On Mon, Nov 26, 2012 at 04:26:39PM -0800, David Daney wrote: > On 11/26/2012 12:13 PM, Grant Likely wrote: > >On Sun, 25 Nov 2012 20:53:56 -0800, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > >>Some I2C devices are not or not correctly initialized by the firmware. > >>Configuration would be possible via platform data, but that would require > >>per-driver platform data and a lot of code, and changing it would not be > >>possible without re-compiling the kernel. It is more elegant to do it > >>generically via devicetree properties. > >> > >>Add a generic I2C devicetree property named "reg-init". This property provides > >>a sequence of device initialization commands to be executed prior to calling > >>the probe function for a given device. > >> > >>Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > > >This is a very similar problem to the power sequences series that was > >recently posted to this list. I would like that feature and this > >mechanism use the same approach. > > > I haven't fully studied the power sequencing thing, but just to play > Devil's Advocate, there is precedence for the "reg-init" style in > some of the Ethernet PHY drivers. > That is where I took it from. > Perhaps the "reg-init" should be used as one of the steps in the > sequence, and if there was only a single step it would be > functionally equivalent to the "reg-init" proposal. > My thought is along the same line. I'll have to study the power sequencing proposal a bit more to see if that would work. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
