Minimal device system, implement terminal device and libterminal

kernel/device/device.c

@@ -0,0 +1,72 @@
+#include <device/device.h>
+#include <device/terminal.h>
+#include <libk/fieldlengthof.h>
+#include <libk/rbtree.h>
+#include <libk/std.h>
+#include <libk/string.h>
+#include <m/terminal_device.h>
+#include <mm/liballoc.h>
+#include <sync/spin_lock.h>
+
+static struct rb_node_link* device_tree = NULL;
+static spin_lock_t device_tree_lock;
+
+struct device* device_create (int id, device_op_func_t* ops, size_t ops_len,
+                              bool (*init) (void* arg), void (*fini) (void), void* arg) {
+  if (ops_len >= fieldlengthof (struct device, ops))
+    return NULL;
+
+  struct device* device = malloc (sizeof (*device));
+
+  if (device == NULL)
+    return NULL;
+
+  memset (device, 0, sizeof (*device));
+
+  device->id = id;
+  device->init = init;
+  device->fini = fini;
+  memcpy (device->ops, ops, ops_len * sizeof (device_op_func_t));
+
+  if (!device->init (arg)) {
+    free (device);
+    return NULL;
+  }
+
+  spin_lock (&device_tree_lock);
+  rbtree_insert (struct device, &device_tree, &device->device_tree_link, device_tree_link, id);
+  spin_unlock (&device_tree_lock);
+
+  return device;
+}
+
+void device_delete (struct device* device) {
+  spin_lock (&device_tree_lock);
+  spin_lock (&device->lock);
+
+  rbtree_delete (&device_tree, &device->device_tree_link);
+
+  spin_unlock (&device->lock);
+  spin_unlock (&device_tree_lock);
+
+  device->fini ();
+}
+
+struct device* device_find (int id) {
+  struct device* device = NULL;
+
+  spin_lock (&device_tree_lock);
+  rbtree_find (struct device, &device_tree, id, device, device_tree_link, id);
+  spin_unlock (&device_tree_lock);
+
+  return device;
+}
+
+void devices_init (void) {
+  {
+    device_op_func_t ops[] = {
+        [TERMINAL_PUTSTR] = &terminal_putstr,
+    };
+    device_create (1, ops, lengthof (ops), &terminal_init, &terminal_fini, NULL);
+  }
+}