From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752526AbcANL5b (ORCPT ); Thu, 14 Jan 2016 06:57:31 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:7372 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998AbcANL53 (ORCPT ); Thu, 14 Jan 2016 06:57:29 -0500 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 14 Jan 2016 03:58:52 -0800 Message-ID: <56978AB6.3050001@nvidia.com> Date: Thu, 14 Jan 2016 17:17:02 +0530 From: Laxman Dewangan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Krzysztof Kozlowski , Mark Brown CC: LKML Subject: Re: Need APIs to add regmap in dev References: <56969E11.7060407@nvidia.com> <5696F528.8060506@samsung.com> In-Reply-To: <5696F528.8060506@samsung.com> X-Originating-IP: [10.19.65.30] X-ClientProxiedBy: DRUKMAIL101.nvidia.com (10.25.59.19) To bgmail102.nvidia.com (10.25.59.11) Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 14 January 2016 06:38 AM, Krzysztof Kozlowski wrote: > On 14.01.2016 03:57, Laxman Dewangan wrote: >> Hi Mark, >> when working on unification of Max77620, MAX77686 RTC driver, I came to >> need of APIs from regmap to add the device as devres. >> >> int dev_add_regmap(dev, regmap); >> >> This will add the regmap in the dev resource of device. This will help >> to get the regmap handle from device using dev_get_regmap(). This APIs >> will be different from the regmap_attach_dev() where map->dev is moved >> to new device. >> >> The requirement came from multiple i2c slave address device like MAX77620. >> MAX77620 has 2 i2c address 0x3C and 0x68. 0x68 is for RTC IP block. >> we register device with 0x3C and create dummy i2c client for 0x68 inside >> driver. >> We create two regmap, one from 0x3C i2c client as rmap_0x3c and other >> from 0x68 i2c dummy client rmap_0x68. >> >> Now in RTC driver(mfd device), we have the parent device as dev_0x3c. >> When we try to get the regmap handle, we only get one regmap per device >> as we register regmap with different devices. >> >> If I had above API then I can add the rmap_0x68 in the dev_0x3c as >> dev_res. By this I can have two regmap list on dev_0x3c and get rmap >> handle by dev_get_regmap(dev_0x3c, "pmic-slave") and >> dev_get_regmap(dev_0x3c, "rtc-slave"); >> >> >> I like to know your comment on this approach to add the regmap on >> different device resource. > > As I pointed on previous discussions (e.g. > https://lkml.org/lkml/2016/1/11/1158 ) the child should be responsible > for its I2C dummy device and regmap. You ignored that idea previously - > dunno why. One of discussion, Mark suggested to use dev_get_regmap() and explored to get both regmap handle via this call. That's why did not routed to create one regmap in mfd and other regmap in the rtc driver. > > Just don't create the RTC regmap in parent MFD. Let the child manage its > resources. That is the real decoupling. This is also very possible to handle everything on RTC driver. Will try this route now.