Internal FLASH MTD driver for TI/Stellaris from Max Holtzberg

arch/arm/src/lm/Kconfig

@@ -122,6 +122,12 @@ config LM_ETHERNET
 	---help---
 		This must be set (along with NET) to build the Stellaris Ethernet driver.
 
+config LM_FLASH
+	bool "Stellaris internal FLASH"
+	default n
+	---help---
+		Enable MTD driver support for internal FLASH.
+
 endmenu
 
 menu "Disable GPIO Interrupts"
@@ -245,4 +251,14 @@ config SSI_TXLIMIT
 endmenu
 endif
 
+if LM_FLASH
+menu "Stellaris Internal Flash Driver Configuration"
 
+config LM_FLASH_STARTPAGE
+	int "First page accessible by the MTD driver"
+	default 250
+	---help---
+		To prevent accessing FLASH sections where code is stored.
+
+endmenu
+endif

arch/arm/src/lm/Make.defs

@@ -68,7 +68,7 @@ ifeq ($(CONFIG_ELF),y)
 CMN_CSRCS += up_elf.c
 endif
 
-CHIP_ASRCS  = 
+CHIP_ASRCS  =
 CHIP_CSRCS  = lm_allocateheap.c lm_start.c lm_syscontrol.c lm_irq.c
 CHIP_CSRCS += lm_gpio.c lm_gpioirq.c lm_timerisr.c lm_lowputc.c lm_serial.c
 CHIP_CSRCS += lm_ssi.c lm_dumpgpio.c
@@ -80,3 +80,7 @@ endif
 ifdef CONFIG_NET
 CHIP_CSRCS += lm_ethernet.c
 endif
+
+ifdef CONFIG_LM_FLASH
+CHIP_CSRCS += lm_flash.c
+endif

arch/arm/src/lm/chip/lm_flash.h

@@ -46,6 +46,18 @@
  * Pre-processor Definitions
  ************************************************************************************/
 
+/* FLASH dimensions ****************************************************************/
+
+#if defined(CONFIG_ARCH_CHIP_LM3S6965)
+#  define LM_FLASH_NPAGES        256
+#  define LM_FLASH_PAGESIZE      1024
+#else
+#  error "No flash dimensions defined for selected chip."
+#endif
+
+#define LM_FLASH_SIZE            (LM_FLASH_NPAGES * LM_FLASH_PAGESIZE)
+
+
 /* FLASH register offsets ***********************************************************/
 
 /* The FMA, FMD, FMC, FCRIS, FCIM, and FCMISC registers are relative to the Flash
@@ -111,7 +123,24 @@
 #define LM_FLASH_FMPPE3           (LM_SYSCON_BASE + LM_FLASH_FMPPE3_OFFSET)
 
 /* FLASH register bit defitiions ****************************************************/
-/* To be provided */
+
+#define FLASH_FMA_OFFSET_SHIFT     0         /* Bits 17-0: Address Offset */
+#define FLASH_FMA_OFFSET_MASK      (0x0003ffff << FLASH_FMA_OFFSET_SHIFT)
+
+#define FLASH_FMC_WRITE            (1 << 0)  /* Write a Word into Flash Memory */
+#define FLASH_FMC_ERASE            (1 << 1)  /* Erase a Page of Flash Memory */
+#define FLASH_FMC_MERASE           (1 << 2)  /* Mass Erase Flash Memory */
+#define FLASH_FMC_COMT             (1 << 3)  /* Commit Register Value */
+
+/* This field contains a write key, which is used to minimize the incidence
+ * of accidental flash writes. The value 0xA442 must be written into this
+ * field for a write to occur. Writes to the FMC register without this WRKEY
+ * value are ignored. A read of this field returns the value 0
+ */
+#define FLASH_FMC_WRKEY_SHIFT      16         /* Bits 16-31:  Flash Write Key */
+#define FLASH_FMC_WRKEY_MASK       (0xffff << FLASH_FMC_WRKEY_SHIFT)
+#define FLASH_FMC_WRKEY            (0xa442 << FLASH_FMC_WRKEY_SHIFT) /* Magic write key */
+
 
 /************************************************************************************
  * Public Types

arch/arm/src/lm/lm_flash.c

@@ -0,0 +1,346 @@
+/****************************************************************************
+ * arch/arm/src/lm/lm_flash.c
+ *
+ *   Copyright (c) 2013 Max Holtzberg. All rights reserved.
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *
+ *   Authors: Max Holtzberg <mh@uvc.de>
+ *            Gregory Nutt <gnutt@nuttx.org>
+ *
+ * This code is derived from drivers/mtd/skeleton.c
+ *
+ * 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 <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/fs/ioctl.h>
+#include <nuttx/mtd.h>
+
+#include "up_arch.h"
+#include "chip.h"
+
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define LM_VIRTUAL_NPAGES (LM_FLASH_NPAGES - CONFIG_LM_FLASH_STARTPAGE)
+#define LM_VIRTUAL_BASE   (LM_FLASH_BASE \
+                           + CONFIG_LM_FLASH_STARTPAGE * LM_FLASH_PAGESIZE)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* This type represents the state of the MTD device.  The struct mtd_dev_s
+ * must appear at the beginning of the definition so that you can freely
+ * cast between pointers to struct mtd_dev_s and struct lm_dev_s.
+ */
+
+struct lm_dev_s
+{
+  struct mtd_dev_s mtd;
+
+  /* Other implementation specific data may follow here */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* MTD driver methods */
+
+static int lm_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks);
+static ssize_t lm_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                        FAR uint8_t *buf);
+static ssize_t lm_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                         FAR const uint8_t *buf);
+static ssize_t lm_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
+                       FAR uint8_t *buf);
+#ifdef CONFIG_MTD_BYTE_WRITE
+static ssize_t lm_write(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
+                        FAR const uint8_t *buf);
+#endif
+static int lm_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+/* This structure holds the state of the MTD driver */
+
+static struct lm_dev_s g_lmdev =
+{
+  { lm_erase,
+    lm_bread,
+    lm_bwrite,
+    lm_read,
+#ifdef CONFIG_MTD_BYTE_WRITE
+    lm_write,
+#endif
+    lm_ioctl
+  },
+  /* Initialization of any other implementation specific data goes here */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lm_erase
+ *
+ * Description:
+ *   Erase several blocks, each of the size previously reported.
+ *
+ ****************************************************************************/
+
+static int lm_erase(FAR struct mtd_dev_s *dev, off_t startblock,
+                    size_t nblocks)
+{
+  int curpage;
+  uint32_t pageaddr;
+
+  DEBUGASSERT(nblocks <= LM_VIRTUAL_NPAGES);
+
+  for (curpage = startblock; curpage < nblocks; curpage++)
+    {
+      pageaddr = LM_VIRTUAL_BASE + curpage * LM_FLASH_PAGESIZE;
+
+      fvdbg("Erase page at %08x\n", pageaddr);
+
+      /* set page address */
+
+      putreg32((pageaddr << FLASH_FMA_OFFSET_SHIFT) & FLASH_FMA_OFFSET_MASK,
+               LM_FLASH_FMA);
+
+      /* set flash write key and erase bit */
+
+      putreg32(FLASH_FMC_WRKEY | FLASH_FMC_ERASE, LM_FLASH_FMC);
+
+      /* wait until erase has finished */
+
+      while (getreg32(LM_FLASH_FMC) & FLASH_FMC_ERASE);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: lm_bread
+ *
+ * Description:
+ *   Read the specified number of blocks into the user provided buffer.
+ *
+ ****************************************************************************/
+
+static ssize_t lm_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                        FAR uint8_t *buf)
+{
+  DEBUGASSERT(startblock + nblocks <= LM_VIRTUAL_NPAGES);
+
+  memcpy(buf, (void*)(LM_VIRTUAL_BASE + startblock * LM_FLASH_PAGESIZE),
+         nblocks * LM_FLASH_PAGESIZE);
+
+  return nblocks;
+}
+
+/****************************************************************************
+ * Name: lm_bwrite
+ *
+ * Description:
+ *   Write the specified number of blocks from the user provided buffer.
+ *
+ ****************************************************************************/
+
+static ssize_t lm_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                         FAR const uint8_t *buf)
+{
+  FAR uint32_t *src = (uint32_t*)buf;
+  FAR uint32_t *dst = (uint32_t*)(LM_VIRTUAL_BASE + startblock * LM_FLASH_PAGESIZE);
+  int i;
+
+  DEBUGASSERT(nblocks <= LM_VIRTUAL_NPAGES);
+
+  for (i = 0; i < (nblocks * LM_FLASH_PAGESIZE) >> 2; i++)
+    {
+      /* set data to write  */
+
+      putreg32(*src++, LM_FLASH_FMD);
+
+      /* set destination address */
+
+      putreg32((uint32_t)dst++, LM_FLASH_FMA);
+
+      /* start write */
+
+      putreg32(FLASH_FMC_WRKEY | FLASH_FMC_WRITE, LM_FLASH_FMC);
+
+      /* wait until write has finished */
+
+      while(getreg32(LM_FLASH_FMC) & FLASH_FMC_WRITE);
+    }
+
+  return nblocks;
+}
+
+/****************************************************************************
+ * Name: lm_read
+ *
+ * Description:
+ *   Read the specified number of bytes to the user provided buffer.
+ *
+ ****************************************************************************/
+
+static ssize_t lm_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
+                       FAR uint8_t *buf)
+{
+  DEBUGASSERT(offset + nbytes < LM_VIRTUAL_NPAGES * LM_FLASH_PAGESIZE);
+
+  memcpy(buf, (void*)(LM_VIRTUAL_BASE + offset), nbytes);
+
+  return nbytes;
+}
+
+/****************************************************************************
+ * Name: lm_write
+ *
+ * Description:
+ *   Some FLASH parts have the ability to write an arbitrary number of
+ *   bytes to an arbitrary offset on the device.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_MTD_BYTE_WRITE
+static ssize_t lm_write(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
+                        FAR const uint8_t *buf)
+{
+  return -ENOSYS;
+}
+#endif
+
+/****************************************************************************
+ * Name: lm_ioctl
+ ****************************************************************************/
+
+static int lm_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
+{
+  int ret = -EINVAL; /* Assume good command with bad parameters */
+
+  switch (cmd)
+    {
+      case MTDIOC_GEOMETRY:
+        {
+          FAR struct mtd_geometry_s *geo = (FAR struct mtd_geometry_s *)arg;
+          if (geo)
+            {
+              /* Populate the geometry structure with information needed to know
+               * the capacity and how to access the device.
+               *
+               * NOTE: that the device is treated as though it where just an array
+               * of fixed size blocks.  That is most likely not true, but the client
+               * will expect the device logic to do whatever is necessary to make it
+               * appear so.
+               */
+
+              geo->blocksize    = LM_FLASH_PAGESIZE;  /* Size of one read/write block */
+              geo->erasesize    = LM_FLASH_PAGESIZE;  /* Size of one erase block */
+              geo->neraseblocks = LM_VIRTUAL_NPAGES;
+              ret               = OK;
+          }
+        }
+        break;
+
+      case MTDIOC_XIPBASE:
+        {
+          FAR void **ppv = (FAR void**)arg;
+
+          if (ppv)
+            {
+              /* If media is directly acccesible, return (void*) base address
+               * of device memory.  NULL otherwise.  It is acceptable to omit
+               * this case altogether and simply return -ENOTTY.
+               */
+
+              *ppv = (void*)LM_VIRTUAL_BASE;
+              ret  = OK;
+            }
+        }
+        break;
+
+      case MTDIOC_BULKERASE:
+        {
+          /* Erase the entire device */
+
+          lm_erase(dev, 0, LM_VIRTUAL_NPAGES);
+
+          ret = OK;
+        }
+        break;
+
+      default:
+        ret = -ENOTTY; /* Bad command */
+        break;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lm_initialize
+ *
+ * Description:
+ *   Create and initialize an MTD device instance.  MTD devices are not
+ *   registered in the file system, but are created as instances that can
+ *   be bound to other functions (such as a block or character driver front
+ *   end).
+ *
+ ****************************************************************************/
+
+FAR struct mtd_dev_s *up_flashinitialize(void)
+{
+  /* Return the implementation-specific state structure as the MTD device */
+
+  return (FAR struct mtd_dev_s *)&g_lmdev;
+}