From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kumar Gala Subject: Re: [PATCH 1/3] dmaengine: qcom_bam_dma: Generalize BAM register offset calculations Date: Fri, 19 Sep 2014 12:00:44 -0700 Message-ID: References: <1411037575-13153-1-git-send-email-architt@codeaurora.org> Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: Received: from smtp.codeaurora.org ([198.145.11.231]:44692 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757484AbaISTA7 convert rfc822-to-8bit (ORCPT ); Fri, 19 Sep 2014 15:00:59 -0400 In-Reply-To: <1411037575-13153-1-git-send-email-architt@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Archit Taneja Cc: agross@codeaurora.org, linux-arm-msm@vger.kernel.org On Sep 18, 2014, at 3:52 AM, Archit Taneja wrote: > The BAM DMA IP comes in different versions. The register offset layout varies > among these versions. The layouts depend on which generation/family of SoCs they > belong to. > > The current SoCs(like 8084, 8074) have a layout where the Top level registers > come in the beginning of the address range, followed by pipe and event > registers. The BAM revision numbers fall above 1.4.0. > > The older SoCs (like 8064, 8960) have a layout where the pipe registers come > first, and the top level come later. These have BAM revision numbers lesser than > 1.4.0. > > It isn't suitable to have macros provide the register offsets with the layouts > changed. Future BAM revisions may have different register layouts too. The > register addresses are now calculated by referring a table which contains a base > offset and multipliers for pipe/evnt/ee registers. > > We have a common function bam_addr() which computes addresses for all the > registers. When computing address of top level/ee registers, we pass 0 to the > pipe argument in addr() since they don't have any multiple instances. > > Some of the unused register definitions are removed. We can add new registers as > we need them. > > Signed-off-by: Archit Taneja > --- > drivers/dma/qcom_bam_dma.c | 176 +++++++++++++++++++++++++++++---------------- > 1 file changed, 113 insertions(+), 63 deletions(-) Reviewed-by: Kumar Gala - k -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation