smbus: Add Host Notify and smbalert API

Add API for SMBus Host Notify and SMBALERT.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

drivers/smbus/smbus_handlers.c

@@ -4,8 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-#include <zephyr/drivers/smbus.h>
+#include <zephyr/sys/slist.h>
 #include <zephyr/syscall_handler.h>
+#include <zephyr/drivers/smbus.h>
 
 static inline int z_vrfy_smbus_configure(const struct device *dev,
 					 uint32_t dev_config)
@@ -142,3 +143,23 @@ static inline int z_vrfy_smbus_block_pcall(const struct device *dev,
 					rcv_count, rcv_buf);
 }
 #include <syscalls/smbus_block_pcall_mrsh.c>
+
+static inline int z_vrfy_smbus_manage_smbalert_cb(const struct device *dev,
+						  struct smbus_callback *cb,
+						  bool set)
+{
+	Z_OOPS(Z_SYSCALL_OBJ(dev, K_OBJ_DRIVER_SMBUS));
+
+	return z_impl_smbus_manage_smbalert_cb(dev, cb, set);
+}
+#include <syscalls/smbus_manage_smbalert_cb_mrsh.c>
+
+static inline int z_vrfy_smbus_manage_host_notify_cb(const struct device *dev,
+						     struct smbus_callback *cb,
+						     bool set)
+{
+	Z_OOPS(Z_SYSCALL_OBJ(dev, K_OBJ_DRIVER_SMBUS));
+
+	return z_impl_smbus_manage_host_notify_cb(dev, cb, set);
+}
+#include <syscalls/smbus_manage_host_notify_cb_mrsh.c>

include/zephyr/drivers/smbus.h

@@ -209,6 +209,12 @@ extern "C" {
 /** Support Packet Error Code (PEC) checking */
 #define SMBUS_MODE_PEC			BIT(1)
 
+/** Support Host Notify functionality */
+#define SMBUS_MODE_HOST_NOTIFY		BIT(2)
+
+/** Support SMBALERT signal functionality */
+#define SMBUS_MODE_SMBALERT		BIT(3)
+
 /** @} */
 
 /**
@@ -247,6 +253,32 @@ enum smbus_direction {
 #define SMBUS_MSG_RW_MASK		BIT(0)
 /** @endcond  */
 
+struct smbus_callback;
+
+typedef void (*smbus_callback_handler_t)(const struct device *dev,
+					 struct smbus_callback *cb,
+					 uint8_t addr);
+
+/**
+ * @brief SMBus callback structure
+ *
+ * Used to register a callback in the driver instance callback list.
+ * As many callbacks as needed can be added as long as each of them
+ * are unique pointers of struct smbus_callback.
+ *
+ * Note: Such struct should not be allocated on stack.
+ */
+struct smbus_callback {
+	/** This should be used in driver for a callback list management */
+	sys_snode_t node;
+
+	/** Actual callback function being called when relevant */
+	smbus_callback_handler_t handler;
+
+	/** Peripheral device address */
+	uint8_t addr;
+};
+
 /**
  * @brief Complete SMBus DT information
  *
@@ -326,6 +358,12 @@ typedef int (*smbus_api_block_pcall_t)(const struct device *dev,
 				       uint16_t addr, uint8_t cmd,
 				       uint8_t send_count, uint8_t *send_buf,
 				       uint8_t *recv_count, uint8_t *recv_buf);
+typedef int (*smbus_api_manage_smbalert_cb_t)(const struct device *dev,
+					      struct smbus_callback *cb,
+					      bool set);
+typedef int (*smbus_api_manage_host_notify_cb_t)(const struct device *dev,
+						 struct smbus_callback *cb,
+						 bool set);
 
 __subsystem struct smbus_driver_api {
 	smbus_api_configure_t configure;
@@ -341,6 +379,8 @@ __subsystem struct smbus_driver_api {
 	smbus_api_block_write_t smbus_block_write;
 	smbus_api_block_read_t smbus_block_read;
 	smbus_api_block_pcall_t smbus_block_pcall;
+	smbus_api_manage_smbalert_cb_t smbus_manage_smbalert_cb;
+	smbus_api_manage_host_notify_cb_t smbus_manage_host_notify_cb;
 };
 
 /**
@@ -547,6 +587,64 @@ static inline int z_impl_smbus_get_config(const struct device *dev,
 	return api->get_config(dev, dev_config);
 }
 
+/**
+ * @brief Add SMBUSALERT callback for a SMBus host controller.
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ * @param cb Pointer to a callback structure.
+ * @param set A boolean indicating insertion or removal of the callback.
+ *
+ * @retval 0 If successful.
+ * @retval -EIO General input / output error, failed to configure device.
+ * @retval -ENOSYS If get config is not implemented
+ */
+__syscall int smbus_manage_smbalert_cb(const struct device *dev,
+				       struct smbus_callback *cb,
+				       bool set);
+
+static inline int z_impl_smbus_manage_smbalert_cb(const struct device *dev,
+						  struct smbus_callback *cb,
+						  bool set)
+{
+	const struct smbus_driver_api *api =
+		(const struct smbus_driver_api *)dev->api;
+
+	if (api->smbus_manage_smbalert_cb == NULL) {
+		return -ENOSYS;
+	}
+
+	return api->smbus_manage_smbalert_cb(dev, cb, set);
+}
+
+/**
+ * @brief Add Host Notify callback for a SMBus host controller.
+ *
+ * @param dev Pointer to the device structure for the driver instance.
+ * @param cb Pointer to a callback structure.
+ * @param set A boolean indicating insertion or removal of the callback.
+ *
+ * @retval 0 If successful.
+ * @retval -EIO General input / output error, failed to configure device.
+ * @retval -ENOSYS If get config is not implemented
+ */
+__syscall int smbus_manage_host_notify_cb(const struct device *dev,
+					  struct smbus_callback *cb,
+					  bool set);
+
+static inline int z_impl_smbus_manage_host_notify_cb(const struct device *dev,
+						     struct smbus_callback *cb,
+						     bool set)
+{
+	const struct smbus_driver_api *api =
+		(const struct smbus_driver_api *)dev->api;
+
+	if (api->smbus_manage_host_notify_cb == NULL) {
+		return -ENOSYS;
+	}
+
+	return api->smbus_manage_host_notify_cb(dev, cb, set);
+}
+
 /**
  * @brief Perform SMBus Quick operation
  *

include/zephyr/drivers/smbus_utils.h

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2022 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_DRIVERS_SMBUS_SMBUS_UTILS_H_
+#define ZEPHYR_DRIVERS_SMBUS_SMBUS_UTILS_H_
+
+/**
+ * @brief Generic function to insert or remove a callback from a callback list
+ *
+ * @param callbacks A pointer to the original list of callbacks (can be NULL)
+ * @param callback A pointer of the callback to insert or remove from the list
+ * @param set A boolean indicating insertion or removal of the callback
+ *
+ * @return 0 on success, negative errno otherwise.
+ */
+static inline int smbus_manage_smbus_callback(sys_slist_t *callbacks,
+					      struct smbus_callback *callback,
+					      bool set)
+{
+	__ASSERT(callback, "No callback!");
+	__ASSERT(callback->handler, "No callback handler!");
+
+	if (!sys_slist_is_empty(callbacks)) {
+		if (!sys_slist_find_and_remove(callbacks, &callback->node)) {
+			if (!set) {
+				return -ENOENT;
+			}
+		}
+	} else {
+		if (!set) {
+			return -ENOENT;
+		}
+	}
+
+	if (set) {
+		sys_slist_prepend(callbacks, &callback->node);
+	}
+
+	return 0;
+}
+
+/**
+ * @brief Generic function to go through and fire callback from a callback list
+ *
+ * @param list A pointer on the SMBus callback list
+ * @param dev A pointer on the SMBus device instance
+ * @param addr A SMBus peripheral device address.
+ */
+static inline void smbus_fire_callbacks(sys_slist_t *list,
+					const struct device *dev,
+					uint8_t addr)
+{
+	struct smbus_callback *cb, *tmp;
+
+	SYS_SLIST_FOR_EACH_CONTAINER_SAFE(list, cb, tmp, node) {
+		if (cb->addr == addr) {
+			__ASSERT(cb->handler, "No callback handler!");
+			cb->handler(dev, cb, addr);
+		}
+	}
+}
+
+/**
+ * @brief Helper to initialize a struct smbus_callback properly
+ *
+ * @param callback A valid Application's callback structure pointer.
+ * @param handler A valid handler function pointer.
+ * @param addr A SMBus peripheral device address.
+ */
+static inline void smbus_init_callback(struct smbus_callback *callback,
+				       smbus_callback_handler_t handler,
+				       uint8_t addr)
+{
+	__ASSERT(callback, "Callback pointer should not be NULL");
+	__ASSERT(handler, "Callback handler pointer should not be NULL");
+
+	callback->handler = handler;
+	callback->addr = addr;
+}
+
+
+#endif /*  ZEPHYR_DRIVERS_SMBUS_SMBUS_UTILS_H_ */