Re: [PATCH] platform/x86: thinkpad_acpi: Add support to detect hardware damage detection capability.

[Nitin]

Hi Ilpo,

Thank you for reviewing the patch.

On 12/3/25 18:44, Ilpo Järvinen wrote:
> On Wed, 3 Dec 2025, Nitin Joshi wrote:
>
> > Thinkpads are adding the ability to detect and report hardware damage
> > status. Add new sysfs interface to identify the impacted component
> > with status.
> > Initial support is available for the USB-C replaceable connector.
> >
> > Reviewed-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> > Signed-off-by: Nitin Joshi<nitjoshi@xxxxxxxxx>
> > ---
> >   .../admin-guide/laptops/thinkpad-acpi.rst     |  26 +++
> >   drivers/platform/x86/lenovo/thinkpad_acpi.c   | 179 ++++++++++++++++++
> >   2 files changed, 205 insertions(+)
> >
> > diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> > index 4ab0fef7d440..4a3220529489 100644
> > --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> > +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst
> > @@ -54,6 +54,7 @@ detailed description):
> >   	- Setting keyboard language
> >   	- WWAN Antenna type
> >   	- Auxmac
> > +	- Hardware damage detection capability
> >   
> >   A compatibility table by model and feature is maintained on the web
> >   site, http://ibm-acpi.sf.net/. I appreciate any success or failure
> > @@ -1576,6 +1577,31 @@ percentage level, above which charging will stop.
> >   The exact semantics of the attributes may be found in
> >   Documentation/ABI/testing/sysfs-class-power.
> >   
> > +Hardware damage detection capability
> > +-----------------
> > +
> > +sysfs attributes: hwdd_status
> > +
> > +Thinkpads are adding the ability to detect and report hardware damage.
> > +Add new sysfs interface to identify the impacted component.
> > +Initial support is available for the USB-C replaceable connector.
> > +
> > +The available commands are::
> > +
> > +        cat /sys/devices/platform/thinkpad_acpi/hwdd_status
> > +
> > +This value displays device type and location of device with damage status.
> > +For example:
> > +if no damage is detected:
> > +  No damage detected
> > +if damage detected:
> > +  Damage detected:
> > +  Device: TYPE-C
> > +  Location: Base, Right side, Center port
> > +
> > +The property is read-only. If feature is not supported then sysfs
> > +class is not created.
> > +
> >   Multiple Commands, Module Parameters
> >   ------------------------------------
> >   
> > diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> > index cc19fe520ea9..c3629bed9a8e 100644
> > --- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
> > +++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
> > @@ -11080,6 +11080,180 @@ static const struct attribute_group auxmac_attr_group = {
> >   	.attrs = auxmac_attributes,
> >   };
> >   
> > +/*************************************************************************
> > + * HWDD subdriver, for the Lenovo Hardware Damage Detection feature.
> > + */
> > +
> > +#define HWDD_GET_DMG_USBC 0x80000001
> > +#define HWDD_GET_CAP 0
> > +#define HWDD_NOT_SUPPORTED BIT(31)
> > +#define HWDD_SUPPORT_USBC BIT(0)
> Align values.

Ack, i will align values like below:

#define HWDD_GET_CAP 0
#define HWDD_GET_DMG_USBC 0x80000001
#define HWDD_SUPPORT_USBC BIT(0)
#define HWDD_NOT_SUPPORTED BIT(31)

> > +#define HWDD_GET_CAP       0
> > +
> > +#define DAMAGE_STATUS_BIT  BIT(0)
> > +#define PORT_STATUS_OFFSET  4
> > +#define LID_STATUS_OFFSET  8
> > +#define BASE_STATUS_OFFSET 12
> > +#define PORT_DETAIL_OFFSET 16
> > +
> > +#define PORT_POS_OFFSET    2
> > +#define PORT_LOC_MASK      0x3
> > +
> > +#define PANEL_TOP   0
> > +#define PANEL_BASE  1
> > +#define PANEL_LEFT  2
> > +#define PANEL_RIGHT 3
> > +
> > +#define POS_LEFT    0
> > +#define POS_CENTER  1
> > +#define POS_RIGHT   2
> > +
> > +#define NUM_PORTS 4
> Add an empty line
Ack.
> > +static bool hwdd_support_available;
> > +static bool ucdd_supported;
> Add an empty line
Ack.
> > +static int hwdd_command(int command, int *output)
> > +{
> > +	acpi_handle hwdd_handle;
> > +
> > +	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "HWDD", &hwdd_handle)))
> > +		return -ENODEV;
> > +
> > +	if (!acpi_evalf(hwdd_handle, output, NULL, "dd", command))
> > +		return -EIO;
> > +
> > +	return 0;
> > +}
> > +
> > +static bool display_damage(char *buf, int *count, char *type, unsigned int dmg_status)
> > +{
> > +	unsigned char lid_status, base_status, port_status;
> > +	unsigned char loc_status, pos_status, panel_status;
> > +	bool damage_detected = false;
> > +	unsigned int i;
> > +
> > +	port_status = (dmg_status >> PORT_STATUS_OFFSET) & 0xF;
> > +	lid_status = (dmg_status >> LID_STATUS_OFFSET) & 0xF;
> > +	base_status = (dmg_status >> BASE_STATUS_OFFSET) & 0xF;
> Define these as fields using GENMASK() and use FIELD_GET() here. Don't
> forget to check you also have the includes for those.
Ack. I will recheck and modify it.
> > +	for (i = 0; i < NUM_PORTS; i++) {
> > +		if (dmg_status & BIT(i)) {
> > +			if (port_status & BIT(i)) {
> Reverse the logic in these and use continue to bring down indentation
> level.
Ack. I will recheck and modify it.
> > +				*count += sysfs_emit_at(buf, *count, "%s damage detected:\n", type);
> > +				loc_status = (dmg_status >> (PORT_DETAIL_OFFSET + (4 * i))) & 0xF;
> > +				pos_status = (loc_status  >> PORT_POS_OFFSET) & PORT_LOC_MASK;
> Extra space & use FIELD_GET().
Ack.
> > +				panel_status = loc_status & PORT_LOC_MASK;
> > +
> > +				*count += sysfs_emit_at(buf, *count, "Location: ");
> > +				if (lid_status & BIT(i))
> > +					*count += sysfs_emit_at(buf, *count, "Lid, ");
> > +				if (base_status & BIT(i))
> > +					*count += sysfs_emit_at(buf, *count, "Base, ");
> > +
> > +				switch (pos_status) {
> > +				case PANEL_TOP:
> > +					*count += sysfs_emit_at(buf, *count, "Top, ");
> > +					break;
> > +				case PANEL_BASE:
> > +					*count += sysfs_emit_at(buf, *count, "Bottom, ");
> > +					break;
> > +				case PANEL_LEFT:
> > +					*count += sysfs_emit_at(buf, *count, "Left, ");
> > +					break;
> > +				case PANEL_RIGHT:
> > +					*count += sysfs_emit_at(buf, *count, "Right, ");
> > +					break;
> Some checkers likely won't be happy if you're not having default: at all,
> even if it is unnecessary here. So add something like this:
>
> 				default:
> 					WARN_ON(1);
> 					return ...;
Ack, I will recheck and modify it.
> > +				};
> > +
> > +				switch (panel_status) {
> > +				case POS_LEFT:
> > +					*count += sysfs_emit_at(buf, *count, "Left port\n");
> > +					break;
> > +				case POS_CENTER:
> > +					*count += sysfs_emit_at(buf, *count, "Center port\n");
> > +					break;
> > +				case POS_RIGHT:
> > +					*count += sysfs_emit_at(buf, *count, "Right port\n");
> > +					break;
> > +				default:
> > +					*count += sysfs_emit_at(buf, *count, "Undefined\n");
> > +					break;
> > +				};
> > +				damage_detected = true;
> > +			}
> > +		}
> > +	}
> > +	return damage_detected;
> > +}
> > +
> > +/* sysfs typc damage detection capability */
> > +static ssize_t hwdd_status_show(struct device *dev,
> > +				struct device_attribute *attr,
> > +				char *buf)
> > +{
> > +	bool damage_detected = false;
> > +	unsigned int damage_status;
> > +	int err, count = 0;
> > +
> > +	if (ucdd_supported) {
> > +		/* Get USB TYPE-C damage status */
> > +		err = hwdd_command(HWDD_GET_DMG_USBC, &damage_status);
> > +		if (err)
> > +			return err;
> > +
> > +		if (display_damage(buf, &count, "Type-C", damage_status))
> > +			damage_detected = true;
> > +	}
> > +
> > +	if (!damage_detected)
> > +		count  = count + sysfs_emit_at(buf, count, "No damage detected\n");
> Extra space, please also use += instead.
Ack.
> > +
> > +	return count;
> > +}
> > +static DEVICE_ATTR_RO(hwdd_status);
> > +
> > +static struct attribute *hwdd_attributes[] = {
> > +	&dev_attr_hwdd_status.attr,
> > +	NULL
> > +};
> > +
> > +static umode_t hwdd_attr_is_visible(struct kobject *kobj,
> > +				struct attribute *attr, int n)
> > +{
> > +	return hwdd_support_available ? attr->mode : 0;
> > +}
> > +
> > +static const struct attribute_group hwdd_attr_group = {
> > +	.is_visible = hwdd_attr_is_visible,
> > +	.attrs = hwdd_attributes,
> > +};
> > +
> > +static int tpacpi_hwdd_init(struct ibm_init_struct *iibm)
> > +{
> > +	int err, output;
> > +
> > +	/* Below command checks the HWDD damage capability */
> > +	err = hwdd_command(HWDD_GET_CAP, &output);
> > +	if (err)
> > +		return err;
> > +
> > +	if (!(output & HWDD_NOT_SUPPORTED))
> > +		return -ENODEV;
> > +
> > +	hwdd_support_available = true;
> > +
> > +	/*
> > +	 * BIT(0) is assigned to check capability of damage detection is
> > +	 * supported for USB Type-C port or not.
> > +	 */
> > +	if (output & HWDD_SUPPORT_USBC)
> > +		ucdd_supported = true;
> > +
> > +	return err;
> > +}
> > +
> > +static struct ibm_struct hwdd_driver_data = {
> > +	.name = "hwdd",
> > +};
> > +
> >   /* --------------------------------------------------------------------- */
> >   
> >   static struct attribute *tpacpi_driver_attributes[] = {
> > @@ -11139,6 +11313,7 @@ static const struct attribute_group *tpacpi_groups[] = {
> >   	&kbdlang_attr_group,
> >   	&dprc_attr_group,
> >   	&auxmac_attr_group,
> > +	&hwdd_attr_group,
> >   	NULL,
> >   };
> >   
> > @@ -11752,6 +11927,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
> >   		.init = auxmac_init,
> >   		.data = &auxmac_data,
> >   	},
> > +	{
> > +		.init = tpacpi_hwdd_init,
> > +		.data = &hwdd_driver_data,
> > +	},
> >   };
> >   
> >   static int __init set_ibm_param(const char *val, const struct kernel_param *kp)