From patchwork Thu May 28 22:23:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11577067 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 86A1F1391 for ; Thu, 28 May 2020 22:26:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7637B208A7 for ; Thu, 28 May 2020 22:26:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437177AbgE1WY6 (ORCPT ); Thu, 28 May 2020 18:24:58 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:44666 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437102AbgE1WYR (ORCPT ); Thu, 28 May 2020 18:24:17 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id B2AFC8030772; Thu, 28 May 2020 22:24:12 +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 0okL1buVKGVd; Fri, 29 May 2020 01:24:12 +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 v4 06/11] dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config Date: Fri, 29 May 2020 01:23:56 +0300 Message-ID: <20200528222401.26941-7-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200528222401.26941-1-Sergey.Semin@baikalelectronics.ru> References: <20200528222401.26941-1-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 Full multi-block transfers functionality is enabled in DW DMA controller only if CHx_MULTI_BLK_EN is set. But LLP-based transfers can be executed only if hardcode channel x LLP register feature isn't enabled, which can be switched on at the IP core synthesis for optimization. If it's enabled then the LLP register is hardcoded to zero, so the blocks chaining based on the LLPs is unsupported. 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 v2: - Rearrange SoBs. - Add comment about why hardware accelerated LLP list support depends on both MBLK_EN and HC_LLP configs setting. - Use explicit bits state comparison operator. Changelog v3: - Move the patch to the head of the series. --- drivers/dma/dw/core.c | 11 ++++++++++- drivers/dma/dw/regs.h | 1 + 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 21cb2a58dbd2..33e99d95b3d3 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1178,8 +1178,17 @@ int do_dma_probe(struct dw_dma_chip *chip) */ dwc->block_size = (4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1; + + /* + * According to the DW DMA databook the true scatter- + * gether LLPs aren't available if either multi-block + * config is disabled (CHx_MULTI_BLK_EN == 0) or the + * LLP register is hard-coded to zeros + * (CHx_HC_LLP == 1). + */ dwc->nollp = - (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0; + (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0 || + (dwc_params >> DWC_PARAMS_HC_LLP & 0x1) == 1; } else { dwc->block_size = pdata->block_size; dwc->nollp = !pdata->multi_block[i]; diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h index 3fce66ecee7a..1ab840b06e79 100644 --- a/drivers/dma/dw/regs.h +++ b/drivers/dma/dw/regs.h @@ -125,6 +125,7 @@ struct dw_dma_regs { /* Bitfields in DWC_PARAMS */ #define DWC_PARAMS_MBLK_EN 11 /* multi block transfer */ +#define DWC_PARAMS_HC_LLP 13 /* set LLP register to zero */ /* bursts size */ enum dw_dma_msize {