/*
* Copyright ┬й 2009 Nuvoton technology corporation.
*
* Wan ZongShun <mcuos.com@gmail.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;version 2 of the License.
*
*/

#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>

#define REG_FMICSR 0x00
#define REG_SMCSR 0xa0
#define REG_SMISR 0xac
#define REG_SMCMD 0xb0
#define REG_SMADDR 0xb4
#define REG_SMDATA 0xb8

#define RESET_FMI 0x01
#define NAND_EN 0x08
#define READYBUSY (0x01 << 18)

#define SWRST 0x01
#define PSIZE (0x01 << 3)
#define DMARWEN (0x03 << 1)
#define BUSWID (0x01 << 4)
#define ECC4EN (0x01 << 5)
#define WP (0x01 << 24)
#define NANDCS (0x01 << 25)
#define ENDADDR (0x01 << 31)

#define read_data_reg(dev) \
__raw_readl((dev)->reg + REG_SMDATA)

#define write_data_reg(dev, val) \
__raw_writel((val), (dev)->reg + REG_SMDATA)

#define write_cmd_reg(dev, val) \
__raw_writel((val), (dev)->reg + REG_SMCMD)

#define write_addr_reg(dev, val) \
__raw_writel((val), (dev)->reg + REG_SMADDR)

struct nuc900_nand {
struct mtd_info mtd;
struct nand_chip chip;
void __iomem *reg;
struct clk *clk;
spinlock_t lock;
};

static const struct mtd_partition partitions[] = {
{
.name = "NAND FS 0",
.offset = 0,
.size = 8 * 1024 * 1024
},
{
.name = "NAND FS 1",
.offset = MTDPART_OFS_APPEND,
.size = MTDPART_SIZ_FULL
}
};

static unsigned char nuc900_nand_read_byte(struct mtd_info *mtd)
{
unsigned char ret;
struct nuc900_nand *nand;

nand = container_of(mtd, struct nuc900_nand, mtd);

ret = (unsigned char)read_data_reg(nand);

return ret;
}

static void nuc900_nand_read_buf(struct mtd_info *mtd,
unsigned char *buf, int len){
int i;
struct nuc900_nand *nand;
//printk("nuc900_nand_read_buf:\r\n");
nand = container_of(mtd, struct nuc900_nand, mtd);

for (i = 0; i < len; i++)
buf[i] = (unsigned char)read_data_reg(nand);
}

static void nuc900_nand_write_buf(struct mtd_info *mtd,
const unsigned char *buf, int len)
{
int i;
struct nuc900_nand *nand;

nand = container_of(mtd, struct nuc900_nand, mtd);

for (i = 0; i < len; i++)
write_data_reg(nand, buf[i]);
}

static int nuc900_verify_buf(struct mtd_info *mtd,
const unsigned char *buf, int len)
{
int i;
struct nuc900_nand *nand;

nand = container_of(mtd, struct nuc900_nand, mtd);

for (i = 0; i < len; i++) {
if (buf[i] != (unsigned char)read_data_reg(nand))
return -EFAULT;
}

return 0;
}

static int nuc900_check_rb(struct nuc900_nand *nand)
{
unsigned int val;
spin_lock(&nand->lock);
//val = __raw_readl(REG_SMISR);
val = __raw_readl(nand->reg + REG_SMISR);
val &= READYBUSY;
spin_unlock(&nand->lock);

return val;
}

static int nuc900_nand_devready(struct mtd_info *mtd)
{
struct nuc900_nand *nand;
int ready;

nand = container_of(mtd, struct nuc900_nand, mtd);

ready = (nuc900_check_rb(nand)) ? 1 : 0;
return ready;
}

static void nuc900_nand_command_lp(struct mtd_info *mtd, unsigned int command,
int column, int page_addr)
{
register struct nand_chip *chip = mtd->priv;
struct nuc900_nand *nand;

nand = container_of(mtd, struct nuc900_nand, mtd);

if (command == NAND_CMD_READOOB) {
column += mtd->writesize;
command = NAND_CMD_READ0;
}

write_cmd_reg(nand, command & 0xff);

if (column != -1 || page_addr != -1) {

if (column != -1) {
if (chip->options & NAND_BUSWIDTH_16)
column >>= 1;
write_addr_reg(nand, column);
write_addr_reg(nand, column >> 8 | ENDADDR);
}
if (page_addr != -1) {
write_addr_reg(nand, page_addr);

if (chip->chipsize > (128 << 20)) {
write_addr_reg(nand, page_addr >> 8);
write_addr_reg(nand, page_addr >> 16 | ENDADDR);
} else {
write_addr_reg(nand, page_addr >> 8 | ENDADDR);
}
}
}

switch (command) {
case NAND_CMD_CACHEDPROG:
case NAND_CMD_PAGEPROG:
case NAND_CMD_ERASE1:
case NAND_CMD_ERASE2:
case NAND_CMD_SEQIN:
case NAND_CMD_RNDIN:
case NAND_CMD_STATUS:
case NAND_CMD_DEPLETE1:
return;

case NAND_CMD_STATUS_ERROR:
case NAND_CMD_STATUS_ERROR0:
case NAND_CMD_STATUS_ERROR1:
case NAND_CMD_STATUS_ERROR2:
case NAND_CMD_STATUS_ERROR3:
udelay(chip->chip_delay);
return;

case NAND_CMD_RESET:
if (chip->dev_ready)
break;
udelay(chip->chip_delay);

write_cmd_reg(nand, NAND_CMD_STATUS);
write_cmd_reg(nand, command);

while (!nuc900_check_rb(nand))
;

return;

case NAND_CMD_RNDOUT:
write_cmd_reg(nand, NAND_CMD_RNDOUTSTART);
return;

case NAND_CMD_READ0:

write_cmd_reg(nand, NAND_CMD_READSTART);
default:

if (!chip->dev_ready) {
udelay(chip->chip_delay);
return;
}
}

/* Apply this short delay always to ensure that we do wait tWB in
* any case on any machine. */
ndelay(100);

while (!chip->dev_ready(mtd))
;
}


static void nuc900_nand_enable(struct nuc900_nand *nand){
unsigned int val;
spin_lock(&nand->lock);
//printk("nuc900_nand_enable: nand->reg = 0x%X\r\n", nand->reg);
__raw_writel(RESET_FMI, (nand->reg + REG_FMICSR));

val = __raw_readl(nand->reg + REG_FMICSR);
//printk("nuc900_nand_enable: val_1 = 0x%X\r\n", val);

// if (!(val & NAND_EN)){
__raw_writel((val | NAND_EN), (nand->reg + REG_FMICSR) );
// }
//printk("enable NAND_EN\r\n");
val = __raw_readl(nand->reg + REG_SMCSR);
//printk("nuc900_nand_enable: val_2 = 0x%X\r\n", val);

val &= ~(SWRST|PSIZE|DMARWEN|BUSWID|ECC4EN|NANDCS);
val |= WP;
//printk("nuc900_nand_enable: val_3 = 0x%X\r\n", val);

__raw_writel(val, nand->reg + REG_SMCSR);
//printk("nuc900_nand_enable: end\r\n");

spin_unlock(&nand->lock);
}

static int __devinit nuc900_nand_probe(struct platform_device *pdev)
{
struct nuc900_nand *nuc900_nand;
struct nand_chip *chip;
int retval;
struct resource *res;

retval = 0;

nuc900_nand = kzalloc(sizeof(struct nuc900_nand), GFP_KERNEL);
if (!nuc900_nand)
return -ENOMEM;
chip = &(nuc900_nand->chip);

nuc900_nand->mtd.priv = chip;
nuc900_nand->mtd.owner = THIS_MODULE;
spin_lock_init(&nuc900_nand->lock);

nuc900_nand->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(nuc900_nand->clk)) {
retval = -ENOENT;
goto fail1;
}
clk_enable(nuc900_nand->clk);

chip->cmdfunc = nuc900_nand_command_lp;
chip->dev_ready = nuc900_nand_devready;
chip->read_byte = nuc900_nand_read_byte;
chip->write_buf = nuc900_nand_write_buf;
chip->read_buf = nuc900_nand_read_buf;
chip->verify_buf = nuc900_verify_buf;
chip->chip_delay = 50;
chip->options = 0;
chip->ecc.mode = NAND_ECC_SOFT;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
retval = -ENXIO;
goto fail1;
}

if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
retval = -EBUSY;
goto fail1;
}
//printk("nand_probe: start 0x%X, size 0x%X\r\n", res->start, resource_size(res));
nuc900_nand->reg = ioremap(res->start, resource_size(res));
if (!nuc900_nand->reg) {
retval = -ENOMEM;
goto fail2;
}
//printk("nand_probe: ioremap 0x%X\r\n", nuc900_nand->reg);

nuc900_nand_enable(nuc900_nand);

if (nand_scan(&(nuc900_nand->mtd), 1)) {
retval = -ENXIO;
goto fail3;
}

add_mtd_partitions(&(nuc900_nand->mtd), partitions,
ARRAY_SIZE(partitions));

platform_set_drvdata(pdev, nuc900_nand);

return retval;

fail3: iounmap(nuc900_nand->reg);
fail2: release_mem_region(res->start, resource_size(res));
fail1: kfree(nuc900_nand);
return retval;
}

static int __devexit nuc900_nand_remove(struct platform_device *pdev)
{
struct nuc900_nand *nuc900_nand = platform_get_drvdata(pdev);
struct resource *res;

iounmap(nuc900_nand->reg);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, resource_size(res));

clk_disable(nuc900_nand->clk);
clk_put(nuc900_nand->clk);

kfree(nuc900_nand);

platform_set_drvdata(pdev, NULL);

return 0;
}

static struct platform_driver nuc900_nand_driver = {
.probe = nuc900_nand_probe,
.remove = __devexit_p(nuc900_nand_remove),
.driver = {
.name = "nuc900-fmi",
.owner = THIS_MODULE,
},
};

static int __init nuc900_nand_init(void)
{
return platform_driver_register(&nuc900_nand_driver);
}

static void __exit nuc900_nand_exit(void)
{
platform_driver_unregister(&nuc900_nand_driver);
}

module_init(nuc900_nand_init);
module_exit(nuc900_nand_exit);

MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("w90p910/NUC9xx nand driver!");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nuc900-fmi");