lpc313x uart driver code complete

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2446 42af7a65-404d-4744-a932-0658087f49c3

arch/arm/src/arm/up_head.S

@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include "arm.h"
+#include "chip.h"
 #include "up_internal.h"
 #include "up_arch.h"
 

arch/arm/src/lpc313x/Make.defs

@@ -50,4 +50,5 @@ CGU_CSRCS	= lpc313x_clkdomain.c lpc313x_clkfreq.c lpc313x_esrndx.c \
 		  lpc313x_fdcndx.c lpc313x_softreset.c
 
 CHIP_ASRCS	= $(CGU_ASRCS)
-CHIP_CSRCS	= lpc313x_allocateheap.c lpc313x_irq.c lpc313x_timerisr.c $(CGU_CSRCS)
+CHIP_CSRCS	= lpc313x_allocateheap.c lpc313x_irq.c lpc313x_lowputc.c \
+		  lpc313x_serial.c lpc313x_timerisr.c $(CGU_CSRCS)

arch/arm/src/lpc313x/lpc313x_lowputc.c

@@ -0,0 +1,325 @@
+/****************************************************************************
+ * arch/arm/src/lpc313x/lpc313x_lowputc.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "up_arch.h"
+#include "up_internal.h"
+
+#include "lpc313x_cgudrvr.h"
+#include "lpc313x_uart.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_waittxready
+ ****************************************************************************/
+
+static inline void up_waittxready(void)
+{
+  int tmp;
+
+  /* Limit how long we will wait for the TX available condition */
+
+  for (tmp = 1000 ; tmp > 0 ; tmp--)
+    {
+      /* Check if the tranmitter holding register (THR) is empty */
+ 
+      if ((getreg32(LPC313X_UART_LSR) & UART_LSR_THRE) != 0)
+        {
+          /* The THR is empty, return */
+
+          break;
+        }
+    }
+}
+
+/****************************************************************************
+ * Name: up_configbaud
+ ****************************************************************************/
+
+#ifndef CONFIG_USE_EARLYSERIALINIT
+static inline void up_configbaud(void)
+{
+  /* In a buckled-up, embedded system, there is no reason to constantly
+   * calculate the following.  The calculation can be skipped if the
+   * MULVAL, DIVADDVAL, and DIVISOR values are provided in the configuration
+   * file.
+   */
+
+#ifndef CONFIG_LPC313X_UART_MULVAL
+  uint32_t qtrclk;
+  uint32_t regval;
+
+  /* Test values calculated for every multiplier/divisor combination */
+
+  uint32_t tdiv;
+  uint32_t terr;
+  int      tmulval;
+  int      tdivaddval;
+
+  /* Optimal multiplier/divider values */
+
+  uint32_t div       = 0;
+  uint32_t err       = 100000;
+  int      mulval    = 1;
+  int      divaddval = 0;
+
+  /* Baud is generated using FDR and DLL-DLM registers
+   *
+   *   baud = clock * (mulval/(mulval+divaddval) / (16 * div)
+   *
+   * Or
+   *
+   *   div = (clock/16) * (mulval/(mulval+divaddval) / baud
+   *
+   * Where mulval    = Fractional divider multiplier
+   *       divaddval = Fractional divider pre-scale div
+   *       div       = DLL-DLM divisor
+   */
+
+  /* Get UART block clock divided by 16 */
+  
+  qtrclk = lpc313x_clkfreq(CLKID_UARTUCLK, DOMAINID_UART) >> 4;
+
+  /* Try every valid multiplier, tmulval (or until a perfect
+   * match is found).
+   */
+
+  for (tmulval = 1 ; tmulval <= 15 && err > 0; tmulval++)
+    {
+      /* Try every valid pre-scale div, tdivaddval (or until a perfect
+       * match is found).
+       */
+
+      for (tdivaddval = 0 ; tdivaddval <= 15 && err > 0; tdivaddval++)
+        {
+          /* Calculate the divisor with these fractional divider settings */
+
+          uint32_t tmp = (tmulval * qtrclk) / ((tmulval + tdivaddval));
+          tdiv         = (tmp + (CONFIG_UART_BAUD>>1)) / CONFIG_UART_BAUD;
+
+          /* Check if this candidate divisor is within a valid range */
+
+          if (tdiv > 2 && tdiv < 0x10000)
+            {
+              /* Calculate the actual baud and the error */
+
+              uint32_t actualbaud = tmp / tdiv;
+
+              if (actualbaud <= CONFIG_UART_BAUD)
+                {
+                  terr = CONFIG_UART_BAUD - actualbaud;
+                }
+              else
+                {
+                  terr = actualbaud - CONFIG_UART_BAUD;
+                }
+
+              /* Is this the smallest error we have encountered? */
+
+              if (terr < err)
+                {
+                  /* Yes, save these settings as the new, candidate optimal settings */
+
+                  mulval     = tmulval ;
+                  divaddval = tdivaddval;
+                  div       = tdiv;
+                  err       = terr;
+                }
+            }
+        }
+    }
+
+    /* Set the Divisor Latch Access Bit (DLAB) to enable DLL/DLM access */
+
+    regval  = getreg32(LPC313X_UART_LCR);
+    regval |= UART_LCR_DLAB;
+    putreg32(regval, LPC313X_UART_LCR);
+
+    /* Configure the MS and LS DLAB registers */
+
+    putreg32(div & UART_DLL_MASK, LPC313X_UART_DLL);
+    putreg32((div >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);
+
+    regval &= ~UART_LCR_DLAB;
+    putreg32(regval, LPC313X_UART_LCR);
+
+    /* Configure the Fractional Divider Register (FDR) */
+
+    putreg32((mulval    << UART_FDR_MULVAL_SHIFT) |
+             (divaddval << UART_FDR_DIVADDVAL_SHIFT),
+             LPC313X_UART_FDR);
+#else
+    /* Set the Divisor Latch Access Bit (DLAB) to enable DLL/DLM access */
+
+    regval  = getreg32(LPC313X_UART_LCR);
+    regval |= UART_LCR_DLAB;
+    putreg32(regval, LPC313X_UART_LCR);
+
+    /* Configure the MS and LS DLAB registers */
+
+    putreg32(CONFIG_LPC313X_UART_DIVISOR & UART_DLL_MASK, LPC313X_UART_DLL);
+    putreg32((CONFIG_LPC313X_UART_DIVISOR >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);
+
+    regval &= ~UART_LCR_DLAB;
+    putreg32(regval, LPC313X_UART_LCR);
+
+    /* Configure the Fractional Divider Register (FDR) */
+
+    putreg32((CONFIG_LPC313X_UART_MULVAL    << UART_FDR_MULVAL_SHIFT) |
+             (CONFIG_LPC313X_UART_DIVADDVAL << UART_FDR_DIVADDVAL_SHIFT),
+             LPC313X_UART_FDR);
+#endif
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+/****************************************************************************
+ * Name: up_lowsetup
+ *
+ * Description:
+ *   Configure the UART baud, bits, parity, fifos, etc. This method is called
+ *   the first time that the serial port is opened.
+ *
+ ****************************************************************************/
+
+void up_lowsetup(void)
+{
+#ifndef CONFIG_SUPPRESS_LPC313X_UART_CONFIG
+  uint32_t regval;
+
+  /* Enable UART system clock */
+
+  lpc313x_enableclock(CLKID_UARTAPBCLK);
+  lpc313x_enableclock(CLKID_UARTUCLK);
+
+  /* Clear fifos */
+
+  putreg32((UART_FCR_RXFIFORST|UART_FCR_TXFIFORST), LPC313X_UART_FCR);
+
+  /* Set trigger */
+
+  putreg32((UART_FCR_FIFOENABLE|UART_FCR_RXTRIGLEVEL_16), LPC313X_UART_FCR);
+
+  /* Set up the LCR */
+
+  regval = 0;
+
+#if CONFIG_UART_BITS == 5
+  regval |= UART_LCR_WDLENSEL_5BITS;
+#elif CONFIG_UART_BITS == 6
+  regval |= UART_LCR_WDLENSEL_6BITS;
+#elif CONFIG_UART_BITS == 7
+  regval |= UART_LCR_WDLENSEL_7BITS;
+#else
+  regval |= UART_LCR_WDLENSEL_8BITS;
+#endif
+
+#if CONFIG_UART_2STOP > 0
+  regval |= UART_LCR_NSTOPBITS;
+#endif
+
+#if CONFIG_UART_PARITY == 1
+  regval |= UART_LCR_PAREN;
+#elif CONFIG_UART_PARITY == 2
+  regval |= (UART_LCR_PAREVEN|UART_LCR_PAREN);
+#endif
+  putreg32(regval, LPC313X_UART_LCR);
+
+  /* Set the BAUD divisor */
+
+  up_configbaud();
+
+  /* Configure the FIFOs */
+
+  putreg32((UART_FCR_RXTRIGLEVEL_16|UART_FCR_TXFIFORST|
+            UART_FCR_RXFIFORST|UART_FCR_FIFOENABLE),
+           LPC313X_UART_FCR);
+
+  /* The NuttX serial driver waits for the first THRE interrrupt before
+   * sending serial data... However, it appears that the lpc313x hardware
+   * does not generate that interrupt until a transition from not-empty
+   * to empty.  So, the current kludge here is to send one NULL at
+   * startup to kick things off.
+   */
+
+  putreg32('\0', LPC313X_UART_THR);
+#endif
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_lowputc
+ *
+ * Description:
+ *   Provide priority, low-level access to support OS debug  writes
+ *
+ ****************************************************************************/
+
+void up_lowputc(char ch)
+{
+  up_waittxready();
+  putreg32((uint32_t)ch, LPC313X_UART_THR);
+}

arch/arm/src/lpc313x/lpc313x_memorymap.h

@@ -142,6 +142,7 @@
  */
 
 /* For now, just to get through the compilation */
+
 #define NUTTX_START_VADDR            0x00000000
 
 /************************************************************************************

arch/arm/src/lpc313x/lpc313x_serial.c

@@ -57,7 +57,7 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-#include "lpc313x_cgudriver.h"
+#include "lpc313x_cgudrvr.h"
 #include "lpc313x_uart.h"
 
 #ifdef CONFIG_USE_SERIALDRIVER
@@ -79,6 +79,12 @@ struct up_dev_s
  * Private Function Prototypes
  ****************************************************************************/
 
+static inline void up_disableuartint(struct up_dev_s *priv, uint8_t *ier);
+static inline void up_restoreuartint(struct up_dev_s *priv, uint8_t ier);
+static inline void up_enablebreaks(void);
+static inline void up_disablebreaks(void);
+static inline void up_configbaud(void);
+
 static int  up_setup(struct uart_dev_s *dev);
 static void up_shutdown(struct uart_dev_s *dev);
 static int  up_attach(struct uart_dev_s *dev);
@@ -166,44 +172,25 @@ static inline void up_restoreuartint(struct up_dev_s *priv, uint8_t ier)
   putreg32((uint32_t)priv->ier, LPC313X_UART_IER);
 }
 
-/****************************************************************************
- * Name: up_waittxready
- ****************************************************************************/
-
-static inline void up_waittxready(struct up_dev_s *priv)
-{
-  int tmp;
-
-  /* Limit how long we will wait for the TX available condition */
-
-  for (tmp = 1000 ; tmp > 0 ; tmp--)
-    {
-      /* Check if the tranmitter holding register (THR) is empty */
- 
-      if ((getreg32(LPC313X_UART_LSR) & UART_LSR_THRE) != 0)
-        {
-          /* The THR is empty, return */
-
-          break;
-        }
-    }
-}
-
 /****************************************************************************
  * Name: up_enablebreaks
  ****************************************************************************/
 
-static inline void up_enablebreaks(struct up_dev_s *priv, bool enable)
+static inline void up_enablebreaks(void)
-{
-  uint32_t_t lcr = getreg32(LPC313X_UART_LCR);
-  if (enable)
 {
+  uint32_t lcr = getreg32(LPC313X_UART_LCR);
   lcr |= UART_LCR_BRKCTRL;
+  putreg32(lcr, LPC313X_UART_LCR);
 }
-  else
+
+/****************************************************************************
+ * Name: up_disablebreaks
+ ****************************************************************************/
+
+static inline void up_disablebreaks(void)
 {
+  uint32_t lcr = getreg32(LPC313X_UART_LCR);
   lcr &= ~UART_LCR_BRKCTRL;
-    }
   putreg32(lcr, LPC313X_UART_LCR);
 }
 
@@ -305,43 +292,43 @@ static inline void up_configbaud(void)
 
     /* Set the Divisor Latch Access Bit (DLAB) to enable DLL/DLM access */
 
-    regval  = getreg32(LPV313X_UART_LCR);
+    regval  = getreg32(LPC313X_UART_LCR);
-    regval |= UART_LCR_DLAB
+    regval |= UART_LCR_DLAB;
-    putreg32(regval, LPV313X_UART_LCR);
+    putreg32(regval, LPC313X_UART_LCR);
 
     /* Configure the MS and LS DLAB registers */
 
     putreg32(div & UART_DLL_MASK, LPC313X_UART_DLL);
-    putreg32((div >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);\
+    putreg32((div >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);
 
-    regval &~= UART_LCR_DLAB
+    regval &= ~UART_LCR_DLAB;
-    putreg32(regval, LPV313X_UART_LCR);
+    putreg32(regval, LPC313X_UART_LCR);
 
     /* Configure the Fractional Divider Register (FDR) */
 
     putreg32((mulval    << UART_FDR_MULVAL_SHIFT) |
              (divaddval << UART_FDR_DIVADDVAL_SHIFT),
-             LPC313X_UART_FRD);
+             LPC313X_UART_FDR);
 #else
     /* Set the Divisor Latch Access Bit (DLAB) to enable DLL/DLM access */
 
-    regval  = getreg32(LPV313X_UART_LCR);
+    regval  = getreg32(LPC313X_UART_LCR);
-    regval |= UART_LCR_DLAB
+    regval |= UART_LCR_DLAB;
-    putreg32(regval, LPV313X_UART_LCR);
+    putreg32(regval, LPC313X_UART_LCR);
 
     /* Configure the MS and LS DLAB registers */
 
     putreg32(CONFIG_LPC313X_UART_DIVISOR & UART_DLL_MASK, LPC313X_UART_DLL);
-    putreg32((CONFIG_LPC313X_UART_DIVISOR >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);\
+    putreg32((CONFIG_LPC313X_UART_DIVISOR >> 8) & UART_DLL_MASK, LPC313X_UART_DLM);
 
-    regval &~= UART_LCR_DLAB
+    regval &= ~UART_LCR_DLAB;
-    putreg32(regval, LPV313X_UART_LCR);
+    putreg32(regval, LPC313X_UART_LCR);
 
     /* Configure the Fractional Divider Register (FDR) */
 
     putreg32((CONFIG_LPC313X_UART_MULVAL    << UART_FDR_MULVAL_SHIFT) |
              (CONFIG_LPC313X_UART_DIVADDVAL << UART_FDR_DIVADDVAL_SHIFT),
-             LPC313X_UART_FRD);
+             LPC313X_UART_FDR);
 #endif
 }
 
@@ -392,10 +379,10 @@ static int up_setup(struct uart_dev_s *dev)
 
 #if CONFIG_UART_PARITY == 1
   regval |= UART_LCR_PAREN;
-#elif CONFIG_UART_PARITY == 2)
+#elif CONFIG_UART_PARITY == 2
   regval |= (UART_LCR_PAREVEN|UART_LCR_PAREN);
 #endif
-  putreg32(regval, LPV313X_UART_LCR);
+  putreg32(regval, LPC313X_UART_LCR);
 
   /* Set the BAUD divisor */
 
@@ -403,7 +390,7 @@ static int up_setup(struct uart_dev_s *dev)
 
   /* Configure the FIFOs */
 
-  putreg32((UART_FCR_RXTRIGLEVEL_16|UART_FCR_TXFIFORST|\
+  putreg32((UART_FCR_RXTRIGLEVEL_16|UART_FCR_TXFIFORST|
             UART_FCR_RXFIFORST|UART_FCR_FIFOENABLE),
            LPC313X_UART_FCR);
 
@@ -496,7 +483,6 @@ static void up_detach(struct uart_dev_s *dev)
 static int up_interrupt(int irq, void *context)
 {
   struct uart_dev_s *dev   = &g_uartport;
-  struct up_dev_s   *priv  = &g_uartpriv;
   uint8_t            status;
   int                passes;
 
@@ -592,7 +578,6 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
 {
   struct inode      *inode = filep->f_inode;
   struct uart_dev_s *dev   = inode->i_private;
-  struct up_dev_s   *priv  = (struct up_dev_s*)dev->priv;
   int                ret    = OK;
 
   switch (cmd)
@@ -614,7 +599,7 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
     case TIOCSBRK:  /* BSD compatibility: Turn break on, unconditionally */
       {
         irqstate_t flags = irqsave();
-        up_enablebreaks(priv, true);
+        up_enablebreaks();
         irqrestore(flags);
       }
       break;
@@ -623,7 +608,7 @@ static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
       {
         irqstate_t flags;
         flags = irqsave();
-        up_enablebreaks(priv, false);
+        up_disablebreaks();
         irqrestore(flags);
       }
       break;
@@ -690,7 +675,6 @@ static void up_rxint(struct uart_dev_s *dev, bool enable)
 
 static bool up_rxavailable(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   return ((getreg32(LPC313X_UART_LSR) & UART_LSR_RDR) != 0);
 }
 
@@ -704,7 +688,6 @@ static bool up_rxavailable(struct uart_dev_s *dev)
 
 static void up_send(struct uart_dev_s *dev, int ch)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   putreg32((uint32_t)ch, LPC313X_UART_THR);
 }
 
@@ -742,7 +725,6 @@ static void up_txint(struct uart_dev_s *dev, bool enable)
 
 static bool up_txready(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   return ((getreg32(LPC313X_UART_LSR) & UART_LSR_THRE) != 0);
 }
 
@@ -756,12 +738,11 @@ static bool up_txready(struct uart_dev_s *dev)
 
 static bool up_txempty(struct uart_dev_s *dev)
 {
-  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
   return ((getreg32(LPC313X_UART_LSR) & UART_LSR_TEMT) != 0);
 }
 
 /****************************************************************************
- * Public Funtions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
@@ -820,12 +801,14 @@ void up_serialinit(void)
 
 int up_putc(int ch)
 {
-  struct up_dev_s *priv = g_uartpriv;
+  struct up_dev_s *priv = &g_uartpriv;
   uint8_t ier;
 
+  /* Keep UART interrupts disabled so that we do not interfere with the
+   * serial driver.
+   */
+
   up_disableuartint(priv, &ier);
-  up_waittxready(priv);
-  putreg32((uint32_t)ch, LPC313X_UART_THR);
 
   /* Check for LF */
 
@@ -833,11 +816,12 @@ int up_putc(int ch)
     {
       /* Add CR */
 
-      up_waittxready(priv);
+      up_lowputc('\r');
-      putreg32('\r', LPC313X_UART_THR);
     }
 
-  up_waittxready(priv);
+  /* Output the character */
+
+  up_lowputc(ch);
   up_restoreuartint(priv, ier);
   return ch;
 }
@@ -863,6 +847,8 @@ int up_putc(int ch)
       up_lowputc('\r');
     }
 
+  /* Output the character */
+
   up_lowputc(ch);
   return ch;
 }