drivers/at: add URC registering and parsing feature

drivers/at/at.c

@@ -266,3 +266,52 @@ out:
     }
     return res;
 }
+
+#ifdef MODULE_AT_URC
+void at_add_urc(at_dev_t *dev, at_urc_t *urc)
+{
+    assert(urc);
+    assert(urc->code);
+    assert(strlen(urc->code) != 0);
+    assert(urc->cb);
+
+    clist_rpush(&dev->urc_list, &urc->list_node);
+}
+
+void at_remove_urc(at_dev_t *dev, at_urc_t *urc)
+{
+    clist_remove(&dev->urc_list, &urc->list_node);
+}
+
+static int _check_urc(clist_node_t *node, void *arg)
+{
+    const char *buf = arg;
+    at_urc_t *urc = container_of(node, at_urc_t, list_node);
+
+    DEBUG("Trying to match with %s\n", urc->code);
+
+    if (strncmp(buf, urc->code, strlen(urc->code)) == 0) {
+        urc->cb(urc->arg, buf);
+        return 1;
+    }
+
+    return 0;
+}
+
+void at_process_urc(at_dev_t *dev, uint32_t timeout)
+{
+    char buf[AT_BUF_SIZE];
+
+    DEBUG("Processing URC (timeout=%" PRIu32 "us)\n", timeout);
+
+    ssize_t res;
+    /* keep reading while received data are shorter than EOL */
+    while ((res = at_readline(dev, buf, sizeof(buf), true, timeout)) <
+           (ssize_t)sizeof(AT_RECV_EOL_1 AT_RECV_EOL_2) - 1) {
+        if (res < 0) {
+            return;
+        }
+    }
+    clist_foreach(&dev->urc_list, _check_urc, buf);
+}
+#endif

drivers/include/at.h

@@ -39,6 +39,7 @@
 
 #include "isrpipe.h"
 #include "periph/uart.h"
+#include "clist.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -77,12 +78,41 @@ extern "C" {
 #define AT_RECV_ERROR "ERROR"
 #endif
 
+#if defined(MODULE_AT_URC) || DOXYGEN
+#ifndef AT_BUF_SIZE
+/** Internal buffer size used to process unsolicited result code data */
+#define AT_BUF_SIZE (128)
+#endif
+
+/**
+ * @brief   Unsolicited result code callback
+ *
+ * @param[in]   arg     optional argument
+ * @param[in]   code    urc string received from the device
+ */
+typedef void (*at_urc_cb_t)(void *arg, const char *code);
+
+/**
+ * @brief   Unsolicited result code data structure
+ */
+typedef struct {
+    clist_node_t list_node; /**< node list */
+    at_urc_cb_t cb;         /**< callback */
+    const char *code;       /**< URC string which must match */
+    void *arg;              /**< optional argument */
+} at_urc_t;
+
+#endif /* MODULE_AT_URC */
+
 /**
  * @brief AT device structure
  */
 typedef struct {
     isrpipe_t isrpipe;      /**< isrpipe used for getting data from uart */
     uart_t uart;            /**< UART device where the AT device is attached */
+#ifdef MODULE_AT_URC
+    clist_node_t urc_list;  /**< list to keep track of all registered urc's */
+#endif
 } at_dev_t;
 
 /**
@@ -226,6 +256,32 @@ ssize_t at_readline(at_dev_t *dev, char *resp_buf, size_t len, bool keep_eol, ui
  */
 void at_drain(at_dev_t *dev);
 
+#if defined(MODULE_AT_URC) || DOXYGEN
+/**
+ * @brief   Add a callback for an unsolicited response code
+ *
+ * @param[in]   dev     device to operate on
+ * @param[in]   urc     unsolicited result code to register
+ */
+void at_add_urc(at_dev_t *dev, at_urc_t *urc);
+
+/**
+ * @brief   Remove an unsolicited response code from the list
+ *
+ * @param[in]   dev     device to operate on
+ * @param[in]   urc     unsolicited result code to remove
+ */
+void at_remove_urc(at_dev_t *dev, at_urc_t *urc);
+
+/**
+ * @brief   Process out-of-band data received from the device
+ *
+ * @param[in]   dev     device to operate on
+ * @param[in]   timeout timeout (in usec)
+ */
+void at_process_urc(at_dev_t *dev, uint32_t timeout);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

makefiles/pseudomodules.inc.mk

@@ -1,3 +1,4 @@
+PSEUDOMODULES += at_urc
 PSEUDOMODULES += auto_init_gnrc_rpl
 PSEUDOMODULES += can_mbox
 PSEUDOMODULES += can_pm