From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 30 Aug 2017 22:26:30 -0700 From: Stephen Boyd To: "A.s. Dong" Cc: Shawn Guo , Michael Turquette , "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: <20170831052630.GU21656@codeaurora.org> References: <1502243442-28055-1-git-send-email-shawnguo@kernel.org> <20170809173318.GD2146@codeaurora.org> <20170813141851.GD31819@dragon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: List-ID: On 08/30, A.s. Dong wrote: > > -----Original Message----- > > From: Shawn Guo [mailto:shawnguo@kernel.org] > > Sent: Sunday, August 13, 2017 10:19 PM > > To: Stephen Boyd > > Cc: Michael Turquette; A.s. Dong; 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 > > > > 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? > > > > Flags may be better used for extending per clk feature support in the future. > > IMHO how about implement a of_clk_bulk_get() to handle this issue as we already > have a of_clk_get? > e.g. > > int __must_check of_clk_bulk_get(struct device_node *np, int num_clks, > struct clk_bulk_data *clks) > { > for (i = 0; i < num_clks; i++) { > clks[i].clk = of_clk_get(dev, clks[i].id); > ... > > } > > Then it's less intrusive. > This looks ok too. Go ahead and send this version instead. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Wed, 30 Aug 2017 22:26:30 -0700 Subject: [PATCH] clk: bulk: call of_clk_get() when id is NULL In-Reply-To: References: <1502243442-28055-1-git-send-email-shawnguo@kernel.org> <20170809173318.GD2146@codeaurora.org> <20170813141851.GD31819@dragon> Message-ID: <20170831052630.GU21656@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/30, A.s. Dong wrote: > > -----Original Message----- > > From: Shawn Guo [mailto:shawnguo at kernel.org] > > Sent: Sunday, August 13, 2017 10:19 PM > > To: Stephen Boyd > > Cc: Michael Turquette; A.s. Dong; linux-clk at vger.kernel.org; linux-arm- > > kernel at lists.infradead.org; Shawn Guo > > Subject: Re: [PATCH] clk: bulk: call of_clk_get() when id is NULL > > > > 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? > > > > Flags may be better used for extending per clk feature support in the future. > > IMHO how about implement a of_clk_bulk_get() to handle this issue as we already > have a of_clk_get? > e.g. > > int __must_check of_clk_bulk_get(struct device_node *np, int num_clks, > struct clk_bulk_data *clks) > { > for (i = 0; i < num_clks; i++) { > clks[i].clk = of_clk_get(dev, clks[i].id); > ... > > } > > Then it's less intrusive. > This looks ok too. Go ahead and send this version instead. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project