Re: [PATCH 2/3] msm: Peripheral Image Loader (PIL) driver
From: Daniel Walker
Date: Wed Mar 23 2011 - 08:27:16 EST
On Wed, 2011-03-16 at 11:48 -0700, Saravana Kannan wrote:
> On 03/16/2011 11:40 AM, David Brown wrote:
> > On Wed, Mar 16 2011, Daniel Walker wrote:
> >> On Wed, 2011-03-09 at 20:44 -0800, Stephen Boyd wrote:
> >>> On 8660, the modem, dsp, and sensors peripherals require their
> >>> firmware to be loaded into memory before they can be properly
> >>> taken out of reset.
> >>> Drivers are expected to call pil_get() when they wish to load a
> >>> peripheral. This will initiate multiple firmware_request()s for
> >>> the metadata and image blobs for a peripheral. Once the image has
> >>> been loaded into memory, it is validated and brought out of reset
> >>> via the peripheral reset driver.
> >> Why can't this be part of the generic firmware request API ?
> > Can you clarify what you mean by this? The firmware request API is used
> > to get the firmware itself, which this code uses. This code is what
> > manages making those calls for the various MSM peripherals that require
> > firmware.
> >>> diff --git a/arch/arm/mach-msm/Kconfig b/arch/arm/mach-msm/Kconfig
> >>> index 997c5bd..25b73b0 100644
> >>> --- a/arch/arm/mach-msm/Kconfig
> >>> +++ b/arch/arm/mach-msm/Kconfig
> >>> @@ -210,4 +210,17 @@ config IOMMU_API
> >>> config MSM_SCM
> >>> bool
> >>> +
> >>> +config MSM_PIL
> >>> + bool "Peripheral image loading (PIL)"
> >>> + select FW_LOADER
> >>> + select MSM_SCM
> >>> + depends on ARCH_MSM8X60
> >>> + help
> >>> + Some peripherals need to be loaded into memory before they
> >>> can be
> >>> + brought out of reset.
> >>> +
> >>> + Say yes to support these devices.
> >>> +
> >>> +
> >> You shouldn't be adding anything like this to the Kconfig. To me if you
> >> add stuff like this it's a big red flag.
> > Can you clarify what you mean "stuff like this".
> > It seems to me that this option should be selected by the drivers that
> > need it, since it doesn't make sense to have this if there are no
> > drivers that need it, and it is required when those drivers are
> > included.
> > I do think there are valid hardware configurations that don't have any
> > peripherals needing firmware, and would think that those should be able
> > to avoid requiring the code to manage that. Saravana/Stephen can
> > clarify that, though.
> Correct. There are plenty of Qualcomm SoCs that don't need this driver.
> There are also valid 8660 configurations that would not need this.
Being a driver it shouldn't be in mach-msm.
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