Re: [PATCH] ACPI: Add new sysfs interface to export device description
> > To address your comment, I was trying to differentiate between the existence > of the _STR method and the failure to evaluate it. > If an STR method exists, we create the sysfs file. If it fails to evaluate, we will see "No Description" when we read the file. > This would indicate that something is wrong as opposed to the system not > having an _STR. > If you feel that this is unnecessary, or should be done differently let me > know. This patch looks useful, and I this does seem like a logical place to export this information. however, I'd think that an empty attribute instead of "No description" is sufficient to cover the case of _STR existing, but for some reason failing to evaluate. thanks, Len Brown, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] ACPI: Add new sysfs interface to export device description
To address your comment, I was trying to differentiate between the existence of the _STR method and the failure to evaluate it. If an STR method exists, we create the sysfs file. If it fails to evaluate, we will see No Description when we read the file. This would indicate that something is wrong as opposed to the system not having an _STR. If you feel that this is unnecessary, or should be done differently let me know. This patch looks useful, and I this does seem like a logical place to export this information. however, I'd think that an empty attribute instead of No description is sufficient to cover the case of _STR existing, but for some reason failing to evaluate. thanks, Len Brown, Intel Open Source Technology Center -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH] ACPI: Add new sysfs interface to export device description
Comment Below...
> -Original Message-
> From: Yasuaki Ishimatsu [mailto:isimatu.yasu...@jp.fujitsu.com]
> Sent: Tuesday, September 18, 2012 11:45 PM
> To: Ortiz, Lance E
> Cc: r...@landley.net; l...@kernel.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org; linux-a...@vger.kernel.org
> Subject: Re: [PATCH] ACPI: Add new sysfs interface to export device
> description
>
> Hi Lance,
>
> 2012/09/08 1:28, Lance Ortiz wrote:
> > Add support to export the device description obtained from the ACPI
> _STR
> > method, if one exists for a device, to user-space via a sysfs
> interface.
> > This new interface provides a standard and platform neutral way for
> users
> > to obtain the description text stored in the ACPI _STR method. If no
> > _STR method exists for the device, no sysfs 'description' file will
> be
> > created. The 'description' file will be located in the /sys/devices/
> > directory using the device's path.
> >
> > /sys/device/// path>.../firmware_node/description
> >
> > Example:
> >
> >
> /sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/descrip
> tion
> >
> > It can also be located using the ACPI device path, for example:
> >
> >
> /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/dev
> ice:15/description
> >
> /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/
> description
> >
> > Execute the 'cat' command on the 'description' file to obtain the
> > description string for that device.
> >
> > This patch also includes documentation describing how the new sysfs
> > interface works
> >
> > Signed-off-by: Lance Ortiz
> > ---
>
> Tested-by: Yasuaki Ishimatsu
>
> There is a comment as follows.
>
> > .../ABI/testing/sysfs-devices-firmware_node| 17 ++
> > drivers/acpi/scan.c| 58
> +++-
> > include/acpi/acpi_bus.h|1 +
> > 3 files changed, 74 insertions(+), 2 deletions(-)
> > create mode 100644 Documentation/ABI/testing/sysfs-devices-
> firmware_node
> >
> > diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
> b/Documentation/ABI/testing/sysfs-devices-firmware_node
> > new file mode 100644
> > index 000..46badc9
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
> > @@ -0,0 +1,17 @@
> > +What: /sys/devices/.../firmware_node/
> > +Date: September 2012
> > +Contact: <>
> > +Description:
> > + The /sys/devices/.../firmware_node directory contains
> attributes
> > + allowing the user space to check and modify some firmware
> > + related properties of given device.
> > +
> > +What: /sys/devices/.../firmware_node/description
> > +Date: September 2012
> > +Contact: Lance Ortiz
> > +Description:
> > + The /sys/devices/.../firmware/description attribute
> contains a string
> > + that describes the device as provided by the _STR method in
> the ACPI
> > + namespace. This attribute is read-only. If the device
> does not have
> > + an _STR method associated with it in the ACPI namespace,
> this
> > + attribute is not present.
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index c8a1f3b..c9c91e1 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -10,6 +10,7 @@
> > #include
> > #include
> > #include
> > +#include
> >
> > #include
> >
> > @@ -192,8 +193,38 @@ end:
> > }
> > static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
> >
> > +/* sysfs file that shows description text from the ACPI _STR method
> */
> > +static ssize_t description_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf) {
> > + struct acpi_device *acpi_dev = to_acpi_device(dev);
> > + int result;
> > +
> > + if (acpi_dev->pnp.str_obj == NULL) {
> > + result = sprintf(buf, "No Description\n");
> > + goto end;
> > + }
> > +
> > + /*
> > +* The _STR object contains a Unicode identifier for a device.
> > +* We need to convert to utf-8 so it can be displayed.
> > +*/
> > + result = utf16s_to_utf8s(
> > +
RE: [PATCH] ACPI: Add new sysfs interface to export device description
Comment Below...
-Original Message-
From: Yasuaki Ishimatsu [mailto:isimatu.yasu...@jp.fujitsu.com]
Sent: Tuesday, September 18, 2012 11:45 PM
To: Ortiz, Lance E
Cc: r...@landley.net; l...@kernel.org; linux-...@vger.kernel.org; linux-
ker...@vger.kernel.org; linux-a...@vger.kernel.org
Subject: Re: [PATCH] ACPI: Add new sysfs interface to export device
description
Hi Lance,
2012/09/08 1:28, Lance Ortiz wrote:
Add support to export the device description obtained from the ACPI
_STR
method, if one exists for a device, to user-space via a sysfs
interface.
This new interface provides a standard and platform neutral way for
users
to obtain the description text stored in the ACPI _STR method. If no
_STR method exists for the device, no sysfs 'description' file will
be
created. The 'description' file will be located in the /sys/devices/
directory using the device's path.
/sys/device/bus/bridge path/device
path.../firmware_node/description
Example:
/sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/descrip
tion
It can also be located using the ACPI device path, for example:
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/dev
ice:15/description
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/
description
Execute the 'cat' command on the 'description' file to obtain the
description string for that device.
This patch also includes documentation describing how the new sysfs
interface works
Signed-off-by: Lance Ortiz lance.or...@hp.com
---
Tested-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
There is a comment as follows.
.../ABI/testing/sysfs-devices-firmware_node| 17 ++
drivers/acpi/scan.c| 58
+++-
include/acpi/acpi_bus.h|1 +
3 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-
firmware_node
diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
b/Documentation/ABI/testing/sysfs-devices-firmware_node
new file mode 100644
index 000..46badc9
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
@@ -0,0 +1,17 @@
+What: /sys/devices/.../firmware_node/
+Date: September 2012
+Contact:
+Description:
+ The /sys/devices/.../firmware_node directory contains
attributes
+ allowing the user space to check and modify some firmware
+ related properties of given device.
+
+What: /sys/devices/.../firmware_node/description
+Date: September 2012
+Contact: Lance Ortiz lance.or...@hp.com
+Description:
+ The /sys/devices/.../firmware/description attribute
contains a string
+ that describes the device as provided by the _STR method in
the ACPI
+ namespace. This attribute is read-only. If the device
does not have
+ an _STR method associated with it in the ACPI namespace,
this
+ attribute is not present.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c8a1f3b..c9c91e1 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -10,6 +10,7 @@
#include linux/signal.h
#include linux/kthread.h
#include linux/dmi.h
+#include linux/nls.h
#include acpi/acpi_drivers.h
@@ -192,8 +193,38 @@ end:
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+/* sysfs file that shows description text from the ACPI _STR method
*/
+static ssize_t description_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf) {
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ int result;
+
+ if (acpi_dev-pnp.str_obj == NULL) {
+ result = sprintf(buf, No Description\n);
+ goto end;
+ }
+
+ /*
+* The _STR object contains a Unicode identifier for a device.
+* We need to convert to utf-8 so it can be displayed.
+*/
+ result = utf16s_to_utf8s(
+ (wchar_t *)acpi_dev-pnp.str_obj-buffer.pointer,
+ acpi_dev-pnp.str_obj-buffer.length,
+ UTF16_LITTLE_ENDIAN, buf,
+ PAGE_SIZE);
+
+ buf[result++] = '\n';
+
+end:
+ return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
acpi_handle temp;
int result = 0;
@@ -217,6 +248,21 @@ static int acpi_device_setup_files(struct
acpi_device *dev)
goto end;
}
+ /*
+* If device has _STR, 'description' file is created
+*/
+ status = acpi_get_handle(dev-handle, _STR, temp
Re: [PATCH] ACPI: Add new sysfs interface to export device description
Hi Lance,
2012/09/08 1:28, Lance Ortiz wrote:
> Add support to export the device description obtained from the ACPI _STR
> method, if one exists for a device, to user-space via a sysfs interface.
> This new interface provides a standard and platform neutral way for users
> to obtain the description text stored in the ACPI _STR method. If no
> _STR method exists for the device, no sysfs 'description' file will be
> created. The 'description' file will be located in the /sys/devices/
> directory using the device's path.
>
> /sys/device///.../firmware_node/description
>
> Example:
>
> /sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/description
>
> It can also be located using the ACPI device path, for example:
>
> /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
> /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
>
> Execute the 'cat' command on the 'description' file to obtain the
> description string for that device.
>
> This patch also includes documentation describing how the new sysfs
> interface works
>
> Signed-off-by: Lance Ortiz
> ---
Tested-by: Yasuaki Ishimatsu
There is a comment as follows.
> .../ABI/testing/sysfs-devices-firmware_node| 17 ++
> drivers/acpi/scan.c| 58
> +++-
> include/acpi/acpi_bus.h|1 +
> 3 files changed, 74 insertions(+), 2 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-devices-firmware_node
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
> b/Documentation/ABI/testing/sysfs-devices-firmware_node
> new file mode 100644
> index 000..46badc9
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
> @@ -0,0 +1,17 @@
> +What:/sys/devices/.../firmware_node/
> +Date:September 2012
> +Contact: <>
> +Description:
> + The /sys/devices/.../firmware_node directory contains attributes
> + allowing the user space to check and modify some firmware
> + related properties of given device.
> +
> +What:/sys/devices/.../firmware_node/description
> +Date:September 2012
> +Contact: Lance Ortiz
> +Description:
> + The /sys/devices/.../firmware/description attribute contains a
> string
> + that describes the device as provided by the _STR method in the
> ACPI
> + namespace. This attribute is read-only. If the device does
> not have
> + an _STR method associated with it in the ACPI namespace, this
> + attribute is not present.
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index c8a1f3b..c9c91e1 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -10,6 +10,7 @@
> #include
> #include
> #include
> +#include
>
> #include
>
> @@ -192,8 +193,38 @@ end:
> }
> static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
>
> +/* sysfs file that shows description text from the ACPI _STR method */
> +static ssize_t description_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf) {
> + struct acpi_device *acpi_dev = to_acpi_device(dev);
> + int result;
> +
> + if (acpi_dev->pnp.str_obj == NULL) {
> + result = sprintf(buf, "No Description\n");
> + goto end;
> + }
> +
> + /*
> + * The _STR object contains a Unicode identifier for a device.
> + * We need to convert to utf-8 so it can be displayed.
> + */
> + result = utf16s_to_utf8s(
> + (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
> + acpi_dev->pnp.str_obj->buffer.length,
> + UTF16_LITTLE_ENDIAN, buf,
> + PAGE_SIZE);
> +
> + buf[result++] = '\n';
> +
> +end:
> + return result;
> +}
> +static DEVICE_ATTR(description, 0444, description_show, NULL);
> +
> static int acpi_device_setup_files(struct acpi_device *dev)
> {
> + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
> acpi_status status;
> acpi_handle temp;
> int result = 0;
> @@ -217,6 +248,21 @@ static int acpi_device_setup_files(struct acpi_device
> *dev)
> goto end;
> }
>
> + /*
> + * If device has _STR, 'description' file is created
> + */
> + status = acpi_get_handle(dev->handle, "_STR", );
> + if (ACPI_SUCCESS(status)) {
> + status = acpi_evaluate_object(dev->handle, "_STR",
> + NULL, );
> + if (ACPI_FAILURE(status))
> + buffer.pointer = NULL;
> + dev->pnp.str_obj = buffer.pointer;
> + result = device_create_file(>dev, _attr_description);
A description sysfs is created even if "acpi_evaluate_object()" fails.
Why do
Re: [PATCH] ACPI: Add new sysfs interface to export device description
Hi Lance,
2012/09/08 1:28, Lance Ortiz wrote:
Add support to export the device description obtained from the ACPI _STR
method, if one exists for a device, to user-space via a sysfs interface.
This new interface provides a standard and platform neutral way for users
to obtain the description text stored in the ACPI _STR method. If no
_STR method exists for the device, no sysfs 'description' file will be
created. The 'description' file will be located in the /sys/devices/
directory using the device's path.
/sys/device/bus/bridge path/device path.../firmware_node/description
Example:
/sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/description
It can also be located using the ACPI device path, for example:
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
Execute the 'cat' command on the 'description' file to obtain the
description string for that device.
This patch also includes documentation describing how the new sysfs
interface works
Signed-off-by: Lance Ortiz lance.or...@hp.com
---
Tested-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
There is a comment as follows.
.../ABI/testing/sysfs-devices-firmware_node| 17 ++
drivers/acpi/scan.c| 58
+++-
include/acpi/acpi_bus.h|1 +
3 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-firmware_node
diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
b/Documentation/ABI/testing/sysfs-devices-firmware_node
new file mode 100644
index 000..46badc9
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
@@ -0,0 +1,17 @@
+What:/sys/devices/.../firmware_node/
+Date:September 2012
+Contact:
+Description:
+ The /sys/devices/.../firmware_node directory contains attributes
+ allowing the user space to check and modify some firmware
+ related properties of given device.
+
+What:/sys/devices/.../firmware_node/description
+Date:September 2012
+Contact: Lance Ortiz lance.or...@hp.com
+Description:
+ The /sys/devices/.../firmware/description attribute contains a
string
+ that describes the device as provided by the _STR method in the
ACPI
+ namespace. This attribute is read-only. If the device does
not have
+ an _STR method associated with it in the ACPI namespace, this
+ attribute is not present.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c8a1f3b..c9c91e1 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -10,6 +10,7 @@
#include linux/signal.h
#include linux/kthread.h
#include linux/dmi.h
+#include linux/nls.h
#include acpi/acpi_drivers.h
@@ -192,8 +193,38 @@ end:
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+/* sysfs file that shows description text from the ACPI _STR method */
+static ssize_t description_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf) {
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ int result;
+
+ if (acpi_dev-pnp.str_obj == NULL) {
+ result = sprintf(buf, No Description\n);
+ goto end;
+ }
+
+ /*
+ * The _STR object contains a Unicode identifier for a device.
+ * We need to convert to utf-8 so it can be displayed.
+ */
+ result = utf16s_to_utf8s(
+ (wchar_t *)acpi_dev-pnp.str_obj-buffer.pointer,
+ acpi_dev-pnp.str_obj-buffer.length,
+ UTF16_LITTLE_ENDIAN, buf,
+ PAGE_SIZE);
+
+ buf[result++] = '\n';
+
+end:
+ return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
acpi_handle temp;
int result = 0;
@@ -217,6 +248,21 @@ static int acpi_device_setup_files(struct acpi_device
*dev)
goto end;
}
+ /*
+ * If device has _STR, 'description' file is created
+ */
+ status = acpi_get_handle(dev-handle, _STR, temp);
+ if (ACPI_SUCCESS(status)) {
+ status = acpi_evaluate_object(dev-handle, _STR,
+ NULL, buffer);
+ if (ACPI_FAILURE(status))
+ buffer.pointer = NULL;
+ dev-pnp.str_obj = buffer.pointer;
+ result = device_create_file(dev-dev, dev_attr_description);
A description sysfs is created even if
[PATCH] ACPI: Add new sysfs interface to export device description
Add support to export the device description obtained from the ACPI _STR
method, if one exists for a device, to user-space via a sysfs interface.
This new interface provides a standard and platform neutral way for users
to obtain the description text stored in the ACPI _STR method. If no
_STR method exists for the device, no sysfs 'description' file will be
created. The 'description' file will be located in the /sys/devices/
directory using the device's path.
/sys/device///.../firmware_node/description
Example:
/sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/description
It can also be located using the ACPI device path, for example:
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
Execute the 'cat' command on the 'description' file to obtain the
description string for that device.
This patch also includes documentation describing how the new sysfs
interface works
Signed-off-by: Lance Ortiz
---
.../ABI/testing/sysfs-devices-firmware_node| 17 ++
drivers/acpi/scan.c| 58 +++-
include/acpi/acpi_bus.h|1 +
3 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-firmware_node
diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
b/Documentation/ABI/testing/sysfs-devices-firmware_node
new file mode 100644
index 000..46badc9
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
@@ -0,0 +1,17 @@
+What: /sys/devices/.../firmware_node/
+Date: September 2012
+Contact: <>
+Description:
+ The /sys/devices/.../firmware_node directory contains attributes
+ allowing the user space to check and modify some firmware
+ related properties of given device.
+
+What: /sys/devices/.../firmware_node/description
+Date: September 2012
+Contact: Lance Ortiz
+Description:
+ The /sys/devices/.../firmware/description attribute contains a
string
+ that describes the device as provided by the _STR method in the
ACPI
+ namespace. This attribute is read-only. If the device does
not have
+ an _STR method associated with it in the ACPI namespace, this
+ attribute is not present.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c8a1f3b..c9c91e1 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -10,6 +10,7 @@
#include
#include
#include
+#include
#include
@@ -192,8 +193,38 @@ end:
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+/* sysfs file that shows description text from the ACPI _STR method */
+static ssize_t description_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf) {
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ int result;
+
+ if (acpi_dev->pnp.str_obj == NULL) {
+ result = sprintf(buf, "No Description\n");
+ goto end;
+ }
+
+ /*
+* The _STR object contains a Unicode identifier for a device.
+* We need to convert to utf-8 so it can be displayed.
+*/
+ result = utf16s_to_utf8s(
+ (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
+ acpi_dev->pnp.str_obj->buffer.length,
+ UTF16_LITTLE_ENDIAN, buf,
+ PAGE_SIZE);
+
+ buf[result++] = '\n';
+
+end:
+ return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
acpi_handle temp;
int result = 0;
@@ -217,6 +248,21 @@ static int acpi_device_setup_files(struct acpi_device *dev)
goto end;
}
+ /*
+* If device has _STR, 'description' file is created
+*/
+ status = acpi_get_handle(dev->handle, "_STR", );
+ if (ACPI_SUCCESS(status)) {
+ status = acpi_evaluate_object(dev->handle, "_STR",
+ NULL, );
+ if (ACPI_FAILURE(status))
+ buffer.pointer = NULL;
+ dev->pnp.str_obj = buffer.pointer;
+ result = device_create_file(>dev, _attr_description);
+ if (result)
+ goto end;
+ }
+
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
@@ -234,8 +280,16 @@ static void acpi_device_remove_files(struct acpi_device
*dev)
acpi_handle temp;
/*
-* If device has _EJ0, 'eject' file is created that is
[PATCH] ACPI: Add new sysfs interface to export device description
Add support to export the device description obtained from the ACPI _STR
method, if one exists for a device, to user-space via a sysfs interface.
This new interface provides a standard and platform neutral way for users
to obtain the description text stored in the ACPI _STR method. If no
_STR method exists for the device, no sysfs 'description' file will be
created. The 'description' file will be located in the /sys/devices/
directory using the device's path.
/sys/device/bus/bridge path/device path.../firmware_node/description
Example:
/sys/devices/pci:00/:00.07.0/:0e:00.0/firmware_node/description
It can also be located using the ACPI device path, for example:
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
/sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
Execute the 'cat' command on the 'description' file to obtain the
description string for that device.
This patch also includes documentation describing how the new sysfs
interface works
Signed-off-by: Lance Ortiz lance.or...@hp.com
---
.../ABI/testing/sysfs-devices-firmware_node| 17 ++
drivers/acpi/scan.c| 58 +++-
include/acpi/acpi_bus.h|1 +
3 files changed, 74 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-devices-firmware_node
diff --git a/Documentation/ABI/testing/sysfs-devices-firmware_node
b/Documentation/ABI/testing/sysfs-devices-firmware_node
new file mode 100644
index 000..46badc9
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-firmware_node
@@ -0,0 +1,17 @@
+What: /sys/devices/.../firmware_node/
+Date: September 2012
+Contact:
+Description:
+ The /sys/devices/.../firmware_node directory contains attributes
+ allowing the user space to check and modify some firmware
+ related properties of given device.
+
+What: /sys/devices/.../firmware_node/description
+Date: September 2012
+Contact: Lance Ortiz lance.or...@hp.com
+Description:
+ The /sys/devices/.../firmware/description attribute contains a
string
+ that describes the device as provided by the _STR method in the
ACPI
+ namespace. This attribute is read-only. If the device does
not have
+ an _STR method associated with it in the ACPI namespace, this
+ attribute is not present.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c8a1f3b..c9c91e1 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -10,6 +10,7 @@
#include linux/signal.h
#include linux/kthread.h
#include linux/dmi.h
+#include linux/nls.h
#include acpi/acpi_drivers.h
@@ -192,8 +193,38 @@ end:
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+/* sysfs file that shows description text from the ACPI _STR method */
+static ssize_t description_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf) {
+ struct acpi_device *acpi_dev = to_acpi_device(dev);
+ int result;
+
+ if (acpi_dev-pnp.str_obj == NULL) {
+ result = sprintf(buf, No Description\n);
+ goto end;
+ }
+
+ /*
+* The _STR object contains a Unicode identifier for a device.
+* We need to convert to utf-8 so it can be displayed.
+*/
+ result = utf16s_to_utf8s(
+ (wchar_t *)acpi_dev-pnp.str_obj-buffer.pointer,
+ acpi_dev-pnp.str_obj-buffer.length,
+ UTF16_LITTLE_ENDIAN, buf,
+ PAGE_SIZE);
+
+ buf[result++] = '\n';
+
+end:
+ return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
static int acpi_device_setup_files(struct acpi_device *dev)
{
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
acpi_handle temp;
int result = 0;
@@ -217,6 +248,21 @@ static int acpi_device_setup_files(struct acpi_device *dev)
goto end;
}
+ /*
+* If device has _STR, 'description' file is created
+*/
+ status = acpi_get_handle(dev-handle, _STR, temp);
+ if (ACPI_SUCCESS(status)) {
+ status = acpi_evaluate_object(dev-handle, _STR,
+ NULL, buffer);
+ if (ACPI_FAILURE(status))
+ buffer.pointer = NULL;
+ dev-pnp.str_obj = buffer.pointer;
+ result = device_create_file(dev-dev, dev_attr_description);
+ if (result)
+ goto end;
+ }
+
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
@@ -234,8 +280,16 @@ static void
