4  * SPDX-License-Identifier: Apache-2.0
28 	     "Size of off_t must be equal or less than size of size_t");
41  * @brief	Callback API to get size of retained memory area.
44 typedef ssize_t (*retained_mem_size_api)(const struct device *dev);
51 typedef int (*retained_mem_read_api)(const struct device *dev, off_t offset, uint8_t *buffer,
52 				     size_t size);
59 typedef int (*retained_mem_write_api)(const struct device *dev, off_t offset,
60 				      const uint8_t *buffer, size_t size);
67 typedef int (*retained_mem_clear_api)(const struct device *dev);
74  * non-initialised RAM region, or in specific registers, but is not reset when a different
76  * byte-level reading and writing without a need to erase data before writing.
81 	retained_mem_size_api size;  member
88  * @brief		Returns the size of the retained memory area.
90  * @param dev		Retained memory device to use.
92  * @retval		Positive value indicating size in bytes on success, else negative errno
95 __syscall ssize_t retained_mem_size(const struct device *dev);
97 static inline ssize_t z_impl_retained_mem_size(const struct device *dev)  in z_impl_retained_mem_size()  argument
99 	struct retained_mem_driver_api *api = (struct retained_mem_driver_api *)dev->api;  in z_impl_retained_mem_size()
101 	return api->size(dev);  in z_impl_retained_mem_size()
107  * @param dev		Retained memory device to use.
110  * @param size		Size of data to read.
114 __syscall int retained_mem_read(const struct device *dev, off_t offset, uint8_t *buffer,
115 				size_t size);
117 static inline int z_impl_retained_mem_read(const struct device *dev, off_t offset,  in z_impl_retained_mem_read()  argument
118 					   uint8_t *buffer, size_t size)  in z_impl_retained_mem_read()  argument
120 	struct retained_mem_driver_api *api = (struct retained_mem_driver_api *)dev->api;  in z_impl_retained_mem_read()
123 	/* Validate user-supplied parameters */  in z_impl_retained_mem_read()
124 	if (size == 0) {  in z_impl_retained_mem_read()
128 	area_size = api->size(dev);  in z_impl_retained_mem_read()
130 	if (offset < 0 || size > area_size || (area_size - size) < (size_t)offset) {  in z_impl_retained_mem_read()
131 		return -EINVAL;  in z_impl_retained_mem_read()
134 	return api->read(dev, offset, buffer, size);  in z_impl_retained_mem_read()
138  * @brief		Writes data to the Retained memory area - underlying data does not need to
141  * @param dev		Retained memory device to use.
144  * @param size		Size of data to be written.
148 __syscall int retained_mem_write(const struct device *dev, off_t offset, const uint8_t *buffer,
149 				 size_t size);
151 static inline int z_impl_retained_mem_write(const struct device *dev, off_t offset,  in z_impl_retained_mem_write()  argument
152 					    const uint8_t *buffer, size_t size)  in z_impl_retained_mem_write()  argument
154 	struct retained_mem_driver_api *api = (struct retained_mem_driver_api *)dev->api;  in z_impl_retained_mem_write()
157 	/* Validate user-supplied parameters */  in z_impl_retained_mem_write()
158 	if (size == 0) {  in z_impl_retained_mem_write()
162 	area_size = api->size(dev);  in z_impl_retained_mem_write()
164 	if (offset < 0 || size > area_size || (area_size - size) < (size_t)offset) {  in z_impl_retained_mem_write()
165 		return -EINVAL;  in z_impl_retained_mem_write()
168 	return api->write(dev, offset, buffer, size);  in z_impl_retained_mem_write()
174  * @param dev		Retained memory device to use.
178 __syscall int retained_mem_clear(const struct device *dev);
180 static inline int z_impl_retained_mem_clear(const struct device *dev)  in z_impl_retained_mem_clear()  argument
182 	struct retained_mem_driver_api *api = (struct retained_mem_driver_api *)dev->api;  in z_impl_retained_mem_clear()
184 	return api->clear(dev);  in z_impl_retained_mem_clear()