From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966085AbdAKMkx (ORCPT ); Wed, 11 Jan 2017 07:40:53 -0500 Received: from fllnx210.ext.ti.com ([198.47.19.17]:22426 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936886AbdAKMkv (ORCPT ); Wed, 11 Jan 2017 07:40:51 -0500 Subject: Re: [PATCH 2/2] gpio: davinci: Remove gpio2regs function to accommodate multi instances To: Linus Walleij References: <1483518389-6200-1-git-send-email-j-keerthy@ti.com> <1483518389-6200-2-git-send-email-j-keerthy@ti.com> CC: "linux-kernel@vger.kernel.org" , "linux-gpio@vger.kernel.org" , Alexandre Courbot , Tero Kristo From: Keerthy Message-ID: <55d29408-2ccc-d6a1-8ef6-5418ba8df0b7@ti.com> Date: Wed, 11 Jan 2017 18:10:46 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 11 January 2017 04:34 PM, Linus Walleij wrote: > On Wed, Jan 4, 2017 at 9:26 AM, Keerthy wrote: > >> gpio2regs is written making an assumption that driver supports only >> one instance of gpio controller. Removing this and adding a generic >> array so as to support multiple instances of gpio controllers. >> >> Signed-off-by: Keerthy > >> - regs = gpio2regs(base); >> + regs = gpio_base + offset_array[i]; > > I understand this. > >> - struct davinci_gpio_regs __iomem *g = gpio2regs(hw); >> + struct davinci_gpio_controller *chips = >> + (struct davinci_gpio_controller *)d->host_data; >> + struct davinci_gpio_regs __iomem *g = chips[hw / 32].regs; > > And this, if each instans has 32 GPIOs. > >> - g = gpio2regs(0); >> + g = chips[0].regs; > > Also makes sense. > >> - g = gpio2regs(gpio); >> + g = chips[bank / 2].regs; > > But what is this? I don't understand that /2 at all. Please insert a > comment explaining it so I can figure it out. Are there two banks > per instance? Yes! There are register sets for 32 GPIOs. 2 banks of 16 GPIOs are covered by each set of registers hence /2. Shall i add a comment and send this patch alone separately? > > Yours, > Linus Walleij >