From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Dolca Subject: Re: [PATCH RFC] i2c: Use ID table to detect ACPI I2C devices Date: Wed, 20 May 2015 13:49:02 +0300 Message-ID: References: <1432044209-27858-1-git-send-email-robert.dolca@intel.com> <20150520074708.GQ1490@lahna.fi.intel.com> <20150520094829.GS1490@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <20150520094829.GS1490-3PARRvDOhMZrdx17CPfAsdBPR1lH4CV8@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mika Westerberg Cc: Robert Dolca , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Wolfram Sang , "Rafael J. Wysocki" , Len Brown , Daniel Baluta List-Id: linux-i2c@vger.kernel.org On Wed, May 20, 2015 at 12:48 PM, Mika Westerberg wrote: > On Wed, May 20, 2015 at 12:39:22PM +0300, Robert Dolca wrote: >> Currently, if the name used for DT (in dts) matches one of the names >> specified in the id table you will have a match. Isn't that an >> intended behavior? > > I thought one needs to put IDs to the driver .of_match_table. This is > also what i2c_device_match() is expecting, if I read it right. If you put the DT id in of_match_table it will match here: i2c_device_match /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) return 1; If you don't specify of_match_table and you put the same ID in i2c_device_id table it wil match here: i2c_device_match driver = to_i2c_driver(drv); /* match on an id table if there is one */ if (driver->id_table) return i2c_match_id(driver->id_table, client) != NULL; This is happening because the name from dts is used for client->name. i2c_match_id does the matching based on the client name. > BTW, how modules are supposed to be matched if we allow putting ACPI > identifiers to i2c_device_id table? My aproach was like this: if the driver specifies .acpi_match table it will work like before. i2c_device_match /* Then ACPI style match */ if (acpi_driver_match_device(dev, drv)) return 1; If the driver does not specify .acpi_match table the i2c core will atempt to match against the i2c_match_id table (the same way it does for DT). In the ACPI case the client->name has that :nn suffix and what the patch does is to ignore that when i2c_match_id is called. i2c_device_match driver = to_i2c_driver(drv); /* match on an id table if there is one */ if (driver->id_table) return i2c_match_id(driver->id_table, client) != NULL; The final goal is to simplify the driver and remove redundant code. Robert