Hello Lee, On 09/17/2014 06:31 PM, Lee Jones wrote: >> >> -static const struct mfd_cell cros_devs[] = { >> - { >> - .name = "cros-ec-keyb", >> - .id = 1, >> - .of_compatible = "google,cros-ec-keyb", >> - }, >> - { >> - .name = "cros-ec-i2c-tunnel", >> - .id = 2, >> - .of_compatible = "google,cros-ec-i2c-tunnel", >> - }, >> -}; >> - >> int cros_ec_register(struct cros_ec_device *ec_dev) >> { >> struct device *dev = ec_dev->dev; >> + struct device_node *node = dev->of_node; >> int err = 0; >> >> if (ec_dev->din_size) { >> @@ -140,12 +129,12 @@ int cros_ec_register(struct cros_ec_device *ec_dev) >> >> mutex_init(&ec_dev->lock); >> >> - err = mfd_add_devices(dev, 0, cros_devs, >> - ARRAY_SIZE(cros_devs), >> - NULL, ec_dev->irq, NULL); >> - if (err) { >> - dev_err(dev, "failed to add mfd devices\n"); >> - return err; > > So these devices will only ever probe with DT now ... > Well, these are preparatory patches to reduce the delta between upstream and the downstream so the missing functionality could be added. One of the missing drivers is the cros_ec_dev.c [0] which allows user-space to access the ChromeOS Embedded Controller using a virtual character device (/dev/cros_ec). Since that is a virtual device, it does not fit on the DT which only describes hw and also is used on x86 machines so that subdevice is still probed using mfd_add_devices() and the mfd_cells array is not empty in the downstream cros_ec driver [1]. That's why I didn't just made the cros_ec MFD to depend on OF, since I didn't want to diverge too much from the downstream driver because the idea of the series was to reduce the difference in order to add the missing bits on top. >> + if (node) { > > So it would be wrong for dev->of_node not to be populated. > As explained above, DT, non-DT and x86 platforms instantiate the cros-ec-dev cells but DT platforms can define other child nodes. But I can remove the conditional if you want and reintroduce it once cros-ec-dev support is added. >> + err = of_platform_populate(node, NULL, NULL, dev); >> + if (err) { >> + dev_err(dev, "Failed to register subordinate devices"); >> + return err; >> + } >> } >> >> dev_info(dev, "Chrome EC device registered\n"); > Best regards, Javier [0]: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/mfd/cros_ec_dev.c [1]: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8/drivers/mfd/cros_ec.c#93 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html