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

Parshuram Thombare
2020-05-11T13:14:08Z

add i3c_secondary_master_register which is used
to register secondary masters.

Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
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