lkml.org 
[lkml]   [2020]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4 2/2] mfd: cros_ec: Add cros-usbpd-notify subdevice
From
Date
Hi Prashant,

On 3/1/20 0:52, Prashant Malani wrote:
> Hi Enric,
>
>
> On Mon, Dec 23, 2019 at 12:29 PM Prashant Malani <pmalani@chromium.org> wrote:
>>
>> Hi Enric,
>>
>> On Sun, Dec 22, 2019 at 11:25 PM Enric Balletbo i Serra
>> <enric.balletbo@collabora.com> wrote:
>>>
>>> Hi Prashant,
>>>
>>> On 20/12/19 20:38, Prashant Malani wrote:
>>>> Add the cros-usbpd-notify driver as a subdevice on non-ACPI platforms
>>>> that support the EC_FEATURE_USB_PD EC feature flag.
>>>>
>>>> This driver allows other cros-ec devices to receive PD event
>>>> notifications from the Chrome OS Embedded Controller (EC) via a
>>>> notification chain.
>>>>
>>>> Signed-off-by: Prashant Malani <pmalani@chromium.org>
>>>> ---
>>>>
>>>> Changes in v4:
>>>> - Removed #ifndef usage; instead, moved cros-usbpd-notify to a separate
>>>> mfd_cell and used an IS_ENABLED() check.
>>>> - Changed commit title and description slightly to reflect change in
>>>> code.
>>>>
>>>> drivers/mfd/cros_ec_dev.c | 21 +++++++++++++++++++++
>>>> 1 file changed, 21 insertions(+)
>>>>
>>>> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
>>>> index c4b977a5dd966..da198abe2b0a6 100644
>>>> --- a/drivers/mfd/cros_ec_dev.c
>>>> +++ b/drivers/mfd/cros_ec_dev.c
>>>> @@ -5,6 +5,7 @@
>>>> * Copyright (C) 2014 Google, Inc.
>>>> */
>>>>
>>>> +#include <linux/kconfig.h>
>>>> #include <linux/mfd/core.h>
>>>> #include <linux/mfd/cros_ec.h>
>>>> #include <linux/module.h>
>>>> @@ -87,6 +88,10 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
>>>> { .name = "cros-usbpd-logger", },
>>>> };
>>>>
>>>> +static const struct mfd_cell cros_usbpd_notify_cells[] = {
>>>> + { .name = "cros-usbpd-notify", },
>>>> +};
>>>> +
>>>> static const struct cros_feature_to_cells cros_subdevices[] = {
>>>> {
>>>> .id = EC_FEATURE_CEC,
>>>> @@ -202,6 +207,22 @@ static int ec_device_probe(struct platform_device *pdev)
>>>> }
>>>> }
>>>>
>>>> + /*
>>>> + * The PD notifier driver cell is separate since it only needs to be
>>>> + * explicitly added on non-ACPI platforms.
>>>
>>>
>>> Sorry to not catch this before, but a worry arose. Is non-ACPI platforms or
>>> non-X86 platforms or on OF platforms?
>>>
>>> ARM64 for example has the CONFIG_ACPI symbol set to yes, with the below
>>> condition condition will not work on Kevin for example and IIUC this is not what
>>> we want, I think we want IS_ENABLED(CONFIG_OF)?
>> Thanks for noting this. I will check with a kevin, and with the
>> internal build flags to verify whether there are ARM64 which have the
>> GOOG0003 PD notification device.
>> I'll update this thread with my findings.
> AFAICT from the Chrome OS kernel build step .config output, kevin
> doesn't have CONFIG_ACPI enabled (it is marked as "# CONFIG_ACPI is
> not set"), and it doesn't look like there are Chrome OS ARM devices
> that use ACPI (I believe it's only used on Chrome OS x86-based
> devices). So perhaps it is not a concern?
>

The problem is, although it is not used in your configs, it can be selected, and
fwiw some defconfigs in mainline have it enabled, i.e the arm64 defconfig.

I think you're testing the patch on x86 but I suspect we want also the notifier
on some arm64 platforms (like kevin) right? In such case I won't get the
notifier because CONFIG_OF and CONFIG_ACPI is enabled on my defconfig.

My guess is that the logic should be if IS_ENABLED(CONFIG_OF) call
cros_ec_check_features, otherwise ACPI will do the magic instead of
(!IS_ENABLED(CONFIG_ACPI))

Best,
Enric

>>
>> Best,
>>
>>>
>>> Thanks,
>>> Enric
>>>
>>>> + */
>>>> + if (!IS_ENABLED(CONFIG_ACPI)) {
>>>> + if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
>>>> + retval = mfd_add_hotplug_devices(ec->dev,
>>>> + cros_usbpd_notify_cells,
>>>> + ARRAY_SIZE(cros_usbpd_notify_cells));
>>>> + if (retval)
>>>> + dev_err(ec->dev,
>>>> + "failed to add PD notify devices: %d\n",
>>>> + retval);
>>>> + }
>>>> + }
>>>> +
>>>> /*
>>>> * The following subdevices cannot be detected by sending the
>>>> * EC_FEATURE_GET_CMD to the Embedded Controller device.
>>>>

\
 
 \ /
  Last update: 2020-01-07 17:51    [W:0.111 / U:2.528 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site