Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752272AbaF3F5H (ORCPT ); Mon, 30 Jun 2014 01:57:07 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:45853 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150AbaF3F5F (ORCPT ); Mon, 30 Jun 2014 01:57:05 -0400 Message-ID: <53B0FC27.5040002@ti.com> Date: Mon, 30 Jun 2014 08:56:55 +0300 From: Peter Ujfalusi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Javier Martinez Canillas CC: Mike Turquette , Grant Likely , "devicetree@vger.kernel.org" , Linux Kernel , "linux-omap@vger.kernel.org" , , , Nishanth Menon , Rob Herring Subject: Re: [RESEND 2/2] clk: Add driver for Palmas clk32kg and clk32kgaudio clocks References: <1403848871-26519-1-git-send-email-peter.ujfalusi@ti.com> <1403848871-26519-3-git-send-email-peter.ujfalusi@ti.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Javier, On 06/27/2014 09:23 PM, Javier Martinez Canillas wrote: > Hello Peter, > > On Fri, Jun 27, 2014 at 8:01 AM, Peter Ujfalusi wrote: >> Palmas class of devices can provide 32K clock(s) to be used by other devices >> on the board. Depending on the actual device the provided clocks can be: >> CLK32K_KG and CLK32K_KGAUDIO >> or only one: >> CLK32K_KG (TPS659039 for example) >> >> Use separate compatible flags for the two 32K clock. >> A system which needs or have only one of the 32k clock from >> Palmas will need to add node(s) for each clock as separate section >> in the dts file. >> The two compatible property is: >> "ti,palmas-clk32kg" for clk32kg clock >> "ti,palmas-clk32kgaudio" for clk32kgaudio clock >> >> Apart from the register control of the clocks - which is done via >> the clock API there is a posibility to enable the external sleep >> control. In this way the clock can be enabled/disabled on demand by the >> user of the clock. >> >> See the documentation for more details. >> >> Signed-off-by: Peter Ujfalusi >> Reviewed-by: Nishanth Menon >> +static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw, >> + unsigned long parent_rate) >> +{ >> + return 32768; >> +} > > I see that other clock drivers using a constant rate return 0 if the > clock has not been enabled. and there are examples when similar fixed clock drivers returns only the clock value, like clk-max77686. I can not find clear guidelines neither in the documentation or around the header/c files for this. Mike, what is the appropriate way of handling the recalc_rate? > So maybe is more correct to have something > like the following? > > if (__clk_is_enabled(hw->clk)) > return 32768; > else > return 0; > > Best regards, > Javier > -- Péter -- 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/