From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755439AbaE3J2d (ORCPT ); Fri, 30 May 2014 05:28:33 -0400 Received: from mail-ig0-f169.google.com ([209.85.213.169]:60636 "EHLO mail-ig0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755156AbaE3J2b (ORCPT ); Fri, 30 May 2014 05:28:31 -0400 Date: Fri, 30 May 2014 10:28:25 +0100 From: Lee Jones To: "Zhu, Lejun" Cc: broonie@kernel.org, sameo@linux.intel.com, linux-kernel@vger.kernel.org, jacob.jun.pan@linux.intel.com, bin.yang@intel.com Subject: Re: [PATCH v4 1/3] mfd: intel_soc_pmic: Core driver Message-ID: <20140530092825.GG2619@lee--X1> References: <1401347968-24410-1-git-send-email-lejun.zhu@linux.intel.com> <1401347968-24410-2-git-send-email-lejun.zhu@linux.intel.com> <20140529114052.GI1954@lee--X1> <53880FF5.8070500@linux.intel.com> <20140530080848.GB2619@lee--X1> <5388497C.3000106@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5388497C.3000106@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > >>>> +static const struct i2c_device_id intel_soc_pmic_i2c_id[] = { > >>>> + {"INT33FD:00", (kernel_ulong_t)&intel_soc_pmic_config_crc}, > >>>> + { } > >>>> +}; > >>>> +MODULE_DEVICE_TABLE(i2c, intel_soc_pmic_i2c_id); > >>>> + > >>>> +static struct acpi_device_id intel_soc_pmic_acpi_match[] = { > >>>> + {"INT33FD", (kernel_ulong_t)&intel_soc_pmic_config_crc}, > >>>> + { }, > >>>> +}; > >>>> +MODULE_DEVICE_TABLE(acpi, intel_soc_pmic_acpi_match); > >>> > >>> Does ACPI have a match function to extact it's .driver_data attribute? > >>> > >>> If so, are you using it here? If not, why not? > >>> > >> > >> The ACPI table is used in i2c_device_match(), and the i2c table is used > >> in i2c_device_probe(), so the id in the i2c table is actually fed to > >> intel_soc_pmic_probe(). But I only found out now that having the i2c > >> table alone is enough, because i2c_device_match will fallback to the i2c > >> table if there's no ACPI table. So to keep it simple, I'll remove the > >> ACPI table completely. > > > > Actually, can you do it the other way round? Minimise the i2c table > > and populate the ACPI one. I'm just about to work on a separate > > patch-set which deprecates the use of the i2c table on DT and/or ACPI > > only registered devices. > > Current i2c_device_probe will only feed driver_data from i2c_device_id > table to intel_soc_pmic_probe(), because it uses i2c_match_id(). So if I > remove "&intel_soc_pmic_config_crc" from the i2c table, I will get NULL > from id->driver_data until your new patch fixes it. Right, which is why I asked if ACPI has a match function - I just looked and it does. So what you need to do is supply a very simple i2c_device_id struct (just until my patch lands, then there'll be no reason to supply one at all) and use acpi_match_device() instead of using id->driver_data. > So for the driver to work for the i2c code both today and in the future, > I think it's best to keep the driver_data populated in both tables. What > do you think? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog