Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933367AbcLSMQn (ORCPT ); Mon, 19 Dec 2016 07:16:43 -0500 Received: from mail-wj0-f196.google.com ([209.85.210.196]:35635 "EHLO mail-wj0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933225AbcLSMQX (ORCPT ); Mon, 19 Dec 2016 07:16:23 -0500 From: Jan Glauber To: Ulf Hansson Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, David Daney , "Steven J . Hill" , Jan Glauber Subject: [PATCH v10 7/8] mmc: thunderx: Support DDR mode for eMMC devices Date: Mon, 19 Dec 2016 13:15:51 +0100 Message-Id: <20161219121552.18316-8-jglauber@cavium.com> X-Mailer: git-send-email 2.9.0.rc0.21.g7777322 In-Reply-To: <20161219121552.18316-1-jglauber@cavium.com> References: <20161219121552.18316-1-jglauber@cavium.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1551 Lines: 46 Add support for switching to DDR mode for eMMC devices. Although the host controller only supports 3.3 Volt and DDR52 uses 1.8 Volt according to the specification it is possible to use DDR also with 3.3 Volt for eMMC chips. To switch to DDR mode MMC_CAP_1_8V_DDR is required. Signed-off-by: Jan Glauber --- drivers/mmc/host/cavium_core_mmc.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/cavium_core_mmc.c b/drivers/mmc/host/cavium_core_mmc.c index 3cd4849..ca0748c 100644 --- a/drivers/mmc/host/cavium_core_mmc.c +++ b/drivers/mmc/host/cavium_core_mmc.c @@ -841,6 +841,10 @@ static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) break; } + /* DDR is available for 4/8 bit bus width */ + if (ios->bus_width && ios->timing == MMC_TIMING_MMC_DDR52) + bus_width |= 4; + slot->bus_width = bus_width; if (!ios->clock) @@ -1065,8 +1069,15 @@ int cvm_mmc_slot_probe(struct device *dev, struct cvm_mmc_host *host) /* Set up host parameters */ mmc->ops = &cvm_mmc_ops; + /* + * We only have a 3.3v supply, we cannot support any + * of the UHS modes. We do support the high speed DDR + * modes up to 52MHz. And we need to lie about 1.8v support, + * otherwise the MMC layer will not switch to DDR. + */ mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED | - MMC_CAP_ERASE | MMC_CAP_CMD23; + MMC_CAP_ERASE | MMC_CAP_CMD23 | + MMC_CAP_1_8V_DDR; if (host->use_sg) mmc->max_segs = 16; -- 2.9.0.rc0.21.g7777322