From patchwork Thu Jan 21 05:26:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen-Yu Tsai X-Patchwork-Id: 8078241 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id A3312BEEE5 for ; Thu, 21 Jan 2016 05:38:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D16D5205DA for ; Thu, 21 Jan 2016 05:38:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECA1F205B5 for ; Thu, 21 Jan 2016 05:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935239AbcAUFfb (ORCPT ); Thu, 21 Jan 2016 00:35:31 -0500 Received: from smtp.csie.ntu.edu.tw ([140.112.30.61]:54936 "EHLO smtp.csie.ntu.edu.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932745AbcAUFdl (ORCPT ); Thu, 21 Jan 2016 00:33:41 -0500 Received: from mirror2.csie.ntu.edu.tw (mirror2.csie.ntu.edu.tw [140.112.30.76]) (Authenticated sender: b93043) by smtp.csie.ntu.edu.tw (Postfix) with ESMTPSA id EB1B524F67; Thu, 21 Jan 2016 13:33:30 +0800 (CST) Received: by mirror2.csie.ntu.edu.tw (Postfix, from userid 1000) id 96C345F7F9; Thu, 21 Jan 2016 13:33:30 +0800 (CST) From: Chen-Yu Tsai To: Ulf Hansson , Maxime Ripard Cc: Chen-Yu Tsai , Hans de Goede , linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com Subject: [PATCH RFC 01/15] mmc: sunxi: Document host init sequence Date: Thu, 21 Jan 2016 13:26:28 +0800 Message-Id: <1453354002-28366-2-git-send-email-wens@csie.org> X-Mailer: git-send-email 2.7.0.rc3 In-Reply-To: <1453354002-28366-1-git-send-email-wens@csie.org> References: <1453354002-28366-1-git-send-email-wens@csie.org> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP sunxi_mmc_init_host() originated from Allwinner kernel sources. The magic numbers written to various registers was never documented. Add comments for values found in Allwinner user manuals. Signed-off-by: Chen-Yu Tsai --- drivers/mmc/host/sunxi-mmc.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c index 83de82bceafc..cce5ca540857 100644 --- a/drivers/mmc/host/sunxi-mmc.c +++ b/drivers/mmc/host/sunxi-mmc.c @@ -284,16 +284,28 @@ static int sunxi_mmc_init_host(struct mmc_host *mmc) if (sunxi_mmc_reset_host(host)) return -EIO; + /* + * Burst 8 transfers, RX trigger level: 7, TX trigger level: 8 + * + * TODO: sun9i has a larger FIFO and supports higher trigger values + */ mmc_writel(host, REG_FTRGL, 0x20070008); + /* Maximum timeout value */ mmc_writel(host, REG_TMOUT, 0xffffffff); + /* Unmask SDIO interrupt if needed */ mmc_writel(host, REG_IMASK, host->sdio_imask); + /* Clear all pending interrupts */ mmc_writel(host, REG_RINTR, 0xffffffff); + /* Debug register? undocumented */ mmc_writel(host, REG_DBGC, 0xdeb); + /* Enable CEATA support */ mmc_writel(host, REG_FUNS, SDXC_CEATA_ON); + /* Set DMA descriptor list base address */ mmc_writel(host, REG_DLBA, host->sg_dma); rval = mmc_readl(host, REG_GCTRL); rval |= SDXC_INTERRUPT_ENABLE_BIT; + /* Undocumented, but found in Allwinner code */ rval &= ~SDXC_ACCESS_DONE_DIRECT; mmc_writel(host, REG_GCTRL, rval);