On Mon, 17 Jul 2017, Enric Balletbo Serra wrote: > Hi Gwendal, > > 2017-07-13 22:33 GMT+02:00 Gwendal Grignou <gwendal@xxxxxxxxxxxx>: > > On Wed, Jul 12, 2017 at 3:13 AM, Enric Balletbo i Serra > > <enric.balletbo@xxxxxxxxxxxxx> wrote: > >> The cros_ec_dev driver should be used only to expose the Chrome OS Embedded > >> Controller to user-space and should not be used to add MFD devices by > >> calling mfd_add_devices. This patch moves this logic to the MFD cros_ec > >> driver and removes the MFD bits from the character device driver. Also > >> makes independent the IIO driver from the character device as also has no > >> sense. > > > > cros_ec_dev serves another purpose: it allows to represent an EC that > > does not have a cros_ec structure. It happens when there are several > > EC in a chromebook, and one EC is connected through another EC. > > One example is Samus (Pixel 2): where we have: > > > > (main SOC, Application Processor) AP --> (main Embedded Controller) EC > > ---> (Power Delivery [PD}) EC > > > > We access to the PD EC via pass-through commands through the main EC. > > Each EC has a cros_ec_dev structure, but only the main EC as a > > cros_ec_device structure (I will forever regret the structure names). > > > > Now form the AP point of view, both ECs use the same protocol. That > > why the sensors and other devcies that are registered by looking at > > the feature fields are registered with cros_ec_dev as their parent. > > Other devices that are registered from the device tree, predating the > > feature field support, are registered with cros_ec_device as their > > parent. > > > > Interesting I didn't know that. So are you saying that this patch will > break support for devices like Pixel 2? I tested the patches on > various devices but not on Pixel 2 so could be. Does this affect the rest of the series? Or should I review/apply as usual? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
