Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755168AbbGCOwv (ORCPT ); Fri, 3 Jul 2015 10:52:51 -0400 Received: from foss.arm.com ([217.140.101.70]:53655 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755443AbbGCOwn (ORCPT ); Fri, 3 Jul 2015 10:52:43 -0400 Message-ID: <5596A1B6.8020307@arm.com> Date: Fri, 03 Jul 2015 15:52:38 +0100 From: Sudeep Holla User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Stephen Boyd CC: Sudeep Holla , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-clk@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Liviu Dudau , Lorenzo Pieralisi , "Jon Medhurst (Tixy)" , Arnd Bergmann , Kevin Hilman , Olof Johansson , Mike Turquette Subject: Re: [PATCH v4 3/8] clk: add support for clocks provided by SCP(System Control Processor) References: <1433760002-24120-1-git-send-email-sudeep.holla@arm.com> <1433760002-24120-4-git-send-email-sudeep.holla@arm.com> <20150702172310.GF4301@codeaurora.org> In-Reply-To: <20150702172310.GF4301@codeaurora.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3862 Lines: 141 Hi Stephen, Thanks for the review. On 02/07/15 18:23, Stephen Boyd wrote: > On 06/08, Sudeep Holla wrote: >> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig >> index 9897f353bf1a..0fe8daefc105 100644 >> --- a/drivers/clk/Kconfig >> +++ b/drivers/clk/Kconfig >> @@ -59,6 +59,16 @@ config COMMON_CLK_RK808 >> clocked at 32KHz each. Clkout1 is always on, Clkout2 can off >> by control register. >> >> +config COMMON_CLK_SCPI >> + tristate "Clock driver controlled via SCPI interface" >> + depends on ARM_SCPI_PROTOCOL || COMPILE_TEST >> + ---help--- >> + This driver provides support for clocks that are controlled >> + by firmware that implements the SCPI interface. >> + >> + This driver uses SCPI Message Protocol to interact with the >> + firmware providing all the clock controls. > > The tabbing is weird here. Both paragraphs should have the same > alignment. > Indeed, sorry for that, fixed now. >> diff --git a/drivers/clk/clk-scpi.c b/drivers/clk/clk-scpi.c >> new file mode 100644 >> index 000000000000..707b3430c55f >> --- /dev/null >> +++ b/drivers/clk/clk-scpi.c >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include > > Please include as well. > Added now, didn't bother as of_platform.h includes it. >> + >> +struct scpi_clk { >> + u32 id; >> + const char *name; > > Do you need this? Or can you just use __clk_get_name() in places > where the name is used? > Not used, so removed it. [...] >> +static long scpi_clk_round_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long *parent_rate) >> +{ > > Maybe a comment here like: > > /* > * We can't figure out what rate it will be, so just return the rate > * back to the caller. scpi_clk_recalc_rate() will be called > * after the rate is set and we'll know what rate the clock is > * running at then. > */ > Done >> + return rate; >> +} >> + >> +static int scpi_clk_set_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long parent_rate) >> +{ >> + struct scpi_clk *clk = to_scpi_clk(hw); >> + >> + return clk->scpi_ops->clk_set_val(clk->id, rate); >> +} >> + >> +static void scpi_clk_disable(struct clk_hw *hw) >> +{ >> + scpi_clk_set_rate(hw, 0, 0); > > Does this mean you have to set a rate to enable the clock? Are > you relying on drivers to call clk_set_rate() to implicitly > enable the clock? If so, it would be better to cache the rate of > the clock in set_rate if the clock isn't enabled in software and > then send the cached rate during enable. > Agreed, I have asked the firmware/SCPI specification guys about more details on what to expect from firmware. Once they get back, will update the code considering your feedback. [...] >> +static int __scpi_find_dvfs_index(struct scpi_clk *clk, unsigned long rate) >> +{ >> + int idx, max_opp = clk->info->count; >> + struct scpi_opp *opp = clk->info->opps; > > const? > All the 3 above fixed now. [...] >> + >> + clk = devm_clk_register(dev, &sclk->hw); >> + if (!IS_ERR(clk) && max) >> + clk_set_rate_range(clk, min, max); > > Hm.. we're planning to make clk_register() return a struct > clk_hw, so this will block that. We need some sort of clk_hw API > that allows us to setup min/max limits on the clock from the > provider side. Care to add that? > Can you provide pointer to the patches or the tree containing those changes ? Are they targeted for v4.3 ? Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/