From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from eu1sys200aog106.obsmtp.com (eu1sys200aog106.obsmtp.com [207.126.144.121]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BF6A4B7C15 for ; Tue, 17 Nov 2009 01:15:32 +1100 (EST) Message-ID: <4B0157D4.2020100@st.com> Date: Mon, 16 Nov 2009 14:47:00 +0100 From: Francesco VIRLINZI MIME-Version: 1.0 To: Linux-sh , linux-embedded@vger.kernel.org, linux-arm-kernel@lists.infradead.o, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [Proposal] [PATCH] [RESEND] generic clock framework Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi all I'm Francesco and I work in STMicroelectronics In the last ELC-E_2009 I spoke on a generic clock framework I'm working on (see http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2009Presentations?action=AttachFile&do=view&target=ELC_E_2009_Generic_Clock_Framework.pdf). I wrote the gcf to manage both clocks the platform_devices during a clock operation. The main features are: - it's integrated in the LDM - it tracks the clock-to-clock relationship - it tracks the clock-to-device relationship - it has sysfs interface - - the user can navigate the clock tree under /sys/clocks/... - it uses the linux API () with some extra functions (to register/unregister a clock and other utility functions as clk_for_each()) - it involves the platform_device and the platform_driver in the clock propagation. - - basically each clock operation is managed as a transaction which evolves step by step. - - all the clock rates are evaluated (before the clk operation is actually done) - - each platform_device can check (before the clk operation is actually done) the clk environment it will have at the end of clock operation and if required it can reject the operation. - - each clock operation is actually executed only if all the platform_devices accept the operation it-self Moreover a common clock framework could be used to avoid a lot of duplicated and/or similar code just a grep of 'EXPORT_SYMBOL\(clk_enable' under arch/arm finds 22 entries. The patch is based on a 2.6.30 kernel also if it has a preliminary integration with the PM_RUNTIME support. It works on our st40 (an sh4 cpu based system) no test/porting was done on other platforms. It would be mainly a starting point for a discussion and I'm available to extend/fix/share it. Regards Francesco