Difference between revisions of "Zephyr device driver model"
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The device initialization macros populate some data structures at build time which are split into read-only and runtime-mutable parts. At a high level we have: | The device initialization macros populate some data structures at build time which are split into read-only and runtime-mutable parts. At a high level we have: | ||
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struct device { | struct device { | ||
const char *name; | const char *name; | ||
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const void *api; | const void *api; | ||
void * const data; | void * const data; | ||
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Revision as of 05:37, 13 August 2021
Excerpt from Zephyr project drivers documentation:
-
Driver Data Structures
The device initialization macros populate some data structures at build time which are split into read-only and runtime-mutable parts. At a high level we have:
struct device {
const char *name;
const void *config;
const void *api;
void * const data;
};
Excerpt from file ~/ncs/zephyr/include/drivers/sensor.h:
382 /**
383 * @brief Set an attribute for a sensor
384 *
385 * @param dev Pointer to the sensor device
386 * @param chan The channel the attribute belongs to, if any. Some
387 * attributes may only be set for all channels of a device, depending on
388 * device capabilities.
389 * @param attr The attribute to set
390 * @param val The value to set the attribute to
391 *
392 * @return 0 if successful, negative errno code if failure.
393 */
394 __syscall int sensor_attr_set(const struct device *dev,
395 enum sensor_channel chan,
396 enum sensor_attribute attr,
397 const struct sensor_value *val);
398
399 static inline int z_impl_sensor_attr_set(const struct device *dev,
400 enum sensor_channel chan,
401 enum sensor_attribute attr,
402 const struct sensor_value *val)
403 {
404 const struct sensor_driver_api *api =
405 (const struct sensor_driver_api *)dev->api;
406
407 if (api->attr_set == NULL) {
408 return -ENOSYS;
409 }
410
411 return api->attr_set(dev, chan, attr, val);
412 }
413
