i3c: Add I3C target support

Extend the existing core implementation with I3C target support.
Add missing I3C target driver API.

Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>

3 files changed, 55 insertions, 0 deletions

diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index c31624535fbf..e632941575bd 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -179,6 +179,7 @@ struct i3c_driver {
 	int (*probe)(struct i3c_device *dev);
 	void (*remove)(struct i3c_device *dev);
 	const struct i3c_device_id *id_table;
+	bool target;
 };
 
 static inline struct i3c_driver *drv_to_i3cdrv(struct device_driver *drv)
@@ -294,6 +295,8 @@ int i3c_device_do_priv_xfers(struct i3c_device *dev,
 			     struct i3c_priv_xfer *xfers,
 			     int nxfers);
 
+int i3c_device_generate_ibi(struct i3c_device *dev, const u8 *data, int len);
+
 void i3c_device_get_info(struct i3c_device *dev, struct i3c_device_info *info);
 
 struct i3c_ibi_payload {
@@ -335,4 +338,10 @@ int i3c_device_disable_ibi(struct i3c_device *dev);
 
 int i3c_device_getstatus_ccc(struct i3c_device *dev, struct i3c_device_info *info);
 
+struct i3c_target_read_setup {
+	void (*handler)(struct i3c_device *dev, const u8 *data, size_t len);
+};
+
+int i3c_target_read_register(struct i3c_device *dev, const struct i3c_target_read_setup *setup);
+
 #endif /* I3C_DEV_H */
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 11cdcc062b3e..5d35a6d1c992 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -22,6 +22,7 @@
 #define I3C_BROADCAST_ADDR		0x7e
 #define I3C_MAX_ADDR			GENMASK(6, 0)
 
+struct i3c_target_ops;
 struct i3c_master_controller;
 struct i3c_bus;
 struct i2c_device;
@@ -185,10 +186,20 @@ struct i3c_dev_boardinfo {
 };
 
 /**
+ * struct i3c_target_info - target information attached to a specific device
+ * @read handler: handler specified at i3c_target_read_register() call time.
+ */
+
+struct i3c_target_info {
+	void (*read_handler)(struct i3c_device *dev, const u8 *data, size_t len);
+};
+
+/**
  * struct i3c_dev_desc - I3C device descriptor
  * @common: common part of the I3C device descriptor
  * @info: I3C device information. Will be automatically filled when you create
  *	  your device with i3c_master_add_i3c_dev_locked()
+ * @target_info: I3C target information.
  * @ibi_lock: lock used to protect the &struct_i3c_device->ibi
  * @ibi: IBI info attached to a device. Should be NULL until
  *	 i3c_device_request_ibi() is called
@@ -207,6 +218,7 @@ struct i3c_dev_boardinfo {
 struct i3c_dev_desc {
 	struct i3c_i2c_dev_desc common;
 	struct i3c_device_info info;
+	struct i3c_target_info target_info;
 	struct mutex ibi_lock;
 	struct i3c_device_ibi_info *ibi;
 	struct i3c_device *dev;
@@ -463,6 +475,8 @@ struct i3c_master_controller_ops {
  *	 registered to the I2C subsystem to be as transparent as possible to
  *	 existing I2C drivers
  * @ops: master operations. See &struct i3c_master_controller_ops
+ * @target_ops: target operations. See &struct i3c_target_ops
+ * @target: true if the underlying I3C device acts as a target on I3C bus
  * @secondary: true if the master is a secondary master
  * @init_done: true when the bus initialization is done
  * @boardinfo.i3c: list of I3C  boardinfo objects
@@ -485,6 +499,8 @@ struct i3c_master_controller {
 	struct i3c_dev_desc *this;
 	struct i2c_adapter i2c;
 	const struct i3c_master_controller_ops *ops;
+	const struct i3c_target_ops *target_ops;
+	unsigned int target : 1;
 	unsigned int secondary : 1;
 	unsigned int init_done : 1;
 	unsigned int jdec_spd : 1;
@@ -545,6 +561,13 @@ int i3c_master_register(struct i3c_master_controller *master,
 			bool secondary);
 int i3c_master_unregister(struct i3c_master_controller *master);
 
+int i3c_register(struct i3c_master_controller *master,
+		 struct device *parent,
+		 const struct i3c_master_controller_ops *master_ops,
+		 const struct i3c_target_ops *target_ops,
+		 bool secondary);
+int i3c_unregister(struct i3c_master_controller *master);
+
 /**
  * i3c_dev_get_master_data() - get master private data attached to an I3C
  *			       device descriptor
diff --git a/include/linux/i3c/target.h b/include/linux/i3c/target.h
new file mode 100644
index 000000000000..9e71124b5325
--- /dev/null
+++ b/include/linux/i3c/target.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2022, Intel Corporation */
+
+#ifndef I3C_TARGET_H
+#define I3C_TARGET_H
+
+#include <linux/device.h>
+#include <linux/i3c/device.h>
+
+struct i3c_master_controller;
+
+struct i3c_target_ops {
+	int (*bus_init)(struct i3c_master_controller *master);
+	void (*bus_cleanup)(struct i3c_master_controller *master);
+	int (*priv_xfers)(struct i3c_dev_desc *dev, struct i3c_priv_xfer *xfers, int nxfers);
+	int (*generate_ibi)(struct i3c_dev_desc *dev, const u8 *data, int len);
+};
+
+int i3c_target_register(struct i3c_master_controller *master, struct device *parent,
+			const struct i3c_target_ops *ops);
+int i3c_target_unregister(struct i3c_master_controller *master);
+
+#endif