From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754666AbdFNInL (ORCPT ); Wed, 14 Jun 2017 04:43:11 -0400 Received: from mga07.intel.com ([134.134.136.100]:53107 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754206AbdFNImx (ORCPT ); Wed, 14 Jun 2017 04:42:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,340,1493708400"; d="scan'208";a="114731294" Date: Wed, 14 Jun 2017 14:15:29 +0530 From: Vinod Koul To: Icenowy Zheng Cc: linux-arm-kernel@lists.infradead.org, Chen-Yu Tsai , linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com, Icenowy Zheng , dmaengine@vger.kernel.org, Maxime Ripard Subject: Re: [PATCH 1/2] dmaengine: sun6i: make gate bit in sun8i's DMA engines a common quirk Message-ID: <20170614084529.GL13020@localhost> References: <20170605123348.26137-1-icenowy@aosc.io> <20170605123348.26137-2-icenowy@aosc.io> <20170614083252.GK13020@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 14, 2017 at 04:32:57PM +0800, Icenowy Zheng wrote: > > > 于 2017年6月14日 GMT+08:00 下午4:32:52, Vinod Koul 写到: > >On Mon, Jun 05, 2017 at 08:33:47PM +0800, Icenowy Zheng wrote: > >> From: Icenowy Zheng > >> > >> Originally we enable a special gate bit when the compatible indicates > >> A23/33. > >> > >> But according to BSP sources and user manuals, more SoCs will need > >this > >> gate bit. > >> > >> So make it a common quirk configured in the config struct. > >> > >> Signed-off-by: Icenowy Zheng > >> --- > >> Changes since original codec patchset v3: > >> - Refactored comments to cover some words found in official > >documents. > >> - Removed the comments when toggling the gate bit. > >> > >> drivers/dma/sun6i-dma.c | 20 +++++++++++++------- > >> 1 file changed, 13 insertions(+), 7 deletions(-) > >> > >> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > >> index a2358780ab2c..252b59c1d1d5 100644 > >> --- a/drivers/dma/sun6i-dma.c > >> +++ b/drivers/dma/sun6i-dma.c > >> @@ -101,6 +101,17 @@ struct sun6i_dma_config { > >> u32 nr_max_channels; > >> u32 nr_max_requests; > >> u32 nr_max_vchans; > >> + /* > >> + * In the datasheets/user manuals of newer Allwinner SoCs, a > >special > >> + * bit (bit 2 at register 0x20) is present. > >> + * It's named "DMA MCLK interface circuit auto gating bit" in the > >> + * documents, and the footnote of this register says that this bit > >> + * should be set up when initializing the DMA controller. > >> + * Allwinner A23/A33 user manuals do not have this bit documented, > >> + * however these SoCs really have and need this bit, as seen in the > >> + * BSP kernel source code. > >> + */ > >> + bool gate_needed; > > > >Since this is a hw property, why is this not added as an optional DT > >property? > > As it's SoC-specified. > > Some SoCs need it, and some don't. and that is the reason it should be a property > > SoC info is in compatible, so there's no reason to make it a property. that's why it would need to be optional for the SoC's that needs these.. > > > > >> }; > >> > >> /* > >> @@ -1009,6 +1020,7 @@ static struct sun6i_dma_config > >sun8i_a23_dma_cfg = { > >> .nr_max_channels = 8, > >> .nr_max_requests = 24, > >> .nr_max_vchans = 37, > >> + .gate_needed = true, > >> }; > >> > >> static struct sun6i_dma_config sun8i_a83t_dma_cfg = { > >> @@ -1174,13 +1186,7 @@ static int sun6i_dma_probe(struct > >platform_device *pdev) > >> goto err_dma_unregister; > >> } > >> > >> - /* > >> - * sun8i variant requires us to toggle a dma gating register, > >> - * as seen in Allwinner's SDK. This register is not documented > >> - * in the A23 user manual. > >> - */ > >> - if (of_device_is_compatible(pdev->dev.of_node, > >> - "allwinner,sun8i-a23-dma")) > >> + if (sdc->cfg->gate_needed) > >> writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE); > >> > >> return 0; > >> -- > >> 2.12.2 > >> -- ~Vinod