[PATCH v6 6/8] i3c: master: secondary master initialization

[Parshuram Thombare]

This patch add secondary master support to
I3C master subsystem.

Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
---
 drivers/i3c/master.c       | 153 ++++++++++++++++++++++++++++---------
 include/linux/i3c/master.h |   1 +
 2 files changed, 116 insertions(+), 38 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 19d4800ed573..39a412b32c59 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1621,10 +1621,6 @@ int i3c_master_set_info(struct i3c_master_controller *master,
 	if (!i3c_bus_dev_addr_is_avail(&master->bus, info->dyn_addr))
 		return -EINVAL;
 
-	if (I3C_BCR_DEVICE_ROLE(info->bcr) == I3C_BCR_I3C_MASTER &&
-	    master->secondary)
-		return -EINVAL;
-
 	if (master->this)
 		return -EINVAL;
 
@@ -2040,9 +2036,10 @@ EXPORT_SYMBOL_GPL(i3c_master_process_defslvs);
  * 1. Attach I2C and statically defined I3C 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
- *    (pure bus or mixed fast/slow bus)
+ * 2. Should have called &i3c_master_controller_ops->bus_init()
+ *    method with pure bus mode to initialize the master controller.
+ *    That's usually where the bus mode is selected (pure bus or
+ *    mixed fast/slow bus)
  *
  * 3. Instruct all devices on the bus to drop their dynamic address. This is
  *    particularly important when the bus was previously configured by someone
@@ -2126,14 +2123,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 		}
 	}
 
-	/*
-	 * Now execute the controller specific ->bus_init() routine, which
-	 * might configure its internal logic to match the bus limitations.
-	 */
-	ret = master->ops->bus_init(master);
-	if (ret)
-		goto err_detach_devs;
-
 	ret = master->ops->master_set_info(master);
 	if (ret)
 		goto err_detach_devs;
@@ -2146,7 +2135,7 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 		dev_err(&master->dev,
 			"master_set_info() was not called in ->bus_init()\n");
 		ret = -EINVAL;
-		goto err_bus_cleanup;
+		goto err_detach_devs;
 	}
 
 	/*
@@ -2155,14 +2144,14 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	 */
 	ret = i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR);
 	if (ret && ret != I3C_ERROR_M2)
-		goto err_bus_cleanup;
+		goto err_detach_devs;
 
 	/* Disable all slave events before starting DAA. */
 	ret = i3c_master_disec_locked(master, I3C_BROADCAST_ADDR,
 				      I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR |
 				      I3C_CCC_EVENT_HJ);
 	if (ret && ret != I3C_ERROR_M2)
-		goto err_bus_cleanup;
+		goto err_detach_devs;
 
 	/*
 	 * Pre-assign dynamic address and retrieve device information if
@@ -2180,10 +2169,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 err_rstdaa:
 	i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR);
 
-err_bus_cleanup:
-	if (master->ops->bus_cleanup)
-		master->ops->bus_cleanup(master);
-
 err_detach_devs:
 	i3c_master_detach_free_devs(master);
 
@@ -2813,9 +2798,68 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
 	     !ops->recycle_ibi_slot))
 		return -EINVAL;
 
+	if (ops->request_mastership &&
+	    (!ops->enable_mr_events || !ops->disable_mr_events ||
+	     !ops->check_event_set))
+		return -EINVAL;
+
 	return 0;
 }
 
+static void i3c_secondary_master_register(struct work_struct *work)
+{
+	struct i3c_master_controller *master;
+	struct i3c_bus *i3cbus;
+	int ret;
+
+	master = container_of(work, struct i3c_master_controller,
+			      sec_mst_register_work);
+	i3cbus = i3c_master_get_bus(master);
+
+	i3c_bus_normaluse_lock(&master->bus);
+	if (!master->ops->check_event_set(master, I3C_SLV_DEFSLVS_CCC) ||
+	    i3c_master_acquire_bus(master)) {
+		i3c_bus_normaluse_unlock(&master->bus);
+		queue_work(master->wq, work);
+		return;
+	}
+	i3c_bus_normaluse_unlock(&master->bus);
+
+	ret = device_add(&master->dev);
+	if (ret)
+		goto err_cleanup_bus;
+
+	/*
+	 * Expose our I3C bus as an I2C adapter so that I2C devices are exposed
+	 * through the I2C subsystem.
+	 */
+	ret = i3c_master_i2c_adapter_init(master);
+	if (ret)
+		goto err_del_dev;
+
+	/*
+	 * We're done initializing the bus and the controller, we can now
+	 * register I3C devices from defslvs list.
+	 */
+	master->init_done = true;
+	i3c_bus_normaluse_lock(&master->bus);
+	i3c_master_register_new_i3c_devs(master);
+	i3c_bus_normaluse_unlock(&master->bus);
+
+	i3c_master_enable_mr_events(master);
+
+	return;
+
+err_del_dev:
+	device_del(&master->dev);
+
+err_cleanup_bus:
+	if (master->ops->bus_cleanup)
+		master->ops->bus_cleanup(master);
+
+	put_device(&master->dev);
+}
+
 /**
  * i3c_master_register() - register an I3C master
  * @master: master used to send frames on the bus
@@ -2845,10 +2889,10 @@ int i3c_master_register(struct i3c_master_controller *master,
 	struct i3c_bus *i3cbus = i3c_master_get_bus(master);
 	enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
 	struct i2c_dev_boardinfo *i2cbi;
-	int ret;
+	int ret, sz;
 
-	/* We do not support secondary masters yet. */
-	if (secondary)
+	/*Check if controller driver supports secondary masters. */
+	if (secondary && !ops->request_mastership)
 		return -ENOTSUPP;
 
 	ret = i3c_master_check_ops(ops);
@@ -2872,13 +2916,45 @@ int i3c_master_register(struct i3c_master_controller *master,
 	device_initialize(&master->dev);
 	dev_set_name(&master->dev, "i3c-%d", i3cbus->id);
 
+	master->wq = alloc_workqueue("%s", 0, 0, dev_name(parent));
+	if (!master->wq) {
+		ret = -ENOMEM;
+		goto err_put_dev;
+	}
+
+	master->mr_state = I3C_MR_IDLE;
 	INIT_WORK(&master->sec_mst_work, i3c_sec_mst_acquire_bus);
 	INIT_WORK(&master->mst_work, i3c_mst_yield_bus);
 
-	ret = of_populate_i3c_bus(master);
+	ret = i3c_bus_set_mode(i3cbus, mode);
+	if (ret)
+		goto err_put_dev;
+
+	/*
+	 * Now execute the controller specific ->bus_init() routine, which
+	 * might configure its internal logic to match the bus limitations.
+	 */
+	ret = master->ops->bus_init(master);
 	if (ret)
 		goto err_put_dev;
 
+	if (secondary) {
+		sz = sizeof(struct i3c_ccc_dev_desc) * I3C_BUS_MAX_DEVS;
+		master->defslvs_data.devs = devm_kzalloc(&master->dev, sz,
+							 GFP_KERNEL);
+		if (!master->defslvs_data.devs)
+			goto err_put_dev;
+
+		INIT_WORK(&master->sec_mst_register_work,
+			  i3c_secondary_master_register);
+		queue_work(master->wq, &master->sec_mst_register_work);
+		return 0;
+	}
+
+	ret = of_populate_i3c_bus(master);
+	if (ret)
+		goto err_cleanup_bus;
+
 	list_for_each_entry(i2cbi, &master->boardinfo.i2c, node) {
 		switch (i2cbi->lvr & I3C_LVR_I2C_INDEX_MASK) {
 		case I3C_LVR_I2C_INDEX(0):
@@ -2892,23 +2968,13 @@ int i3c_master_register(struct i3c_master_controller *master,
 			break;
 		default:
 			ret = -EINVAL;
-			goto err_put_dev;
+			goto err_cleanup_bus;
 		}
 	}
 
-	ret = i3c_bus_set_mode(i3cbus, mode);
-	if (ret)
-		goto err_put_dev;
-
-	master->wq = alloc_workqueue("%s", 0, 0, dev_name(parent));
-	if (!master->wq) {
-		ret = -ENOMEM;
-		goto err_put_dev;
-	}
-
 	ret = i3c_master_bus_init(master);
 	if (ret)
-		goto err_put_dev;
+		goto err_cleanup_bus;
 
 	ret = device_add(&master->dev);
 	if (ret)
@@ -2931,6 +2997,17 @@ int i3c_master_register(struct i3c_master_controller *master,
 	i3c_master_register_new_i3c_devs(master);
 	i3c_bus_normaluse_unlock(&master->bus);
 
+	ret = i3c_bus_set_mode(i3cbus, mode);
+	if (ret)
+		goto err_del_dev;
+
+	ret = master->ops->bus_init(master);
+	if (ret)
+		goto err_del_dev;
+
+	if (ops->request_mastership)
+		i3c_master_enable_mr_events(master);
+
 	return 0;
 
 err_del_dev:
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index cc482934803b..08b63e285b7b 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -515,6 +515,7 @@ struct i3c_master_controller {
 	} boardinfo;
 	struct i3c_bus bus;
 	struct workqueue_struct *wq;
+	struct work_struct sec_mst_register_work;
 	struct work_struct mst_work;
 	struct work_struct sec_mst_work;
 	struct completion mr_comp;
-- 
2.17.1