Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

[linux-2.6-microblaze.git] / include / linux / tty_ldisc.h

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 49dc172..af01e89 100644 (file)
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -71,7 +71,7 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     call to @receive_buf(). Returning an error will prevent the ldisc from
  *     being attached.
  *
- *     Can sleep.
+ *     Optional. Can sleep.
  *
  * @close: [TTY] ``void ()(struct tty_struct *tty)``
  *
@@ -80,7 +80,7 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     changed to use a new line discipline. At the point of execution no
  *     further users will enter the ldisc code for this tty.
  *
- *     Can sleep.
+ *     Optional. Can sleep.
  *
  * @flush_buffer: [TTY] ``void ()(struct tty_struct *tty)``
  *
@@ -88,8 +88,10 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     input characters it may have queued to be delivered to the user mode
  *     process. It may be called at any point between open and close.
  *
- * @read: [TTY] ``ssize_t ()(struct tty_struct *tty, struct file *file,
- *             unsigned char *buf, size_t nr)``
+ *     Optional.
+ *
+ * @read: [TTY] ``ssize_t ()(struct tty_struct *tty, struct file *file, u8 *buf,
+ *             size_t nr)``
  *
  *     This function is called when the user requests to read from the @tty.
  *     The line discipline will return whatever characters it has buffered up
@@ -97,10 +99,10 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     an %EIO error. Multiple read calls may occur in parallel and the ldisc
  *     must deal with serialization issues.
  *
- *     Can sleep.
+ *     Optional: %EIO unless provided. Can sleep.
  *
  * @write: [TTY] ``ssize_t ()(struct tty_struct *tty, struct file *file,
- *             const unsigned char *buf, size_t nr)``
+ *              const u8 *buf, size_t nr)``
  *
  *     This function is called when the user requests to write to the @tty.
  *     The line discipline will deliver the characters to the low-level tty
@@ -108,7 +110,7 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     characters first. If this function is not defined, the user will
  *     receive an %EIO error.
  *
- *     Can sleep.
+ *     Optional: %EIO unless provided. Can sleep.
  *
  * @ioctl: [TTY] ``int ()(struct tty_struct *tty, unsigned int cmd,
  *             unsigned long arg)``
@@ -120,6 +122,8 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     discpline. So a low-level driver can "grab" an ioctl request before
  *     the line discpline has a chance to see it.
  *
+ *     Optional.
+ *
  * @compat_ioctl: [TTY] ``int ()(struct tty_struct *tty, unsigned int cmd,
  *             unsigned long arg)``
  *
@@ -130,11 +134,15 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     a pointer to wordsize-sensitive structure belongs here, but most of
  *     ldiscs will happily leave it %NULL.
  *
+ *     Optional.
+ *
  * @set_termios: [TTY] ``void ()(struct tty_struct *tty, const struct ktermios *old)``
  *
  *     This function notifies the line discpline that a change has been made
  *     to the termios structure.
  *
+ *     Optional.
+ *
  * @poll: [TTY] ``int ()(struct tty_struct *tty, struct file *file,
  *               struct poll_table_struct *wait)``
  *
@@ -142,6 +150,8 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     device. It is solely the responsibility of the line discipline to
  *     handle poll requests.
  *
+ *     Optional.
+ *
  * @hangup: [TTY] ``void ()(struct tty_struct *tty)``
  *
  *     Called on a hangup. Tells the discipline that it should cease I/O to
@@ -149,10 +159,10 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     but should wait until any pending driver I/O is completed. No further
  *     calls into the ldisc code will occur.
  *
- *     Can sleep.
+ *     Optional. Can sleep.
  *
- * @receive_buf: [DRV] ``void ()(struct tty_struct *tty,
- *                    const unsigned char *cp, const char *fp, int count)``
+ * @receive_buf: [DRV] ``void ()(struct tty_struct *tty, const u8 *cp,
+ *                    const u8 *fp, size_t count)``
  *
  *     This function is called by the low-level tty driver to send characters
  *     received by the hardware to the line discpline for processing. @cp is
@@ -161,6 +171,8 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     character was received with a parity error, etc. @fp may be %NULL to
  *     indicate all data received is %TTY_NORMAL.
  *
+ *     Optional.
+ *
  * @write_wakeup: [DRV] ``void ()(struct tty_struct *tty)``
  *
  *     This function is called by the low-level tty driver to signal that line
@@ -170,13 +182,17 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     send, please arise a tasklet or workqueue to do the real data transfer.
  *     Do not send data in this hook, it may lead to a deadlock.
  *
+ *     Optional.
+ *
  * @dcd_change: [DRV] ``void ()(struct tty_struct *tty, bool active)``
  *
  *     Tells the discipline that the DCD pin has changed its status. Used
  *     exclusively by the %N_PPS (Pulse-Per-Second) line discipline.
  *
- * @receive_buf2: [DRV] ``int ()(struct tty_struct *tty,
- *                     const unsigned char *cp, const char *fp, int count)``
+ *     Optional.
+ *
+ * @receive_buf2: [DRV] ``ssize_t ()(struct tty_struct *tty, const u8 *cp,
+ *                     const u8 *fp, size_t count)``
  *
  *     This function is called by the low-level tty driver to send characters
  *     received by the hardware to the line discpline for processing. @cp is a
@@ -186,8 +202,10 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     indicate all data received is %TTY_NORMAL. If assigned, prefer this
  *     function for automatic flow control.
  *
- * @lookahead_buf: [DRV] ``void ()(struct tty_struct *tty,
- *                     const unsigned char *cp, const char *fp, int count)``
+ *     Optional.
+ *
+ * @lookahead_buf: [DRV] ``void ()(struct tty_struct *tty, const u8 *cp,
+ *                      const u8 *fp, size_t count)``
  *
  *     This function is called by the low-level tty driver for characters
  *     not eaten by ->receive_buf() or ->receive_buf2(). It is useful for
@@ -198,6 +216,8 @@ int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
  *     same characters (e.g. by skipping the actions for high-priority
  *     characters already handled by ->lookahead_buf()).
  *
+ *     Optional.
+ *
  * @owner: module containting this ldisc (for reference counting)
  *
  * This structure defines the interface between the tty line discipline
@@ -218,11 +238,10 @@ struct tty_ldisc_ops {
        int     (*open)(struct tty_struct *tty);
        void    (*close)(struct tty_struct *tty);
        void    (*flush_buffer)(struct tty_struct *tty);
-       ssize_t (*read)(struct tty_struct *tty, struct file *file,
-                       unsigned char *buf, size_t nr,
-                       void **cookie, unsigned long offset);
+       ssize_t (*read)(struct tty_struct *tty, struct file *file, u8 *buf,
+                       size_t nr, void **cookie, unsigned long offset);
        ssize_t (*write)(struct tty_struct *tty, struct file *file,
-                        const unsigned char *buf, size_t nr);
+                        const u8 *buf, size_t nr);
        int     (*ioctl)(struct tty_struct *tty, unsigned int cmd,
                        unsigned long arg);
        int     (*compat_ioctl)(struct tty_struct *tty, unsigned int cmd,
@@ -235,14 +254,14 @@ struct tty_ldisc_ops {
        /*
         * The following routines are called from below.
         */
-       void    (*receive_buf)(struct tty_struct *tty, const unsigned char *cp,
-                              const char *fp, int count);
+       void    (*receive_buf)(struct tty_struct *tty, const u8 *cp,
+                              const u8 *fp, size_t count);
        void    (*write_wakeup)(struct tty_struct *tty);
        void    (*dcd_change)(struct tty_struct *tty, bool active);
-       int     (*receive_buf2)(struct tty_struct *tty, const unsigned char *cp,
-                               const char *fp, int count);
-       void    (*lookahead_buf)(struct tty_struct *tty, const unsigned char *cp,
-                                const unsigned char *fp, unsigned int count);
+       size_t  (*receive_buf2)(struct tty_struct *tty, const u8 *cp,
+                               const u8 *fp, size_t count);
+       void    (*lookahead_buf)(struct tty_struct *tty, const u8 *cp,
+                                const u8 *fp, size_t count);
 
        struct  module *owner;
 };