Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753373AbaBPSQ5 (ORCPT ); Sun, 16 Feb 2014 13:16:57 -0500 Received: from perceval.ideasonboard.com ([95.142.166.194]:56589 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbaBPSQz (ORCPT ); Sun, 16 Feb 2014 13:16:55 -0500 From: Laurent Pinchart To: Thomas Gleixner Cc: Laurent Pinchart , linux-sh@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Daniel Lezcano Subject: Re: [PATCH 11/27] clocksource: sh_cmt: Add support for multiple channels per device Date: Sun, 16 Feb 2014 19:18 +0100 Message-ID: <7782053.5pYg74TXhN@avalon> User-Agent: KMail/4.11.5 (Linux/3.10.25-gentoo; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <1392339605-20691-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <1392339605-20691-12-git-send-email-laurent.pinchart+renesas@ideasonboard.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Saturday 15 February 2014 13:46:54 Thomas Gleixner wrote: > On Fri, 14 Feb 2014, Laurent Pinchart wrote: > > CMT hardware devices can support multiple channels, with global > > registers and per-channel registers. The sh_cmt driver currently models > > the hardware with one Linux device per channel. This model makes it > > difficult to handle global registers in a clean way. > > > > Add support for a new model that uses one Linux device per timer with > > multiple channels per device. This requires changes to platform data, > > add new channel configuration fields. > > > > Support for the legacy model is kept and will be removed after all > > platforms switch to the new model. > > > > Signed-off-by: Laurent Pinchart > > > > --- > > > > drivers/clocksource/sh_cmt.c | 299 +++++++++++++++++++++++++++++--------- > > include/linux/sh_timer.h | 9 ++ > > 2 files changed, 239 insertions(+), 69 deletions(-) > > > > diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c > > index 5280231..8390f0f 100644 > > --- a/drivers/clocksource/sh_cmt.c > > +++ b/drivers/clocksource/sh_cmt.c > > @@ -53,7 +53,16 @@ struct sh_cmt_device; > > > > * channel registers block. All other versions have a shared start/stop > > register * located in the global space. > > * > > > > - * Note that CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing > > 32-bit + * Channels are indexed from 0 to N-1 in the documentation. The > > channel index + * infers the start/stop bit position in the control > > register and the channel + * registers block address. Some CMT instances > > have a subset of channels + * available, in which case the index in the > > documentation doesn't match the + * "real" index as implemented in > > hardware. This is for instance the case with + * CMT0 on r8a7740, which > > is a 32-bit variant with a single channel numbered 0 + * in the > > documentation but using start/stop bit 5 and having its registers + * > > block at 0x60. > > + * > > + * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing > > 32-bit> > > * channels only, is a 48-bit gen2 CMT with the 48-bit channels > > unavailable. > > */ > > > > @@ -85,11 +94,15 @@ struct sh_cmt_info { > > > > struct sh_cmt_channel { > > > > struct sh_cmt_device *cmt; > > > > - unsigned int index; > > > > - void __iomem *base; > > + unsigned int index; /* Index in the documentation */ > > + unsigned int hwidx; /* Real hardware index */ > > + > > + void __iomem *iostart; > > + void __iomem *ioctrl; > > > > struct irqaction irqaction; > > While you are at it, can you please get rid of that irqaction and use > request_irq() ? The driver claims it can't use request_irq() because the function is not available for early platform devices. If the situation has changed I'd gladly get rid of irqaction. -- Regards, Laurent Pinchart -- 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/