[PATCH v3 13/27] thunderbolt: Read vendor and device name from DROM

[Mika Westerberg]

The device DROM contains name of the vendor and device among other
things. Extract this information and expose it to the userspace via two
new attributes.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@xxxxxxxxx>
Reviewed-by: Michael Jamet <michael.jamet@xxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-bus-thunderbolt | 14 +++++++++++
 drivers/thunderbolt/eeprom.c                    | 32 +++++++++++++++++++++++++
 drivers/thunderbolt/switch.c                    | 22 +++++++++++++++++
 drivers/thunderbolt/tb.h                        |  4 ++++
 4 files changed, 72 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
index 9f1bd0086938..29a516f53d2c 100644
--- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
+++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
@@ -5,6 +5,13 @@ Contact:	thunderbolt-software@xxxxxxxxxxxx
 Description:	This attribute contains id of this device extracted from
 		the device DROM.
 
+What:		/sys/bus/thunderbolt/devices/.../device_name
+Date:		Sep 2017
+KernelVersion:	4.13
+Contact:	thunderbolt-software@xxxxxxxxxxxx
+Description:	This attribute contains name of this device extracted from
+		the device DROM.
+
 What:		/sys/bus/thunderbolt/devices/.../vendor
 Date:		Sep 2017
 KernelVersion:	4.13
@@ -12,6 +19,13 @@ Contact:	thunderbolt-software@xxxxxxxxxxxx
 Description:	This attribute contains vendor id of this device extracted
 		from the device DROM.
 
+What:		/sys/bus/thunderbolt/devices/.../vendor_name
+Date:		Sep 2017
+KernelVersion:	4.13
+Contact:	thunderbolt-software@xxxxxxxxxxxx
+Description:	This attribute contains vendor name of this device extracted
+		from the device DROM.
+
 What:		/sys/bus/thunderbolt/devices/.../unique_id
 Date:		Sep 2017
 KernelVersion:	4.13
diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 5c7d80a109b1..d40a5f07fc4c 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -204,6 +204,11 @@ struct tb_drom_entry_header {
 	enum tb_drom_entry_type type:1;
 } __packed;
 
+struct tb_drom_entry_generic {
+	struct tb_drom_entry_header header;
+	u8 data[0];
+} __packed;
+
 struct tb_drom_entry_port {
 	/* BYTES 0-1 */
 	struct tb_drom_entry_header header;
@@ -295,6 +300,32 @@ int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid)
 	return 0;
 }
 
+static int tb_drom_parse_entry_generic(struct tb_switch *sw,
+		struct tb_drom_entry_header *header)
+{
+	const struct tb_drom_entry_generic *entry =
+		(const struct tb_drom_entry_generic *)header;
+
+	switch (header->index) {
+	case 1:
+		/* Length includes 2 bytes header so remove it before copy */
+		sw->vendor_name = kstrndup(entry->data,
+			header->len - sizeof(*header), GFP_KERNEL);
+		if (!sw->vendor_name)
+			return -ENOMEM;
+		break;
+
+	case 2:
+		sw->device_name = kstrndup(entry->data,
+			header->len - sizeof(*header), GFP_KERNEL);
+		if (!sw->device_name)
+			return -ENOMEM;
+		break;
+	}
+
+	return 0;
+}
+
 static int tb_drom_parse_entry_port(struct tb_switch *sw,
 				    struct tb_drom_entry_header *header)
 {
@@ -350,6 +381,7 @@ static int tb_drom_parse_entries(struct tb_switch *sw)
 
 		switch (entry->type) {
 		case TB_DROM_ENTRY_GENERIC:
+			res = tb_drom_parse_entry_generic(sw, entry);
 			break;
 		case TB_DROM_ENTRY_PORT:
 			res = tb_drom_parse_entry_port(sw, entry);
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 0ce8b600a23f..0a592ccb7923 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -319,6 +319,15 @@ static ssize_t device_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(device);
 
+static ssize_t
+device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sprintf(buf, "%s\n", sw->device_name ? sw->device_name : "");
+}
+static DEVICE_ATTR_RO(device_name);
+
 static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
@@ -328,6 +337,15 @@ static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(vendor);
 
+static ssize_t
+vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sprintf(buf, "%s\n", sw->vendor_name ? sw->vendor_name : "");
+}
+static DEVICE_ATTR_RO(vendor_name);
+
 static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
@@ -339,7 +357,9 @@ static DEVICE_ATTR_RO(unique_id);
 
 static struct attribute *switch_attrs[] = {
 	&dev_attr_device.attr,
+	&dev_attr_device_name.attr,
 	&dev_attr_vendor.attr,
+	&dev_attr_vendor_name.attr,
 	&dev_attr_unique_id.attr,
 	NULL,
 };
@@ -358,6 +378,8 @@ static void tb_switch_release(struct device *dev)
 	struct tb_switch *sw = tb_to_switch(dev);
 
 	kfree(sw->uuid);
+	kfree(sw->device_name);
+	kfree(sw->vendor_name);
 	kfree(sw->ports);
 	kfree(sw->drom);
 	kfree(sw);
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 350c3f21924e..5e66dce53c65 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -23,6 +23,8 @@
  * @uuid: UUID of the switch (or %NULL if not supported)
  * @vendor: Vendor ID of the switch
  * @device: Device ID of the switch
+ * @vendor_name: Name of the vendor (or %NULL if not known)
+ * @device_name: Name of the device (or %NULL if not known)
  * @cap_plug_events: Offset to the plug events capability (%0 if not found)
  * @is_unplugged: The switch is going away
  * @drom: DROM of the switch (%NULL if not found)
@@ -36,6 +38,8 @@ struct tb_switch {
 	uuid_be *uuid;
 	u16 vendor;
 	u16 device;
+	const char *vendor_name;
+	const char *device_name;
 	int cap_plug_events;
 	bool is_unplugged;
 	u8 *drom;
-- 
2.11.0