import RT-Thread@9217865c without bsp, libcpu and components/net

components/drivers/tty/tty_ldisc.c

@@ -0,0 +1,179 @@
+#include <tty.h>
+#include <tty_ldisc.h>
+
+#define DBG_TAG               "TTY_LDISC"
+#ifdef RT_TTY_DEBUG
+#define DBG_LVL               DBG_LOG
+#else
+#define DBG_LVL               DBG_INFO
+#endif /* RT_TTY_DEBUG */
+#include <rtdbg.h>
+
+extern struct tty_ldisc_ops n_tty_ops;
+static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS] = {
+    &n_tty_ops, /* N_TTY = 0 */
+};
+
+static struct tty_ldisc_ops *get_ldops(int disc)
+{
+    struct tty_ldisc_ops *ldops = RT_NULL;
+    int level = 0;
+    level = rt_hw_interrupt_disable();
+    ldops = tty_ldiscs[disc];
+    if (ldops)
+    {
+        ldops->refcount++;
+    }
+    rt_hw_interrupt_enable(level);
+    return ldops;
+}
+
+static void put_ldops(struct tty_ldisc_ops *ldops)
+{
+    int level = 0;
+
+    level = rt_hw_interrupt_disable();
+    ldops->refcount--;
+    rt_hw_interrupt_enable(level);
+}
+
+static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
+{
+    struct tty_ldisc *ld = RT_NULL;
+    struct tty_ldisc_ops *ldops = RT_NULL;
+
+    if (disc < N_TTY || disc >= NR_LDISCS)
+    {
+        return RT_NULL;
+    }
+
+    ldops = get_ldops(disc);
+    if (ldops == RT_NULL)
+    {
+        LOG_E("tty ldisc get error\n");
+        return RT_NULL;
+    }
+
+    ld = rt_malloc(sizeof(struct tty_ldisc));
+    if (ld == RT_NULL)
+    {
+        ldops->refcount--;
+        return RT_NULL;
+    }
+
+    ld->ops = ldops;
+    ld->tty = tty;
+
+    return ld;
+}
+
+/**
+ *  tty_ldisc_put       -   release the ldisc
+ *
+ *  Complement of tty_ldisc_get().
+ */
+static void tty_ldisc_put(struct tty_ldisc *ld)
+{
+    if (ld)
+    {
+        put_ldops(ld->ops);
+        rt_free(ld);
+    }
+}
+
+/**
+ *  tty_ldisc_close     -   close a line discipline
+ *  @tty: tty we are opening the ldisc on
+ *  @ld: discipline to close
+ *
+ *  A helper close method. Also a convenient debugging and check
+ *  point.
+ */
+static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+    if (ld && ld->ops->close)
+    {
+        ld->ops->close(tty);
+    }
+}
+
+/**
+ *  tty_ldisc_kill  -   teardown ldisc
+ *  @tty: tty being released
+ *
+ *  Perform final close of the ldisc and reset tty->ldisc
+ */
+void tty_ldisc_kill(struct tty_struct *tty)
+{
+    if (tty && tty->ldisc)
+    {
+        /*
+        * Now kill off the ldisc
+        */
+        tty_ldisc_close(tty, tty->ldisc);
+        tty_ldisc_put(tty->ldisc);
+        /* Force an oops if we mess this up */
+        tty->ldisc = NULL;
+    }
+}
+
+int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
+{
+    int ret = 0;
+    int level = 0;
+
+    if (disc < N_TTY || disc >= NR_LDISCS)
+    {
+        return -EINVAL;
+    }
+
+    level = rt_hw_interrupt_disable();
+    tty_ldiscs[disc] = new_ldisc;
+    new_ldisc->num = disc;
+    new_ldisc->refcount = 0;
+    rt_hw_interrupt_enable(level);
+
+    return ret;
+}
+
+/**
+ *  tty_ldisc_release       -   release line discipline
+ *  @tty: tty being shut down (or one end of pty pair)
+ *
+ *  Called during the final close of a tty or a pty pair in order to shut
+ *  down the line discpline layer. On exit, each tty's ldisc is NULL.
+ */
+
+void tty_ldisc_release(struct tty_struct *tty)
+{
+    int level = 0;
+    struct tty_struct *o_tty = tty->other_struct;
+
+    /*
+     * Shutdown this line discipline. As this is the final close,
+     * it does not race with the set_ldisc code path.
+     */
+    level = rt_hw_interrupt_disable();
+    tty_ldisc_kill(tty);
+    if (o_tty)
+    {
+        tty_ldisc_kill(o_tty);
+    }
+    rt_hw_interrupt_enable(level);
+}
+
+/**
+ *  tty_ldisc_init      -   ldisc setup for new tty
+ *  @tty: tty being allocated
+ *
+ *  Set up the line discipline objects for a newly allocated tty. Note that
+ *  the tty structure is not completely set up when this call is made.
+ */
+
+void tty_ldisc_init(struct tty_struct *tty)
+{
+    if (tty)
+    {
+        tty->ldisc = tty_ldisc_get(tty, N_TTY);
+    }
+}