RE: [PATCH v4 1/2] clk: Provide managed helper to get and enable bulk clocks

[Shradha Todi]

> -----Original Message-----
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> Sent: 29 January 2024 12:25
> To: Shradha Todi <shradha.t@xxxxxxxxxxx>
> Cc: linux-clk@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-samsung-
> soc@xxxxxxxxxxxxxxx; mturquette@xxxxxxxxxxxx; sboyd@xxxxxxxxxx;
> jingoohan1@xxxxxxxxx; lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; robh@xxxxxxxxxx;
> bhelgaas@xxxxxxxxxx; krzysztof.kozlowski@xxxxxxxxxx;
> alim.akhtar@xxxxxxxxxxx; linux@xxxxxxxxxxxxxxx;
> m.szyprowski@xxxxxxxxxxx; pankaj.dubey@xxxxxxxxxxx
> Subject: Re: [PATCH v4 1/2] clk: Provide managed helper to get and enable bulk
> clocks
> 
> On Wed, Jan 24, 2024 at 04:08:37PM +0530, Shradha Todi wrote:
> > Provide a managed devm_clk_bulk* wrapper to get and enable all bulk
> > clocks in order to simplify drivers that keeps all clocks enabled for
> > the time of driver operation.
> >
> > Suggested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
> > ---
> >  drivers/clk/clk-devres.c | 40
> ++++++++++++++++++++++++++++++++++++++++
> >  include/linux/clk.h      | 24 ++++++++++++++++++++++++
> >  2 files changed, 64 insertions(+)
> >
> > diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c index
> > 4fb4fd4b06bd..cbbd2cc339c3 100644
> > --- a/drivers/clk/clk-devres.c
> > +++ b/drivers/clk/clk-devres.c
> > @@ -182,6 +182,46 @@ int __must_check devm_clk_bulk_get_all(struct
> > device *dev,  }  EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all);
> >
> > +static void devm_clk_bulk_release_all_enable(struct device *dev, void
> > +*res) {
> > +	struct clk_bulk_devres *devres = res;
> > +
> > +	clk_bulk_disable_unprepare(devres->num_clks, devres->clks);
> > +	clk_bulk_put_all(devres->num_clks, devres->clks); }
> > +
> > +int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
> > +					      struct clk_bulk_data **clks) {
> > +	struct clk_bulk_devres *devres;
> > +	int ret;
> > +
> > +	devres = devres_alloc(devm_clk_bulk_release_all_enable,
> > +			      sizeof(*devres), GFP_KERNEL);
> > +	if (!devres)
> > +		return -ENOMEM;
> > +
> > +	ret = clk_bulk_get_all(dev, &devres->clks);
> > +	if (ret > 0) {
> > +		*clks = devres->clks;
> > +		devres->num_clks = ret;
> > +	} else {
> > +		devres_free(devres);
> > +		return ret;
> > +	}
> 
> How about:
> 
> 	ret = clk_bulk_get_all(dev, &devres->clks);
> 	if (ret <= 0) {
> 		devres_free(devres);
> 		return ret;
> 	}
> 
> 	*clks = devres->clks;
> 	devres->num_clks = ret;
> 
> Even though this patch follows the pattern used by the rest of the APIs in the
> driver, IMO above makes it more readable.
> 

Since I have usually seen that maintainers suggest to maintain the coding style of the file, I followed the same.
If you have a stronger reason to change this, please let me know
Marek, Michael, Stephen please let us know what do you think about this?

> > +
> > +	ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
> > +	if (!ret) {
> > +		devres_add(dev, devres);
> > +	} else {
> > +		clk_bulk_put_all(devres->num_clks, devres->clks);
> > +		devres_free(devres);
> > +	}
> > +
> 
> Same as above:
> 
> 	ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
> 	if (ret) {
> 		clk_bulk_put_all(devres->num_clks, devres->clks);
> 		devres_free(devres);
> 		return ret;
> 	}
> 
> 	devres_add(dev, devres);
> 
> > +	return ret;
> 
> 	return 0;
> 

Same as above

> > +}
> > +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all_enable);
> > +
> >  static int devm_clk_match(struct device *dev, void *res, void *data)
> > {
> >  	struct clk **c = res;
> > diff --git a/include/linux/clk.h b/include/linux/clk.h index
> > 1ef013324237..a005e709b7bd 100644
> > --- a/include/linux/clk.h
> > +++ b/include/linux/clk.h
> > @@ -438,6 +438,23 @@ int __must_check
> > devm_clk_bulk_get_optional(struct device *dev, int num_clks,  int
> __must_check devm_clk_bulk_get_all(struct device *dev,
> >  				       struct clk_bulk_data **clks);
> >
> > +/**
> > + * devm_clk_bulk_get_all_enable - managed get multiple clk consumers and
> > + *				  enable all clks
> 
> "Get and enable all clocks of the consumer (managed)"
> 

Will take this up in the next patchset

> > + * @dev: device for clock "consumer"
> > + * @clks: pointer to the clk_bulk_data table of consumer
> > + *
> > + * Returns success (0) or negative errno.
> > + *
> > + * This helper function allows drivers to get several clk
> 
> "This helper function allows drivers to get all clocks of the consumer and enables
> them..."
> 
> - Mani
> 

Will take this up. Thanks for your review Mani!

> > + * consumers and enable all of them in one operation with management.
> > + * The clks will automatically be disabled and freed when the device
> > + * is unbound.
> > + */
> > +
> > +int __must_check devm_clk_bulk_get_all_enable(struct device *dev,
> > +					      struct clk_bulk_data **clks);
> > +
> >  /**
> >   * devm_clk_get - lookup and obtain a managed reference to a clock producer.
> >   * @dev: device for clock "consumer"
> > @@ -960,6 +977,13 @@ static inline int __must_check
> devm_clk_bulk_get_all(struct device *dev,
> >  	return 0;
> >  }
> >
> > +static inline int __must_check devm_clk_bulk_get_all_enable(struct device
> *dev,
> > +						struct clk_bulk_data **clks)
> > +{
> > +
> > +	return 0;
> > +}
> > +
> >  static inline struct clk *devm_get_clk_from_child(struct device *dev,
> >  				struct device_node *np, const char *con_id)  {
> > --
> > 2.17.1
> >
> 
> --
> மணிவண்ணன் சதாசிவம்