("%s: PMC is unavailable\n", __func__);
> >>> + return -ENODEV;
> >>> + }
> >>> +
> >>> + if (enable && !device_may_wakeup(&pdev->dev))
> >>> + return -EINVAL;
> >>
> >> Who is setting can_wakeup for these devices?
> >
> > The device driver is responsible to set can_wakeup.
>
> How would the device driver know how to set it? Wouldn't this depend on
> the particular SoC and low power mode?

It is based on the "fsl,magic-packet" and "fsl,wake-on-filer" device tree properties.

Leo



\
 
 \ /
  Last update: 2012-06-05 07:01    [W:0.060 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site