Fix readline return value; Add support for removable serial devices

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5589 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -4069,4 +4069,8 @@
 	  this.
 	* arch/arm/src/lm/chip/lm4f_memorymap.h: More LM4F changes from
 	  Jose Pablo Carballo.
-
+	* drivers/serial/serial.c, include/nuttx/serial/serial.h,
+	  drivers/usbdev/cdcacm.c, and drivers/pl2303.c: Add support for
+	  removable serial devices (like USB serial).  This support is enabled
+	  by CONFIG_SERIAL_REMOVABLE and requires VBUS sensing support from
+	  the board-specific logic.

configs/stm32f4discovery/usbnsh/defconfig

@@ -95,9 +95,7 @@ CONFIG_BOARD_LOOPSPERMSEC=16717
 #
 # CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC is not set
 # CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT is not set
-# CONFIG_ARMV7M_TOOLCHAIN_CODEREDL is not set
 # CONFIG_ARMV7M_TOOLCHAIN_CODEREDW is not set
-# CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL is not set
 CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
 # CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM is not set
 # CONFIG_ARMV7M_TOOLCHAIN_GNU_EABI is not set
@@ -374,6 +372,7 @@ CONFIG_SPI_EXCHANGE=y
 # CONFIG_SERCOMM_CONSOLE is not set
 CONFIG_SERIAL=y
 # CONFIG_DEV_LOWCONSOLE is not set
+CONFIG_SERIAL_REMOVABLE=y
 # CONFIG_16550_UART is not set
 CONFIG_ARCH_HAVE_USART2=y
 CONFIG_MCU_SERIAL=y
@@ -458,6 +457,7 @@ CONFIG_CDCACM_PRODUCTSTR="CDC/ACM Serial"
 #
 # System Logging
 #
+# CONFIG_SYSLOG_ENABLE is not set
 CONFIG_SYSLOG=y
 CONFIG_SYSLOG_CHAR=y
 CONFIG_SYSLOG_DEVPATH="/dev/ttyS0"
@@ -686,6 +686,10 @@ CONFIG_NSH_NESTDEPTH=3
 # CONFIG_NSH_DISABLEBG is not set
 CONFIG_NSH_CONSOLE=y
 # CONFIG_NSH_USBCONSOLE is not set
+
+#
+# USB Trace Support
+#
 # CONFIG_NSH_CONDEV is not set
 CONFIG_NSH_ARCHINIT=y
 
@@ -736,3 +740,7 @@ CONFIG_READLINE_ECHO=y
 # Sysinfo
 #
 # CONFIG_SYSTEM_SYSINFO is not set
+
+#
+# USB Monitor
+#

drivers/serial/Kconfig

@@ -10,6 +10,9 @@ config DEV_LOWCONSOLE
 	---help---
 		Use the simple, low-level, write-only serial console driver (minimal support)
 
+config SERIAL_REMOVABLE
+	bool
+
 config 16550_UART
 	bool "16550 UART Chip support"
 	default n

drivers/serial/serial.c

@@ -1,7 +1,7 @@
 /************************************************************************************
  * drivers/serial/serial.c
  *
- *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -157,7 +157,11 @@ static void uart_pollnotify(FAR uart_dev_t *dev, pollevent_t eventset)
       struct pollfd *fds = dev->fds[i];
       if (fds)
         {
+#ifdef CONFIG_SERIAL_REMOVABLE
+          fds->revents |= ((fds->events | (POLLERR|POLLHUP)) & eventset);
+#else
           fds->revents |= (fds->events & eventset);
+#endif
           if (fds->revents != 0)
             {
               fvdbg("Report events: %02x\n", fds->revents);
@@ -219,6 +223,15 @@ static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
           uart_disabletxint(dev);
           irqrestore(flags);
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+          /* Check if the removable device is no longer connected */
+
+          if (dev->disconnected)
+            {
+              return -ENOTCONN;
+            }
+#endif
+
           /* Check if we were awakened by signal. */
 
           if (ret < 0)
@@ -279,6 +292,15 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
   ssize_t           nread  = buflen;
   int               ret;
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+  /* If the removable device is no longer connected, refuse to write to the device */
+
+  if (dev->disconnected)
+    {
+      return -ENOTCONN;
+    }
+#endif
+
   /* We may receive console writes through this path from interrupt handlers and
    * from debug output in the IDLE task!  In these cases, we will need to do things
    * a little differently.
@@ -395,6 +417,15 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
   int16_t           tail;
   int               ret;
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+  /* If the removable device is no longer connected, refuse to read from the device */
+
+  if (dev->disconnected)
+    {
+      return -ENOTCONN;
+    }
+#endif
+
   /* Only one user can access dev->recv.tail at a time */
 
   ret = uart_takesem(&dev->recv.sem, true);
@@ -525,9 +556,15 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
               ret = uart_takesem(&dev->recvsem, true);
               irqrestore(flags);
 
-              /* Was a signal received while waiting for data to be received? */
+              /* Was a signal received while waiting for data to be
+               * received?  Was a removable device disconnected?
+               */
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+              if (ret < 0 || dev->disconnected)
+#else
               if (ret < 0)
+#endif
                 {
                   /* POSIX requires that we return after a signal is received.
                    * If some bytes were read, we need to return the number of bytes
@@ -541,7 +578,11 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
                        * set the errno value appropriately.
                        */
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+                      recvd = dev->disconnected ? -ENOTCONN : -EINTR;
+#else
                       recvd = -EINTR;
+#endif
                     }
 
                   break;
@@ -656,12 +697,12 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
 
       if (ndx != dev->xmit.tail)
        {
-         eventset |= POLLOUT;
+         eventset |= (fds->events & POLLOUT);
        }
 
       uart_givesem(&dev->xmit.sem);
 
-      /* Check if the receive buffer is empty
+      /* Check if the receive buffer is empty.
        *
        * Get exclusive access to the recv buffer indices.  NOTE: that we do not
        * let this wait be interrupted by a signal (we probably should, but that
@@ -671,11 +712,20 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
       (void)uart_takesem(&dev->recv.sem, false);
       if (dev->recv.head != dev->recv.tail)
        {
-         eventset |= POLLIN;
+         eventset |= (fds->events & POLLIN);
        }
 
       uart_givesem(&dev->recv.sem);
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+      /* Check if a removable device has been disconnected. */
+
+      if (dev->disconnected)
+        {
+           eventset |= (POLLERR|POLLHUP);
+        }
+#endif
+
       if (eventset)
         {
           uart_pollnotify(dev, eventset);
@@ -796,6 +846,15 @@ static int uart_open(FAR struct file *filep)
   uint8_t       tmp;
   int           ret;
 
+#ifdef CONFIG_SERIAL_REMOVABLE
+  /* If the removable device is no longer connected, refuse to open the device */
+
+  if (dev->disconnected)
+    {
+      return -ENOTCONN;
+    }
+#endif
+
   /* If the port is the middle of closing, wait until the close is finished.
    * If a signal is received while we are waiting, then return EINTR.
    */
@@ -915,10 +974,12 @@ int uart_register(FAR const char *path, FAR uart_dev_t *dev)
 
 void uart_datareceived(FAR uart_dev_t *dev)
 {
-  /* Awaken any awaiting read() operations */
+  /* Is there a thread waiting for read data?  */
 
   if (dev->recvwaiting)
     {
+      /* Yes... wake it up */
+
       dev->recvwaiting = false;
       (void)sem_post(&dev->recvsem);
     }
@@ -942,8 +1003,12 @@ void uart_datareceived(FAR uart_dev_t *dev)
 
 void uart_datasent(FAR uart_dev_t *dev)
 {
+  /* Is there a thread waiting for space in xmit.buffer?  */
+
   if (dev->xmitwaiting)
     {
+      /* Yes... wake it up */
+
       dev->xmitwaiting = false;
       (void)sem_post(&dev->xmitsem);
     }
@@ -953,4 +1018,64 @@ void uart_datasent(FAR uart_dev_t *dev)
   uart_pollnotify(dev, POLLOUT);
 }
 
+/************************************************************************************
+ * Name: uart_connected
+ *
+ * Description:
+ *   Serial devices (like USB serial) can be removed.  In that case, the "upper
+ *   half" serial driver must be informed that there is no longer a valid serial
+ *   channel associated with the driver.
+ *
+ *   In this case, the driver will terminate all pending transfers wint ENOTCONN and
+ *   will refuse all further transactions while the "lower half" is disconnected.
+ *   The driver will continue to be registered, but will be in an unusable state.
+ *
+ *   Conversely, the "upper half" serial driver needs to know when the serial
+ *   device is reconnected so that it can resume normal operations.
+ *
+ * Assumptions/Limitations:
+ *   This function may be called from an interrupt handler.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+void uart_connected(FAR uart_dev_t *dev, bool connected)
+{
+  /* Is the device disconnected? */
+
+  dev->disconnected = !connected;
+  if (!connected)
+    {
+      /* Yes.. wake up all waiting threads.  Each thread should detect the
+       * disconnection and return the ENOTCONN error.
+       */
+
+      /* Is there a thread waiting for space in xmit.buffer?  */
+
+      if (dev->xmitwaiting)
+        {
+          /* Yes... wake it up */
+
+          dev->xmitwaiting = false;
+          (void)sem_post(&dev->xmitsem);
+        }
+
+      /* Is there a thread waiting for read data?  */
+
+      if (dev->recvwaiting)
+        {
+          /* Yes... wake it up */
+
+          dev->recvwaiting = false;
+          (void)sem_post(&dev->recvsem);
+        }
+
+      /* Notify all poll/select waiters that and hangup/error occurred */
+
+      uart_pollnotify(dev, (POLLERR|POLLHUP));
+    }
+}
+#endif
+
+
 

drivers/usbdev/Kconfig

@@ -150,6 +150,7 @@ endif
 menuconfig PL2303
 	bool "Prolific PL2303 serial/USB converter emulation"
 	default n
+	select SERIAL_REMOVABLE
 	---help---
 		This logic emulates the Prolific PL2303 serial/USB converter
 
@@ -222,6 +223,7 @@ endif
 menuconfig CDCACM
 	bool "USB Modem (CDC ACM) support"
 	default n
+	select SERIAL_REMOVABLE
 	---help---
 		Enables USB Modem (CDC ACM) support
 

drivers/usbdev/cdcacm.c

@@ -570,6 +570,14 @@ static void cdcacm_resetconfig(FAR struct cdcacm_dev_s *priv)
 
       priv->config = CDCACM_CONFIGIDNONE;
 
+      /* Inform the "upper half" driver that there is no (functional) USB
+       * connection.
+       */
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+      uart_connected(&priv->serdev, false);
+#endif
+
       /* Disable endpoints.  This should force completion of all pending
        * transfers.
        */
@@ -731,10 +739,20 @@ static int cdcacm_setconfig(FAR struct cdcacm_dev_s *priv, uint8_t config)
           usbtrace(TRACE_CLSERROR(USBSER_TRACEERR_RDSUBMIT), (uint16_t)-ret);
           goto errout;
         }
+
       priv->nrdq++;
     }
 
+  /* We are successfully configured */
+
   priv->config = config;
+
+  /* Inform the "upper half" driver that we are "open for business" */
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+  uart_connected(&priv->serdev, true);
+#endif
+
   return OK;
 
 errout:
@@ -1575,12 +1593,20 @@ static void cdcacm_disconnect(FAR struct usbdevclass_driver_s *driver,
     }
 #endif
 
-  /* Reset the configuration */
+  /* Inform the "upper half serial driver that we have lost the USB serial
+   * connection.
+   */
 
   flags = irqsave();
+#ifdef CONFIG_SERIAL_REMOVABLE
+  uart_connected(&priv->serdev, false);
+#endif
+
+  /* Reset the configuration */
+
   cdcacm_resetconfig(priv);
 
-  /* Clear out all data in the circular buffer */
+  /* Clear out all outgoing data in the circular buffer */
 
   priv->serdev.xmit.head = 0;
   priv->serdev.xmit.tail = 0;
@@ -2045,12 +2071,17 @@ int cdcacm_classobject(int minor, FAR struct usbdevclass_driver_s **classdev)
 
   /* Initialize the serial driver sub-structure */
 
-  priv->serdev.recv.size   = CONFIG_CDCACM_RXBUFSIZE;
+      /* The initial state is disconnected */
-  priv->serdev.recv.buffer = priv->rxbuffer;
+
-  priv->serdev.xmit.size   = CONFIG_CDCACM_TXBUFSIZE;
+#ifdef CONFIG_SERIAL_REMOVABLE
-  priv->serdev.xmit.buffer = priv->txbuffer;
+  priv->serdev.disconnected = true;
-  priv->serdev.ops         = &g_uartops;
+#endif
-  priv->serdev.priv        = priv;
+  priv->serdev.recv.size    = CONFIG_CDCACM_RXBUFSIZE;
+  priv->serdev.recv.buffer  = priv->rxbuffer;
+  priv->serdev.xmit.size    = CONFIG_CDCACM_TXBUFSIZE;
+  priv->serdev.xmit.buffer  = priv->txbuffer;
+  priv->serdev.ops          = &g_uartops;
+  priv->serdev.priv         = priv;
 
   /* Initialize the USB class driver structure */
 

drivers/usbdev/pl2303.c

@@ -983,6 +983,14 @@ static void usbclass_resetconfig(FAR struct pl2303_dev_s *priv)
 
       priv->config = PL2303_CONFIGIDNONE;
 
+      /* Inform the "upper half" driver that there is no (functional) USB
+       * connection.
+       */
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+      uart_connected(&priv->serdev, false);
+#endif
+
       /* Disable endpoints.  This should force completion of all pending
        * transfers.
        */
@@ -1112,10 +1120,20 @@ static int usbclass_setconfig(FAR struct pl2303_dev_s *priv, uint8_t config)
           usbtrace(TRACE_CLSERROR(USBSER_TRACEERR_RDSUBMIT), (uint16_t)-ret);
           goto errout;
         }
+
       priv->nrdq++;
     }
 
+  /* We are successfully configured */
+
   priv->config = config;
+
+  /* Inform the "upper half" driver that we are "open for business" */
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+  uart_connected(&priv->serdev, true);
+#endif
+
   return OK;
 
 errout:
@@ -1844,12 +1862,20 @@ static void usbclass_disconnect(FAR struct usbdevclass_driver_s *driver,
     }
 #endif
 
-  /* Reset the configuration */
+  /* Inform the "upper half serial driver that we have lost the USB serial
+   * connection.
+   */
 
   flags = irqsave();
+#ifdef CONFIG_SERIAL_REMOVABLE
+  uart_connected(&priv->serdev, false);
+#endif
+
+  /* Reset the configuration */
+
   usbclass_resetconfig(priv);
 
-  /* Clear out all data in the circular buffer */
+  /* Clear out all outgoing data in the circular buffer */
 
   priv->serdev.xmit.head = 0;
   priv->serdev.xmit.tail = 0;
@@ -2185,12 +2211,15 @@ int usbdev_serialinitialize(int minor)
 
   /* Initialize the serial driver sub-structure */
 
-  priv->serdev.recv.size   = CONFIG_PL2303_RXBUFSIZE;
+#ifdef CONFIG_SERIAL_REMOVABLE
-  priv->serdev.recv.buffer = priv->rxbuffer;
+  priv->serdev.disconnected = true;
-  priv->serdev.xmit.size   = CONFIG_PL2303_TXBUFSIZE;
+#endif
-  priv->serdev.xmit.buffer = priv->txbuffer;
+  priv->serdev.recv.size    = CONFIG_PL2303_RXBUFSIZE;
-  priv->serdev.ops         = &g_uartops;
+  priv->serdev.recv.buffer  = priv->rxbuffer;
-  priv->serdev.priv        = priv;
+  priv->serdev.xmit.size    = CONFIG_PL2303_TXBUFSIZE;
+  priv->serdev.xmit.buffer  = priv->txbuffer;
+  priv->serdev.ops          = &g_uartops;
+  priv->serdev.priv         = priv;
 
   /* Initialize the USB class driver structure */
 

include/nuttx/serial/serial.h

@@ -1,7 +1,7 @@
 /************************************************************************************
  * include/nuttx/serial/serial.h
  *
- *   Copyright (C) 2007-2008, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2008, 2012-2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -46,6 +46,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <semaphore.h>
+
 #include <nuttx/fs/fs.h>
 
 /************************************************************************************
@@ -190,20 +191,23 @@ struct uart_ops_s
 
 struct uart_dev_s
 {
-  uint8_t              open_count;  /* Number of times the device has been opened */
+  uint8_t              open_count;   /* Number of times the device has been opened */
-  volatile bool        xmitwaiting; /* true: User waiting for space in xmit.buffer */
+  volatile bool        xmitwaiting;  /* true: User waiting for space in xmit.buffer */
-  volatile bool        recvwaiting; /* true: User waiting for data in recv.buffer */
+  volatile bool        recvwaiting;  /* true: User waiting for data in recv.buffer */
-  bool                 isconsole;   /* true: This is the serial console */
+#ifdef CONFIG_SERIAL_REMOVABLE
-  sem_t                closesem;    /* Locks out new open while close is in progress */
+  volatile bool        disconnected; /* true: Removable device is not connected */
-  sem_t                xmitsem;     /* Wakeup user waiting for space in xmit.buffer */
-  sem_t                recvsem;     /* Wakeup user waiting for data in recv.buffer */
-#ifndef CONFIG_DISABLE_POLL
-  sem_t                pollsem;     /* Manages exclusive access to fds[] */
 #endif
-  struct uart_buffer_s xmit;        /* Describes transmit buffer */
+  bool                 isconsole;    /* true: This is the serial console */
-  struct uart_buffer_s recv;        /* Describes receive buffer */
+  sem_t                closesem;     /* Locks out new open while close is in progress */
-  FAR const struct uart_ops_s *ops; /* Arch-specific operations */
+  sem_t                xmitsem;      /* Wakeup user waiting for space in xmit.buffer */
-  FAR void            *priv;        /* Used by the arch-specific logic */
+  sem_t                recvsem;      /* Wakeup user waiting for data in recv.buffer */
+#ifndef CONFIG_DISABLE_POLL
+  sem_t                pollsem;      /* Manages exclusive access to fds[] */
+#endif
+  struct uart_buffer_s xmit;         /* Describes transmit buffer */
+  struct uart_buffer_s recv;         /* Describes receive buffer */
+  FAR const struct uart_ops_s *ops;  /* Arch-specific operations */
+  FAR void            *priv;         /* Used by the arch-specific logic */
 
   /* The following is a list if poll structures of threads waiting for
    * driver events. The 'struct pollfd' reference for each open is also
@@ -213,26 +217,27 @@ struct uart_dev_s
 #ifndef CONFIG_DISABLE_POLL
   struct pollfd *fds[CONFIG_SERIAL_NPOLLWAITERS];
 #endif
-
 };
+
 typedef struct uart_dev_s uart_dev_t;
 
 /************************************************************************************
  * Public Data
  ************************************************************************************/
 
-/************************************************************************************
- * Public Functions
- ************************************************************************************/
-
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
 
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
 /************************************************************************************
  * Name: uart_register
  *
@@ -241,7 +246,7 @@ extern "C" {
  *
  ************************************************************************************/
 
-EXTERN int uart_register(FAR const char *path, FAR uart_dev_t *dev);
+int uart_register(FAR const char *path, FAR uart_dev_t *dev);
 
 /************************************************************************************
  * Name: uart_xmitchars
@@ -254,7 +259,7 @@ EXTERN int uart_register(FAR const char *path, FAR uart_dev_t *dev);
  *
  ************************************************************************************/
 
-EXTERN void uart_xmitchars(FAR uart_dev_t *dev);
+void uart_xmitchars(FAR uart_dev_t *dev);
 
 /************************************************************************************
  * Name: uart_receivechars
@@ -267,7 +272,7 @@ EXTERN void uart_xmitchars(FAR uart_dev_t *dev);
  *
  ************************************************************************************/
 
-EXTERN void uart_recvchars(FAR uart_dev_t *dev);
+void uart_recvchars(FAR uart_dev_t *dev);
 
 /************************************************************************************
  * Name: uart_datareceived
@@ -279,7 +284,7 @@ EXTERN void uart_recvchars(FAR uart_dev_t *dev);
  *
  ************************************************************************************/
 
-EXTERN void uart_datareceived(FAR uart_dev_t *dev);
+void uart_datareceived(FAR uart_dev_t *dev);
 
 /************************************************************************************
  * Name: uart_datasent
@@ -292,7 +297,31 @@ EXTERN void uart_datareceived(FAR uart_dev_t *dev);
  *
  ************************************************************************************/
 
-EXTERN void uart_datasent(FAR uart_dev_t *dev);
+void uart_datasent(FAR uart_dev_t *dev);
+
+/************************************************************************************
+ * Name: uart_connected
+ *
+ * Description:
+ *   Serial devices (like USB serial) can be removed.  In that case, the "upper
+ *   half" serial driver must be informed that there is no longer a valid serial
+ *   channel associated with the driver.
+ *
+ *   In this case, the driver will terminate all pending transfers wint ENOTCONN and
+ *   will refuse all further transactions while the "lower half" is disconnected.
+ *   The driver will continue to be registered, but will be in an unusable state.
+ *
+ *   Conversely, the "upper half" serial driver needs to know when the serial
+ *   device is reconnected so that it can resume normal operations.
+ *
+ * Assumptions/Limitations:
+ *   This function may be called from an interrupt handler.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_SERIAL_REMOVABLE
+void uart_connected(FAR uart_dev_t *dev, bool connected);
+#endif
 
 #undef EXTERN
 #if defined(__cplusplus)