From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v2 1/3] ARM: tegra: Add AHB driver Date: Wed, 25 Apr 2012 12:15:22 +0000 Message-ID: <201204251215.22889.arnd@arndb.de> References: <1335269116-9578-1-git-send-email-hdoyu@nvidia.com> <20120425083747.466f5c98330af8964d980b8c@nvidia.com> <20120425074639.GB3423@arwen.pp.htv.fi> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120425074639.GB3423@arwen.pp.htv.fi> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: balbi@ti.com Cc: Russell King - ARM Linux , Stephen Warren , "devicetree-discuss@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" , Rob Herring , Grant Likely , Olof Johansson , Colin Cross , "linux-tegra@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Hiroshi Doyu List-Id: linux-tegra@vger.kernel.org On Wednesday 25 April 2012, Felipe Balbi wrote: > On Wed, Apr 25, 2012 at 08:37:47AM +0300, Hiroshi Doyu wrote: > > On Tue, 24 Apr 2012 21:56:45 +0200 > > Russell King - ARM Linux wrote: > > > > > On Tue, Apr 24, 2012 at 03:05:14PM +0300, Hiroshi DOYU wrote: > > > > The AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced > > > > High-performance Bus (AHB) architecture. > > > > > > > > The AHB Arbiter controls AHB bus master arbitration. This effectively > > > > forms a second level of arbitration for access to the memory > > > > controller through the AHB Slave Memory device. The AHB pre-fetch > > > > logic can be configured to enhance performance for devices doing > > > > sequential access. Each AHB master is assigned to either the high or > > > > low priority bin. Both Tegra20/30 have this AHB bus. > > > > > > > > Signed-off-by: Hiroshi DOYU > > > > Cc: Felipe Balbi > > > > Cc: Arnd Bergmann > > > > --- > > > > Update: > > > > - Use platform_device to get info from dt dynamically.(Felipe/Arnd) > > > > --- > > > > arch/arm/mach-tegra/Makefile | 1 + > > > > arch/arm/mach-tegra/tegra-ahb.c | 285 +++++++++++++++++++++++++++++++++++++++ > > > > 2 files changed, 286 insertions(+), 0 deletions(-) > > > > > > 1. I thought we weren't going to have any more drivers under > > > arch/arm > > > > Can this driver be located under "drivers/misc"? Or is there any better place? > > maybe drivers/platform/arm/ ?? I really wouldn't want to add that directory: It has the risk of letting people add random crap there that may or may not be related to ARM (the company) and/or ARM (the architecture). I think it could go into drivers/amba/ along with the primecell bus driver. The two drivers are for two different aspects of the AMBA spec and don't actually depend on one another as far as I can tell, but it's at least a fitting name, and it doesn't depend on the ARM architecture, which is important because the driver could be used on other architectures that are connected to an AHB bus. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 25 Apr 2012 12:15:22 +0000 Subject: [PATCH v2 1/3] ARM: tegra: Add AHB driver In-Reply-To: <20120425074639.GB3423@arwen.pp.htv.fi> References: <1335269116-9578-1-git-send-email-hdoyu@nvidia.com> <20120425083747.466f5c98330af8964d980b8c@nvidia.com> <20120425074639.GB3423@arwen.pp.htv.fi> Message-ID: <201204251215.22889.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 25 April 2012, Felipe Balbi wrote: > On Wed, Apr 25, 2012 at 08:37:47AM +0300, Hiroshi Doyu wrote: > > On Tue, 24 Apr 2012 21:56:45 +0200 > > Russell King - ARM Linux wrote: > > > > > On Tue, Apr 24, 2012 at 03:05:14PM +0300, Hiroshi DOYU wrote: > > > > The AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced > > > > High-performance Bus (AHB) architecture. > > > > > > > > The AHB Arbiter controls AHB bus master arbitration. This effectively > > > > forms a second level of arbitration for access to the memory > > > > controller through the AHB Slave Memory device. The AHB pre-fetch > > > > logic can be configured to enhance performance for devices doing > > > > sequential access. Each AHB master is assigned to either the high or > > > > low priority bin. Both Tegra20/30 have this AHB bus. > > > > > > > > Signed-off-by: Hiroshi DOYU > > > > Cc: Felipe Balbi > > > > Cc: Arnd Bergmann > > > > --- > > > > Update: > > > > - Use platform_device to get info from dt dynamically.(Felipe/Arnd) > > > > --- > > > > arch/arm/mach-tegra/Makefile | 1 + > > > > arch/arm/mach-tegra/tegra-ahb.c | 285 +++++++++++++++++++++++++++++++++++++++ > > > > 2 files changed, 286 insertions(+), 0 deletions(-) > > > > > > 1. I thought we weren't going to have any more drivers under > > > arch/arm > > > > Can this driver be located under "drivers/misc"? Or is there any better place? > > maybe drivers/platform/arm/ ?? I really wouldn't want to add that directory: It has the risk of letting people add random crap there that may or may not be related to ARM (the company) and/or ARM (the architecture). I think it could go into drivers/amba/ along with the primecell bus driver. The two drivers are for two different aspects of the AMBA spec and don't actually depend on one another as far as I can tell, but it's at least a fitting name, and it doesn't depend on the ARM architecture, which is important because the driver could be used on other architectures that are connected to an AHB bus. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759218Ab2DYMPm (ORCPT ); Wed, 25 Apr 2012 08:15:42 -0400 Received: from moutng.kundenserver.de ([212.227.126.186]:58084 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759195Ab2DYMP2 (ORCPT ); Wed, 25 Apr 2012 08:15:28 -0400 From: Arnd Bergmann To: balbi@ti.com Subject: Re: [PATCH v2 1/3] ARM: tegra: Add AHB driver Date: Wed, 25 Apr 2012 12:15:22 +0000 User-Agent: KMail/1.12.2 (Linux/3.4.0-rc3; KDE/4.3.2; x86_64; ; ) Cc: Hiroshi Doyu , "Russell King - ARM Linux" , "linux-tegra@vger.kernel.org" , Colin Cross , Olof Johansson , Stephen Warren , Grant Likely , Rob Herring , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" References: <1335269116-9578-1-git-send-email-hdoyu@nvidia.com> <20120425083747.466f5c98330af8964d980b8c@nvidia.com> <20120425074639.GB3423@arwen.pp.htv.fi> In-Reply-To: <20120425074639.GB3423@arwen.pp.htv.fi> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201204251215.22889.arnd@arndb.de> X-Provags-ID: V02:K0:mOKb4yJikfAJLvv6nUwdDDw1X4JoW9Q05TQn9ond1S6 WvRUTtmoA0PKiBU6AH819i5j+x1jGmJHPV+7gJSfGsSbspcUZY CaasacqRsTMBWRP7pN8qTYyjPF3hM5cquTDoKgMZFgCst1Ir0P Rvoly6bNJ/NZ9iuj44a4dKhz3OTsuqPHyUnIAWjp/FLMApDOkJ EaKEk0gKlZ8JKOpWSfRjPiy3yZskB58gTwR1tjXvOi/nsB+y+J ZT5EbcsZWMDPFZcSbhaVdujxmQ0PkQqKEUbCa9n7UWhLvy9HmG Q+yrblXPXJHdmkh2jhyy8Gd3R2k4mYuEwOVfaO3rV3rFffdfPe rskjQxpcyg/86teRb0zk= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 25 April 2012, Felipe Balbi wrote: > On Wed, Apr 25, 2012 at 08:37:47AM +0300, Hiroshi Doyu wrote: > > On Tue, 24 Apr 2012 21:56:45 +0200 > > Russell King - ARM Linux wrote: > > > > > On Tue, Apr 24, 2012 at 03:05:14PM +0300, Hiroshi DOYU wrote: > > > > The AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced > > > > High-performance Bus (AHB) architecture. > > > > > > > > The AHB Arbiter controls AHB bus master arbitration. This effectively > > > > forms a second level of arbitration for access to the memory > > > > controller through the AHB Slave Memory device. The AHB pre-fetch > > > > logic can be configured to enhance performance for devices doing > > > > sequential access. Each AHB master is assigned to either the high or > > > > low priority bin. Both Tegra20/30 have this AHB bus. > > > > > > > > Signed-off-by: Hiroshi DOYU > > > > Cc: Felipe Balbi > > > > Cc: Arnd Bergmann > > > > --- > > > > Update: > > > > - Use platform_device to get info from dt dynamically.(Felipe/Arnd) > > > > --- > > > > arch/arm/mach-tegra/Makefile | 1 + > > > > arch/arm/mach-tegra/tegra-ahb.c | 285 +++++++++++++++++++++++++++++++++++++++ > > > > 2 files changed, 286 insertions(+), 0 deletions(-) > > > > > > 1. I thought we weren't going to have any more drivers under > > > arch/arm > > > > Can this driver be located under "drivers/misc"? Or is there any better place? > > maybe drivers/platform/arm/ ?? I really wouldn't want to add that directory: It has the risk of letting people add random crap there that may or may not be related to ARM (the company) and/or ARM (the architecture). I think it could go into drivers/amba/ along with the primecell bus driver. The two drivers are for two different aspects of the AMBA spec and don't actually depend on one another as far as I can tell, but it's at least a fitting name, and it doesn't depend on the ARM architecture, which is important because the driver could be used on other architectures that are connected to an AHB bus. Arnd