[patch/respin] generic nand driver for SoCs

[patch/respin] generic nand driver for SoCs

[Vitaly Wool]

This is the respin of "generic NAND driver"  patch updated after Thomas's comments.

 drivers/mtd/nand/Kconfig    |    6 +
 drivers/mtd/nand/Makefile   |    1
 drivers/mtd/nand/gen_nand.c |  150 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand.h    |    2
 4 files changed, 159 insertions(+)

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>

Index: linux-2.6/drivers/mtd/nand/gen_nand.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/mtd/nand/gen_nand.c
@@ -0,0 +1,150 @@
+/*
+ * Generic NAND driver
+ *
+ * Author: Vitaly Wool <vitalywool@gmail.com>
+ *
+ * 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/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+struct gen_nand_data {
+	struct nand_chip	chip;
+	struct mtd_info		mtd;
+	void __iomem		*io_base;
+#ifdef CONFIG_MTD_PARTITIONS
+	int			nr_parts;
+	struct mtd_partition	*parts;
+#endif
+};
+
+/*
+ * Probe for the NAND device.
+ */
+static int __init gen_nand_probe(struct platform_device *pdev)
+{
+	struct platform_nand_data *pdata = pdev->dev.platform_data;
+	struct gen_nand_data *data;
+	int res = 0;
+
+	/* Allocate memory for the device structure (and zero it) */
+	data = kzalloc(sizeof(struct gen_nand_data), GFP_KERNEL);
+	if (!data) {
+		dev_err(&pdev->dev, "failed to allocate device structure.\n");
+		return -ENOMEM;
+	}
+
+	data->io_base = ioremap(pdev->resource[0].start,
+				pdev->resource[0].end - pdev->resource[0].start + 1);
+	if (data->io_base == NULL) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		kfree(data);
+		return -EIO;
+	}
+
+	data->chip.priv = &data;
+	data->mtd.priv = &data->chip;
+	data->mtd.owner = THIS_MODULE;
+
+	data->chip.IO_ADDR_R = data->io_base;
+	data->chip.IO_ADDR_W = data->io_base;
+	data->chip.cmd_ctrl = pdata->ctrl.cmd_ctrl;
+	data->chip.dev_ready = pdata->ctrl.dev_ready;
+	data->chip.select_chip = pdata->ctrl.select_chip;
+	data->chip.chip_delay = pdata->chip.chip_delay;
+	data->chip.options |= pdata->chip.options;
+
+	data->chip.ecc.hwctl = pdata->ctrl.hwcontrol;
+	data->chip.ecc.layout = pdata->chip.ecclayout;
+	data->chip.ecc.mode = NAND_ECC_SOFT;
+
+	platform_set_drvdata(pdev, data);
+
+	/* Scan to find existance of the device */
+	if (nand_scan(&data->mtd, 1)) {
+		res = -ENXIO;
+		goto out;
+	}
+
+#ifdef CONFIG_MTD_PARTITIONS
+	if (pdata->chip.part_probe_types) {
+		res = parse_mtd_partitions(&data->mtd,
+					pdata->chip.part_probe_types,
+					&data->parts, 0);
+		if (res > 0) {
+			add_mtd_partitions(&data->mtd, data->parts, res);
+			return 0;
+		}
+	} else if (pdata->chip.partitions) {
+		data->parts = pdata->chip.partitions;
+		res = add_mtd_partitions(&data->mtd, data->parts,
+			pdata->chip.nr_partitions);
+	}
+#else
+	res = add_mtd_device(data->mtd);
+#endif
+
+	if (!res)
+		return res;
+
+	nand_release(&data->mtd);
+out:
+	platform_set_drvdata(pdev, NULL);
+	iounmap(data->io_base);
+	kfree(data);
+	return res;
+}
+
+/*
+ * Remove a NAND device.
+ */
+static int __devexit gen_nand_remove(struct platform_device *pdev)
+{
+	struct gen_nand_data *data = platform_get_drvdata(pdev);
+	struct platform_nand_data *pdata = pdev->dev.platform_data;
+
+	nand_release(&data->mtd);
+#ifdef CONFIG_MTD_PARTITIONS
+	if (data->parts && data->parts != pdata->chip.partitions)
+		kfree(data->parts);
+#endif
+	iounmap(data->io_base);
+	kfree(data);
+
+	return 0;
+}
+
+static struct platform_driver gen_nand_driver = {
+	.probe		= gen_nand_probe,
+	.remove		= gen_nand_remove,
+	.driver		= {
+		.name	= "gen_nand",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init gen_nand_init(void)
+{
+	return platform_driver_register(&gen_nand_driver);
+}
+
+static void __exit gen_nand_exit(void)
+{
+	platform_driver_unregister(&gen_nand_driver);
+}
+
+module_init(gen_nand_init);
+module_exit(gen_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vitaly Wool");
+MODULE_DESCRIPTION("Simple generic NAND driver");
Index: linux-2.6/drivers/mtd/nand/Kconfig
===================================================================
--- linux-2.6.orig/drivers/mtd/nand/Kconfig
+++ linux-2.6/drivers/mtd/nand/Kconfig
@@ -277,4 +277,10 @@ config MTD_NAND_PLATFORM
 	help
 	  This driver enables support for common on-SoC NAND devices.
 
+config MTD_NAND_PLATFORM
+	tristate "Support for generic NAND driver"
+	depends on MTD_NAND
+	help
+	  This driver enables support for common on-SoC NAND devices.
+
 endmenu
Index: linux-2.6/drivers/mtd/nand/Makefile
===================================================================
--- linux-2.6.orig/drivers/mtd/nand/Makefile
+++ linux-2.6/drivers/mtd/nand/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x
 obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
 obj-$(CONFIG_MTD_NAND_AT91)		+= at91_nand.o
 obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
+obj-$(CONFIG_MTD_NAND_PLATFORM)		+= gen_nand.o
 
 nand-objs := nand_base.o nand_bbt.o
 cafe_nand-objs := cafe.o cafe_ecc.o
Index: linux-2.6/include/linux/mtd/nand.h
===================================================================
--- linux-2.6.orig/include/linux/mtd/nand.h
+++ linux-2.6/include/linux/mtd/nand.h
@@ -559,6 +559,7 @@ extern int nand_do_read(struct mtd_info 
  * @chip_delay:		R/B delay value in us
  * @options:		Option flags, e.g. 16bit buswidth
  * @ecclayout:		ecc layout info structure
+ * @part_probe_types:	NULL-terminated array of probe types
  * @priv:		hardware controller specific settings
  */
 struct platform_nand_chip {
@@ -569,6 +570,7 @@ struct platform_nand_chip {
 	struct nand_ecclayout	*ecclayout;
 	int			chip_delay;
 	unsigned int		options;
+	const char		**part_probe_types;
 	void			*priv;
 };
 

Re: [patch/respin] generic nand driver for SoCs

[Thomas Gleixner]

On Wed, 2007-05-02 at 15:38 +0400, Vitaly Wool wrote:

> +#ifdef CONFIG_MTD_PARTITIONS
> +	if (pdata->chip.part_probe_types) {
> +		res = parse_mtd_partitions(&data->mtd,
> +					pdata->chip.part_probe_types,
> +					&data->parts, 0);
> +		if (res > 0) {
> +			add_mtd_partitions(&data->mtd, data->parts, res);
> +			return 0;
> +		}
> +	} else if (pdata->chip.partitions) {
> +		data->parts = pdata->chip.partitions;
> +		res = add_mtd_partitions(&data->mtd, data->parts,
> +			pdata->chip.nr_partitions);
> +	}

Hmm, this looks wrong. When the probing fails, then you do not add
anything at all. You might at least add the device then.

> +config MTD_NAND_PLATFORM
> +	tristate "Support for generic NAND driver"

s/generic/generic platform /

> +	depends on MTD_NAND
> +	help
> +	  This driver enables support for common on-SoC NAND devices.
> +
>  endmenu
> Index: linux-2.6/drivers/mtd/nand/Makefile
> ===================================================================
> --- linux-2.6.orig/drivers/mtd/nand/Makefile
> +++ linux-2.6/drivers/mtd/nand/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x
>  obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
>  obj-$(CONFIG_MTD_NAND_AT91)		+= at91_nand.o
>  obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
> +obj-$(CONFIG_MTD_NAND_PLATFORM)		+= gen_nand.o

Can you please rename to plat_nand so we have am immidiate idea what it
is ?

>  nand-objs := nand_base.o nand_bbt.o
>  cafe_nand-objs := cafe.o cafe_ecc.o
> Index: linux-2.6/include/linux/mtd/nand.h
> ===================================================================
> --- linux-2.6.orig/include/linux/mtd/nand.h
> +++ linux-2.6/include/linux/mtd/nand.h
> @@ -559,6 +559,7 @@ extern int nand_do_read(struct mtd_info 
>   * @chip_delay:		R/B delay value in us
>   * @options:		Option flags, e.g. 16bit buswidth
>   * @ecclayout:		ecc layout info structure
> + * @part_probe_types:	NULL-terminated array of probe types
>   * @priv:		hardware controller specific settings
>   */
>  struct platform_nand_chip {
> @@ -569,6 +570,7 @@ struct platform_nand_chip {
>  	struct nand_ecclayout	*ecclayout;
>  	int			chip_delay;
>  	unsigned int		options;
> +	const char		**part_probe_types;
>  	void			*priv;
>  };

Please fold this into the other patch, which touches nand.h and add a
proper changelog.

Please add proper changelog description for the platform driver as well.

Thanks,

	tglx