[PATCH v2 2/2] i3c: master: fix for SETDASA and DAA process

[Parshuram Thombare]

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.

Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
---
 drivers/i3c/master.c | 119 ++++++++++++++++++++++++++-----------------
 1 file changed, 71 insertions(+), 48 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 3d995f247cb7..5e0438ecf95c 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1426,33 +1426,57 @@ static void i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
 		master->ops->detach_i2c_dev(dev);
 }
 
-static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev)
+static int i3c_master_pre_assign_dyn_addr(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;
+	/*
+	 * We anyway don't attach devices which are not addressable
+	 * (no static_addr and dyn_addr) and devices with static_addr
+	 * but no init_dyn_addr will participate in DAA.
+	 */
+	if (!boardinfo->static_addr || !boardinfo->init_dyn_addr)
+		return -EINVAL;
 
-	ret = i3c_master_setdasa_locked(master, dev->info.static_addr,
-					dev->boardinfo->init_dyn_addr);
+	i3cdev = i3c_master_alloc_i3c_dev(master, &info);
+	if (IS_ERR(i3cdev))
+		return -ENOMEM;
+
+	i3cdev->boardinfo = boardinfo;
+
+	ret = i3c_master_attach_i3c_dev(master, i3cdev);
 	if (ret)
-		return;
+		goto err_attach;
 
-	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_setdasa;
+
+	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_setdasa:
+	i3c_master_detach_i3c_dev(i3cdev);
+err_attach:
+	i3c_master_free_i3c_dev(i3cdev);
+
+	return ret;
 }
 
 static void
@@ -1619,8 +1643,8 @@ static void i3c_master_detach_free_devs(struct i3c_master_controller *master)
  * 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
@@ -1633,7 +1657,8 @@ static void i3c_master_detach_free_devs(struct i3c_master_controller *master)
  * 4. Disable all slave events.
  *
  * 5. Pre-assign dynamic addresses requested by the FW with SETDASA for I3C
- *    devices that have a static address
+ *    devices that have a static address 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
@@ -1647,7 +1672,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	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;
 
@@ -1679,34 +1703,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 			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;
-		}
-	}
 
 	/*
 	 * Now execute the controller specific ->bus_init() routine, which
@@ -1744,10 +1740,26 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 
 	/*
 	 * Pre-assign dynamic address and retrieve device information if
-	 * needed.
+	 * needed. And reserve the init_dyn_addr in case of failure, to retry
+	 * setting the requested address 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) {
+		ret = i3c_master_pre_assign_dyn_addr(master, i3cboardinfo);
+		if (!ret ||  !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);
+	}
 
 	ret = i3c_master_do_daa(master);
 	if (ret)
@@ -1780,6 +1792,7 @@ static void i3c_master_attach_boardinfo(struct i3c_dev_desc *i3cdev)
 {
 	struct i3c_master_controller *master = i3cdev->common.master;
 	struct i3c_dev_boardinfo *i3cboardinfo;
+	u8 init_dyn_addr;
 
 	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
 		if (i3cdev->info.pid != i3cboardinfo->pid)
@@ -1787,6 +1800,16 @@ static void i3c_master_attach_boardinfo(struct i3c_dev_desc *i3cdev)
 
 		i3cdev->boardinfo = i3cboardinfo;
 		i3cdev->info.static_addr = i3cboardinfo->static_addr;
+		init_dyn_addr = i3cboardinfo->init_dyn_addr;
+		/*
+		 * Free reserved init_dyn_addr so that attach can
+		 * get it before trying setnewda.
+		 */
+		if (i3cboardinfo->init_dyn_addr)
+			i3c_bus_set_addr_slot_status(&master->bus,
+						     init_dyn_addr,
+						     I3C_ADDR_SLOT_FREE);
+
 		return;
 	}
 }
-- 
2.17.1