[MTD] [NAND] platform NAND driver: add driver

This patch adds support for generic platform NAND driver.
Updated after tglx's review/discussion in IRC #mtd channel.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

3 files changed, 160 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 03ed2545f094..f1d60b6f048e 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -272,4 +272,13 @@ config MTD_NAND_NANDSIM
           The simulator may simulate various NAND flash chips for the
           MTD nand layer.
 
+config MTD_NAND_PLATFORM
+        tristate "Support for generic platform NAND driver"
+        depends on MTD_NAND
+        help
+          This implements a generic NAND driver for on-SOC platform
+          devices. You will need to provide platform-specific functions
+          via platform_data.
+
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index de1424b06b99..edba1db14bfa 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -26,5 +26,6 @@ obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
 obj-$(CONFIG_MTD_NAND_AT91)             += at91_nand.o
 obj-$(CONFIG_MTD_NAND_CM_X270)          += cmx270_nand.o
 obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)    += excite_nandflash.o
+obj-$(CONFIG_MTD_NAND_PLATFORM)         += plat_nand.o
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/plat_nand.c b/drivers/mtd/nand/plat_nand.c
new file mode 100644
index 000000000000..cd725fc5e813
--- /dev/null
+++ b/drivers/mtd/nand/plat_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 plat_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 plat_nand_probe(struct platform_device *pdev)
+{
+        struct platform_nand_data *pdata = pdev->dev.platform_data;
+        struct plat_nand_data *data;
+        int res = 0;
+
+        /* Allocate memory for the device structure (and zero it) */
+        data = kzalloc(sizeof(struct plat_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;
+                }
+        }
+        if (pdata->chip.partitions) {
+                data->parts = pdata->chip.partitions;
+                res = add_mtd_partitions(&data->mtd, data->parts,
+                        pdata->chip.nr_partitions);
+        } else
+#endif
+        res = add_mtd_device(&data->mtd);
+
+        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 plat_nand_remove(struct platform_device *pdev)
+{
+        struct plat_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 plat_nand_driver = {
+        .probe          = plat_nand_probe,
+        .remove         = plat_nand_remove,
+        .driver         = {
+                .name   = "gen_nand",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init plat_nand_init(void)
+{
+        return platform_driver_register(&plat_nand_driver);
+}
+
+static void __exit plat_nand_exit(void)
+{
+        platform_driver_unregister(&plat_nand_driver);
+}
+
+module_init(plat_nand_init);
+module_exit(plat_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vitaly Wool");
+MODULE_DESCRIPTION("Simple generic NAND driver");