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Groups > linux.kernel > #1692469 > unrolled thread
| Started by | Enric Balletbo Serra <eballetbo@gmail.com> |
|---|---|
| First post | 2017-07-20 08:40 +0200 |
| Last post | 2017-07-20 08:40 +0200 |
| Articles | 1 — 1 participant |
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Re: [PATCH v3 1/4] mfd: cros_ec: Get rid of cros_ec_check_features from cros_ec_dev. Enric Balletbo Serra <eballetbo@gmail.com> - 2017-07-20 08:40 +0200
| From | Enric Balletbo Serra <eballetbo@gmail.com> |
|---|---|
| Date | 2017-07-20 08:40 +0200 |
| Subject | Re: [PATCH v3 1/4] mfd: cros_ec: Get rid of cros_ec_check_features from cros_ec_dev. |
| Message-ID | <u5dhT-3r4-9@gated-at.bofh.it> |
Lee, 2017-07-18 11:19 GMT+02:00 Lee Jones <lee.jones@linaro.org>: > On Mon, 17 Jul 2017, Enric Balletbo Serra wrote: > >> Hi Gwendal, >> >> 2017-07-13 22:33 GMT+02:00 Gwendal Grignou <gwendal@chromium.org>: >> > On Wed, Jul 12, 2017 at 3:13 AM, Enric Balletbo i Serra >> > <enric.balletbo@collabora.com> 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? > Yes, because this patch moves cros_ec_check_features from char dev driver... > Or should I review/apply as usual? > Please, hold on while I figure out what's exactly the problem with Samus. Sorry for the noise. Cheers, Enric > -- > Lee Jones > Linaro STMicroelectronics Landing Team Lead > Linaro.org │ Open source software for ARM SoCs > Follow Linaro: Facebook | Twitter | Blog
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