From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 13 Aug 2017 22:18:53 +0800 From: Shawn Guo To: Stephen Boyd Cc: Michael Turquette , Dong Aisheng , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Shawn Guo Subject: Re: [PATCH] clk: bulk: call of_clk_get() when id is NULL Message-ID: <20170813141851.GD31819@dragon> References: <1502243442-28055-1-git-send-email-shawnguo@kernel.org> <20170809173318.GD2146@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170809173318.GD2146@codeaurora.org> List-ID: Hi Stephen, On Wed, Aug 09, 2017 at 10:33:18AM -0700, Stephen Boyd wrote: > > diff --git a/drivers/clk/clk-bulk.c b/drivers/clk/clk-bulk.c > > index c834f5abfc49..65cee595a67e 100644 > > --- a/drivers/clk/clk-bulk.c > > +++ b/drivers/clk/clk-bulk.c > > @@ -39,7 +39,10 @@ int __must_check clk_bulk_get(struct device *dev, int num_clks, > > clks[i].clk = NULL; > > > > for (i = 0; i < num_clks; i++) { > > - clks[i].clk = clk_get(dev, clks[i].id); > > + if (clks[i].id) > > + clks[i].clk = clk_get(dev, clks[i].id); > > + else if (dev->of_node) > > + clks[i].clk = of_clk_get(dev->of_node, i); > > This seems a little too magical. The omission of an id in an > array of clks would mean that only that one clk is acquired > through of_clk_get(). We could have a mixture of ids and no ids > for some device, and then do very odd things. > > How about we add a flag to clk_bulk_data that indicates we want > it to use of_clk_get() instead of clk_get() for all of the clks? > Then the id is ignored for the entire function. I have sent v2 to add a flag to clk_bulk_data to address your comments. But I just found it might not be what you want exactly, because the current bulk clk APIs defines clk_bulk_data in a different way from what you are asking here. It seems that you think clk_bulk_data represents all the clocks that bulk APIs manage, but actually it only represents one of the multiple clocks. Callers need to prepare an array of clk_bulk_data to represent multiple clocks. That said, the flag we add to clk_bulk_data only affects one clock instead of all clocks. I feel this is something we can improve. clk_bulk_data can be used to represent all clocks, something like below. In this case, bulk clk APIs do not need to take num_clks as a separate parameter, and callers do not need to maintain multiple clk_bulk_data instances. Since we do not have any in tree users of bulk clk APIs yet, we can make this semantic change quickly. Thoughts? diff --git a/include/linux/clk.h b/include/linux/clk.h index 31fee2e8d4a2..ddc4812758f6 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -80,8 +80,10 @@ struct clk_notifier_data { /** * struct clk_bulk_data - Data used for bulk clk operations. * - * @id: clock consumer ID - * @clk: struct clk * to store the associated clock + * @ids: array of clock consumer IDs which should be provided by caller. + * @clks: array of struct clk * to store the associated clocks, which will be + * allocated by clk_bulk_get() and freed by clk_bulk_put(). + * @num_clks: number of clocks that caller wants bulk API to manage. * @flags: bulk clk operation flags * * The CLK APIs provide a series of clk_bulk_() API calls as @@ -93,8 +95,9 @@ struct clk_notifier_data { * clk_bulk_get() API will call of_clk_get() to find clock by index. */ struct clk_bulk_data { - const char *id; - struct clk *clk; + const char **ids; + struct clk **clks; + unsigned int num_clks; unsigned long flags; }; From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawnguo@kernel.org (Shawn Guo) Date: Sun, 13 Aug 2017 22:18:53 +0800 Subject: [PATCH] clk: bulk: call of_clk_get() when id is NULL In-Reply-To: <20170809173318.GD2146@codeaurora.org> References: <1502243442-28055-1-git-send-email-shawnguo@kernel.org> <20170809173318.GD2146@codeaurora.org> Message-ID: <20170813141851.GD31819@dragon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Stephen, On Wed, Aug 09, 2017 at 10:33:18AM -0700, Stephen Boyd wrote: > > diff --git a/drivers/clk/clk-bulk.c b/drivers/clk/clk-bulk.c > > index c834f5abfc49..65cee595a67e 100644 > > --- a/drivers/clk/clk-bulk.c > > +++ b/drivers/clk/clk-bulk.c > > @@ -39,7 +39,10 @@ int __must_check clk_bulk_get(struct device *dev, int num_clks, > > clks[i].clk = NULL; > > > > for (i = 0; i < num_clks; i++) { > > - clks[i].clk = clk_get(dev, clks[i].id); > > + if (clks[i].id) > > + clks[i].clk = clk_get(dev, clks[i].id); > > + else if (dev->of_node) > > + clks[i].clk = of_clk_get(dev->of_node, i); > > This seems a little too magical. The omission of an id in an > array of clks would mean that only that one clk is acquired > through of_clk_get(). We could have a mixture of ids and no ids > for some device, and then do very odd things. > > How about we add a flag to clk_bulk_data that indicates we want > it to use of_clk_get() instead of clk_get() for all of the clks? > Then the id is ignored for the entire function. I have sent v2 to add a flag to clk_bulk_data to address your comments. But I just found it might not be what you want exactly, because the current bulk clk APIs defines clk_bulk_data in a different way from what you are asking here. It seems that you think clk_bulk_data represents all the clocks that bulk APIs manage, but actually it only represents one of the multiple clocks. Callers need to prepare an array of clk_bulk_data to represent multiple clocks. That said, the flag we add to clk_bulk_data only affects one clock instead of all clocks. I feel this is something we can improve. clk_bulk_data can be used to represent all clocks, something like below. In this case, bulk clk APIs do not need to take num_clks as a separate parameter, and callers do not need to maintain multiple clk_bulk_data instances. Since we do not have any in tree users of bulk clk APIs yet, we can make this semantic change quickly. Thoughts? diff --git a/include/linux/clk.h b/include/linux/clk.h index 31fee2e8d4a2..ddc4812758f6 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -80,8 +80,10 @@ struct clk_notifier_data { /** * struct clk_bulk_data - Data used for bulk clk operations. * - * @id: clock consumer ID - * @clk: struct clk * to store the associated clock + * @ids: array of clock consumer IDs which should be provided by caller. + * @clks: array of struct clk * to store the associated clocks, which will be + * allocated by clk_bulk_get() and freed by clk_bulk_put(). + * @num_clks: number of clocks that caller wants bulk API to manage. * @flags: bulk clk operation flags * * The CLK APIs provide a series of clk_bulk_() API calls as @@ -93,8 +95,9 @@ struct clk_notifier_data { * clk_bulk_get() API will call of_clk_get() to find clock by index. */ struct clk_bulk_data { - const char *id; - struct clk *clk; + const char **ids; + struct clk **clks; + unsigned int num_clks; unsigned long flags; };