| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID:
<CAGwozwGq7RiZdpBsYhKxfrTMMfzGPGML2R6q8ayjpVn_W4j=uQ@mail.gmail.com>
Date: Mon, 17 Nov 2025 14:33:56 +0100
From: Antheas Kapenekakis <lkml@...heas.dev>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: platform-driver-x86@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
linux-hwmon@...r.kernel.org, Hans de Goede <hansg@...nel.org>,
Derek John Clark <derekjohn.clark@...il.com>,
Joaquín Ignacio Aramendía <samsagax@...il.com>,
Jean Delvare <jdelvare@...e.com>, Guenter Roeck <linux@...ck-us.net>,
Armin Wolf <W_Armin@....de>
Subject: Re: [PATCH v5 4/6] platform/x86: ayaneo-ec: Add controller power and
modules attributes
On Mon, 17 Nov 2025 at 11:30, Ilpo Järvinen
<ilpo.jarvinen@...ux.intel.com> wrote:
>
> On Thu, 13 Nov 2025, Antheas Kapenekakis wrote:
>
> > The Ayaneo 3 features hot-swappable controller modules. The ejection
> > and management is done through HID. However, after ejecting the modules,
> > the controller needs to be power cycled via the EC to re-initialize.
> >
> > For this, the EC provides a variable that holds whether the left or
> > right modules are connected, and a power control register to turn
> > the controller on or off. After ejecting the modules, the controller
> > should be turned off. Then, after both modules are reinserted,
> > the controller may be powered on again to re-initialize.
>
> If wonder if the ejecting could/should be made to turn it off without need
> for an explicit off command?
Perhaps in the future, this driver leaves the possibility open for it.
However, that'd require a secondary HID driver to handle the full
ejection process, with a shared function hook for this driver.
The eject sequence consists of sending a HID config command to start
the ejection, followed by a secondary config command to turn off the
ejection bits and then waiting for two ready bits to report that the
ejection is finished. Then, the controller is turned off. Apart from
turning off, all of this is done through HID (so HID ready races the
controller_modules value).
The module status of this driver is only used to check when the
controller should be turned on again and to provide visual feedback
about which modules are currently connected while unpowered. When
powered, there is full status reporting over HID, including which
specific modules are connected[1].
The end-to-end sequence is currently in userspace[2]. However, the EC
ports are shielded from userspace so these two specific accesses must
happen through a kernel driver.
Antheas
[1] https://github.com/hhd-dev/hhd/blob/8d842e547441600b8adc806bfb10ded5718e4fe3/src/hhd/device/ayaneo/base.py#L90-L117
[2] https://github.com/hhd-dev/hhd/blob/8d842e547441600b8adc806bfb10ded5718e4fe3/src/hhd/device/ayaneo/base.py
> > This patch introduces two new sysfs attributes:
> > - `controller_modules`: a read-only attribute that indicates whether
> > the left and right modules are connected (none, left, right, both).
> > - `controller_power`: a read-write attribute that allows the user
> > to turn the controller on or off (with '1'/'0').
> >
> > Therefore, after ejection is complete, userspace can power off the
> > controller, then wait until both modules have been reinserted
> > (`controller_modules` will return 'both') to turn on the controller.
> >
> > Reviewed-by: Armin Wolf <W_Armin@....de>
> > Signed-off-by: Antheas Kapenekakis <lkml@...heas.dev>
> > ---
> > .../ABI/testing/sysfs-platform-ayaneo-ec | 19 ++++
> > MAINTAINERS | 1 +
> > drivers/platform/x86/ayaneo-ec.c | 107 ++++++++++++++++++
> > 3 files changed, 127 insertions(+)
> > create mode 100644 Documentation/ABI/testing/sysfs-platform-ayaneo-ec
> >
> > diff --git a/Documentation/ABI/testing/sysfs-platform-ayaneo-ec b/Documentation/ABI/testing/sysfs-platform-ayaneo-ec
> > new file mode 100644
> > index 000000000000..4cffbf5fc7ca
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-platform-ayaneo-ec
> > @@ -0,0 +1,19 @@
> > +What: /sys/devices/platform/ayaneo-ec/controller_power
> > +Date: Nov 2025
> > +KernelVersion: 6.19
> > +Contact: "Antheas Kapenekakis" <lkml@...heas.dev>
> > +Description:
> > + Current controller power state. Allows turning on and off
> > + the controller power (e.g. for power savings). Write 1 to
> > + turn on, 0 to turn off. File is readable and writable.
> > +
> > +What: /sys/devices/platform/ayaneo-ec/controller_modules
> > +Date: Nov 2025
> > +KernelVersion: 6.19
> > +Contact: "Antheas Kapenekakis" <lkml@...heas.dev>
> > +Description:
> > + Shows which controller modules are currently connected to
> > + the device. Possible values are "left", "right" and "both".
> > + File is read-only. The Windows software for this device
> > + will only set controller power to 1 if both module sides
> > + are connected (i.e. this file returns "both").
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index c5bf7207c45f..f8ab009b6224 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -4196,6 +4196,7 @@ AYANEO PLATFORM EC DRIVER
> > M: Antheas Kapenekakis <lkml@...heas.dev>
> > L: platform-driver-x86@...r.kernel.org
> > S: Maintained
> > +F: Documentation/ABI/testing/sysfs-platform-ayaneo
> > F: drivers/platform/x86/ayaneo-ec.c
> >
> > AZ6007 DVB DRIVER
> > diff --git a/drivers/platform/x86/ayaneo-ec.c b/drivers/platform/x86/ayaneo-ec.c
> > index 697bb053a7d6..a0747e7ee43a 100644
> > --- a/drivers/platform/x86/ayaneo-ec.c
> > +++ b/drivers/platform/x86/ayaneo-ec.c
> > @@ -8,6 +8,7 @@
> > */
> >
> > #include <linux/acpi.h>
> > +#include <linux/bits.h>
> > #include <linux/dmi.h>
> > #include <linux/err.h>
> > #include <linux/hwmon.h>
> > @@ -16,6 +17,7 @@
> > #include <linux/module.h>
> > #include <linux/platform_device.h>
> > #include <linux/power_supply.h>
> > +#include <linux/sysfs.h>
> > #include <acpi/battery.h>
> >
> > #define AYANEO_PWM_ENABLE_REG 0x4A
> > @@ -32,9 +34,18 @@
> > #define AYANEO_CHARGE_VAL_AUTO 0xaa
> > #define AYANEO_CHARGE_VAL_INHIBIT 0x55
> >
> > +#define AYANEO_POWER_REG 0x2d
> > +#define AYANEO_POWER_OFF 0xfe
> > +#define AYANEO_POWER_ON 0xff
> > +#define AYANEO_MODULE_REG 0x2f
> > +#define AYANEO_MODULE_LEFT BIT(0)
> > +#define AYANEO_MODULE_RIGHT BIT(1)
> > +#define AYANEO_MODULE_MASK (AYANEO_MODULE_LEFT | AYANEO_MODULE_RIGHT)
> > +
> > struct ayaneo_ec_quirk {
> > bool has_fan_control;
> > bool has_charge_control;
> > + bool has_magic_modules;
> > };
> >
> > struct ayaneo_ec_platform_data {
> > @@ -46,6 +57,7 @@ struct ayaneo_ec_platform_data {
> > static const struct ayaneo_ec_quirk quirk_ayaneo3 = {
> > .has_fan_control = true,
> > .has_charge_control = true,
> > + .has_magic_modules = true,
> > };
> >
> > static const struct dmi_system_id dmi_table[] = {
> > @@ -266,6 +278,100 @@ static int ayaneo_remove_battery(struct power_supply *battery,
> > return 0;
> > }
> >
> > +static ssize_t controller_power_store(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf,
> > + size_t count)
> > +{
> > + bool value;
> > + int ret;
> > +
> > + ret = kstrtobool(buf, &value);
> > + if (ret)
> > + return ret;
> > +
> > + ret = ec_write(AYANEO_POWER_REG, value ? AYANEO_POWER_ON : AYANEO_POWER_OFF);
> > + if (ret)
> > + return ret;
> > +
> > + return count;
> > +}
> > +
> > +static ssize_t controller_power_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + int ret;
> > + u8 val;
> > +
> > + ret = ec_read(AYANEO_POWER_REG, &val);
> > + if (ret)
> > + return ret;
> > +
> > + return sysfs_emit(buf, "%d\n", val == AYANEO_POWER_ON);
> > +}
> > +
> > +static DEVICE_ATTR_RW(controller_power);
> > +
> > +static ssize_t controller_modules_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + char *out;
> > + int ret;
> > + u8 val;
> > +
> > + ret = ec_read(AYANEO_MODULE_REG, &val);
> > + if (ret)
> > + return ret;
> > +
> > + switch (~val & AYANEO_MODULE_MASK) {
>
> Thanks for adding the mask.
>
> Now when reading this again, I also suggest changing variable name from
> "val" to e.g. "unconnected_modules" as that would make the reason for
> inversion more obvious.
>
> > + case AYANEO_MODULE_LEFT | AYANEO_MODULE_RIGHT:
> > + out = "both";
> > + break;
> > + case AYANEO_MODULE_LEFT:
> > + out = "left";
> > + break;
> > + case AYANEO_MODULE_RIGHT:
> > + out = "right";
> > + break;
> > + default:
> > + out = "none";
> > + break;
> > + }
> > +
> > + return sysfs_emit(buf, "%s\n", out);
> > +}
> > +
> > +static DEVICE_ATTR_RO(controller_modules);
> > +
> > +static struct attribute *aya_mm_attrs[] = {
> > + &dev_attr_controller_power.attr,
> > + &dev_attr_controller_modules.attr,
> > + NULL
> > +};
> > +
> > +static umode_t aya_mm_is_visible(struct kobject *kobj,
> > + struct attribute *attr, int n)
> > +{
> > + struct device *dev = kobj_to_dev(kobj);
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct ayaneo_ec_platform_data *data = platform_get_drvdata(pdev);
> > +
> > + if (data->quirks->has_magic_modules)
> > + return attr->mode;
> > + return 0;
> > +}
> > +
> > +static const struct attribute_group aya_mm_attribute_group = {
> > + .is_visible = aya_mm_is_visible,
> > + .attrs = aya_mm_attrs,
> > +};
> > +
> > +static const struct attribute_group *ayaneo_ec_groups[] = {
> > + &aya_mm_attribute_group,
> > + NULL
> > +};
> > +
> > static int ayaneo_ec_probe(struct platform_device *pdev)
> > {
> > const struct dmi_system_id *dmi_entry;
> > @@ -307,6 +413,7 @@ static int ayaneo_ec_probe(struct platform_device *pdev)
> > static struct platform_driver ayaneo_platform_driver = {
> > .driver = {
> > .name = "ayaneo-ec",
> > + .dev_groups = ayaneo_ec_groups,
> > },
> > .probe = ayaneo_ec_probe,
> > };
> >
>
> --
> i.
>
>
Powered by blists - more mailing lists