Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932485Ab3HGStZ (ORCPT ); Wed, 7 Aug 2013 14:49:25 -0400 Received: from mail-ob0-f181.google.com ([209.85.214.181]:61278 "EHLO mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757175Ab3HGStX (ORCPT ); Wed, 7 Aug 2013 14:49:23 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 7 Aug 2013 20:49:22 +0200 Message-ID: Subject: Re: [PATCH v2 2/4] gpio: add LP3943 I2C GPIO expander driver From: Linus Walleij To: "Kim, Milo" Cc: "lee.jones@linaro.org" , "Samuel Ortiz (sameo@linux.intel.com)" , "broonie@kernel.org" , "thierry.reding@gmail.com" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-pwm@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1852 Lines: 47 On Tue, Jul 30, 2013 at 2:42 AM, Kim, Milo wrote: > This is one of LP3943 MFD driver. > LP3943 is configurable as a GPIO expander, up to 16 GPIOs. > > * Application note: how to configure LP3943 as a GPIO expander > http://www.ti.com/lit/an/snva287a/snva287a.pdf > > * Supported GPIO controller operations > request, free, direction_input, direction_output, get and set > > * GPIO direction register not supported > LP3943 doesn't have the GPIO direction register. It only provides input and > output status registers. > So, private data for the direction should be handled manually. > This variable is updated whenever the direction is changed and > used in 'get' operation. > > * Pin assignment > A driver data, 'pin_used' is checked when a GPIO is requested. > If the GPIO is already assigned, then returns as failure. > If the GPIO is available, 'pin_used' is set. > When the GPIO is not used anymore, then it is cleared. > It is defined as unsigned long type for atomic bit operation APIs, > but only LSB 16bits are used because LP3943 has 16 outputs. > > Cc: Linus Walleij > Signed-off-by: Milo Kim > --- > * Patch v2 > Use bitops macros for bit manipulations. > Support device tree structure for the GPIO controller. > Add request() and free() for the pin assignment. This adresses all my concerns, nice driver. Reviewed-by: Linus Walleij I guess this will be merged through the MFD tree along with the MFD core patch? That needs to go in first anyway. Yours, Linus Walleij -- 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/