From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trilok Soni Subject: Re: [PATCH] i2c: QUP based bus driver for Qualcomm MSM chipsets Date: Sat, 24 Jul 2010 20:38:49 +0530 Message-ID: <4C4B0201.9060106@codeaurora.org> References: <1279853264-16311-1-git-send-email-kheitke@codeaurora.org> <4C494086.5080408@codeaurora.org> <4C49E5EE.2070103@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4C49E5EE.2070103-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kenneth Heitke Cc: khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Crane Cai , Samuel Ortiz , Linus Walleij , Ralf Baechle , srinidhi kasagar , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hi Ken, > >> >>> + >>> + if (!pdata->msm_i2c_config_gpio) { >>> + dev_err(&pdev->dev, "config_gpio function not initialized\n"); >>> + ret = -ENOSYS; >>> + goto err_config_failed; >>> + } >> >> I don't agree here. What if I do all the gpio configuration from the bootloader itself, >> because I know that the device I am working on is production device and don't change >> its configuration, then why I should provide the pdata hooks from the board files? > > The reason that this hook is required is so that the driver can enable and disable the GPIOs as needed (although we currently only enable them). > >> >> Please also specify what are the operations we are doing in the msm_i2c_config_gpio? > > Takes ownership of the GPIOs that are needed and assigns the ownership to the i2c controller. The drive strength is also set. Right, so due to these reasons I prefer not to have __must__ have check for pdata->msm_i2c_config_gpio hook's unavailability. It might happen that some of the systems do all these ownership and pad muxing into the bootloader itself. ---Trilok Soni -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.