On Thu, Oct 30, 2014 at 02:16:04PM +0100, Matthias Brugger wrote: > 2014-10-29 6:37 GMT+01:00 Xudong Chen <xudong.chen@xxxxxxxxxxxx>: > > +static int mt_i2c_do_transfer(struct mt_i2c *i2c) > > +{ > > + u16 addr_reg; > > + u16 control_reg; > > + int tmo = i2c->adap.timeout; > > + > > + i2c->trans_stop = false; > > + i2c->irq_stat = 0; > > + > > + /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */ > > + if (i2c->have_pmic) > > + i2c_writew(I2C_CONTROL_WRAPPER, i2c, OFFSET_PATH_DIR); > > So this is some sort of multiplexer bit, right? > I think in this case we need to build a multi function device (mfd) > where the pmic driver will set this bit. This bit is in the i2c controller register space, so it shouldn't be controlled by some other driver. I think the configuration of this register is already in the correct place. What I could think of is that the PMIC could implement a pinctrl driver and the i2c controller driver gets the pins from the PMIC. Anyway, the controlling of this bit would still be in the i2c driver. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html