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Re: [PATCH] PNX8550 NAND flash driver

To: "Vladimir A. Barinov" <vbarinov@ru.mvista.com>
Subject: Re: [PATCH] PNX8550 NAND flash driver
From: Todd Poynor <tpoynor@mvista.com>
Date: Thu, 12 Jan 2006 10:24:02 -0800
Cc: linux-mtd@lists.infradead.org, linux-mips@linux-mips.org
In-reply-to: <43A2F819.1040106@ru.mvista.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <43A2F819.1040106@ru.mvista.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Thunderbird 1.5 (X11/20051201)
Vladimir A. Barinov wrote:
Hi All,

Attached patch is NAND flash driver for PNX8550 based platforms.
Any comments and suggestions are highly appreciated.

Vladimir


------------------------------------------------------------------------

Signed-off-by: vbarinov@ru.mvista.com

drivers/mtd/nand/Kconfig | 6 drivers/mtd/nand/Makefile | 1 drivers/mtd/nand/pnx8550.c | 747 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 754 insertions(+)

Index: linux-2.6.15_0/drivers/mtd/nand/Kconfig
===================================================================
--- linux-2.6.15_0.orig/drivers/mtd/nand/Kconfig
+++ linux-2.6.15_0/drivers/mtd/nand/Kconfig
@@ -90,6 +90,12 @@ config MTD_NAND_S3C2410
          No board specfic support is done by this driver, each board
          must advertise a platform_device for the driver to attach.
+config MTD_NAND_PNX8550
+       tristate "NAND Flash support for PNX8550"
+       depends on PNX8550 && MTD_NAND
+       help
+         This enables the NAND flash controller on the PNX8550.
+
 config MTD_NAND_S3C2410_DEBUG
        bool "S3C2410 NAND driver debug"
        depends on MTD_NAND_S3C2410
Index: linux-2.6.15_0/drivers/mtd/nand/pnx8550.c
===================================================================
--- /dev/null
+++ linux-2.6.15_0/drivers/mtd/nand/pnx8550.c
@@ -0,0 +1,747 @@
+/*
+ * Copyright (C) 2005 Koninklijke Philips Electronics N.V.
+ * All Rights Reserved.
+ *
+ * Based on: drivers/mtd/nand/pnx8550.c by Torbjorn Lundberg
+ * $Id: pnx8550_nand.c,v 1.8 2004/11/12 10:46:58 tobbe Exp $
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * + * Overview:
+ *   This is a device driver for the NAND flash device found on the
+ *   PNX8550 board which utilizes the Samsung K9F5616U0C part. This is
+ *   a 32MByte (16M x 16 bits) NAND flash device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/compatmac.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/partitions.h>
+#include <asm/io.h>
+#include <asm/mach-pnx8550/nand.h>
+
+#define UBTM_NAME                 "microBTM"
+#define UBTM_BLOCK_START         ( 0x00000000)
+#define UBTM_BLOCK_END           ( 0x00004000) /* 16K size, first block */
+#define UBTM_SIZE                ( UBTM_BLOCK_END - UBTM_BLOCK_START)
+
+#define BOOTLOADER_NAME           "bootloader"
+#define BOOTLOADER_BLOCK_START   ( UBTM_BLOCK_END)
+#define BOOTLOADER_BLOCK_END     ( 0x00040000) /* 256K -  16K = 240K    */
+#define BOOTLOADER_SIZE          ( BOOTLOADER_BLOCK_END - 
BOOTLOADER_BLOCK_START)
+
+#define ROMFS_SYS_NAME            "ROMFS-Tools"
+#define ROMFS_SYS_BLOCK_START    ( BOOTLOADER_BLOCK_END)
+#define ROMFS_SYS_BLOCK_END      ( 0x00600000) /*   6M - 256K = 5.75M   */
+#define ROMFS_SYS_SIZE           ( ROMFS_SYS_BLOCK_END - ROMFS_SYS_BLOCK_START)
+
+#define ROMFS_APP_NAME            "ROMFS-User"
+#define ROMFS_APP_BLOCK_START    ( ROMFS_SYS_BLOCK_END)
+#define ROMFS_APP_BLOCK_END      ( 0x01000000) /*  16M -   6M = 10M     */
+#define ROMFS_APP_SIZE           ( ROMFS_APP_BLOCK_END - ROMFS_APP_BLOCK_START)
+
+#define USER_NAME                 "User"
+#define USER_BLOCK_START         ( ROMFS_APP_BLOCK_END)
+#define USER_BLOCK_END           ( 0x02000000) /*  32M -  16M = 16M     */
+#define USER_SIZE                ( USER_BLOCK_END - USER_BLOCK_START)
+
+#define NAND_ADDR(_col, _page) ((_col) & (mtd->oobblock - 1)) + ((_page) << 
this->page_shift)
+
+#define NAND_ADDR_SEND(_addr) pNandAddr[(_addr)/sizeof(u16)] = 0
+
+#define NAND_TRANSFER_TO(_addr, _buffer, _bytes) 
pnx8550_nand_transfer((_buffer), ((u8*)pNandAddr) + (_addr), (_bytes), 1)
+
+#define NAND_TRANSFER_FROM(_addr, _buffer, _bytes) 
pnx8550_nand_transfer(((u8*)pNandAddr) + (_addr), (_buffer), (_bytes), 0)
+
+static void pnx8550_nand_register_setup(u_char cmd_no, u_char addr_no,
+                                       u_char include_data, u_char monitor_ACK,
+                                       u_char enable64M, int cmd_a, int cmd_b);
+
+static inline void pnx8550_nand_wait_for_dev_ready(void);
+
+static void pnx8550_nand_transfer(void *from, void *to, int bytes, int toxio);
+
+static void pnx8550_nand_transferDMA(void *from, void *to, int bytes,
+                                    int toxio);
+
+/*
+ * Define partitions for flash device
+ */
+#define NUM_PARTITIONS 5
+const static struct mtd_partition partition_info[NUM_PARTITIONS] = {
+       {
+        .name = UBTM_NAME,
+        .offset = UBTM_BLOCK_START,
+        .size = UBTM_SIZE},
+       {
+        .name = BOOTLOADER_NAME,
+        .offset = BOOTLOADER_BLOCK_START,
+        .size = BOOTLOADER_SIZE},
+       {
+        .name = ROMFS_SYS_NAME,
+        .offset = ROMFS_SYS_BLOCK_START,
+        .size = ROMFS_SYS_SIZE},
+       {
+        .name = ROMFS_APP_NAME,
+        .offset = ROMFS_APP_BLOCK_START,
+        .size = ROMFS_APP_SIZE},
+       {
+        .name = USER_NAME,
+        .offset = USER_BLOCK_START,
+        .size = USER_SIZE}
+};
+
+/* Bad block descriptor for 16Bit nand flash */
+static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
+static struct nand_bbt_descr nand16bit_memorybased = {
+       .options = 0,
+       .offs = 0,
+       .len = 2,
+       .pattern = scan_ff_pattern
+};
+
+/* OOB Placement information that lines up with the boot loader code */
+static struct nand_oobinfo nand16bit_oob_16 = {
+       .useecc = MTD_NANDECC_AUTOPLACE,
+       .eccbytes = 6,
+       .eccpos = {2, 3, 4, 5, 6, 7},
+       .oobfree = {{8, 8}}
+};
+
+/* Pointer into XIO for access to the 16Bit NAND flash device */
+static volatile u16 *pNandAddr;
+
+/* Last command sent to the pnx8550_nand_command function */
+static int last_command = -1;
+/*
+  Next column address to read/write, set by pnx8550_nand_command
+  updated by the read/write functions
+*/
+static int last_col_addr = -1;
+/*
+  Next page address to read/write, set by pnx8550_nand_command
+  updated by the read/write functions
+*/
+static int last_page_addr = -1;
+
+/*
+    32bit Aligned/DMA buffer
+*/
+static u_char *transferBuffer = NULL;
+
+static struct mtd_info pnx8550_mtd;
+static struct nand_chip pnx8550_nand;
+
+/**
+ * Transfer data to/from the NAND chip.
+ * This function decides whether to use DMA or not depending on
+ * the amount of data to transfer and the alignment of the buffers.
+ *
+ * @from:  Address to transfer data from
+ * @to:    Address to transfer the data to
+ * @bytes: Number of bytes to transfer
+ * @toxio: Whether the transfer is going to XIO or not.
+ */
+static void pnx8550_nand_transfer(void *from, void *to, int bytes, int toxio)
+{
+       u16 *from16 = (u16 *) from;
+       u16 *to16 = (u16 *) to;
+
+       int i;
+
+       if ((u32) from & 3) {
+               printk
+                   ("%s: from buffer not 32bit aligned, will not use fastest 
transfer mechanism\n",
+                    __FUNCTION__);
+       }
+       if ((u32) to & 3) {
+               printk
+                   ("%s: to buffer not 32bit aligned, will not use fastest transfer 
mechanism\n",
+                    __FUNCTION__);

Those printks could get old pretty fast. Debugging info, not needed for normal operation.

+       }
+
+       if (((bytes & 3) || (bytes < 16)) || ((u32) to & 3) || ((u32) from & 
3)) {
+               if (((bytes & 1) == 0) &&
+                   (((u32) to & 1) == 0) && (((u32) from & 1) == 0)) {
+                       int words = bytes / 2;
+
+                       local_irq_disable();
+                       for (i = 0; i < words; i++) {
+                               to16[i] = from16[i];
+                       }
+                       local_irq_enable();

Really necessary to disable all irqs around this transfer? How long can interrupts be off during that time?

+               } else {
+                       printk
+                           ("%s: Transfer failed, byte-aligned transfers no 
allowed!\n",

"non-word-aligned"?

+                            __FUNCTION__);
+               }
+       } else {
+               pnx8550_nand_transferDMA(from, to, bytes, toxio);
+       }
+}
+
+/**
+ * Transfer data to/from the NAND chip using DMA
+ *
+ * @from:  Address to transfer data from
+ * @to:    Address to transfer the data to
+ * @bytes: Number of bytes to transfer
+ * @toxio: Whether the transfer is going to XIO or not.
+ */
+static void pnx8550_nand_transferDMA(void *from, void *to, int bytes, int 
toxio)
+{
+       int cmd = 0;
+       u32 internal;
+       u32 external;
+
+       if (toxio) {
+               cmd = PNX8550_DMA_CTRL_PCI_CMD_WRITE;
+               dma_cache_wback(from, bytes);
+               internal = (u32) virt_to_phys(from);
+               external = (u32) to - KSEG1;
+       } else {
+               cmd = PNX8550_DMA_CTRL_PCI_CMD_READ;
+               internal = (u32) virt_to_phys(to);
+               external = (u32) from - KSEG1;
+       }
+
+       local_irq_disable();
+       PNX8550_DMA_TRANS_SIZE = bytes >> 2;      /* Length in words */
+       PNX8550_DMA_EXT_ADDR = external;
+       PNX8550_DMA_INT_ADDR = internal;
+       PNX8550_DMA_INT_CLEAR = 0xffff;
+       PNX8550_DMA_CTRL = PNX8550_DMA_CTRL_BURST_512 |
+           PNX8550_DMA_CTRL_SND2XIO | PNX8550_DMA_CTRL_INIT_DMA | cmd;
+
+       while ((PNX8550_DMA_INT_STATUS & PNX8550_DMA_INT_COMPL) == 0) ;
+
+       if (!toxio) {
+               dma_cache_inv(to, bytes);
+       }
+       local_irq_enable();

Again, necessary to prevent interrupts?
+}
+
+/**
+ * pnx8550_nand_read_byte - read one byte endianess aware from the chip
+ * @mtd:       MTD device structure
+ *
+ */
+static u_char pnx8550_nand_read_byte(struct mtd_info *mtd)
+{
+       struct nand_chip *this = mtd->priv;
+       u16 data = 0;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       /*
+          Read ID is a special case as we have to read BOTH bytes at the same
+          time otherwise it doesn't work, once we have both bytes we work out
+          which one we want.
+        */
+       if (last_command == NAND_CMD_READID) {
+               u32 *pNandAddr32 = (u32 *) pNandAddr;
+               u32 data32;
+               data32 = cpu_to_le32(pNandAddr32[0]);
+               if (last_col_addr) {
+                       data = (u16) (data32 >> 16);
+               } else {
+                       data = (u16) data32;
+               }
+       } else {
+               data = cpu_to_le16(pNandAddr[(addr / sizeof(u16))]);
+               if ((addr & 0x1) == 1) {
+                       data = (data & 0xff00) >> 16;
+               }
+       }
+       /*
+          Status is a special case, we don't need to increment the address
+          because the address isn't used by the chip
+        */
+       if (last_command != NAND_CMD_STATUS) {
+               last_col_addr++;
+       }
+       return data & 0xff;
+}
+
+/**
+ * pnx8550_nand_read_word - read one word from the chip
+ * @mtd:       MTD device structure
+ *
+ * Read function for 16bit buswith without
+ * endianess conversion
+ */
+static u16 pnx8550_nand_read_word(struct mtd_info *mtd)
+{
+       struct nand_chip *this = mtd->priv;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       u16 data = pNandAddr[(addr / sizeof(u16))];
+       return data;
+}
+
+/**
+ * pnx8550_nand_write_byte - write one byte endianess aware to the chip
+ * @mtd:       MTD device structure
+ * @byte:      pointer to data byte to write
+ *
+ * Write function for 16bit buswith with
+ * endianess conversion
+ */
+static void pnx8550_nand_write_byte(struct mtd_info *mtd, u_char byte)
+{
+       struct nand_chip *this = mtd->priv;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       pNandAddr[(addr / sizeof(u16))] = le16_to_cpu((u16) byte);
+}
+
+/**
+ * pnx8550_nand_write_word - write one word to the chip
+ * @mtd:       MTD device structure
+ * @word:      data word to write
+ *
+ * Write function for 16bit buswith without
+ * endianess conversion
+ */
+static void pnx8550_nand_write_word(struct mtd_info *mtd, u16 word)
+{
+       struct nand_chip *this = mtd->priv;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       pNandAddr[(addr / sizeof(u16))] = word;
+}
+
+/**
+ * pnx8550_nand_write_buf - write buffer to chip
+ * @mtd:       MTD device structure
+ * @buf:       data buffer
+ * @len:       number of bytes to write
+ *
+ */
+static void pnx8550_nand_write_buf(struct mtd_info *mtd, const u_char * buf,
+                                  int len)
+{
+       struct nand_chip *this = mtd->priv;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       int pageLen;
+       int oobLen = 0;
+       u_char *transBuf = (u_char *) buf;
+
+       /* some sanity checking, word access only please */
+       if (len & 1) {
+               printk("%s: non-word aligned length requested!\n",
+                      __FUNCTION__);
+       }
+
+       memcpy(transferBuffer, buf, len);
+       transBuf = transferBuffer;
+
+       /*
+          Work out whether we are going to write to the OOB area
+          after a standard page write.
+          This is not the case when the command function is called
+          with a column address > page size. Then we write as though
+          it is to the page rather than the OOB as the command function
+          has already selected the OOB area.
+        */
+       if ((last_col_addr + len) > mtd->oobblock)
+               oobLen = (last_col_addr + len) - mtd->oobblock;
+       pageLen = len - oobLen;
+
+       /* Clear the done flag */
+       PNX8550_GPXIO_CTRL |= PNX8550_GPXIO_CLR_DONE;
+       if (pageLen > 0) {
+               NAND_TRANSFER_TO(addr, transBuf, pageLen);
+       }
+       if (oobLen > 0) {
+               pnx8550_nand_wait_for_dev_ready();
+
+               pnx8550_nand_register_setup(1, 0, 0, 1, 0, NAND_CMD_READOOB, 0);
+               /* Work out where in the OOB we are going to start to write */
+               addr = NAND_ADDR(last_col_addr - mtd->oobblock, last_page_addr);
+               NAND_ADDR_SEND(addr);
+               pnx8550_nand_register_setup(2, 3, 1, 1, 0, NAND_CMD_SEQIN,
+                                           NAND_CMD_PAGEPROG);
+
+               /* Clear the done flag */
+               PNX8550_GPXIO_CTRL |= PNX8550_GPXIO_CLR_DONE;
+               NAND_TRANSFER_TO(addr, transBuf + pageLen, oobLen);
+       }
+
+       /*
+          Increment the address so on the next write we write in the
+          correct place.
+        */
+       last_col_addr += len;
+       if (last_col_addr >= mtd->oobblock + mtd->oobsize) {
+               last_col_addr -= mtd->oobblock + mtd->oobsize;
+               last_page_addr++;
+       }
+}
+
+/**
+ * pnx8550_nand_read_buf - read chip data into buffer
+ * @mtd:       MTD device structure
+ * @buf:       buffer to store date
+ * @len:       number of bytes to read
+ *
+ */
+static void pnx8550_nand_read_buf(struct mtd_info *mtd, u_char * buf, int len)
+{
+       struct nand_chip *this = mtd->priv;
+       int addr = NAND_ADDR(last_col_addr, last_page_addr);
+       int pageLen;
+       int oobLen = 0;
+       u_char *transBuf = buf;
+
+       /* some sanity checking, word access only please */
+       if (len & 1) {
+               printk("%s: non-word aligned length\n", __FUNCTION__);
+       }
+
+       transBuf = transferBuffer;
+
+       /*
+          Work out whether we are going to read the OOB area
+          after a standard page read.
+          This is not the case when the command function is called
+          with a column address > page size. Then we read as though
+          it is from the page rather than the OOB as the command
+          function has already selected the OOB area.
+        */
+       if ((last_col_addr + len) > mtd->oobblock)
+               oobLen = (last_col_addr + len) - mtd->oobblock;
+       pageLen = len - oobLen;
+
+       if (pageLen) {
+               NAND_TRANSFER_FROM(addr, transBuf, pageLen);
+       }
+       if (oobLen > 0) {
+               pnx8550_nand_register_setup(1, 3, 1, 1, 0, NAND_CMD_READOOB, 0);
+               addr = NAND_ADDR(last_col_addr - mtd->oobblock, last_page_addr);
+               NAND_TRANSFER_FROM(addr, transBuf + pageLen, oobLen);
+       }
+       if (transBuf != buf) {
+               memcpy(buf, transBuf, len);
+       }
+
+       /*
+          Increment the address so on the next read we read from the
+          correct place.
+        */
+       last_col_addr += len;
+       if (last_col_addr > mtd->oobblock + mtd->oobsize) {
+               last_col_addr -= mtd->oobblock + mtd->oobsize;
+               last_page_addr++;
+       }
+       return;
+}
+
+/**
+ * pnx8550_nand_verify_buf -  Verify chip data against buffer
+ * @mtd:       MTD device structure
+ * @buf:       buffer containing the data to compare
+ * @len:       number of bytes to compare
+ *
+ */
+static int pnx8550_nand_verify_buf(struct mtd_info *mtd, const u_char * buf,
+                                  int len)
+{
+       int result = 0;
+
+       /* some sanity checking, word access only please */
+       if (len & 1) {
+               printk("%s: non-word aligned length\n", __FUNCTION__);
+       }
+
+       pnx8550_nand_read_buf(mtd, transferBuffer, len);
+       if (memcmp(buf, transferBuffer, len)) {
+               result = -EFAULT;
+       }
+
+       return result;
+
+}
+
+/**
+ * pnx8550_nand_command - Send command to NAND device
+ * @mtd:       MTD device structure
+ * @command:   the command to be sent
+ * @column:    the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device.
+ */
+static void pnx8550_nand_command(struct mtd_info *mtd, unsigned command,
+                                int column, int page_addr)
+{
+       register struct nand_chip *this = mtd->priv;
+       u_char addr_no = 0;
+       u_char spare = 0;
+       int addr;
+       /*
+          If we are starting a write work out whether it is to the
+          OOB or the main page and position the pointer correctly.
+        */
+       if (command == NAND_CMD_SEQIN) {
+               int readcmd;
+               int col = column;
+               if (column >= mtd->oobblock) {
+                       /* OOB area */
+                       col -= mtd->oobblock;
+                       readcmd = NAND_CMD_READOOB;
+                       spare = 1;
+               } else {
+                       readcmd = NAND_CMD_READ0;
+               }
+               pnx8550_nand_register_setup(1, 0, 0, 1, 0, readcmd, 0);
+               addr = NAND_ADDR(col, page_addr);
+               NAND_ADDR_SEND(addr);
+       }
+
+       /* Check the number of address bytes */
+       if ((column == -1) && (page_addr == -1)) {
+               addr_no = 0;
+               column = 0;
+               page_addr = 0;
+       } else if ((column == -1) && (page_addr != -1)) {
+               addr_no = 2;
+               column = 0;
+       } else if ((column != -1) && (page_addr == -1)) {
+               addr_no = 1;
+               page_addr = 0;
+       } else {
+               addr_no = 3;
+       }
+
+       last_command = command;
+       last_col_addr = column;
+       last_page_addr = page_addr;
+
+       switch (command) {
+
+       case NAND_CMD_PAGEPROG:
+               // Nothing to do, we've already done it!
+               return;
+
+       case NAND_CMD_SEQIN:
+               if (addr_no != 3)
+                       printk
+                           ("NAND: Error. Command %02x needs 3 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+               pnx8550_nand_register_setup(2, 3, 1, 1, spare, NAND_CMD_SEQIN,
+                                           NAND_CMD_PAGEPROG);
+               return;
+
+       case NAND_CMD_ERASE1:
+               if (addr_no != 2)
+                       printk
+                           ("NAND: Error. Command %02x needs 2 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+
+               PNX8550_GPXIO_CTRL |= PNX8550_GPXIO_CLR_DONE;
+
+               pnx8550_nand_register_setup(2, 2, 0, 1, 0, NAND_CMD_ERASE1,
+                                           NAND_CMD_ERASE2);
+               addr = NAND_ADDR(column, page_addr);
+               NAND_ADDR_SEND(addr);
+               return;
+
+       case NAND_CMD_ERASE2:
+               // Nothing to do, we've already done it!
+               return;
+
+       case NAND_CMD_STATUS:
+               if (addr_no != 0)
+                       printk
+                           ("NAND: Error. Command %02x needs 0 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+               pnx8550_nand_register_setup(1, 0, 1, 0, 0, NAND_CMD_STATUS, 0);
+               return;
+
+       case NAND_CMD_RESET:
+               if (addr_no != 0)
+                       printk
+                           ("NAND: Error. Command %02x needs 0 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+               pnx8550_nand_register_setup(1, 0, 0, 0, 0, NAND_CMD_RESET, 0);
+               addr = NAND_ADDR(column, page_addr);
+               NAND_ADDR_SEND(addr);
+               return;
+
+       case NAND_CMD_READ0:
+               if (addr_no != 3)
+                       printk
+                           ("NAND: Error. Command %02x needs 3 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+
+               pnx8550_nand_register_setup(1, 3, 1, 1, 0, NAND_CMD_READ0, 0);
+               return;
+
+       case NAND_CMD_READ1:
+               printk("Wrong command: %02x\n", command);
+               return;
+
+       case NAND_CMD_READOOB:
+               if (addr_no != 3)
+                       printk
+                           ("NAND: Error. Command %02x needs 3 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+               pnx8550_nand_register_setup(1, 3, 1, 1, 0, NAND_CMD_READOOB, 0);
+               return;
+
+       case NAND_CMD_READID:
+               if (addr_no != 1)
+                       printk
+                           ("NAND: Error. Command %02x needs 1 byte address, but 
addr_no = %d\n",
+                            command, addr_no);
+               pnx8550_nand_register_setup(1, 1, 1, 0, 0, NAND_CMD_READID, 0);
+               return;
+       }
+}
+
+/*
+ * Setup the registers in PCIXIO
+ */
+static void pnx8550_nand_register_setup(u_char cmd_no,
+                                       u_char addr_no,
+                                       u_char include_data,
+                                       u_char monitor_ACK,
+                                       u_char enable64M, int cmd_a, int cmd_b)
+{
+       unsigned int reg_nand = 0;
+       reg_nand |= enable64M ? PNX8550_XIO_FLASH_64MB : 0;
+       reg_nand |= include_data ? PNX8550_XIO_FLASH_INC_DATA : 0;
+       reg_nand |= PNX8550_XIO_FLASH_CMD_PH(cmd_no);
+       reg_nand |= PNX8550_XIO_FLASH_ADR_PH(addr_no);
+       reg_nand |= PNX8550_XIO_FLASH_CMD_A(cmd_a);
+       reg_nand |= PNX8550_XIO_FLASH_CMD_B(cmd_b);
+       PNX8550_XIO_FLASH_CTRL = reg_nand;
+       barrier();
+}
+
+/*
+ * Wait for the device to be ready for the next command
+ */
+static inline void pnx8550_nand_wait_for_dev_ready(void)
+{
+       while ((PNX8550_XIO_CTRL & PNX8550_XIO_CTRL_XIO_ACK) == 0) ;
+}
+
+/*
+ * Return true if the device is ready, false otherwise
+ */
+static int pnx8550_nand_dev_ready(struct mtd_info *mtd)
+{
+       return ((PNX8550_XIO_CTRL & PNX8550_XIO_CTRL_XIO_ACK) != 0);
+}
+
+/*
+ *     hardware specific access to control-lines
+ */
+static void pnx8550_nand_hwcontrol(struct mtd_info *mtd, int cmd)
+{
+       // Nothing to do here, its all done by the XIO block
+}
+
+/*
+ * Main initialization routine
+ */
+int __init pnx8550_nand_init(void)
+{
+       struct nand_chip *this;
+
+       /* Get pointer to private data */
+       this = &pnx8550_nand;
+
+       /* Initialize structures */
+       memset((char *)&pnx8550_mtd, 0, sizeof(struct mtd_info));
+       memset((char *)this, 0, sizeof(struct nand_chip));
+
+       /* Work out address of Nand Flash */
+       pNandAddr = (u16 *) (KSEG1 | (PNX8550_BASE18_ADDR & (~0x7)));
+
+       pNandAddr = (u16 *) (((u32) pNandAddr) +
+                            ((PNX8550_XIO_SEL0 & PNX8550_XIO_SEL0_OFFSET_MASK)
+                             >> PNX8550_XIO_SEL0_OFFSET_SHIFT) * 8 * 1024 *
+                            1024);
+
+       /* Link the private data with the MTD structure */
+       pnx8550_mtd.priv = this;
+       this->chip_delay = 15;
+       this->options = NAND_BUSWIDTH_16;
+       this->cmdfunc = pnx8550_nand_command;
+       this->read_byte = pnx8550_nand_read_byte;
+       this->read_word = pnx8550_nand_read_word;
+       this->read_buf = pnx8550_nand_read_buf;
+       this->write_byte = pnx8550_nand_write_byte;
+       this->write_word = pnx8550_nand_write_word;
+       this->write_buf = pnx8550_nand_write_buf;
+       this->verify_buf = pnx8550_nand_verify_buf;
+       this->dev_ready = pnx8550_nand_dev_ready;
+       this->hwcontrol = pnx8550_nand_hwcontrol;
+       this->eccmode = NAND_ECC_SOFT;
+       this->badblock_pattern = &nand16bit_memorybased;
+       this->autooob = &nand16bit_oob_16;
+
+       transferBuffer =
+           kmalloc(pnx8550_mtd.oobblock + pnx8550_mtd.oobsize,
+                   GFP_DMA | GFP_KERNEL);
+       if (!transferBuffer) {
+               printk(KERN_ERR
+                      "Unable to allocate NAND data buffer for PNX8550.\n");
+               return -ENOMEM;
+       }
+
+       /* Scan to find existence of the device */
+       if (nand_scan(&pnx8550_mtd, 1)) {
+               printk("%s: Exiting No Devices\n", __FUNCTION__);
+               return -ENXIO;

Need kfree(transferBuffer)

+       }
+
+       /* Register the partitions */
+       add_mtd_partitions(&pnx8550_mtd, partition_info, NUM_PARTITIONS);

Need Kconfig to select MTD_PARTITIONS if required.

+
+       /* Return happy */
+       return 0;
+}
+
+module_init(pnx8550_nand_init);
+
+/*
+ * Clean up routine
+ */
+#ifdef MODULE
+static void __exit pnx8550_nand_cleanup(void)
+{
+       /* Unregister the device */
+       del_mtd_device(&pnx8550_mtd);

Need del_mtd_partitions I think?

+       if (transferBuffer) {
+               kfree(transferBuffer);

"if (transferBuffer)" not needed and is discouraged
.
+       }
+}
+
+module_exit(pnx8550_nand_cleanup);
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Adam Charrett");
+MODULE_DESCRIPTION("Driver for 16Bit NAND Flash on the XIO bus for PNX8550");
Index: linux-2.6.15_0/drivers/mtd/nand/Makefile
===================================================================
--- linux-2.6.15_0.orig/drivers/mtd/nand/Makefile
+++ linux-2.6.15_0/drivers/mtd/nand/Makefile
@@ -18,5 +18,6 @@ obj-$(CONFIG_MTD_NAND_H1900)          += h1910.o
 obj-$(CONFIG_MTD_NAND_RTC_FROM4)       += rtc_from4.o
 obj-$(CONFIG_MTD_NAND_SHARPSL)         += sharpsl.o
 obj-$(CONFIG_MTD_NAND_NANDSIM)         += nandsim.o
+obj-$(CONFIG_MTD_NAND_PNX8550)         += pnx8550.o
nand-objs = nand_base.o nand_bbt.o


------------------------------------------------------------------------

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Todd

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