/*
* drivers/mtd/nand/gpio.c
*
* Updated, and converted to generic GPIO based driver by Russell King.
*
* Written by Ben Dooks <ben@simtec.co.uk>
* Based on 2.4 version by Mark Whittaker
*
* © 2004 Simtec Electronics
*
* Device driver for NAND connected via GPIO
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/nand-gpio.h>
struct gpiomtd {
void __iomem *io_sync;
struct mtd_info mtd_info;
struct nand_chip nand_chip;
struct gpio_nand_platdata plat;
};
#define gpio_nand_getpriv(x) container_of(x, struct gpiomtd, mtd_info)
#ifdef CONFIG_ARM
/* gpio_nand_dosync()
*
* Make sure the GPIO state changes occur in-order with writes to NAND
* memory region.
* Needed on PXA due to bus-reordering within the SoC itself (see section on
* I/O ordering in PXA manual (section 2.3, p35)
*/
static void gpio_nand_dosync(struct gpiomtd *gpiomtd)
{
unsigned long tmp;
if (gpiomtd->io_sync) {
/*
* Linux memory barriers don't cater for what's required here.
* What's required is what's here - a read from a separate
* region with a dependency on that read.
*/
tmp = readl(gpiomtd->io_sync);
asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp));
}
}
#else
static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {}
#endif
static void gpio_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);
gpio_nand_dosync(gpiomtd);
if (ctrl & NAND_CTRL_CHANGE) {
gpio_set_value(gpiomtd->plat.gpio_nce, !(ctrl & NAND_NCE));
gpio_set_value(gpiomtd->plat.gpio_cle, !!(ctrl & NAND_CLE));
gpio_set_value(gpiomtd->plat.gpio_ale, !!(ctrl & NAND_ALE));
gpio_nand_dosync(gpiomtd);
}
if (cmd == NAND_CMD_NONE)
return;
writeb(cmd, gpiomtd->nand_chip.IO_ADDR_W);
gpio_nand_dosync(gpiomtd);
}
static void gpio_nand_writebuf(struct mtd_info *mtd, const u_char *buf, int len)
{
struct nand_chip *this = mtd->priv;
writesb(this->IO_ADDR_W, buf, len);
}
static void gpio_nand_readbuf(struct mtd_info *mtd, u_char *buf, int len)
{
struct nand_chip *this = mtd->priv;
readsb(this->IO_ADDR_R, buf, len);
}
static int gpio_nand_verifybuf(struct mtd_info *mtd, const u_char *buf, int len)
{
struct nand_chip *this = mtd->priv;
unsigned char read, *p = (unsigned char *) buf;
int i, err = 0;
for (i = 0; i < len; i++) {
read = readb(this->IO_ADDR_R);
if (read != p[i]) {
pr_debug("%s: err at %d (read %04x vs %04x)\n",
__func__, i, read, p[i]);
err = -EFAULT;
}
}
return err;
}
static void gpio_nand_writebuf16(struct mtd_info *mtd, const u_char *buf,
int len)
{
struct nand_chip *this = mtd->priv;
if (IS_ALIGNED((unsigned long)buf, 2)) {
writesw(this->IO_ADDR_W, buf, len>>1);
} else {
int i;
unsigned short *ptr = (unsigned short *)buf;
for (i = 0; i < len; i += 2, ptr++)
writew(*ptr, this->IO_ADDR_W);
}
}
static void gpio_nand_readbuf16(struct mtd_info *mtd, u_char *buf, int len)
{
struct nand_chip *this = mtd->priv;
if (IS_ALIGNED((unsigned long)buf, 2)) {
readsw(this->IO_ADDR_R, buf, len>>1);
} else {
int i;
unsigned short *ptr = (unsigned short *)buf;
for (i = 0; i < len; i += 2, ptr++)
*ptr = readw(this->IO_ADDR_R);
}
}
static int gpio_nand_verifybuf16(struct mtd_info *mtd, const u_char *buf,
int len)
{
struct nand_chip *this = mtd->priv;
unsigned short read, *p = (unsigned short *) buf;
int i, err = 0;
len >>= 1;
for (i = 0; i < len; i++) {
read = readw(this->IO_ADDR_R);
if (read != p[i]) {
pr_debug("%s: err at %d (read %04x vs %04x)\n",
__func__, i, read, p[i]);
err = -EFAULT;
}
}
return err;
}
static int gpio_nand_devready(struct mtd_info *mtd)
{
struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd);
return gpio_get_value(gpiomtd->plat.gpio_rdy);
}
static int __devexit gpio_nand_remove(struct platform_device *dev)
{
struct gpiomtd *gpiomtd = platform_get_drvdata(dev);
struct resource *res;
nand_release(&gpiomtd->mtd_info);
res = platform_get_resource(dev, IORESOURCE_MEM, 1);
iounmap(gpiomtd->io_sync);
if (res)
release_mem_region(res->start, resource_size(res));
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
iounmap(gpiomtd->nand_chip.IO_ADDR_R);
release_mem_region(res->start, resource_size(res));
if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
gpio_set_value(gpiomtd->plat.gpio_nce, 1);
gpio_free(gpiomtd->plat.gpio_cle);
gpio_free(gpiomtd->plat.gpio_ale);
gpio_free(gpiomtd->plat.gpio_nce);
if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
gpio_free(gpiomtd->plat.gpio_nwp);
gpio_free(gpiomtd->plat.gpio_rdy);
kfree(gpiomtd);
return 0;
}
static void __iomem *request_and_remap(struct resource *res, size_t size,
const char *name, int *err)
{
void __iomem *ptr;
if (!request_mem_region(res->start, resource_size(res), name)) {
*err = -EBUSY;
return NULL;
}
ptr = ioremap(res->start, size);
if (!ptr) {
release_mem_region(res->start, resource_size(res));
*err = -ENOMEM;
}
return ptr;
}
static int __devinit gpio_nand_probe(struct platform_device *dev)
{
struct gpiomtd *gpiomtd;
struct nand_chip *this;
struct resource *res0, *res1;
int ret;
if (!dev->dev.platform_data)
return -EINVAL;
res0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res0)
return -EINVAL;
gpiomtd = kzalloc(sizeof(*gpiomtd), GFP_KERNEL);
if (gpiomtd == NULL) {
dev_err(&dev->dev, "failed to create NAND MTD\n");
return -ENOMEM;
}
this = &gpiomtd->nand_chip;
this->IO_ADDR_R = request_and_remap(res0, 2, "NAND", &ret);
if (!this->IO_ADDR_R) {
dev_err(&dev->dev, "unable to map NAND\n");
goto err_map;
}
res1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
if (res1) {
gpiomtd->io_sync = request_and_remap(res1, 4, "NAND sync", &ret);
if (!gpiomtd->io_sync) {
dev_err(&dev->dev, "unable to map sync NAND\n");
goto err_sync;
}
}
memcpy(&gpiomtd->plat, dev->dev.platform_data, sizeof(gpiomtd->plat));
ret = gpio_request(gpiomtd->plat.gpio_nce, "NAND NCE");
if (ret)
goto err_nce;
gpio_direction_output(gpiomtd->plat.gpio_nce, 1);
if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) {
ret = gpio_request(gpiomtd->plat.gpio_nwp, "NAND NWP");
if (ret)
goto err_nwp;
gpio_direction_output(gpiomtd->plat.gpio_nwp, 1);
}
ret = gpio_request(gpiomtd->plat.gpio_ale, "NAND ALE");
if (ret)
goto err_ale;
gpio_direction_output(gpiomtd->plat.gpio_ale, 0);
ret = gpio_request(gpiomtd->plat.gpio_cle, "NAND CLE");
if (ret)
goto err_cle;
gpio_direction_output(gpiomtd->plat.gpio_cle, 0);
ret = gpio_request(gpiomtd->plat.gpio_rdy, "NAND RDY");
if (ret)
goto err_rdy;
gpio_direction_input(gpiomtd->plat.gpio_rdy);
this->IO_ADDR_W = this->IO_ADDR_R;
this->ecc.mode = NAND_ECC_SOFT;
this->options = gpiomtd->plat.options;
this->chip_delay = gpiomtd->plat.chip_delay;
/* install our routines */
this->cmd_ctrl = gpio_nand_cmd_ctrl;
this->dev_ready = gpio_nand_devready;
if (this->options & NAND_BUSWIDTH_16) {
this->read_buf = gpio_nand_readbuf16;
this->write_buf = gpio_nand_writebuf16;
this->verify_buf = gpio_nand_verifybuf16;
} else {
this->read_buf = gpio_nand_readbuf;
this->write_buf = gpio_nand_writebuf;
this->verify_buf = gpio_nand_verifybuf;
}
/* set the mtd private data for the nand driver */
gpiomtd->mtd_info.priv = this;
gpiomtd->mtd_info.owner = THIS_MODULE;
if (nand_scan(&gpiomtd->mtd_info, 1)) {
dev_err(&dev->dev, "no nand chips found?\n");
ret = -ENXIO;
goto err_wp;
}
if (gpiomtd->plat.adjust_parts)
gpiomtd->plat.adjust_parts(&gpiomtd->plat,
gpiomtd->mtd_info.size);
add_mtd_partitions(&gpiomtd->mtd_info, gpiomtd->plat.parts,
gpiomtd->plat.num_parts);
platform_set_drvdata(dev, gpiomtd);
return 0;
err_wp:
if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
gpio_set_value(gpiomtd->plat.gpio_nwp, 0);
gpio_free(gpiomtd->plat.gpio_rdy);
err_rdy:
gpio_free(gpiomtd->plat.gpio_cle);
err_cle:
gpio_free(gpiomtd->plat.gpio_ale);
err_ale:
if (gpio_is_valid(gpiomtd->plat.gpio_nwp))
gpio_free(gpiomtd->plat.gpio_nwp);
err_nwp:
gpio_free(gpiomtd->plat.gpio_nce);
err_nce:
iounmap(gpiomtd->io_sync);
if (res1)
release_mem_region(res1->start, resource_size(res1));
err_sync:
iounmap(gpiomtd->nand_chip.IO_ADDR_R);
release_mem_region(res0->start, resource_size(res0));
err_map:
kfree(gpiomtd);
return ret;
}
static struct platform_driver gpio_nand_driver = {
.probe = gpio_nand_probe,
.remove = gpio_nand_remove,
.driver = {
.name = "gpio-nand",
},
};
static int __init gpio_nand_init(void)
{
printk(KERN_INFO "GPIO NAND driver, © 2004 Simtec Electronics\n");
return platform_driver_register(&gpio_nand_driver);
}
static void __exit gpio_nand_exit(void)
{
platform_driver_unregister(&gpio_nand_driver);
}
module_init(gpio_nand_init);
module_exit(gpio_nand_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("GPIO NAND Driver");
