[U-Boot] [PATCH v4 07/13] dm: clk: Define clk_get_parent() for clk operations

[Peng Fan]

> Subject: Re: [U-Boot] [PATCH v4 07/13] dm: clk: Define clk_get_parent() for
> clk operations
> 
> 
> 
> > -----Original Message-----
> > From: Lukasz Majewski [mailto:lukma at denx.de]
> > Sent: 2019年5月17日 6:11
> > To: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> > <festevam at gmail.com>; Marek Vasut <marex at denx.de>; Simon Glass
> > <sjg at chromium.org>; Tom Rini <trini at konsulko.com>;
> > u-boot at lists.denx.de; Jagan Teki <jagan at amarulasolutions.com>; Peng
> > Fan <peng.fan at nxp.com>; Marcel Ziswiler
> <marcel.ziswiler at toradex.com>;
> > Adam Ford <aford173 at gmail.com>
> > Cc: Lukasz Majewski <lukma at denx.de>; Neil Armstrong
> > <narmstrong at baylibre.com>; Philipp Tomsich
> > <philipp.tomsich at theobroma-systems.com>; Andreas Dannenberg
> > <dannenberg at ti.com>; Fabrice Gasnier <fabrice.gasnier at st.com>; Liviu
> > Dudau <Liviu.Dudau at foss.arm.com>
> > Subject: [PATCH v4 07/13] dm: clk: Define clk_get_parent() for clk
> > operations
> >
> > This commit adds the clk_get_parent() function, which is responsible
> > for getting the parent's struct clock pointer.
> >
> > U-boot's DM support for getting parent is different (the parent
> > relationship is in udevice) than the one in common clock framework
> > (CCF) in Linux. To obtain the pointer to struct clk of parent the
> > pdev->driver_data field is read.
> >
> > Signed-off-by: Lukasz Majewski <lukma at denx.de>
> >
> > ---
> >
> > Changes in v4: None
> > Changes in v3:
> > - New patch
> >
> >  drivers/clk/clk-uclass.c | 15 +++++++++++++++
> >  include/clk.h            |  9 +++++++++
> >  2 files changed, 24 insertions(+)
> >
> > diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index
> > 79b3b0494c..1a726dafaa 100644
> > --- a/drivers/clk/clk-uclass.c
> > +++ b/drivers/clk/clk-uclass.c
> > @@ -379,6 +379,21 @@ ulong clk_get_rate(struct clk *clk)
> >  	return ops->get_rate(clk);
> >  }
> >
> > +struct clk *clk_get_parent(struct clk *clk) {
> > +	struct udevice *pdev;
> > +	struct clk *pclk;
> > +
> > +	debug("%s(clk=%p)\n", __func__, clk);
> > +
> > +	pdev = dev_get_parent(clk->dev);
> > +	pclk = (struct clk *)dev_get_driver_data(pdev);
> 
> This has a trick is that force driver_data to struct clk *, and this requires all clk
> wrappers needs take clk as the first element in the wrapper structure.
> So better add a comment here. Then it is fine to me, and

Sorry, drop my upper comments. The code is correct.
So Reviewed-by: Peng Fan <peng.fan at nxp.com>

> 
> Reviewed-by: Peng Fan <peng.fan at nxp.com>
> 
> > +	if (!pclk)
> > +		return ERR_PTR(-ENODEV);
> > +
> > +	return pclk;
> > +}
> > +
> >  ulong clk_set_rate(struct clk *clk, ulong rate)  {
> >  	const struct clk_ops *ops = clk_dev_ops(clk->dev); diff --git
> > a/include/clk.h b/include/clk.h index 89dc64bfaf..0873b1e507 100644
> > --- a/include/clk.h
> > +++ b/include/clk.h
> > @@ -259,6 +259,15 @@ int clk_free(struct clk *clk);  ulong
> > clk_get_rate(struct clk *clk);
> >
> >  /**
> > + * clk_get_parent() - Get current clock's parent.
> > + *
> > + * @clk:	A clock struct that was previously successfully requested by
> > + *		clk_request/get_by_*().
> > + * @return pointer to parent's struct clk, or error code passed as
> > +pointer  */ struct clk *clk_get_parent(struct clk *clk);
> > +
> > +/**
> >   * clk_set_rate() - Set current clock rate.
> >   *
> >   * @clk:	A clock struct that was previously successfully requested by
> > --
> > 2.11.0
> 
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.d
> enx.de%2Flistinfo%2Fu-boot&data=02%7C01%7CPeng.Fan%40nxp.com
> %7C9d8b9fb6d116473a8af508d6da8b1d64%7C686ea1d3bc2b4c6fa92cd99c5
> c301635%7C0%7C0%7C636936688386713361&sdata=68OR%2Fa6jjixt2
> h5bs0darbR4%2B5Yz88JD51RfjSCfK3Q%3D&reserved=0