Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753518AbbGJH43 (ORCPT ); Fri, 10 Jul 2015 03:56:29 -0400 Received: from mga02.intel.com ([134.134.136.20]:49387 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752963AbbGJH4W (ORCPT ); Fri, 10 Jul 2015 03:56:22 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,445,1432623600"; d="scan'208";a="726283596" Date: Fri, 10 Jul 2015 13:28:07 +0530 From: Vinod Koul To: Shengjiu Wang Cc: dan.j.williams@intel.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] dmaengine: imx-sdma: Add device to device support Message-ID: <20150710075807.GB836@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3992 Lines: 112 On Tue, Jul 07, 2015 at 05:20:04PM +0800, Shengjiu Wang wrote: > +/* > + * p_2_p watermark_level description > + * Bits Name Description > + * 0-7 Lower WML Lower watermark level > + * 8 PS 1: Pad Swallowing > + * 0: No Pad Swallowing > + * 9 PA 1: Pad Adding > + * 0: No Pad Adding > + * 10 SPDIF If this bit is set both source > + * and destination are on SPBA > + * 11 Source Bit(SP) 1: Source on SPBA > + * 0: Source on AIPS > + * 12 Destination Bit(DP) 1: Destination on SPBA > + * 0: Destination on AIPS > + * 13-15 --------- MUST BE 0 > + * 16-23 Higher WML HWML > + * 24-27 N Total number of samples after > + * which Pad adding/Swallowing > + * must be done. It must be odd. > + * 28 Lower WML Event(LWE) SDMA events reg to check for > + * LWML event mask > + * 0: LWE in EVENTS register > + * 1: LWE in EVENTS2 register > + * 29 Higher WML Event(HWE) SDMA events reg to check for > + * HWML event mask > + * 0: HWE in EVENTS register > + * 1: HWE in EVENTS2 register > + * 30 --------- MUST BE 0 > + * 31 CONT 1: Amount of samples to be > + * transferred is unknown and > + * script will keep on > + * transferring samples as long as > + * both events are detected and > + * script must be manually stopped > + * by the application > + * 0: The amount of samples to be > + * transferred is equal to the > + * count field of mode word > + */ > +static void sdma_set_watermarklevel_for_p2p(struct sdma_channel *sdmac) > +{ > + struct sdma_engine *sdma = sdmac->sdma; > + > + int lwml = sdmac->watermark_level & 0xff; > + int hwml = (sdmac->watermark_level >> 16) & 0xff; > + > + __set_bit(sdmac->event_id0 % 32, &sdmac->event_mask[1]); > + __set_bit(sdmac->event_id1 % 32, &sdmac->event_mask[0]); > + > + if (sdmac->event_id0 > 31) > + __set_bit(28, &sdmac->watermark_level); > + > + if (sdmac->event_id1 > 31) > + __set_bit(29, &sdmac->watermark_level); > + > + /* > + * If LWML(src_maxburst) > HWML(dst_maxburst), we need > + * swap LWML and HWML of INFO(A.3.2.5.1), also need swap > + * r0(event_mask[1]) and r1(event_mask[0]). > + */ > + if (lwml > hwml) { > + sdmac->watermark_level &= ~0xff00ff; > + sdmac->watermark_level |= hwml; > + sdmac->watermark_level |= lwml << 16; > + swap(sdmac->event_mask[0], sdmac->event_mask[1]); so typical practice is to define macros for these. For example above can be defined as #define SDMA_WATERMARK_LWML BIT(X) #define SDMA_WATERMARK_PA BIT(Y) Then here you can say sdmac->watermark_level &= SDMA_WATERMARK_PA | .... That way it is easier to read, review and maintain > + } > + > + if (sdmac->per_address2 >= sdma->spba_start_addr && > + sdmac->per_address2 <= sdma->spba_end_addr) > + __set_bit(11, &sdmac->watermark_level); > + > + if (sdmac->per_address >= sdma->spba_start_addr && > + sdmac->per_address <= sdma->spba_end_addr) > + __set_bit(12, &sdmac->watermark_level); > + > + __set_bit(31, &sdmac->watermark_level); All these and few more below will look much better by have defines above > @@ -1221,6 +1311,14 @@ static int sdma_config(struct dma_chan *chan, > sdmac->watermark_level = dmaengine_cfg->src_maxburst * > dmaengine_cfg->src_addr_width; > sdmac->word_size = dmaengine_cfg->src_addr_width; > + } else if (dmaengine_cfg->direction == DMA_DEV_TO_DEV) { > + sdmac->per_address2 = dmaengine_cfg->src_addr; > + sdmac->per_address = dmaengine_cfg->dst_addr; > + sdmac->watermark_level = > + dmaengine_cfg->src_maxburst & 0xff; > + sdmac->watermark_level |= > + (dmaengine_cfg->dst_maxburst & 0xff) << 16; > + sdmac->word_size = dmaengine_cfg->dst_addr_width; Please fix this as well -- ~Vinod -- 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/