[PATCH v6] ACPI: device_sysfs: Add sysfs support for _PLD
From: Won Chung
Date: Thu Feb 10 2022 - 21:30:16 EST
When ACPI table includes _PLD fields for a device, create a new
directory (pld) in sysfs to share _PLD fields.
Currently without PLD information, when there are multiple of same
devices, it is hard to distinguish which device corresponds to which
physical device in which location. For example, when there are two Type
C connectors, it is hard to find out which connector corresponds to the
Type C port on the left panel versus the Type C port on the right panel.
With PLD information provided, we can determine which specific device at
which location is doing what.
Since PLD information is to be used for finding where physical device is
located in user's perspective, pld sysfs directory will only be created
for ACPI_BUS_TYPE_DEVICE with user_visible field set as 1.
Signed-off-by: Won Chung <wonchung@xxxxxxxxxx>
---
Changes in v6:
- Add pld to acpi_device only if it is a user visible device.
Changes in v5:
- Store pld to acpi_device in acpi_store_pld_crc() and rename it as
acpi_store_pld().
Changes in v4:
- Create seperate files for each _PLD fields instead of having a single
file with all fields included.
- Create a new directory pld that contains _PLD fields
Documentation/ABI/testing/sysfs-bus-acpi | 107 +++++++++++++++++++++++
drivers/acpi/device_sysfs.c | 51 +++++++++++
drivers/acpi/scan.c | 12 ++-
include/acpi/acpi_bus.h | 1 +
4 files changed, 168 insertions(+), 3 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-acpi b/Documentation/ABI/testing/sysfs-bus-acpi
index 58abacf59b2a..b8b71c8f3cfd 100644
--- a/Documentation/ABI/testing/sysfs-bus-acpi
+++ b/Documentation/ABI/testing/sysfs-bus-acpi
@@ -96,3 +96,110 @@ Description:
hardware, if the _HRV control method is present. It is mostly
useful for non-PCI devices because lspci can list the hardware
version for PCI devices.
+
+What: /sys/bus/acpi/devices/.../pld/
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ This directory contains the output of the device object's _PLD
+ control method, if present. This information provides details
+ on physical location of a device.
+
+What: /sys/bus/acpi/devices/.../pld/revision
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ The current revision is 0x2.
+
+What: /sys/bus/acpi/devices/.../pld/group_token
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Unique numerical value identifying a group.
+
+What: /sys/bus/acpi/devices/.../pld/group_position
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Identifies this device connection point’s position in the group.
+
+What: /sys/bus/acpi/devices/.../pld/user_visible
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Set if the device connection point can be seen by the user
+ without disassembly.
+
+What: /sys/bus/acpi/devices/.../pld/dock
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Set if the device connection point resides in a docking station
+ or port replicator.
+
+What: /sys/bus/acpi/devices/.../pld/bay
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Set if describing a device in a bay or if device connection
+ point is a bay.
+
+What: /sys/bus/acpi/devices/.../pld/lid
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Set if this device connection point resides on the lid of
+ laptop system.
+
+What: /sys/bus/acpi/devices/.../pld/panel
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Describes which panel surface of the system’s housing the
+ device connection point resides on:
+ 0 - Top
+ 1 - Bottom
+ 2 - Left
+ 3 - Right
+ 4 - Front
+ 5 - Back
+ 6 - Unknown (Vertical Position and Horizontal Position will be
+ ignored)
+
+What: /sys/bus/acpi/devices/.../pld/vertical_position
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ 0 - Upper
+ 1 - Center
+ 2 - Lower
+
+What: /sys/bus/acpi/devices/.../pld/horizontal_position
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ ACPI specification does not define horizontal position field.
+ Can be used as either
+ 0 - Left
+ 1 - Center
+ 2 - Right
+ or
+ 0 - Leftmost
+ and higher numbers going toward the right.
+
+What: /sys/bus/acpi/devices/.../pld/shape
+Date: Feb, 2022
+Contact: Won Chung <wonchung@xxxxxxxxxx>
+Description:
+ Describes the shape of the device connection point.
+ 0 - Round
+ 1 - Oval
+ 2 - Square
+ 3 - Vertical Rectangle
+ 4 - Horizontal Rectangle
+ 5 - Vertical Trapezoid
+ 6 - Horizontal Trapezoid
+ 7 - Unknown - Shape rendered as a Rectangle with dotted lines
+ 8 - Chamfered
+ 15:9 - Reserved
+
diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index d5d6403ba07b..2702f78a2503 100644
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -509,6 +509,49 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(status);
+#define DEV_ATTR_PLD_PROP(prop) \
+ static ssize_t prop##_show(struct device *dev, struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct acpi_device *acpi_dev = to_acpi_device(dev); \
+ if (acpi_dev->pld == NULL) \
+ return -EIO; \
+ return sprintf(buf, "%u\n", acpi_dev->pld->prop); \
+}; \
+static DEVICE_ATTR_RO(prop)
+
+DEV_ATTR_PLD_PROP(revision);
+DEV_ATTR_PLD_PROP(group_token);
+DEV_ATTR_PLD_PROP(group_position);
+DEV_ATTR_PLD_PROP(user_visible);
+DEV_ATTR_PLD_PROP(dock);
+DEV_ATTR_PLD_PROP(bay);
+DEV_ATTR_PLD_PROP(lid);
+DEV_ATTR_PLD_PROP(panel);
+DEV_ATTR_PLD_PROP(vertical_position);
+DEV_ATTR_PLD_PROP(horizontal_position);
+DEV_ATTR_PLD_PROP(shape);
+
+static struct attribute *dev_attr_pld[] = {
+ &dev_attr_revision.attr,
+ &dev_attr_group_token.attr,
+ &dev_attr_group_position.attr,
+ &dev_attr_user_visible.attr,
+ &dev_attr_dock.attr,
+ &dev_attr_bay.attr,
+ &dev_attr_lid.attr,
+ &dev_attr_panel.attr,
+ &dev_attr_vertical_position.attr,
+ &dev_attr_horizontal_position.attr,
+ &dev_attr_shape.attr,
+ NULL,
+};
+
+static struct attribute_group dev_attr_pld_group = {
+ .name = "pld",
+ .attrs = dev_attr_pld,
+};
+
/**
* acpi_device_setup_files - Create sysfs attributes of an ACPI device.
* @dev: ACPI device object.
@@ -595,6 +638,12 @@ int acpi_device_setup_files(struct acpi_device *dev)
&dev_attr_real_power_state);
}
+ if (acpi_has_method(dev->handle, "_PLD") && dev->pld != NULL) {
+ result = device_add_group(&dev->dev, &dev_attr_pld_group);
+ if (result)
+ goto end;
+ }
+
acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
end:
@@ -645,4 +694,6 @@ void acpi_device_remove_files(struct acpi_device *dev)
device_remove_file(&dev->dev, &dev_attr_status);
if (dev->handle)
device_remove_file(&dev->dev, &dev_attr_path);
+ if (acpi_has_method(dev->handle, "_PLD") && dev->pld != NULL)
+ device_remove_group(&dev->dev, &dev_attr_pld_group);
}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 1331756d4cfc..35ac7bcc05ed 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -668,7 +668,7 @@ static int acpi_tie_acpi_dev(struct acpi_device *adev)
return 0;
}
-static void acpi_store_pld_crc(struct acpi_device *adev)
+static void acpi_store_pld(struct acpi_device *adev)
{
struct acpi_pld_info *pld;
acpi_status status;
@@ -678,7 +678,13 @@ static void acpi_store_pld_crc(struct acpi_device *adev)
return;
adev->pld_crc = crc32(~0, pld, sizeof(*pld));
- ACPI_FREE(pld);
+
+ if (adev->device_type == ACPI_BUS_TYPE_DEVICE && pld->user_visible) {
+ adev->pld = pld;
+ } else {
+ adev->pld = NULL;
+ ACPI_FREE(pld);
+ }
}
static int __acpi_device_add(struct acpi_device *device,
@@ -739,7 +745,7 @@ static int __acpi_device_add(struct acpi_device *device,
if (device->wakeup.flags.valid)
list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
- acpi_store_pld_crc(device);
+ acpi_store_pld(device);
mutex_unlock(&acpi_device_lock);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ca88c4706f2b..929e726a666b 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -381,6 +381,7 @@ struct acpi_device {
struct acpi_hotplug_context *hp;
struct acpi_driver *driver;
const struct acpi_gpio_mapping *driver_gpios;
+ struct acpi_pld_info *pld;
void *driver_data;
struct device dev;
unsigned int physical_node_count;
--
2.35.1.265.g69c8d7142f-goog