termios: Partially hide rtems_termios_tty

Move interrupt lock to device context and expose only this structure to
the read, write and set attributes device handler.  This makes these
device handler independent of the general Termios infrastructure
suitable for direct use in printk() support.

1 files changed, 98 insertions, 48 deletions

diff --git a/cpukit/libcsupport/include/rtems/termiostypes.h b/cpukit/libcsupport/include/rtems/termiostypes.h
index 045a91f4c2..71be95fc06 100644
--- a/cpukit/libcsupport/include/rtems/termiostypes.h
+++ b/cpukit/libcsupport/include/rtems/termiostypes.h
@@ -63,6 +63,42 @@ typedef enum {
 struct rtems_termios_tty;
 
 /**
+ * @brief Termios device context.
+ *
+ * @see RTEMS_TERMIOS_DEVICE_CONTEXT_INITIALIZER(),
+ * rtems_termios_device_context_initialize() and
+ * rtems_termios_device_install().
+ */
+typedef struct rtems_termios_device_context {
+  rtems_interrupt_lock interrupt_lock;
+} rtems_termios_device_context;
+
+/**
+ * @brief Initializes a device context.
+ *
+ * @param[in] context The Termios device context.
+ * @param[in] name The name for the interrupt lock.  This name must be a
+ *   string persistent throughout the life time of this lock.  The name is only
+ *   used if profiling is enabled.
+ */
+RTEMS_INLINE_ROUTINE void rtems_termios_device_context_initialize(
+  rtems_termios_device_context *context,
+  const char                   *name
+)
+{
+  rtems_interrupt_lock_initialize( &context->interrupt_lock, name );
+}
+
+/**
+ * @brief Initializer for static initialization of Termios device contexts.
+ *
+ * @param name The name for the interrupt lock.  It must be a string.  The name
+ *   is only used if profiling is enabled.
+ */
+#define RTEMS_TERMIOS_DEVICE_CONTEXT_INITIALIZER( name ) \
+  { RTEMS_INTERRUPT_LOCK_INITIALIZER( name ) }
+
+/**
  * @brief Termios device handler.
  *
  * @see rtems_termios_device_install().
@@ -71,18 +107,24 @@ typedef struct {
   /**
    * @brief First open of this device.
    *
-   * @param[in] tty The Termios control.
+   * @param[in] tty The Termios control.  This parameter may be passed to
+   *   interrupt service routines since it must be provided for the
+   *   rtems_termios_enqueue_raw_characters() and
+   *   rtems_termios_dequeue_characters() functions.
+   * @param[in] context The Termios device context.
+   * @param[in] term The current Termios attributes.
    * @param[in] args The open/close arguments.  This is parameter provided to
    *   support legacy drivers.  It must not be used by new drivers.
    *
    * @retval true Successful operation.
    * @retval false Cannot open device.
    *
-   * @see rtems_termios_get_device_context(), rtems_termios_set_best_baud() and
-   *   rtems_termios_get_termios().
+   * @see rtems_termios_get_device_context() and rtems_termios_set_best_baud().
    */
   bool (*first_open)(
     struct rtems_termios_tty      *tty,
+    rtems_termios_device_context  *context,
+    struct termios                *term,
     rtems_libio_open_close_args_t *args
   );
 
@@ -90,13 +132,13 @@ typedef struct {
    * @brief Last close of this device.
    *
    * @param[in] tty The Termios control.
+   * @param[in] context The Termios device context.
    * @param[in] args The open/close arguments.  This is parameter provided to
    *   support legacy drivers.  It must not be used by new drivers.
-   *
-   * @see rtems_termios_get_device_context().
    */
   void (*last_close)(
     struct rtems_termios_tty      *tty,
+    rtems_termios_device_context  *context,
     rtems_libio_open_close_args_t *args
   );
 
@@ -106,41 +148,39 @@ typedef struct {
    * In case mode is TERMIOS_IRQ_DRIVEN or TERMIOS_TASK_DRIVEN, then data is
    * received via rtems_termios_enqueue_raw_characters().
    *
-   * @param[in] tty The Termios control.
+   * @param[in] context The Termios device context.
    *
    * @retval char The received data encoded as unsigned char.
    * @retval -1 No data currently available.
-   *
-   * @see rtems_termios_get_device_context().
    */
-  int (*poll_read)(struct rtems_termios_tty *tty);
+  int (*poll_read)(rtems_termios_device_context *context);
 
   /**
    * @brief Polled write in case mode is TERMIOS_POLLED or write support
    * otherwise.
    *
-   * @param[in] tty The Termios control.
+   * @param[in] context The Termios device context.
    * @param[in] buf The output buffer.
    * @param[in] len The output buffer length in characters.
-   *
-   * @see rtems_termios_get_device_context().
    */
-  void (*write)(struct rtems_termios_tty *tty, const char *buf, size_t len);
+  void (*write)(
+    rtems_termios_device_context *context,
+    const char *buf,
+    size_t len
+  );
 
   /**
    * @brief Set attributes after a Termios settings change.
    *
-   * @param[in] tty The Termios control.
+   * @param[in] context The Termios device context.
    * @param[in] term The new Termios attributes.
    *
    * @retval true Successful operation.
    * @retval false Invalid attributes.
-   *
-   * @see rtems_termios_get_device_context().
    */
   bool (*set_attributes)(
-    struct rtems_termios_tty *tty,
-    const struct termios     *term
+    rtems_termios_device_context *context,
+    const struct termios         *term
   );
 
   /**
@@ -158,20 +198,16 @@ typedef struct {
   /**
    * @brief Indicate to stop remote transmitter.
    *
-   * @param[in] tty The Termios control.
-   *
-   * @see rtems_termios_get_device_context().
+   * @param[in] context The Termios device context.
    */
-  void (*stop_remote_tx)(struct rtems_termios_tty *tty);
+  void (*stop_remote_tx)(rtems_termios_device_context *context);
 
   /**
    * @brief Indicate to start remote transmitter.
    *
-   * @param[in] tty The Termios control.
-   *
-   * @see rtems_termios_get_device_context().
+   * @param[in] context The Termios device context.
    */
-  void (*start_remote_tx)(struct rtems_termios_tty *tty);
+  void (*start_remote_tx)(rtems_termios_device_context *context);
 } rtems_termios_device_flow;
 
 /**
@@ -185,7 +221,7 @@ typedef struct rtems_termios_device_node {
   rtems_device_minor_number           minor;
   const rtems_termios_device_handler *handler;
   const rtems_termios_device_flow    *flow;
-  void                               *context;
+  rtems_termios_device_context       *context;
   struct rtems_termios_tty           *tty;
 } rtems_termios_device_node;
 
@@ -258,6 +294,11 @@ typedef struct rtems_termios_tty {
   rtems_termios_callbacks  device;
 
   /**
+   * @brief Context for legacy devices using the callbacks.
+   */
+  rtems_termios_device_context legacy_device_context;
+
+  /**
    * @brief The device handler.
    */
   rtems_termios_device_handler handler;
@@ -289,8 +330,6 @@ typedef struct rtems_termios_tty {
   struct ttywakeup tty_rcv;
   int              tty_rcvwakeup;
 
-  rtems_interrupt_lock interrupt_lock;
-
   /**
    * @brief Corresponding device node.
    */
@@ -298,10 +337,8 @@ typedef struct rtems_termios_tty {
 
   /**
    * @brief Context for device driver.
-   *
-   * @see rtems_termios_get_device_context().
    */
-  void *device_context;
+  rtems_termios_device_context *device_context;
 } rtems_termios_tty;
 
 /**
@@ -335,7 +372,7 @@ rtems_status_code rtems_termios_device_install(
   rtems_device_minor_number           minor,
   const rtems_termios_device_handler *handler,
   const rtems_termios_device_flow    *flow,
-  void                               *context
+  rtems_termios_device_context       *context
 );
 
 /**
@@ -382,6 +419,8 @@ rtems_status_code rtems_termios_device_close(void *arg);
 
 /**
  * @brief Returns the device context of an installed Termios device.
+ *
+ * @param[in] tty The Termios control.
  */
 RTEMS_INLINE_ROUTINE void *rtems_termios_get_device_context(
   const rtems_termios_tty *tty
@@ -391,16 +430,33 @@ RTEMS_INLINE_ROUTINE void *rtems_termios_get_device_context(
 }
 
 /**
- * @brief Returns the Termios structure.
+ * @brief Acquires the device lock.
  *
- * It can be used for example in the first open handler to adjust or obtain the
- * initial attributes.
+ * @param[in] context The device context.
+ * @param[in] lock_context The local interrupt lock context for an acquire and
+ *   release pair.
  */
-RTEMS_INLINE_ROUTINE struct termios *rtems_termios_get_termios(
-  rtems_termios_tty *tty
+RTEMS_INLINE_ROUTINE void rtems_termios_device_lock_acquire(
+  rtems_termios_device_context *context,
+  rtems_interrupt_lock_context *lock_context
 )
 {
-  return &tty->termios;
+  rtems_interrupt_lock_acquire( &context->interrupt_lock, lock_context );
+}
+
+/**
+ * @brief Releases the device lock.
+ *
+ * @param[in] context The device context.
+ * @param[in] lock_context The local interrupt lock context for an acquire and
+ *   release pair.
+ */
+RTEMS_INLINE_ROUTINE void rtems_termios_device_lock_release(
+  rtems_termios_device_context *context,
+  rtems_interrupt_lock_context *lock_context
+)
+{
+  rtems_interrupt_lock_release( &context->interrupt_lock, lock_context );
 }
 
 /**
@@ -409,12 +465,12 @@ RTEMS_INLINE_ROUTINE struct termios *rtems_termios_get_termios(
  * The valid Termios baud values are between 0 and 460800.  The Termios baud
  * value is chosen which minimizes the difference to the value specified.
  *
- * @param[in] tty The Termios control.
+ * @param[in] term The Termios attributes.
  * @param[in] baud The current baud setting of the device.
  */
 void rtems_termios_set_best_baud(
-  rtems_termios_tty *tty,
-  uint32_t           baud
+  struct termios *term,
+  uint32_t        baud
 );
 
 struct rtems_termios_linesw {
@@ -498,12 +554,6 @@ int rtems_termios_set_initial_baud(
   rtems_termios_baud_t baud
 );
 
-#define rtems_termios_interrupt_lock_acquire(tty, level) \
-  rtems_interrupt_lock_acquire(&tty->interrupt_lock, level)
-
-#define rtems_termios_interrupt_lock_release(tty, level) \
-  rtems_interrupt_lock_release(&tty->interrupt_lock, level)
-
 #ifdef __cplusplus
 }
 #endif