linux-sg2042/drivers/mtd/nand/excite_nandflash.c

248 lines
6.6 KiB
C

/*
* Copyright (C) 2005 - 2007 by Basler Vision Technologies AG
* Author: Thomas Koeller <thomas.koeller.qbaslerweb.com>
* Original code by Thies Moeller <thies.moeller@baslerweb.com>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/rm9k-ocd.h>
#include <excite_nandflash.h>
#define EXCITE_NANDFLASH_VERSION "0.1"
/* I/O register offsets */
#define EXCITE_NANDFLASH_DATA_BYTE 0x00
#define EXCITE_NANDFLASH_STATUS_BYTE 0x0c
#define EXCITE_NANDFLASH_ADDR_BYTE 0x10
#define EXCITE_NANDFLASH_CMD_BYTE 0x14
/* prefix for debug output */
static const char module_id[] = "excite_nandflash";
/*
* partition definition
*/
static const struct mtd_partition partition_info[] = {
{
.name = "eXcite RootFS",
.offset = 0,
.size = MTDPART_SIZ_FULL
}
};
static inline const struct resource *
excite_nand_get_resource(struct platform_device *d, unsigned long flags,
const char *basename)
{
char buf[80];
if (snprintf(buf, sizeof buf, "%s_%u", basename, d->id) >= sizeof buf)
return NULL;
return platform_get_resource_byname(d, flags, buf);
}
static inline void __iomem *
excite_nand_map_regs(struct platform_device *d, const char *basename)
{
void *result = NULL;
const struct resource *const r =
excite_nand_get_resource(d, IORESOURCE_MEM, basename);
if (r)
result = ioremap_nocache(r->start, r->end + 1 - r->start);
return result;
}
/* controller and mtd information */
struct excite_nand_drvdata {
struct mtd_info board_mtd;
struct nand_chip board_chip;
void __iomem *regs;
void __iomem *tgt;
};
/* Control function */
static void excite_nand_control(struct mtd_info *mtd, int cmd,
unsigned int ctrl)
{
struct excite_nand_drvdata * const d =
container_of(mtd, struct excite_nand_drvdata, board_mtd);
switch (ctrl) {
case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
d->tgt = d->regs + EXCITE_NANDFLASH_CMD_BYTE;
break;
case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
d->tgt = d->regs + EXCITE_NANDFLASH_ADDR_BYTE;
break;
case NAND_CTRL_CHANGE | NAND_NCE:
d->tgt = d->regs + EXCITE_NANDFLASH_DATA_BYTE;
break;
}
if (cmd != NAND_CMD_NONE)
__raw_writeb(cmd, d->tgt);
}
/* Return 0 if flash is busy, 1 if ready */
static int excite_nand_devready(struct mtd_info *mtd)
{
struct excite_nand_drvdata * const drvdata =
container_of(mtd, struct excite_nand_drvdata, board_mtd);
return __raw_readb(drvdata->regs + EXCITE_NANDFLASH_STATUS_BYTE);
}
/*
* Called by device layer to remove the driver.
* The binding to the mtd and all allocated
* resources are released.
*/
static int __exit excite_nand_remove(struct device *dev)
{
struct excite_nand_drvdata * const this = dev_get_drvdata(dev);
dev_set_drvdata(dev, NULL);
if (unlikely(!this)) {
printk(KERN_ERR "%s: called %s without private data!!",
module_id, __func__);
return -EINVAL;
}
/* first thing we need to do is release our mtd
* then go through freeing the resource used
*/
nand_release(&this->board_mtd);
/* free the common resources */
iounmap(this->regs);
kfree(this);
DEBUG(MTD_DEBUG_LEVEL1, "%s: removed\n", module_id);
return 0;
}
/*
* Called by device layer when it finds a device matching
* one our driver can handle. This code checks to see if
* it can allocate all necessary resources then calls the
* nand layer to look for devices.
*/
static int __init excite_nand_probe(struct device *dev)
{
struct platform_device * const pdev = to_platform_device(dev);
struct excite_nand_drvdata *drvdata; /* private driver data */
struct nand_chip *board_chip; /* private flash chip data */
struct mtd_info *board_mtd; /* mtd info for this board */
int scan_res;
drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
if (unlikely(!drvdata)) {
printk(KERN_ERR "%s: no memory for drvdata\n",
module_id);
return -ENOMEM;
}
/* bind private data into driver */
dev_set_drvdata(dev, drvdata);
/* allocate and map the resource */
drvdata->regs =
excite_nand_map_regs(pdev, EXCITE_NANDFLASH_RESOURCE_REGS);
if (unlikely(!drvdata->regs)) {
printk(KERN_ERR "%s: cannot reserve register region\n",
module_id);
kfree(drvdata);
return -ENXIO;
}
drvdata->tgt = drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
/* initialise our chip */
board_chip = &drvdata->board_chip;
board_chip->IO_ADDR_R = board_chip->IO_ADDR_W =
drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
board_chip->cmd_ctrl = excite_nand_control;
board_chip->dev_ready = excite_nand_devready;
board_chip->chip_delay = 25;
board_chip->ecc.mode = NAND_ECC_SOFT;
/* link chip to mtd */
board_mtd = &drvdata->board_mtd;
board_mtd->priv = board_chip;
DEBUG(MTD_DEBUG_LEVEL2, "%s: device scan\n", module_id);
scan_res = nand_scan(&drvdata->board_mtd, 1);
if (likely(!scan_res)) {
DEBUG(MTD_DEBUG_LEVEL2, "%s: register partitions\n", module_id);
add_mtd_partitions(&drvdata->board_mtd, partition_info,
ARRAY_SIZE(partition_info));
} else {
iounmap(drvdata->regs);
kfree(drvdata);
printk(KERN_ERR "%s: device scan failed\n", module_id);
return -EIO;
}
return 0;
}
static struct device_driver excite_nand_driver = {
.name = "excite_nand",
.bus = &platform_bus_type,
.probe = excite_nand_probe,
.remove = __exit_p(excite_nand_remove)
};
static int __init excite_nand_init(void)
{
pr_info("Basler eXcite nand flash driver Version "
EXCITE_NANDFLASH_VERSION "\n");
return driver_register(&excite_nand_driver);
}
static void __exit excite_nand_exit(void)
{
driver_unregister(&excite_nand_driver);
}
module_init(excite_nand_init);
module_exit(excite_nand_exit);
MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
MODULE_DESCRIPTION("Basler eXcite NAND-Flash driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(EXCITE_NANDFLASH_VERSION)