soundwire: bus: add callbacks for device_number allocation

Rather than add logic in the core for vendor-specific usages, add
callbacks for vendor-specific device_number allocation and release.

This patch only moves the existing IDA-based allocator used only by
Intel to the intel_auxdevice.c file and does not change the
functionality. Follow-up patches will extend the behavior by modifying
the Intel callbacks.

Signed-off-by: Pierre-Louis Bossart <[e-mail]>
Reviewed-by: Rander Wang <[e-mail]>
Signed-off-by: Bard Liao <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/soundwire/bus.c

···
 #include "sysfs_local.h"
 
 static DEFINE_IDA(sdw_bus_ida);
-static DEFINE_IDA(sdw_peripheral_ida);
 
 static int sdw_get_id(struct sdw_bus *bus)
 {
···
 
 	if (slave->dev_num) { /* clear dev_num if assigned */
 		clear_bit(slave->dev_num, bus->assigned);
-		if (bus->dev_num_ida_min)
-			ida_free(&sdw_peripheral_ida, slave->dev_num);
+		if (bus->ops && bus->ops->put_device_num)
+			bus->ops->put_device_num(bus, slave);
 	}
 	list_del_init(&slave->node);
 	mutex_unlock(&bus->bus_lock);
···
 /* called with bus_lock held */
 static int sdw_get_device_num(struct sdw_slave *slave)
 {
+	struct sdw_bus *bus = slave->bus;
 	int bit;
 
-	if (slave->bus->dev_num_ida_min) {
-		bit = ida_alloc_range(&sdw_peripheral_ida,
-				      slave->bus->dev_num_ida_min, SDW_MAX_DEVICES,
-				      GFP_KERNEL);
+	if (bus->ops && bus->ops->get_device_num) {
+		bit = bus->ops->get_device_num(bus, slave);
 		if (bit < 0)
 			goto err;
 	} else {
-		bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
+		bit = find_first_zero_bit(bus->assigned, SDW_MAX_DEVICES);
 		if (bit == SDW_MAX_DEVICES) {
 			bit = -ENODEV;
 			goto err;
···
 	 * Do not update dev_num in Slave data structure here,
 	 * Update once program dev_num is successful
 	 */
-	set_bit(bit, slave->bus->assigned);
+	set_bit(bit, bus->assigned);
 
 err:
 	return bit;

drivers/soundwire/intel_auxdevice.c

···
 	return 0;
 }
 
+static DEFINE_IDA(intel_peripheral_ida);
+
+static int intel_get_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
+{
+	return ida_alloc_range(&intel_peripheral_ida,
+			       INTEL_DEV_NUM_IDA_MIN, SDW_MAX_DEVICES,
+			       GFP_KERNEL);
+}
+
+static void intel_put_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
+{
+	return ida_free(&intel_peripheral_ida, slave->dev_num);
+}
+
 static struct sdw_master_ops sdw_intel_ops = {
 	.read_prop = intel_prop_read,
 	.override_adr = sdw_dmi_override_adr,
···
 	.pre_bank_switch = generic_pre_bank_switch,
 	.post_bank_switch = generic_post_bank_switch,
 	.read_ping_status = cdns_read_ping_status,
+	.get_device_num =  intel_get_device_num_ida,
+	.put_device_num = intel_put_device_num_ida,
 	.new_peripheral_assigned = generic_new_peripheral_assigned,
 };
 
···
 	cdns->msg_count = 0;
 
 	bus->link_id = auxdev->id;
-	bus->dev_num_ida_min = INTEL_DEV_NUM_IDA_MIN;
 	bus->clk_stop_timeout = 1;
 
 	sdw_cdns_probe(cdns);

include/linux/soundwire/sdw.h

···
  * @post_bank_switch: Callback for post bank switch
  * @read_ping_status: Read status from PING frames, reported with two bits per Device.
  * Bits 31:24 are reserved.
+ * @get_device_num: Callback for vendor-specific device_number allocation
+ * @put_device_num: Callback for vendor-specific device_number release
  * @new_peripheral_assigned: Callback to handle enumeration of new peripheral.
  */
 struct sdw_master_ops {
···
 	int (*pre_bank_switch)(struct sdw_bus *bus);
 	int (*post_bank_switch)(struct sdw_bus *bus);
 	u32 (*read_ping_status)(struct sdw_bus *bus);
+	int (*get_device_num)(struct sdw_bus *bus, struct sdw_slave *slave);
+	void (*put_device_num)(struct sdw_bus *bus, struct sdw_slave *slave);
 	void (*new_peripheral_assigned)(struct sdw_bus *bus,
 					struct sdw_slave *slave,
 					int dev_num);
···
  * meaningful if multi_link is set. If set to 1, hardware-based
  * synchronization will be used even if a stream only uses a single
  * SoundWire segment.
- * @dev_num_ida_min: if set, defines the minimum values for the IDA
- * used to allocate system-unique device numbers. This value needs to be
- * identical across all SoundWire bus in the system.
  */
 struct sdw_bus {
 	struct device *dev;
···
 	u32 bank_switch_timeout;
 	bool multi_link;
 	int hw_sync_min_links;
-	int dev_num_ida_min;
 };
 
 int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,