From patchwork Wed Jun 17 23:40:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11610955 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5AE6E92A for ; Wed, 17 Jun 2020 23:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D5DE21582 for ; Wed, 17 Jun 2020 23:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727868AbgFQXl0 (ORCPT ); Wed, 17 Jun 2020 19:41:26 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:57888 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726854AbgFQXkr (ORCPT ); Wed, 17 Jun 2020 19:40:47 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id AA1FF803202D; Wed, 17 Jun 2020 23:40:43 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5-AOd3nY21cY; Thu, 18 Jun 2020 02:40:43 +0300 (MSK) From: Serge Semin To: Vinod Koul , Viresh Kumar , Andy Shevchenko , Dan Williams CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , , , Subject: [PATCH v6 8/9] dmaengine: dw: Initialize min and max burst DMA device capability Date: Thu, 18 Jun 2020 02:40:27 +0300 Message-ID: <20200617234028.25808-9-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200617234028.25808-1-Sergey.Semin@baikalelectronics.ru> References: <20200617234028.25808-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org According to the DW APB DMAC data book the minimum burst transaction length is 1 and it's true for any version of the controller since isn't parametrised in the coreAssembler so can't be changed at the IP-core synthesis stage. The maximum burst transaction can vary from channel to channel and from controller to controller depending on a IP-core parameter the system engineer activated during the IP-core synthesis. Let's initialise both min_burst and max_burst members of the DMA controller descriptor with extreme values so the DMA clients could use them to properly optimize the DMA requests. The channels and controller-specific max_burst length initialization will be introduced by the follow-up patches. Signed-off-by: Serge Semin Reviewed-by: Andy Shevchenko Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org --- Changelog v4: - This is a new patch suggested by Andy. Changelog v5: - Introduce macro with extreme min and max burst length supported by the DW DMA controller. - Initialize max_burst length capability with extreme burst length supported by the DW DMAC IP-core. --- drivers/dma/dw/core.c | 2 ++ include/linux/platform_data/dma-dw.h | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index ceded21537e2..4887aa2fc73c 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1229,6 +1229,8 @@ int do_dma_probe(struct dw_dma_chip *chip) dw->dma.device_issue_pending = dwc_issue_pending; /* DMA capabilities */ + dw->dma.min_burst = DW_DMA_MIN_BURST; + dw->dma.max_burst = DW_DMA_MAX_BURST; dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS; dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS; dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | diff --git a/include/linux/platform_data/dma-dw.h b/include/linux/platform_data/dma-dw.h index f3eaf9ec00a1..369e41e9dcc9 100644 --- a/include/linux/platform_data/dma-dw.h +++ b/include/linux/platform_data/dma-dw.h @@ -12,6 +12,8 @@ #define DW_DMA_MAX_NR_MASTERS 4 #define DW_DMA_MAX_NR_CHANNELS 8 +#define DW_DMA_MIN_BURST 1 +#define DW_DMA_MAX_BURST 256 /** * struct dw_dma_slave - Controller-specific information about a slave