From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lanttor Subject: Re: i2c adapter scan device issue Date: Wed, 25 Nov 2009 16:42:02 +0800 Message-ID: <4B0CEDDA.2000909@freescale.com> References: <4B0CAFFD.7030603@freescale.com> <20091125091218.518d47af@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091125091218.518d47af-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org > > Yes, you are correct. You can't predefine I2C devices with > i2c_register_board_info() if you don't also set I2C adapter numbers > with i2c_add_numbered_adapter(). Trying would be equivalent to sending a > letter to someone when you know the city and street number but not the > street name: unlikely to succeed. > Thanks Jean. In fact my bus driver used i2c_add_adapter() not i2c_add_numbered_adapter(). Now I use i2c_add_numbered_adapter() to replace 2c_add_adapter() and set the bus number first. In one word, you mean that i2c_add_adapter() can not work normally if useing i2c_register_board_info() to pre-declare the i2c device, right? I really need track i2c-stack in detail. Best Regards, Lanttor ------------------------------------------------------------------------ *From:* Jean Delvare *Sent:* 11/25/2009 4:12:18 PM +0800 *To:* Lanttor *CC:* linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org *Subject:* i2c adapter scan device issue > On Wed, 25 Nov 2009 12:18:05 +0800, Lanttor wrote: > >> Hi, >> >> I have a confused problem as follows: >> >> I instantiate a i2c device with function i2c_register_board_info(); >> This function pre-declare the I2C devices which live on this bus and the >> call of it >> is before the real i2c bus driver loaded. >> >> In i2c_register_board_info(), >> __i2c_first_dynamic_bus_num = busnum +1; >> >> My i2c bus driver use i2c_add_adapter() to register adapter, In >> i2c_add_adapter(), >> res = idr_get_new_above(&i2c_adapter_idr, adapter, >> __i2c_first_dynamic_bus_num , &id); >> >> adapter->nr = id; >> >> That means if I pass busnum 0 to i2c_register_board_info(), but my i2c >> adapter will get >> busnum 1 and so it can't scan pre-declared i2c devices. >> In fact, I only have one i2c adapter. >> >> It seems I can't use i2c_add_adapter(), instead of using >> i2c_add_numbered_adapter, right? >> > > Yes, you are correct. You can't predefine I2C devices with > i2c_register_board_info() if you don't also set I2C adapter numbers > with i2c_add_numbered_adapter(). Trying would be equivalent to sending a > letter to someone when you know the city and street number but not the > street name: unlikely to succeed. > >