[PATCH v4 2/2] ACPI: Export PLD (Physical Location of Device)

Samuel Ortiz
2014-08-13T17:18:59Z

From: Faouaz TENOUTIT <faouaz.tenoutit@intel.com>

This patch exports a sysfs directory with ACPI _PLD information:

$ ls -l /sys/bus/acpi/devices/ACPI-DEV/pld
-r--r--r-- root root 4096 2014-05-30 08:39 panel
-r--r--r-- root root 4096 2014-05-30 08:39 revision
-r--r--r-- root root 4096 2014-05-30 08:39 rotation
-r--r--r-- root root 4096 2014-05-30 08:39 shape

This information can be used by user applications to:
- Determine which specific connector or device input mechanism may be used
for a given task.
- Describes which panel surface of the system's housing the device
connection point resides on (Front, Back, ...)

More information about these _PLD fields can be found here:
Documentation/ABI/testing/sysfs-bus-acpi

Signed-off-by: Faouaz TENOUTIT <faouaz.tenoutit@intel.com>
Acked-by: Samuel Ortiz <samuel.ortiz@intel.com>
Acked-by: Andrew J Ross <andrew.j.ross@intel.com>
---
Documentation/ABI/testing/sysfs-bus-acpi | 60 ++++++++++++++++++++++++++++++++
drivers/acpi/scan.c | 53 ++++++++++++++++++++++++----
2 files changed, 107 insertions(+), 6 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-acpi b/Documentation/ABI/testing/sysfs-bus-acpi
index 7fa9cbc..be58159 100644
--- a/Documentation/ABI/testing/sysfs-bus-acpi
+++ b/Documentation/ABI/testing/sysfs-bus-acpi
@@ -56,3 +56,63 @@ Description:
Writing 1 to this attribute will trigger hot removal of
this device object. This file exists for every device
object that has _EJ0 method.
+
+What: /sys/bus/acpi/devices/.../pld
+Date: August 2014
+Contact: Faouaz Tenoutit <faouaz.tenoutit@intel.com>
+Description:
+ This optional directory provides description of the physical
+ location, orientation and position of external devices.
+ It is for example used to describe how camera sensors are
+ physically mounted and allows user space software to rotate
+ images accordingly.
+
+What: /sys/bus/acpi/devices/.../pld/revision
+Date: August 2014
+Contact: Faouaz Tenoutit <faouaz.tenoutit@intel.com>
+Description:
+ The current Revision is 0x2
+
+What: /sys/bus/acpi/devices/.../pld/panel
+Date: August 2014
+Contact: Faouaz Tenoutit <faouaz.tenoutit@intel.com>
+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
+
+What: /sys/bus/acpi/devices/.../pld/shape
+Date: August 2014
+Contact: Faouaz Tenoutit <faouaz.tenoutit@intel.com>
+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
+
+What: /sys/bus/acpi/devices/.../pld/rotation
+Date: August 2014
+Contact: Faouaz Tenoutit <faouaz.tenoutit@intel.com>
+Description:
+ Rotates the Shape clockwise in 45 degree steps around its
+ origin where:
+ 0 0°
+ 1 45°
+ 2 90°
+ 3 135°
+ 4 180°
+ 5 225°
+ 6 270°
+ 7 315°
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 2ca42d5..19889a3 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -686,6 +686,36 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(status);

+#define ACPI_SYSFS_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); \
+ return sprintf(buf, "%d\n", acpi_dev->pld->prop); \
+}; \
+static DEVICE_ATTR_RO(prop)
+
+/*
+ * sysfs PLD parameters
+ */
+ACPI_SYSFS_PLD_PROP(revision);
+ACPI_SYSFS_PLD_PROP(panel);
+ACPI_SYSFS_PLD_PROP(shape);
+ACPI_SYSFS_PLD_PROP(rotation);
+
+static struct attribute *acpi_pld_attrs[] = {
+ &dev_attr_revision.attr,
+ &dev_attr_panel.attr,
+ &dev_attr_shape.attr,
+ &dev_attr_rotation.attr,
+ NULL,
+};
+
+static const struct attribute_group acpi_pld_attr_group = {
+ .name = "pld",
+ .attrs = acpi_pld_attrs,
+};
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
@@ -768,11 +798,20 @@ static int acpi_device_setup_files(struct acpi_device *dev)
}

/*
- * If device has _PLD, initialize the 'pld' struct
+ * If device has _PLD, 'pld' directory is created
*/
- if (acpi_has_method(dev->handle, "_PLD"))
- acpi_get_physical_device_location(dev->handle,
- &dev->pld);
+ if (acpi_has_method(dev->handle, "_PLD")) {
+ status = acpi_get_physical_device_location(dev->handle,
+ &dev->pld);
+ if (ACPI_SUCCESS(status)) {
+ result = sysfs_create_group(&dev->dev.kobj,
+ &acpi_pld_attr_group);
+ if (result) {
+ ACPI_FREE(dev->pld);
+ dev->pld = NULL;
+ }
+ }
+ }

end:
return result;
@@ -815,10 +854,12 @@ static void acpi_device_remove_files(struct acpi_device *dev)
device_remove_file(&dev->dev, &dev_attr_path);

/*
- * If device has _PLD, free 'pld' struct
+ * If device has _PLD, remove 'pld' directory
*/
- if (dev->pld)
+ if (dev->pld) {
+ sysfs_remove_group(&dev->dev.kobj, &acpi_pld_attr_group);
ACPI_FREE(dev->pld);
+ }
}
/* --------------------------------------------------------------------------
ACPI Bus operations
--
2.0.0

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