[MTD,NAND] GPIO NAND flash driver

David Woodhouse wrote:
> 
> Please can I have it in a form I can apply, with changelog and
> signed-off-by, and without those silly 'u16' types in it. The C language
> has perfectly good types for specifying unsigned 16-bit integers; use
> them.
> 
> Thanks.

The patch adds support for NAND flashes connected to GPIOs.

Signed-off-by: Ben Dooks <ben-linux-arm@fluff.org>
Signed-off-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Mike Rapoport <mike@compulab.co.il>

 drivers/mtd/nand/Kconfig      |    6 +
 drivers/mtd/nand/Makefile     |    1 +
 drivers/mtd/nand/gpio.c       |  375 +++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand-gpio.h |   19 ++
 4 files changed, 401 insertions(+), 0 deletions(-)

On Wed, Oct 15, 2008 at 08:38:49AM +0200, Mike Rapoport wrote:
> David Woodhouse wrote:
> > 
> > Please can I have it in a form I can apply, with changelog and
> > signed-off-by, and without those silly 'u16' types in it. The C language
> > has perfectly good types for specifying unsigned 16-bit integers; use
> > them.
> > 
> > Thanks.
> 
> The patch adds support for NAND flashes connected to GPIOs.
> 
> Signed-off-by: Ben Dooks <ben-linux-arm@fluff.org>
> Signed-off-by: Russell King <linux@arm.linux.org.uk>

So you're adding signed-off-by's without asking the original people to
provide them...  That's very bad - you're making a statement about
others which they've not made.

Please change mine to:

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

> Signed-off-by: Mike Rapoport <mike@compulab.co.il>
> 
>  drivers/mtd/nand/Kconfig      |    6 +
>  drivers/mtd/nand/Makefile     |    1 +
>  drivers/mtd/nand/gpio.c       |  375 +++++++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/nand-gpio.h |   19 ++
>  4 files changed, 401 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> index 41f361c..e98991b 100644
> --- a/drivers/mtd/nand/Kconfig
> +++ b/drivers/mtd/nand/Kconfig
> @@ -56,6 +56,12 @@ config MTD_NAND_H1900
>  	help
>  	  This enables the driver for the iPAQ h1900 flash.
> 
> +config MTD_NAND_GPIO
> +	tristate "GPIO NAND Flash driver"
> +	depends on GENERIC_GPIO
> +	help
> +	  This enables a GPIO based NAND flash driver.
> +
>  config MTD_NAND_SPIA
>  	tristate "NAND Flash device on SPIA board"
>  	depends on ARCH_P720T
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index b786c5d..39eefc2 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_MTD_NAND_NANDSIM)		+= nandsim.o
>  obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o
>  obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
>  obj-$(CONFIG_MTD_NAND_ATMEL)		+= atmel_nand.o
> +obj-$(CONFIG_MTD_NAND_GPIO)		+= gpio.o
>  obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270_nand.o
>  obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
>  obj-$(CONFIG_MTD_NAND_PXA3xx)		+= pxa3xx_nand.o
> diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
> new file mode 100644
> index 0000000..083bab4
> --- /dev/null
> +++ b/drivers/mtd/nand/gpio.c
> @@ -0,0 +1,375 @@
> +/*
> + * 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
> + *
> + * (c) 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, res->end - res->start + 1);
> +
> +	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> +	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
> +	release_mem_region(res->start, res->end - res->start + 1);
> +
> +	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, res->end - res->start + 1, name)) {
> +		*err = -EBUSY;
> +		return NULL;
> +	}
> +
> +	ptr = ioremap(res->start, size);
> +	if (!ptr) {
> +		release_mem_region(res->start, res->end - res->start + 1);
> +		*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, res1->end - res1->start + 1);
> +err_sync:
> +	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
> +	release_mem_region(res0->start, res0->end - res0->start + 1);
> +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, (c) 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");
> diff --git a/include/linux/mtd/nand-gpio.h b/include/linux/mtd/nand-gpio.h
> new file mode 100644
> index 0000000..51534e5
> --- /dev/null
> +++ b/include/linux/mtd/nand-gpio.h
> @@ -0,0 +1,19 @@
> +#ifndef __LINUX_MTD_NAND_GPIO_H
> +#define __LINUX_MTD_NAND_GPIO_H
> +
> +#include <linux/mtd/nand.h>
> +
> +struct gpio_nand_platdata {
> +	int	gpio_nce;
> +	int	gpio_nwp;
> +	int	gpio_cle;
> +	int	gpio_ale;
> +	int	gpio_rdy;
> +	void	(*adjust_parts)(struct gpio_nand_platdata *, size_t);
> +	struct mtd_partition *parts;
> +	unsigned int num_parts;
> +	unsigned int options;
> +	int	chip_delay;
> +};
> +
> +#endif
> 
> 
> 
> -- 
> Sincerely yours,
> Mike.
>

Russell King - ARM Linux wrote:
> On Wed, Oct 15, 2008 at 08:38:49AM +0200, Mike Rapoport wrote:
>> David Woodhouse wrote:
>>> Please can I have it in a form I can apply, with changelog and
>>> signed-off-by, and without those silly 'u16' types in it. The C language
>>> has perfectly good types for specifying unsigned 16-bit integers; use
>>> them.
>>>
>>> Thanks.
>> The patch adds support for NAND flashes connected to GPIOs.
>>
>> Signed-off-by: Ben Dooks <ben-linux-arm@fluff.org>
>> Signed-off-by: Russell King <linux@arm.linux.org.uk>
> 
> So you're adding signed-off-by's without asking the original people to
> provide them...  That's very bad - you're making a statement about
> others which they've not made.

I apologize for that, it seems that I misunderstood Documentation/SubmittingPatches.

Ben, can I add your "signed-off-by"?

> Please change mine to:
> 
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> 
>> Signed-off-by: Mike Rapoport <mike@compulab.co.il>
>>
>>  drivers/mtd/nand/Kconfig      |    6 +
>>  drivers/mtd/nand/Makefile     |    1 +
>>  drivers/mtd/nand/gpio.c       |  375 +++++++++++++++++++++++++++++++++++++++++
>>  include/linux/mtd/nand-gpio.h |   19 ++
>>  4 files changed, 401 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 41f361c..e98991b 100644
>> --- a/drivers/mtd/nand/Kconfig
>> +++ b/drivers/mtd/nand/Kconfig
>> @@ -56,6 +56,12 @@ config MTD_NAND_H1900
>>  	help
>>  	  This enables the driver for the iPAQ h1900 flash.
>>
>> +config MTD_NAND_GPIO
>> +	tristate "GPIO NAND Flash driver"
>> +	depends on GENERIC_GPIO
>> +	help
>> +	  This enables a GPIO based NAND flash driver.
>> +
>>  config MTD_NAND_SPIA
>>  	tristate "NAND Flash device on SPIA board"
>>  	depends on ARCH_P720T
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index b786c5d..39eefc2 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -24,6 +24,7 @@ obj-$(CONFIG_MTD_NAND_NANDSIM)		+= nandsim.o
>>  obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o
>>  obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
>>  obj-$(CONFIG_MTD_NAND_ATMEL)		+= atmel_nand.o
>> +obj-$(CONFIG_MTD_NAND_GPIO)		+= gpio.o
>>  obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270_nand.o
>>  obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
>>  obj-$(CONFIG_MTD_NAND_PXA3xx)		+= pxa3xx_nand.o
>> diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
>> new file mode 100644
>> index 0000000..083bab4
>> --- /dev/null
>> +++ b/drivers/mtd/nand/gpio.c
>> @@ -0,0 +1,375 @@
>> +/*
>> + * 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
>> + *
>> + * (c) 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, res->end - res->start + 1);
>> +
>> +	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
>> +	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
>> +	release_mem_region(res->start, res->end - res->start + 1);
>> +
>> +	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, res->end - res->start + 1, name)) {
>> +		*err = -EBUSY;
>> +		return NULL;
>> +	}
>> +
>> +	ptr = ioremap(res->start, size);
>> +	if (!ptr) {
>> +		release_mem_region(res->start, res->end - res->start + 1);
>> +		*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, res1->end - res1->start + 1);
>> +err_sync:
>> +	iounmap(gpiomtd->nand_chip.IO_ADDR_R);
>> +	release_mem_region(res0->start, res0->end - res0->start + 1);
>> +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, (c) 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");
>> diff --git a/include/linux/mtd/nand-gpio.h b/include/linux/mtd/nand-gpio.h
>> new file mode 100644
>> index 0000000..51534e5
>> --- /dev/null
>> +++ b/include/linux/mtd/nand-gpio.h
>> @@ -0,0 +1,19 @@
>> +#ifndef __LINUX_MTD_NAND_GPIO_H
>> +#define __LINUX_MTD_NAND_GPIO_H
>> +
>> +#include <linux/mtd/nand.h>
>> +
>> +struct gpio_nand_platdata {
>> +	int	gpio_nce;
>> +	int	gpio_nwp;
>> +	int	gpio_cle;
>> +	int	gpio_ale;
>> +	int	gpio_rdy;
>> +	void	(*adjust_parts)(struct gpio_nand_platdata *, size_t);
>> +	struct mtd_partition *parts;
>> +	unsigned int num_parts;
>> +	unsigned int options;
>> +	int	chip_delay;
>> +};
>> +
>> +#endif
>>
>>
>>
>> -- 
>> Sincerely yours,
>> Mike.
>>
>