[PATCH] ARM: MTD: add NOR lash driver for Freescale MXC

[Alberto Panizzo]

Hi Daniel,
comment inline..

On Tue, 19 May 2009 14:07:10 +0200
Daniel Mack <daniel at caiaq.de> wrote:

> This adds a driver for Freescale MXC's NOR flash.
> The driver is taken from Freescale's BSP - I just made it compile for
> current kernel versions and cleaned up the CodingStyle here and there.
> 
> Successfully tested on a MX31 board.
> 
> Signed-off-by: Daniel Mack <daniel at caiaq.de>
> Cc: Sascha Hauer <s.hauer at pengutronix.de>
> Cc: linux-mtd <linux-mtd at lists.infradead.org>
> ---
>  drivers/mtd/maps/Kconfig   |   10 +++
>  drivers/mtd/maps/Makefile  |    1 +
>  drivers/mtd/maps/mxc_nor.c |  184 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 195 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/mtd/maps/mxc_nor.c
> 
> diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
> index 82923bd..af9ebf8 100644
> --- a/drivers/mtd/maps/Kconfig
> +++ b/drivers/mtd/maps/Kconfig
> @@ -562,4 +562,14 @@ config MTD_VMU
>  	  To build this as a module select M here, the module will be called
>  	  vmu-flash.
>  
> +config MTD_MXC
> +	tristate "Map driver for Freescale MXC boards"
> +	depends on MTD && ARCH_MXC
> +	default y
> +	select MTD_CFI
> +	select MTD_PARTITIONS
> +	help
> +	  This enables access to the flash chips on Freescale MXC based
> +	  platforms. If you have such a board, say 'Y'.
> +
>  endmenu
> diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
> index 2dbc1be..c131717 100644
> --- a/drivers/mtd/maps/Makefile
> +++ b/drivers/mtd/maps/Makefile
> @@ -62,3 +62,4 @@ obj-$(CONFIG_MTD_INTEL_VR_NOR)	+= intel_vr_nor.o
>  obj-$(CONFIG_MTD_BFIN_ASYNC)	+= bfin-async-flash.o
>  obj-$(CONFIG_MTD_RBTX4939)	+= rbtx4939-flash.o
>  obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o
> +obj-$(CONFIG_MTD_MXC)		+= mxc_nor.o
> diff --git a/drivers/mtd/maps/mxc_nor.c b/drivers/mtd/maps/mxc_nor.c
> new file mode 100644
> index 0000000..0b808b4
> --- /dev/null
> +++ b/drivers/mtd/maps/mxc_nor.c
> @@ -0,0 +1,184 @@
> +/*
> + * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
> + * (c) 2005 MontaVista Software, Inc.
> + *
> + * This file contains the MTD Mapping information on the MXC.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/err.h>
> +#include <linux/ioport.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/map.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/clocksource.h>
> +#include <asm/mach-types.h>
> +#include <asm/mach/flash.h>
> +
> +#define DVR_VER "2.0"
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +static const char *part_probes[] = { "RedBoot", "cmdlinepart", NULL };
> +#endif
> +
> +#ifdef CONFIG_MTD_XIP
> +struct clocksource *mtd_xip_clksrc;
> +#endif
> +
> +struct mxcflash_info {
> +	struct mtd_partition *parts;
> +	struct mtd_info *mtd;
> +	struct map_info map;
> +};
> +
> +static int __devinit mxcflash_probe(struct platform_device *pdev)
> +{
> +	int err, nr_parts = 0;
> +	struct mxcflash_info *info;
> +	struct flash_platform_data *flash = pdev->dev.platform_data;
> +	struct resource *res = pdev->resource;
> +	unsigned long size = res->end - res->start + 1;
> +
> +	info = kzalloc(sizeof(struct mxcflash_info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	if (!request_mem_region(res->start, size, "flash")) {
> +		err = -EBUSY;
> +		goto out_free_info;
> +	}
> +
> +	info->map.virt = ioremap(res->start, size);
> +	if (!info->map.virt) {
> +		err = -ENOMEM;
> +		goto out_release_mem_region;
> +	}
> +
> +	info->map.name = pdev->name;
> +	info->map.phys = res->start;
> +	info->map.size = size;
> +	info->map.bankwidth = flash->width;
> +
> +#ifdef CONFIG_MTD_XIP
> +	mtd_xip_clksrc = clocksource_get_next();
> +#endif
> +
> +	simple_map_init(&info->map);
> +	info->mtd = do_map_probe(flash->map_name, &info->map);
> +
> +	if (!info->mtd) {
> +		err = -EIO;
> +		goto out_iounmap;
> +	}
> +
> +	info->mtd->owner = THIS_MODULE;
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +	nr_parts =
> +	    parse_mtd_partitions(info->mtd, part_probes, &info->parts, 0);
> +	if (nr_parts > 0) {
> +		add_mtd_partitions(info->mtd, info->parts, nr_parts);
> +	} else if (nr_parts < 0 && flash->parts) {

Since cmdlinepart partition parser return 0 also if no partition definition is passed 
by command line, I suggest:

	} else if (nr_parts <= 0 && flash->parts) {

so static partitioning is supported.

> +		add_mtd_partitions(info->mtd, flash->parts, flash->nr_parts);
> +	} else
> +#endif
> +	{
> +		dev_info(&pdev->dev, "no partition info available, "
> +				"registering whole flash\n");
> +		add_mtd_device(info->mtd);
> +	}
> +
> +	platform_set_drvdata(pdev, info);
> +	return 0;
> +
> +out_iounmap:
> +	iounmap(info->map.virt);
> +out_release_mem_region:
> +	release_mem_region(res->start, size);
> +out_free_info:
> +	kfree(info);
> +
> +	return err;
> +}
> +
> +static int __devexit mxcflash_remove(struct platform_device *pdev)
> +{
> +
> +	struct mxcflash_info *info = platform_get_drvdata(pdev);
> +	struct flash_platform_data *flash = pdev->dev.platform_data;
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	if (!info)
> +		return 0;
> +
> +	if (info->parts) {
> +		del_mtd_partitions(info->mtd);
> +		kfree(info->parts);
> +	} else if (flash->parts)
> +		del_mtd_partitions(info->mtd);
> +	else
> +		del_mtd_device(info->mtd);
> +
> +	map_destroy(info->mtd);
> +	release_mem_region(info->map.phys, info->map.size);
> +	iounmap((void __iomem *)info->map.virt);
> +	kfree(info);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver mxcflash_driver = {
> +	.driver = {
> +		   .name = "mxc_nor_flash",
> +	},
> +	.probe = mxcflash_probe,
> +	.remove = __devexit_p(mxcflash_remove),
> +};
> +
> +/*
> + * This is the module's entry function. It passes board specific
> + * config details into the MTD physmap driver which then does the
> + * real work for us. After this function runs, our job is done.
> + */
> +static int __init mxc_mtd_init(void)
> +{
> +	pr_info("MXC MTD nor Driver %s\n", DVR_VER);
> +	if (platform_driver_register(&mxcflash_driver) != 0) {
> +		printk(KERN_ERR "Driver register failed for mxcflash_driver\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * This function is the module's exit function. It's empty because the
> + * MTD physmap driver is doing the real work and our job was done after
> + * mxc_mtd_init() runs.
> + */
> +static void __exit mxc_mtd_exit(void)
> +{
> +	platform_driver_unregister(&mxcflash_driver);
> +}
> +
> +module_init(mxc_mtd_init);
> +module_exit(mxc_mtd_exit);
> +
> +MODULE_AUTHOR("Freescale Semiconductor, Inc.");
> +MODULE_DESCRIPTION("MTD map and partitions for Freescale MXC boards");
> +MODULE_LICENSE("GPL");
> +