On 02/15/2013 12:46 PM, Doug Anderson wrote: > The i2c-arbitrator-cros-ec driver implements the arbitration scheme > that the Embedded Controller (EC) on the ARM Chromebook expects to use > for bus multimastering. This i2c-arbitrator-cros-ec driver could also > be used in other places where standard I2C bus arbitration can't be > used and two extra GPIOs are available for arbitration. > > This driver is based on code that Simon Glass added to the i2c-s3c2410 > driver in the Chrome OS kernel 3.4 tree. The current incarnation as a > mux driver is as suggested by Grant Likely. See > <https://patchwork.kernel.org/patch/1877311/> for some history. Reviewed-by: Stephen Warren <swarren@xxxxxxxxxx> > diff --git a/drivers/i2c/muxes/i2c-arbitrator-cros-ec.c b/drivers/i2c/muxes/i2c-arbitrator-cros-ec.c > +static int i2c_arbitrator_probe(struct platform_device *pdev) > + /* Request GPIOs */ > + ret = of_get_named_gpio_flags(np, "ap-claim-gpio", 0, &gpio_flags); > + if (ret == -EPROBE_DEFER || WARN_ON(!gpio_is_valid(ret))) > + return ret; I think by the time that doesn't return -EPROBE_DEFER ... > + arb->ap_gpio = ret; > + arb->ap_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW); > + out_init = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? > + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; > + ret = devm_gpio_request_one(&pdev->dev, arb->ap_gpio, out_init, > + "ap-claim-gpio"); > + if (ret == -EPROBE_DEFER || WARN_ON(ret)) > + return ret; ... that won't either, since of_get_named_gpio_flags()'s implementation requires the relevant GPIO driver to be active already. Still, there's no harm in the code as it stands, so no need to change. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
