[PATCH v3 5/6] ARM: mxs: add usb phy operations

From: LW@KARO-electronics.de (Lothar Waßmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 5/6] ARM: mxs: add usb phy operations
Date: Wed, 27 Jul 2011 11:24:57 +0200	[thread overview]
Message-ID: <20015.55657.95716.938713@ipc1.ka-ro> (raw)
In-Reply-To: <97D3A72708D04647A5AC84A04996E5B5166AD6@039-SN1MPN1-006.039d.mgd.msft.net>

Hi,

Lin Tony-B19295 writes:
> > -----Original Message-----
> > From: Lothar Wa?mann [mailto:LW at KARO-electronics.de]
> > Sent: Wednesday, July 27, 2011 4:48 PM
> > To: Lin Tony-B19295
> > Cc: linux-usb at vger.kernel.org; koen.beel.barco at gmail.com;
> > stern at rowland.harvard.edu; s.hauer at pengutronix.de; linux-arm-
> > kernel at lists.infradead.org
> > Subject: Re: [PATCH v3 5/6] ARM: mxs: add usb phy operations
> > 
> > Hi,
> > 
> > Tony Lin writes:
> > > add usb phy register definitions and functions usb host driver will
> > > use these callback functions to initialize usb phy and change working
> > > mode
> > >
> > > Signed-off-by: Tony Lin <tony.lin@freescale.com>
> > > ---
> > >  arch/arm/mach-mxs/Kconfig           |    1 +
> > >  arch/arm/mach-mxs/Makefile          |    1 +
> > >  arch/arm/mach-mxs/mxs_usb.c         |  288
> > +++++++++++++++++++++++++++++++++++
> > >  arch/arm/mach-mxs/regs-usbphy-mxs.h |  240
> > > +++++++++++++++++++++++++++++
> > >  4 files changed, 530 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
> > > index 4cd0231..1c4264f 100644
> > > --- a/arch/arm/mach-mxs/Kconfig
> > > +++ b/arch/arm/mach-mxs/Kconfig
> > > @@ -49,6 +49,7 @@ config MACH_MX28EVK
> > >  	select MXS_HAVE_PLATFORM_MXS_MMC
> > >  	select MXS_HAVE_PLATFORM_MXSFB
> > >  	select MXS_OCOTP
> > > +	select USB_ARCH_HAS_EHCI
> > >  	help
> > >  	  Include support for MX28EVK platform. This includes specific
> > >  	  configurations for the board and its peripherals.
> > > diff --git a/arch/arm/mach-mxs/Makefile b/arch/arm/mach-mxs/Makefile
> > > index 6c38262..726c49f 100644
> > > --- a/arch/arm/mach-mxs/Makefile
> > > +++ b/arch/arm/mach-mxs/Makefile
> > > @@ -12,5 +12,6 @@ obj-$(CONFIG_MACH_MX23EVK) += mach-mx23evk.o
> > >  obj-$(CONFIG_MACH_MX28EVK) += mach-mx28evk.o
> > >  obj-$(CONFIG_MODULE_TX28) += module-tx28.o
> > >  obj-$(CONFIG_MACH_TX28)    += mach-tx28.o
> > > +obj-$(CONFIG_USB_EHCI_MXC)   += mxs_usb.o
> > >
> > >  obj-y += devices/
> > > diff --git a/arch/arm/mach-mxs/mxs_usb.c b/arch/arm/mach-mxs/mxs_usb.c
> > > new file mode 100644 index 0000000..9acc611
> > > --- /dev/null
> > > +++ b/arch/arm/mach-mxs/mxs_usb.c
> > [...]
> > > +static struct mxs_usb_private_date usbh_private = {
> > > +	.internal_phy_clk_already_on = 0,
> > > +};
> > > +
> > > +static struct mxc_usbh_platform_data usbh_config = {
> > > +	.init = fsl_usb_host_init,
> > > +	.exit = fsl_usb_host_uninit,
> > > +	.portsc = MXC_EHCI_MODE_ULPI,
> > > +	.otg = NULL,
> > > +	.plt_irq_handler = fsl_plt_usbh_irq_handler,
> > > +	.ppriv = &usbh_private,
> >         ^^^^^^^^^^^^^^^^^^^^^^^
> > This is an abuse of the platform_data. platform_data is meant to convey
> > platform specific information to a driver, not for drivers storing their
> > internal state. It should be handled read-only by drivers.
> > 
> > If you want to associate driver internal data with a platform_device you
> > should use platform_set_drvdata()/platform_get_drvdata() to
> > store/retrieve a pointer to the driver's internal data.
> > 
> > 
> The ppriv is not for storing driver internal state. Actually driver needs some callback functions which locates in platform.
> So that this pointer stores platform specific information used in callbacks to distinguish such as register address, clk
> Information.
>
Your fsl_usb_host_init() function has this:
|+	ppriv->phy_regs = ioremap(MX28_USBPHY1_BASE_ADDR, SZ_8K);
|+	ppriv->ctrl_regs = ioremap(MX28_USBCTRL1_BASE_ADDR, SZ_8K);
|+	ppriv->usb_clk = clk_get(&pdev->dev, "usb1");
|+	ppriv->usb_phy_clk = clk_get(&pdev->dev, "usb1_phy");

Thus the driver is modifying the data provided via the platform_data
pointer!

Lothar Wa?mann
-- 
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