switchtec: Add sysfs attributes to the Switchtec driver

Add 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.

Tested-by: Krishna Dhulipala <[e-mail]>
Signed-off-by: Logan Gunthorpe <[e-mail]>
Signed-off-by: Stephen Bates <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Reviewed-by: Wei Zhang <[e-mail]>
Reviewed-by: Jens Axboe <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ABI/testing/sysfs-class-switchtec

···
+switchtec - Microsemi Switchtec PCI Switch Management Endpoint
+
+For details on this subsystem look at Documentation/switchtec.txt.
+
+What: 		/sys/class/switchtec
+Date:		05-Jan-2017
+KernelVersion:	v4.11
+Contact:	Logan Gunthorpe <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+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 <[e-mail]>
+Description:	Product vendor as stored in the hardware (eg. MICROSEM)
+		(read only)
+Values: 	arbitrary string.

MAINTAINERS

···
 L:	[e-mail]
 S:	Maintained
 F:	Documentation/switchtec.txt
+F:	Documentation/ABI/testing/sysfs-class-switchtec
 F:	drivers/pci/switch/switchtec*
 
 PCI DRIVER FOR NVIDIA TEGRA

drivers/pci/switch/switchtec.c

···
 	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;
···
 	device_initialize(dev);
 	dev->class = switchtec_class;
 	dev->parent = &pdev->dev;
+	dev->groups = switchtec_device_groups;
 	dev->release = stdev_release;
 
 	minor = ida_simple_get(&switchtec_minor_ida, 0, 0,