Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934105AbaDIP7a (ORCPT ); Wed, 9 Apr 2014 11:59:30 -0400 Received: from mail-ob0-f173.google.com ([209.85.214.173]:59607 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934005AbaDIP7W (ORCPT ); Wed, 9 Apr 2014 11:59:22 -0400 MIME-Version: 1.0 In-Reply-To: <5344A209.7010507@wwwdotorg.org> References: <1396532680-30352-1-git-send-email-bart.tanghe@thomasmore.be> <5344A209.7010507@wwwdotorg.org> Date: Wed, 9 Apr 2014 08:59:21 -0700 Message-ID: Subject: Re: [rfc]pwm: add BCM2835 PWM driver From: Tim Kryger To: Stephen Warren Cc: Bart Tanghe , Thierry Reding , "linux-kernel@vger.kernel.org" , Linux PWM List , linux-rpi-kernel@lists.infradead.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 8, 2014 at 6:27 PM, Stephen Warren wrote: > On 04/08/2014 05:02 PM, Tim Kryger wrote: >> On Thu, Apr 3, 2014 at 6:44 AM, Bart Tanghe wrote: >>> need some recommendation >>> the memory mapped io registers of the bcm2835 pwm hardware are spreaded >>> over the memory mapped io >>> gpio config 0x20200004 - clk config 0x201010A0 - pwm configuration 0x2020C000 >>> to handle this, I've used the base address of the memory mapped io >>> so I can use positive offsets >> >> So the registers for this PWM are located in three distinct memory regions? > ... >>> +struct bcm2835_pwm_chip { >>> + struct pwm_chip chip; >>> + struct device *dev; >>> + int channel; >>> + void __iomem *mmio; >> >> One pointer isn't going to be enough. You need three. >> >> I suggest renaming the first and adding two more: >> >> void __iomem *base_pwm; >> void __iomem *base_clk; >> void __iomem *base_alt; > > Sorry, I forgot about this patch. One comment here; the PWM driver can't > touch the clock or alt registers; those should be owned by the clock > driver, and the driver for whatever alt is (pinmux - don't recall what > it's touching there). Absolutely. If these registers are owned by other drivers, go through them. -- 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/