sys: added SAUL registry

sys/include/saul_reg.h

@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2015 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    sys_saul_reg SAUL registry
+ * @ingroup     sys
+ * @brief       Global sensor/actuator registry for SAUL devices
+ *
+ * @{
+ *
+ * @file
+ * @brief       SAUL registry interface definition
+ *
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ */
+
+#ifndef SAUL_REG_H
+#define SAUL_REG_H
+
+#include <stdint.h>
+
+#include "saul.h"
+#include "phydat.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   SAUL registry entry
+ */
+typedef struct saul_reg_t {
+    struct saul_reg_t *next;        /**< pointer to the next device */
+    void *dev;                      /**< pointer to the device descriptor */
+    const char *name;               /**< string identifier for the device */
+    saul_driver_t const *driver;    /**< the devices read callback */
+} saul_reg_t;
+
+/**
+ * @brief   Additional data to collect for each entry
+ */
+typedef struct {
+    const char *name;           /**< string identifier for a device */
+} saul_reg_info_t;
+
+/**
+ * @brief   Register a device with the SAUL registry
+ *
+ * @note    Make sure the registry entry the @p dev pointer is pointing to
+ *          resides in some persistent memory location and not on some position
+ *          on the stack where it will be overwritten...
+ *
+ * @param[in] dev       pointer to a pre-populated registry entry
+ *
+ * @return      0 on success
+ * @return      -ENODEV on invalid entry given
+ */
+int saul_reg_add(saul_reg_t *dev);
+
+/**
+ * @brief   Unregister a device from the SAUL registry
+ *
+ * @param[in] dev       pointer to a registry entry
+ *
+ * @return      0 on success
+ * @return      -ENODEV if device was not found in the registry
+ */
+int saul_reg_rm(saul_reg_t *dev);
+
+/**
+ * @brief   Get the first device from the list of registered devices
+ *
+ * @return      pointer to the first device in the list
+ * @return      NULL if list is empty
+ */
+saul_reg_t *saul_reg_get(void);
+
+/**
+ * @brief   Find a device by it's position in the registry
+ *
+ * @param[in] pos       position to look up
+ *
+ * @return      pointer to the device at position specified by @p pos
+ * @return      NULL if no device is registered at that position
+ */
+saul_reg_t *saul_reg_find_nth(int pos);
+
+/**
+ * @brief   Find the first device of the given type in the registry
+ *
+ * @param[in] type      device type to look for
+ *
+ * @return      pointer to the first device matching the given type
+ * @return      NULL if no device of that type could be found
+ */
+saul_reg_t *saul_reg_find_type(uint8_t type);
+
+/**
+ * @brief   Find a device by its name
+ *
+ * @param[in] name      the name to look for
+ *
+ * @return      pointer to the first device matching the given name
+ * @return      NULL if no device with that name could be found
+ */
+saul_reg_t *saul_reg_find_name(const char *name);
+
+/**
+ * @brief   Read data from the given device
+ *
+ * @param[in] dev       device to read from
+ * @param[out] res      location to store the results in
+ *
+ * @return      the number of data elements read to @p res [1-3]
+ * @return      -ENODEV if given device is invalid
+ * @return      -ENOTSUP if read operation is not supported by the device
+ * @return      -ECANCELED on device errors
+ */
+int saul_reg_read(saul_reg_t *dev, phydat_t *res);
+
+/**
+ * @brief   Write data to the given device
+ *
+ * @param[in] dev       device to write to
+ * @param[in] data      data to write to the device
+ *
+ * @return      the number of data elements read to @p res [1-3]
+ * @return      -ENODEV if given device is invalid
+ * @return      -ENOTSUP if read operation is not supported by the device
+ * @return      -ECANCELED on device errors
+ */
+int saul_reg_write(saul_reg_t *dev, phydat_t *data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SAUL_REG_H */
+/** @} */

sys/saul_reg/Makefile

@@ -0,0 +1 @@
+include $(RIOTBASE)/Makefile.base

sys/saul_reg/saul_reg.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2015 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     sys_saul_reg
+ * @{
+ *
+ * @file
+ * @brief       SAUL registry implementation
+ *
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "saul_reg.h"
+
+/**
+ * @brief   Keep the head of the device list
+ */
+static saul_reg_t *reg = NULL;
+
+
+int saul_reg_add(saul_reg_t *dev)
+{
+    saul_reg_t *tmp = reg;
+
+    if (dev == NULL) {
+        return -ENODEV;
+    }
+
+    /* prepare new entry */
+    dev->next = NULL;
+    /* add to registry */
+    if (reg == NULL) {
+        reg = dev;
+    }
+    else {
+        while (tmp->next != NULL) {
+            tmp = tmp->next;
+        }
+        tmp->next = dev;
+    }
+    return 0;
+}
+
+int saul_reg_rm(saul_reg_t *dev)
+{
+    saul_reg_t *tmp = reg;
+
+    if (reg == NULL || dev == NULL) {
+        return -EINVAL;
+    }
+    if (reg == dev) {
+        reg = dev->next;
+    }
+    while (tmp->next && (tmp->next != dev)) {
+        tmp = tmp->next;
+    }
+    if (tmp->next == dev) {
+        tmp->next = dev->next;
+    }
+    else {
+        return -ENODEV;
+    }
+    return 0;
+}
+
+saul_reg_t *saul_reg_get(void)
+{
+    return reg;
+}
+
+saul_reg_t *saul_reg_find_nth(int pos)
+{
+    saul_reg_t *tmp = reg;
+
+    for (int i = 0; (i < pos) && tmp; i++) {
+        tmp = tmp->next;
+    }
+    return tmp;
+}
+
+saul_reg_t *saul_reg_find_type(uint8_t type)
+{
+    saul_reg_t *tmp = reg;
+
+    while (tmp) {
+        if (tmp->driver->type == type) {
+            return tmp;
+        }
+        tmp = tmp->next;
+    }
+    return NULL;
+}
+
+saul_reg_t *saul_reg_find_name(const char *name)
+{
+    saul_reg_t *tmp = reg;
+
+    while (tmp) {
+        if (strcmp(tmp->name, name) == 0) {
+            return tmp;
+        }
+        tmp = tmp->next;
+    }
+    return NULL;
+}
+
+int saul_reg_read(saul_reg_t *dev, phydat_t *res)
+{
+    if (dev == NULL) {
+        return -ENODEV;
+    }
+    return dev->driver->read(dev->dev, res);
+}
+
+int saul_reg_write(saul_reg_t *dev, phydat_t *data)
+{
+    if (dev == NULL) {
+        return -ENODEV;
+    }
+    return dev->driver->write(dev->dev, data);
+}