soundwire: bus: add unique bus id

Adding an unique id for each bus.

Suggested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index a807279..03d72fa 100644 (file)
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -9,6 +9,19 @@
 #include <linux/soundwire/sdw.h>
 #include "bus.h"
 
+static DEFINE_IDA(sdw_ida);
+
+static int sdw_get_id(struct sdw_bus *bus)
+{
+       int rc = ida_alloc(&sdw_ida, GFP_KERNEL);
+
+       if (rc < 0)
+               return rc;
+
+       bus->id = rc;
+       return 0;
+}
+
 /**
  * sdw_bus_master_add() - add a bus Master instance
  * @bus: bus instance
@@ -29,6 +42,12 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
                return -ENODEV;
        }
 
+       ret = sdw_get_id(bus);
+       if (ret) {
+               dev_err(bus->dev, "Failed to get bus id\n");
+               return ret;
+       }
+
        if (!bus->ops) {
                dev_err(bus->dev, "SoundWire Bus ops are not set\n");
                return -EINVAL;
@@ -144,6 +163,7 @@ void sdw_bus_master_delete(struct sdw_bus *bus)
        device_for_each_child(bus->dev, NULL, sdw_delete_slave);
 
        sdw_bus_debugfs_exit(bus);
+       ida_free(&sdw_ida, bus->id);
 }
 EXPORT_SYMBOL(sdw_bus_master_delete);
 

diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index 2003e8c..a32cb26 100644 (file)
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -789,6 +789,7 @@ struct sdw_master_ops {
  * struct sdw_bus - SoundWire bus
  * @dev: Master linux device
  * @link_id: Link id number, can be 0 to N, unique for each Master
+ * @id: bus system-wide unique id
  * @slaves: list of Slaves on this bus
  * @assigned: Bitmap for Slave device numbers.
  * Bit set implies used number, bit clear implies unused number.
@@ -813,6 +814,7 @@ struct sdw_master_ops {
 struct sdw_bus {
        struct device *dev;
        unsigned int link_id;
+       int id;
        struct list_head slaves;
        DECLARE_BITMAP(assigned, SDW_MAX_DEVICES);
        struct mutex bus_lock;