Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754367AbbGBCfX (ORCPT ); Wed, 1 Jul 2015 22:35:23 -0400 Received: from mail-ie0-f171.google.com ([209.85.223.171]:34131 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753577AbbGBCfR (ORCPT ); Wed, 1 Jul 2015 22:35:17 -0400 MIME-Version: 1.0 In-Reply-To: <5593B971.1010601@samsung.com> References: <1435734774-10993-1-git-send-email-chunyan.zhang@spreadtrum.com> <5593B971.1010601@samsung.com> Date: Thu, 2 Jul 2015 10:35:16 +0800 Message-ID: Subject: Re: [RFC PATCH] mmc: sprd: add MMC host driver for Spreadtrum SoC From: Chunyan Zhang To: Jaehoon Chung Cc: Chunyan Zhang , ulf.hansson@linaro.org, Lee Jones , Shawn Guo , Grant Likely , "robh+dt@kernel.org" , Arnd Bergmann , billows.wu@spreadtrum.com, =?UTF-8?B?V2VpIFFpYW8gKOS5lOS8nyk=?= , baolin.wang@spreadtrum.com, ning.yang@spreadtrum.com, orson.zhai@spreadtrum.com, jason.wu@spreadtrum.com, linux-mmc@vger.kernel.org, "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , chris@printf.net Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1394 Lines: 33 On Wed, Jul 1, 2015 at 5:57 PM, Jaehoon Chung wrote: > Hi, > > Is sdhost based on SDHCI controller? > Why don't use sdhci.c? Is there any reason? > > Best Regards, > Jaehoon Chung > Because of base64 code problem of his email server, I'm reporting his reply instead. >From Billows Wu ---------------------------------------------------------------------------------------------------------------------------------------- Hi Jaehoon, Sdhost driver is not based on SDHCI controller. Our MMC controller is not a standard controller which meets host controller specification completely. We add some registers and change some bits in the remaining register, such as about clock and regulator portion. If our driver base on SDHCI controller, we must change many codes in sdhci.c, and our MMC driver will become more complicated. In order to better use our controller capability and make MMC driver more compact, we do not use SDHCI controller. Thanks. -------------------------------------------------------------------------------------------------------------------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/