From patchwork Thu Apr 21 13:54:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ludovic Desroches X-Patchwork-Id: 8901011 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 D8182BF29F for ; Thu, 21 Apr 2016 13:53:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 04FD32020F for ; Thu, 21 Apr 2016 13:53:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A529320034 for ; Thu, 21 Apr 2016 13:53:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752617AbcDUNxk (ORCPT ); Thu, 21 Apr 2016 09:53:40 -0400 Received: from eusmtp01.atmel.com ([212.144.249.243]:8531 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752614AbcDUNxj (ORCPT ); Thu, 21 Apr 2016 09:53:39 -0400 Received: from ibiza.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.31) with Microsoft SMTP Server id 14.3.235.1; Thu, 21 Apr 2016 15:53:29 +0200 From: Ludovic Desroches To: , CC: , , , , Ludovic Desroches Subject: [PATCH] mmc: sdhci-of-at91: add presets setup Date: Thu, 21 Apr 2016 15:54:06 +0200 Message-ID: <1461246846-30925-1-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 2.5.0 MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-7.9 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 The controller claims to support SDR104. In fact, it only supports a degraded SDR104 since the maximum frequency of the SD clock is 120 MHz instead of 208 MHz. The sdhci core is unaware of it and will compute a wrong clock divider. We can deal with this specific case by using presets. Signed-off-by: Ludovic Desroches --- drivers/mmc/host/sdhci-of-at91.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c index c1923c0..76308b1 100644 --- a/drivers/mmc/host/sdhci-of-at91.c +++ b/drivers/mmc/host/sdhci-of-at91.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -163,6 +164,7 @@ static int sdhci_at91_probe(struct platform_device *pdev) unsigned int clk_base, clk_mul; unsigned int gck_rate, real_gck_rate; int ret; + unsigned int preset_div, preset_common = 0x400; /* drv type B, programmable clock mode */ match = of_match_device(sdhci_at91_dt_match, &pdev->dev); if (!match) @@ -230,6 +232,28 @@ static int sdhci_at91_probe(struct platform_device *pdev) clk_mul, real_gck_rate); } + /* + * We have to set preset values because it depends on the clk_mul + * value. Moreover, SDR104 is supported in a degraded mode since the + * maximum sd clock value is 120 MHz instead of 208 MHz. For that + * reason, we need to use presets to support SDR104. + */ + preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1; + writew(preset_common | preset_div, + host->ioaddr + SDHCI_PRESET_FOR_SDR12); + preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1; + writew(preset_common | preset_div, + host->ioaddr + SDHCI_PRESET_FOR_SDR25); + preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1; + writew(preset_common | preset_div, + host->ioaddr + SDHCI_PRESET_FOR_SDR50); + preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1; + writew(preset_common | preset_div, + host->ioaddr + SDHCI_PRESET_FOR_SDR104); + preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1; + writew(preset_common | preset_div, + host->ioaddr + SDHCI_PRESET_FOR_DDR50); + clk_prepare_enable(priv->mainck); clk_prepare_enable(priv->gck);