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Date: Wed, 24 Jan 2024 12:23:15 +0530
From: "Shradha Todi" <shradha.t@...sung.com>
To: "'Manivannan Sadhasivam'" <manivannan.sadhasivam@...aro.org>
Cc: <linux-clk@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-pci@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>,
<linux-samsung-soc@...r.kernel.org>, <mturquette@...libre.com>,
<sboyd@...nel.org>, <jingoohan1@...il.com>, <lpieralisi@...nel.org>,
<kw@...ux.com>, <robh@...nel.org>, <bhelgaas@...gle.com>,
<krzysztof.kozlowski@...aro.org>, <alim.akhtar@...sung.com>,
<linux@...linux.org.uk>, <m.szyprowski@...sung.com>,
<pankaj.dubey@...sung.com>
Subject: RE: [PATCH v3 1/2] clk: Provide managed helper to get and enable
bulk clocks
> -----Original Message-----
> From: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
> Sent: 20 January 2024 20:33
> To: Shradha Todi <shradha.t@...sung.com>
> Cc: linux-clk@...r.kernel.org; linux-kernel@...r.kernel.org; linux-
> pci@...r.kernel.org; linux-arm-kernel@...ts.infradead.org; linux-samsung-
> soc@...r.kernel.org; mturquette@...libre.com; sboyd@...nel.org;
> jingoohan1@...il.com; lpieralisi@...nel.org; kw@...ux.com; robh@...nel.org;
> bhelgaas@...gle.com; krzysztof.kozlowski@...aro.org;
> alim.akhtar@...sung.com; linux@...linux.org.uk;
> m.szyprowski@...sung.com
> Subject: Re: [PATCH v3 1/2] clk: Provide managed helper to get and enable bulk
> clocks
>
> On Wed, Jan 10, 2024 at 04:31:14PM +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@...sung.com>
> > Signed-off-by: Shradha Todi <shradha.t@...sung.com>
> > ---
> > drivers/clk/clk-devres.c | 41
> ++++++++++++++++++++++++++++++++++++++++
> > include/linux/clk.h | 25 ++++++++++++++++++++++++
> > 2 files changed, 66 insertions(+)
> >
> > diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c index
> > 4fb4fd4b06bd..05b0ff4bc1d4 100644
> > --- a/drivers/clk/clk-devres.c
> > +++ b/drivers/clk/clk-devres.c
> > @@ -102,6 +102,7 @@
> EXPORT_SYMBOL_GPL(devm_clk_get_optional_enabled);
> > struct clk_bulk_devres {
> > struct clk_bulk_data *clks;
> > int num_clks;
> > + void (*exit)(int num_clks, const struct clk_bulk_data *clks);
> > };
> >
> > static void devm_clk_bulk_release(struct device *dev, void *res) @@
> > -182,6 +183,46 @@ 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_enabled(struct device *dev,
> > +void *res) {
> > + struct clk_bulk_devres *devres = res;
> > +
> > + if (devres->exit)
> > + devres->exit(devres->num_clks, devres->clks);
> > +
> > + clk_bulk_put_all(devres->num_clks, devres->clks); }
> > +
> > +int __must_check devm_clk_bulk_get_all_enabled(struct device *dev,
> > + struct clk_bulk_data **clks, int *num_clks)
>
> What is the user supposed to do with "num_clks" when you are already handling
> the enable part?
>
Since the initial clk_bulk_get_all was returning the num_clks value, the thought was to maintain this
as the user might want to have a check in their driver whether x number of clocks were successfully
retrieved and enabled.
> > +{
> > + struct clk_bulk_devres *devres;
> > + int ret;
> > +
> > + devres = devres_alloc(devm_clk_bulk_release_all_enabled,
> > + 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;
> > + *num_clks = ret;
> > + devres_add(dev, devres);
>
> If you move the statements inside this condition to the end of this function, you
> could get rid of the exit() callback and directly use
> clk_bulk_disable_unprepare() in devm_clk_bulk_release_all_enabled().
>
Okay! I will change this in the next patchset as suggested
> > + } else {
> > + devres_free(devres);
> > + return ret;
> > + }
> > +
> > + ret = clk_bulk_prepare_enable(devres->num_clks, *clks);
> > + if (!ret)
> > + devres->exit = clk_bulk_disable_unprepare;
>
> Here you can just do clk_bulk_put_all() and devres_free() directly because you
> know that the driver won't proceed after this error.
>
> - Mani
>
Thanks for the review, Mani. Will change this as suggested!
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(devm_clk_bulk_get_all_enabled);
> > +
> > 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..bf3e9bee5754 100644
> > --- a/include/linux/clk.h
> > +++ b/include/linux/clk.h
> > @@ -438,6 +438,24 @@ 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_enabled - managed get multiple clk consumers and
> > + * enable all clk
> > + * @dev: device for clock "consumer"
> > + * @clks: pointer to the clk_bulk_data table of consumer
> > + * @num_clks: out parameter to store the number of clk_bulk_data
> > + *
> > + * Returns success (0) or negative errno.
> > + *
> > + * This helper function allows drivers to get several clk
> > + * 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_enabled(struct device *dev,
> > + struct clk_bulk_data **clks, int *num_clks);
> > +
> > /**
> > * devm_clk_get - lookup and obtain a managed reference to a clock producer.
> > * @dev: device for clock "consumer"
> > @@ -960,6 +978,13 @@ 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_enabled(struct device
> *dev,
> > + struct clk_bulk_data **clks, int *num_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
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