[PATCH v7 3/7] i3c: master: add i3c_secondary_master_register

[Parshuram Thombare]

add i3c_secondary_master_register which is used
to register secondary masters.

Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
---
 drivers/i3c/master.c       | 154 ++++++++++++++++++++++++++++++++++++-
 include/linux/i3c/master.h |   3 +
 2 files changed, 156 insertions(+), 1 deletion(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index ba07a7d49633..669bd7e45810 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1768,6 +1768,90 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	return ret;
 }
 
+/**
+ * i3c_secondary_master_bus_init() - initialize an I3C bus for secondary
+ * master
+ * @master: secondary master initializing the bus
+ *
+ * This function does
+ *
+ * 1. Attach I2C devs to the master
+ *
+ * 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)
+ *
+ * Once this is done, I2C devices should be usable.
+ *
+ * Return: a 0 in case of success, an negative error code otherwise.
+ */
+static int i3c_secondary_master_bus_init(struct i3c_master_controller *master)
+{
+	enum i3c_addr_slot_status status;
+	struct i2c_dev_boardinfo *i2cboardinfo;
+	struct i2c_dev_desc *i2cdev;
+	int ret;
+
+	/*
+	 * First attach all devices with static definitions provided by the
+	 * FW.
+	 */
+	list_for_each_entry(i2cboardinfo, &master->boardinfo.i2c, node) {
+		status = i3c_bus_get_addr_slot_status(&master->bus,
+						      i2cboardinfo->base.addr);
+		if (status != I3C_ADDR_SLOT_FREE) {
+			ret = -EBUSY;
+			goto err_detach_devs;
+		}
+
+		i3c_bus_set_addr_slot_status(&master->bus,
+					     i2cboardinfo->base.addr,
+					     I3C_ADDR_SLOT_I2C_DEV);
+
+		i2cdev = i3c_master_alloc_i2c_dev(master, i2cboardinfo);
+		if (IS_ERR(i2cdev)) {
+			ret = PTR_ERR(i2cdev);
+			goto err_detach_devs;
+		}
+
+		ret = i3c_master_attach_i2c_dev(master, i2cdev);
+		if (ret) {
+			i3c_master_free_i2c_dev(i2cdev);
+			goto err_detach_devs;
+		}
+	}
+
+	/*
+	 * 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;
+
+	/*
+	 * The master device should have been instantiated in ->bus_init(),
+	 * complain if this was not the case.
+	 */
+	if (!master->this) {
+		dev_err(&master->dev,
+			"master_set_info() was not called in ->bus_init()\n");
+		ret = -EINVAL;
+		goto err_bus_cleanup;
+	}
+
+	return 0;
+
+err_bus_cleanup:
+	if (master->ops->bus_cleanup)
+		master->ops->bus_cleanup(master);
+
+err_detach_devs:
+	i3c_master_detach_free_devs(master);
+
+	return ret;
+}
+
 static void i3c_master_bus_cleanup(struct i3c_master_controller *master)
 {
 	if (master->ops->bus_cleanup)
@@ -2457,7 +2541,10 @@ static int i3c_master_init(struct i3c_master_controller *master,
 		goto err_put_dev;
 	}
 
-	ret = i3c_master_bus_init(master);
+	if (secondary)
+		ret = i3c_secondary_master_bus_init(master);
+	else
+		ret = i3c_master_bus_init(master);
 	if (ret)
 		goto err_put_dev;
 
@@ -2535,6 +2622,71 @@ int i3c_master_register(struct i3c_master_controller *master,
 }
 EXPORT_SYMBOL_GPL(i3c_master_register);
 
+/**
+ * i3c_secondary_master_register() - register an I3C secondary master
+ * @master: master used to send frames on the bus
+ * @parent: the parent device (the one that provides this I3C master
+ *	    controller)
+ * @ops: the master controller operations
+ *
+ * This function does minimal required initialization for secondary
+ * master, rest functionality like creating and registering I2C
+ * and I3C devices is done in defslvs processing.
+ *
+ *  i3c_secondary_master_register() does following things -
+ * - creates and initializes the I3C bus
+ * - populates the bus with static I2C devs if @parent->of_node is not
+ *   NULL
+ *   initialization
+ * - allocate memory for defslvs_data.devs, which is used to receive
+ *   defslvs list
+ * - create I3C device representing this master
+ * - registers the I2C adapter and all I2C devices
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int i3c_secondary_master_register(struct i3c_master_controller *master,
+				  struct device *parent,
+				  const struct i3c_master_controller_ops *ops)
+{
+	int ret;
+
+	ret = i3c_master_init(master, parent, ops, true);
+	if (ret)
+		return ret;
+
+	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;
+
+	return 0;
+
+err_del_dev:
+	device_del(&master->dev);
+
+err_cleanup_bus:
+	i3c_master_bus_cleanup(master);
+
+	put_device(&master->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i3c_secondary_master_register);
+
 /**
  * i3c_master_unregister() - unregister an I3C master
  * @master: master used to send frames on the bus
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index f5ba82c390bc..5124ff4831eb 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -534,6 +534,9 @@ int i3c_master_set_info(struct i3c_master_controller *master,
 int i3c_master_register(struct i3c_master_controller *master,
 			struct device *parent,
 			const struct i3c_master_controller_ops *ops);
+int i3c_secondary_master_register(struct i3c_master_controller *master,
+				  struct device *parent,
+				  const struct i3c_master_controller_ops *ops);
 int i3c_master_unregister(struct i3c_master_controller *master);
 
 /**
-- 
2.17.1