[PATCH v2 3/4] switchtec: Add sysfs attributes to the Switchtec driver
Bjorn Helgaas
helgaas at kernel.org
Thu Feb 23 14:43:17 PST 2017
On Thu, Feb 02, 2017 at 11:06:02AM -0700, Logan Gunthorpe wrote:
> This patch adds a few read-only sysfs attributes which provide
> some device information that is exposed from the devices. Primarily
> component and device names and versions. These are documented in
> Documentation/ABI/testing/sysfs-class-switchtec.
>
> Signed-off-by: Logan Gunthorpe <logang at deltatee.com>
> Signed-off-by: Stephen Bates <stephen.bates at microsemi.com>
> ---
> Documentation/ABI/testing/sysfs-class-switchtec | 96 ++++++++++++++++++++
> MAINTAINERS | 1 +
> drivers/pci/switch/switchtec.c | 113 ++++++++++++++++++++++++
> 3 files changed, 210 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-switchtec
>
> diff --git a/Documentation/ABI/testing/sysfs-class-switchtec b/Documentation/ABI/testing/sysfs-class-switchtec
> new file mode 100644
> index 0000000..48cb4c1
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-switchtec
> @@ -0,0 +1,96 @@
> +switchtec - Microsemi Switchtec PCI Switch Management Endpoint
> +
> +For details on this subsystem look at Documentation/switchtec.txt.
> +
> +What: /sys/class/switchtec
This path seems a little generic. I don't see other cases where a
product brand name ("Switchtec") appears at the top level of
/sys/class/...
My question is based on "ls Documentation/ABI/testing/sysfs-class*",
not on any great knowledge of sysfs, and I see Greg has already given
a Reviewed-by for this, so maybe this is the right approach.
It does seem like the path could include a clue that this is related
to PCI.
Is there a link to the switch PCI device itself, e.g., to
/sys/devices/pci*? Should these attributes simply be put in a
subdirectory there, e.g., in
/sys/devices/pci0000:00/0000:00:00.0/stats/...
instead of in /sys/class/? It seems like it'd be useful for userspace
to be able to connect this info with the switch somehow.
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: The switchtec class subsystem folder.
> + Each registered switchtec driver is represented by a switchtecX
> + subfolder (X being an integer >= 0).
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/component_id
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Component identifier as stored in the hardware (eg. PM8543)
> + (read only)
> +Values: arbitrary string.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/component_revision
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Component revision stored in the hardware (read only)
> +Values: integer.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/component_vendor
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Component vendor as stored in the hardware (eg. MICROSEM)
> + (read only)
> +Values: arbitrary string.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/device_version
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Device version as stored in the hardware (read only)
> +Values: integer.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/fw_version
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Currently running firmware version (read only)
> +Values: integer (in hexadecimal).
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/partition
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Partition number for this device in the switch (read only)
> +Values: integer.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/partition_count
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Total number of partitions in the switch (read only)
> +Values: integer.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/product_id
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Product identifier as stored in the hardware (eg. PSX 48XG3)
> + (read only)
> +Values: arbitrary string.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/product_revision
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Product revision stored in the hardware (eg. RevB)
> + (read only)
> +Values: arbitrary string.
> +
> +
> +What: /sys/class/switchtec/switchtec[0-9]+/product_vendor
> +Date: 05-Jan-2017
> +KernelVersion: v4.11
> +Contact: Logan Gunthorpe <logang at deltatee.com>
> +Description: Product vendor as stored in the hardware (eg. MICROSEM)
> + (read only)
> +Values: arbitrary string.
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0ab858d..d39b7fd 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9514,6 +9514,7 @@ M: Logan Gunthorpe <logang at deltatee.com>
> L: linux-pci at vger.kernel.org
> S: Maintained
> F: Documentation/switchtec.txt
> +F: Documentation/ABI/testing/sysfs-class-switchtec
> F: drivers/pci/switch/switchtec*
>
> PCI DRIVER FOR NVIDIA TEGRA
> diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
> index e4a4294..354ddfd 100644
> --- a/drivers/pci/switch/switchtec.c
> +++ b/drivers/pci/switch/switchtec.c
> @@ -485,6 +485,118 @@ static void mrpc_timeout_work(struct work_struct *work)
> mutex_unlock(&stdev->mrpc_mutex);
> }
>
> +static ssize_t device_version_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> + u32 ver;
> +
> + ver = ioread32(&stdev->mmio_sys_info->device_version);
> +
> + return sprintf(buf, "%x\n", ver);
> +}
> +static DEVICE_ATTR_RO(device_version);
> +
> +static ssize_t fw_version_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> + u32 ver;
> +
> + ver = ioread32(&stdev->mmio_sys_info->firmware_version);
> +
> + return sprintf(buf, "%08x\n", ver);
> +}
> +static DEVICE_ATTR_RO(fw_version);
> +
> +static ssize_t io_string_show(char *buf, void __iomem *attr, size_t len)
> +{
> + int i;
> +
> + memcpy_fromio(buf, attr, len);
> + buf[len] = '\n';
> + buf[len + 1] = 0;
> +
> + for (i = len - 1; i > 0; i--) {
> + if (buf[i] != ' ')
> + break;
> + buf[i] = '\n';
> + buf[i + 1] = 0;
> + }
> +
> + return strlen(buf);
> +}
> +
> +#define DEVICE_ATTR_SYS_INFO_STR(field) \
> +static ssize_t field ## _show(struct device *dev, \
> + struct device_attribute *attr, char *buf) \
> +{ \
> + struct switchtec_dev *stdev = to_stdev(dev); \
> + return io_string_show(buf, &stdev->mmio_sys_info->field, \
> + sizeof(stdev->mmio_sys_info->field)); \
> +} \
> +\
> +static DEVICE_ATTR_RO(field)
> +
> +DEVICE_ATTR_SYS_INFO_STR(vendor_id);
> +DEVICE_ATTR_SYS_INFO_STR(product_id);
> +DEVICE_ATTR_SYS_INFO_STR(product_revision);
> +DEVICE_ATTR_SYS_INFO_STR(component_vendor);
> +
> +static ssize_t component_id_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> + int id = ioread16(&stdev->mmio_sys_info->component_id);
> +
> + return sprintf(buf, "PM%04X\n", id);
> +}
> +static DEVICE_ATTR_RO(component_id);
> +
> +static ssize_t component_revision_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> + int rev = ioread8(&stdev->mmio_sys_info->component_revision);
> +
> + return sprintf(buf, "%d\n", rev);
> +}
> +static DEVICE_ATTR_RO(component_revision);
> +
> +static ssize_t partition_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> +
> + return sprintf(buf, "%d\n", stdev->partition);
> +}
> +static DEVICE_ATTR_RO(partition);
> +
> +static ssize_t partition_count_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct switchtec_dev *stdev = to_stdev(dev);
> +
> + return sprintf(buf, "%d\n", stdev->partition_count);
> +}
> +static DEVICE_ATTR_RO(partition_count);
> +
> +static struct attribute *switchtec_device_attrs[] = {
> + &dev_attr_device_version.attr,
> + &dev_attr_fw_version.attr,
> + &dev_attr_vendor_id.attr,
> + &dev_attr_product_id.attr,
> + &dev_attr_product_revision.attr,
> + &dev_attr_component_vendor.attr,
> + &dev_attr_component_id.attr,
> + &dev_attr_component_revision.attr,
> + &dev_attr_partition.attr,
> + &dev_attr_partition_count.attr,
> + NULL,
> +};
> +
> +ATTRIBUTE_GROUPS(switchtec_device);
> +
> static int switchtec_dev_open(struct inode *inode, struct file *filp)
> {
> struct switchtec_dev *stdev;
> @@ -699,6 +811,7 @@ static struct switchtec_dev *stdev_create(struct pci_dev *pdev)
> dev->devt = MKDEV(MAJOR(switchtec_devt), minor);
> dev->class = switchtec_class;
> dev->parent = &pdev->dev;
> + dev->groups = switchtec_device_groups;
> dev->release = stdev_release;
> dev_set_name(dev, "switchtec%d", minor);
>
> --
> 2.1.4
>
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