i3c: master: fix for SETDASA and DAA process

This patch fix following issue.
Controller slots blocked for devices with static_addr
but no init_dyn_addr may limit the number of I3C devices
on the bus which gets dynamic address in DAA. So
instead of attaching all the devices with static_addr,
now we only attach the devices which successfully
complete SETDASA. For remaining devices with init_dyn_addr,
i3c_master_add_i3c_dev_locked() will try to set requested
dynamic address after DAA.

Signed-off-by: Parshuram Thombare <[e-mail]>
Signed-off-by: Boris Brezillon <[e-mail]>
Link: https://lore.kernel.org/linux-i3c/[e-mail]

drivers/i3c/master.c

···
 	enum i3c_addr_slot_status status;
 	int ret;
 
-	if (dev->info.dyn_addr != old_dyn_addr) {
+	if (dev->info.dyn_addr != old_dyn_addr &&
+	    (!dev->boardinfo ||
+	     dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) {
 		status = i3c_bus_get_addr_slot_status(&master->bus,
 						      dev->info.dyn_addr);
 		if (status != I3C_ADDR_SLOT_FREE)
···
 		master->ops->detach_i2c_dev(dev);
 }
 
-static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev)
+static int i3c_master_early_i3c_dev_add(struct i3c_master_controller *master,
+					  struct i3c_dev_boardinfo *boardinfo)
 {
-	struct i3c_master_controller *master = i3c_dev_get_master(dev);
+	struct i3c_device_info info = {
+		.static_addr = boardinfo->static_addr,
+	};
+	struct i3c_dev_desc *i3cdev;
 	int ret;
 
-	if (!dev->boardinfo || !dev->boardinfo->init_dyn_addr ||
-	    !dev->boardinfo->static_addr)
-		return;
+	i3cdev = i3c_master_alloc_i3c_dev(master, &info);
+	if (IS_ERR(i3cdev))
+		return -ENOMEM;
 
-	ret = i3c_master_setdasa_locked(master, dev->info.static_addr,
-					dev->boardinfo->init_dyn_addr);
+	i3cdev->boardinfo = boardinfo;
+
+	ret = i3c_master_attach_i3c_dev(master, i3cdev);
 	if (ret)
-		return;
+		goto err_free_dev;
 
-	dev->info.dyn_addr = dev->boardinfo->init_dyn_addr;
-	ret = i3c_master_reattach_i3c_dev(dev, 0);
+	ret = i3c_master_setdasa_locked(master, i3cdev->info.static_addr,
+					i3cdev->boardinfo->init_dyn_addr);
+	if (ret)
+		goto err_detach_dev;
+
+	i3cdev->info.dyn_addr = i3cdev->boardinfo->init_dyn_addr;
+	ret = i3c_master_reattach_i3c_dev(i3cdev, 0);
 	if (ret)
 		goto err_rstdaa;
 
-	ret = i3c_master_retrieve_dev_info(dev);
+	ret = i3c_master_retrieve_dev_info(i3cdev);
 	if (ret)
 		goto err_rstdaa;
 
-	return;
+	return 0;
 
 err_rstdaa:
-	i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr);
+	i3c_master_rstdaa_locked(master, i3cdev->boardinfo->init_dyn_addr);
+err_detach_dev:
+	i3c_master_detach_i3c_dev(i3cdev);
+err_free_dev:
+	i3c_master_free_i3c_dev(i3cdev);
+
+	return ret;
 }
 
 static void
···
  * This function is following all initialisation steps described in the I3C
  * specification:
  *
- * 1. Attach I2C and statically defined I3C devs to the master so that the
- *    master can fill its internal device table appropriately
+ * 1. Attach I2C devs to the master so that the master can fill its internal
+ *    device table appropriately
  *
  * 2. Call &i3c_master_controller_ops->bus_init() method to initialize
  *    the master controller. That's usually where the bus mode is selected
···
  *
  * 4. Disable all slave events.
  *
- * 5. Pre-assign dynamic addresses requested by the FW with SETDASA for I3C
- *    devices that have a static address
+ * 5. Reserve address slots for I3C devices with init_dyn_addr. And if devices
+ *    also have static_addr, try to pre-assign dynamic addresses requested by
+ *    the FW with SETDASA and attach corresponding statically defined I3C
+ *    devices to the master.
  *
  * 6. Do a DAA (Dynamic Address Assignment) to assign dynamic addresses to all
  *    remaining I3C devices
···
 	enum i3c_addr_slot_status status;
 	struct i2c_dev_boardinfo *i2cboardinfo;
 	struct i3c_dev_boardinfo *i3cboardinfo;
-	struct i3c_dev_desc *i3cdev;
 	struct i2c_dev_desc *i2cdev;
 	int ret;
 
···
 		ret = i3c_master_attach_i2c_dev(master, i2cdev);
 		if (ret) {
 			i3c_master_free_i2c_dev(i2cdev);
-			goto err_detach_devs;
-		}
-	}
-	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
-		struct i3c_device_info info = {
-			.static_addr = i3cboardinfo->static_addr,
-		};
-
-		if (i3cboardinfo->init_dyn_addr) {
-			status = i3c_bus_get_addr_slot_status(&master->bus,
-						i3cboardinfo->init_dyn_addr);
-			if (status != I3C_ADDR_SLOT_FREE) {
-				ret = -EBUSY;
-				goto err_detach_devs;
-			}
-		}
-
-		i3cdev = i3c_master_alloc_i3c_dev(master, &info);
-		if (IS_ERR(i3cdev)) {
-			ret = PTR_ERR(i3cdev);
-			goto err_detach_devs;
-		}
-
-		i3cdev->boardinfo = i3cboardinfo;
-
-		ret = i3c_master_attach_i3c_dev(master, i3cdev);
-		if (ret) {
-			i3c_master_free_i3c_dev(i3cdev);
 			goto err_detach_devs;
 		}
 	}
···
 		goto err_bus_cleanup;
 
 	/*
-	 * Pre-assign dynamic address and retrieve device information if
-	 * needed.
+	 * Reserve init_dyn_addr first, and then try to pre-assign dynamic
+	 * address and retrieve device information if needed.
+	 * In case pre-assign dynamic address fails, setting dynamic address to
+	 * the requested init_dyn_addr is retried after DAA is done in
+	 * i3c_master_add_i3c_dev_locked().
 	 */
-	i3c_bus_for_each_i3cdev(&master->bus, i3cdev)
-		i3c_master_pre_assign_dyn_addr(i3cdev);
+	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
+
+		/*
+		 * We don't reserve a dynamic address for devices that
+		 * don't explicitly request one.
+		 */
+		if (!i3cboardinfo->init_dyn_addr)
+			continue;
+
+		ret = i3c_bus_get_addr_slot_status(&master->bus,
+						   i3cboardinfo->init_dyn_addr);
+		if (ret != I3C_ADDR_SLOT_FREE) {
+			ret = -EBUSY;
+			goto err_rstdaa;
+		}
+
+		i3c_bus_set_addr_slot_status(&master->bus,
+					     i3cboardinfo->init_dyn_addr,
+					     I3C_ADDR_SLOT_I3C_DEV);
+
+		/*
+		 * Only try to create/attach devices that have a static
+		 * address. Other devices will be created/attached when
+		 * DAA happens, and the requested dynamic address will
+		 * be set using SETNEWDA once those devices become
+		 * addressable.
+		 */
+
+		if (i3cboardinfo->static_addr)
+			i3c_master_early_i3c_dev_add(master, i3cboardinfo);
+	}
 
 	ret = i3c_master_do_daa(master);
 	if (ret)