feat: simple device abstraction layer

[lunaix-os.git] / lunaix-os / kernel / device.c

diff --git a/lunaix-os/kernel/device.c b/lunaix-os/kernel/device.c
new file mode 100644 (file)
index 0000000..9cb2fa1
--- /dev/null
+++ b/lunaix-os/kernel/device.c
@@ -0,0 +1,84 @@
+#include <klibc/stdio.h>
+#include <lunaix/device.h>
+#include <lunaix/fs/twifs.h>
+#include <lunaix/mm/valloc.h>
+
+struct llist_header dev_list;
+
+static struct twifs_node* dev_root;
+
+int
+__dev_read(struct v_file* file, void* buffer, size_t len);
+
+int
+__dev_write(struct v_file* file, void* buffer, size_t len);
+
+void
+device_init()
+{
+    dev_root = twifs_toplevel_node("dev", 3);
+
+    llist_init_head(&dev_list);
+}
+
+struct device*
+device_add(struct device* parent, void* underlay, char* name_fmt, ...)
+{
+    struct device* dev = vzalloc(sizeof(struct device));
+
+    va_list args;
+    va_start(args, name_fmt);
+
+    size_t strlen =
+      __sprintf_internal(dev->name_val, name_fmt, DEVICE_NAME_SIZE, args);
+
+    dev->name = HSTR(dev->name_val, strlen);
+    dev->parent = parent;
+    dev->underlay = underlay;
+
+    hstr_rehash(&dev->name, HSTR_FULL_HASH);
+    llist_append(&dev_list, &dev->dev_list);
+
+    struct twifs_node* dev_node =
+      twifs_file_node(dev_root, dev->name_val, strlen);
+    dev_node->data = dev;
+    dev_node->fops.read = __dev_read;
+    dev_node->fops.write = __dev_write;
+
+    dev->fs_node = dev_node;
+
+    va_end(args);
+    return dev;
+}
+
+int
+__dev_read(struct v_file* file, void* buffer, size_t len)
+{
+    struct twifs_node* dev_node = (struct twifs_node*)file->inode->data;
+    struct device* dev = (struct device*)dev_node->data;
+
+    if (!dev->read) {
+        return ENOTSUP;
+    }
+    return dev->read(dev, buffer, file->f_pos, len);
+}
+
+int
+__dev_write(struct v_file* file, void* buffer, size_t len)
+{
+    struct twifs_node* dev_node = (struct twifs_node*)file->inode->data;
+    struct device* dev = (struct device*)dev_node->data;
+
+    if (!dev->write) {
+        return ENOTSUP;
+    }
+    return dev->write(dev, buffer, file->f_pos, len);
+}
+
+void
+device_remove(struct device* dev)
+{
+    llist_delete(&dev->dev_list);
+    twifs_rm_node((struct twifs_node*)dev->fs_node);
+    vfree(dev);
+}
\ No newline at end of file