Changeset 15c5418 in mainline for uspace/lib/c/generic/io/chardev.c

Timestamp:

2017-11-18T20:06:15Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

75fcf9b

Parents:

efb9fd08

Message:

chardev_open, chardev_close.

File:

• uspace/lib/c/generic/io/chardev.c (modified) (3 diffs)

uspace/lib/c/generic/io/chardev.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2011 Jan Vesely
+ * Copyright (c) 2017 Jiri Svoboda
  * All rights reserved.
  *
@@ -27 +28 @@
  */
 
+/** @addtogroup libc
+ * @{
+ */
+/**
+ * @file
+ * @brief Character device client interface
+ */
+
 #include <errno.h>
 #include <mem.h>
 #include <io/chardev.h>
 #include <ipc/chardev.h>
+#include <stdlib.h>
 
-ssize_t chardev_read(async_exch_t *exch, void *data, size_t size)
+/** Open character device.
+ *
+ * @param sess Session with the character device
+ * @param rchardev Place to store pointer to the new character device structure
+ *
+ * @return EOK on success, ENOMEM if out of memory, EIO on I/O error
+ */
+int chardev_open(async_sess_t *sess, chardev_t **rchardev)
 {
-        if (!exch)
-                return EBADMEM;
+        chardev_t *chardev;
+
+        chardev = calloc(1, sizeof(chardev_t));
+        if (chardev == NULL)
+                return ENOMEM;
+
+        chardev->sess = sess;
+        *rchardev = chardev;
+
+        /* EIO might be used in a future implementation */
+        return EOK;
+}
+
+/** Close character device.
+ *
+ * Frees the character device structure. The underlying session is
+ * not affected.
+ *
+ * @param chardev Character device or @c NULL
+ */
+void chardev_close(chardev_t *chardev)
+{
+        free(chardev);
+}
+
+ssize_t chardev_read(chardev_t *chardev, void *data, size_t size)
+{
         if (size > 4 * sizeof(sysarg_t))
                 return ELIMIT;
 
+        async_exch_t *exch = async_exchange_begin(chardev->sess);
         sysarg_t message[4] = { 0 };
         const ssize_t ret = async_req_1_4(exch, CHARDEV_READ, size,
             &message[0], &message[1], &message[2], &message[3]);
+        async_exchange_end(exch);
         if (ret > 0 && (size_t)ret <= size)
                 memcpy(data, message, size);
@@ -47 +91 @@
 }
 
-ssize_t chardev_write(async_exch_t *exch, const void *data, size_t size)
+ssize_t chardev_write(chardev_t *chardev, const void *data, size_t size)
 {
-        if (!exch)
-                return EBADMEM;
+        int ret;
+
         if (size > 3 * sizeof(sysarg_t))
                 return ELIMIT;
 
+        async_exch_t *exch = async_exchange_begin(chardev->sess);
         sysarg_t message[3] = { 0 };
         memcpy(message, data, size);
-        return async_req_4_0(exch, CHARDEV_WRITE, size,
+        ret = async_req_4_0(exch, CHARDEV_WRITE, size,
             message[0], message[1], message[2]);
+        async_exchange_end(exch);
+        return ret;
 }
+
+/** @}
+ */