[MTD] NAND: AT91 NAND driver

This version only differs from version posted by Savin Zlobec (20 Jun
2006) in that the AT91RM9200-specific chip-select / bus setup code has
been moved from the at91_nand.c driver into the processor-specific file.

From: Savin Zlobec <savin@epico.si>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 1831340..b4b1656 100644 (file)
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -232,6 +232,13 @@ config MTD_NAND_CS553X
 
          If you say "m", the module will be called "cs553x_nand.ko".
 
+config MTD_NAND_AT91
+       bool "Support for NAND Flash / SmartMedia on AT91"
+       depends on MTD_NAND && ARCH_AT91
+       help
+         Enables support for NAND Flash / Smart Media Card interface
+         on Atmel AT91 processors.
+
 config MTD_NAND_NANDSIM
        tristate "Support for NAND Flash Simulator"
        depends on MTD_NAND && MTD_PARTITIONS

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index f747593..27c9f0a 100644 (file)
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -22,5 +22,6 @@ obj-$(CONFIG_MTD_NAND_TS7250)         += ts7250.o
 obj-$(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_AT91)            += at91_nand.o
 
 nand-objs = nand_base.o nand_bbt.o

diff --git a/drivers/mtd/nand/at91_nand.c b/drivers/mtd/nand/at91_nand.c
new file mode 100644 (file)
index 0000000..a58ed37
--- /dev/null
+++ b/drivers/mtd/nand/at91_nand.c
@@ -0,0 +1,220 @@
+/*
+ * drivers/mtd/nand/at91_nand.c
+ *
+ *  Copyright (C) 2003 Rick Bronson
+ *
+ *  Derived from drivers/mtd/nand/autcpu12.c
+ *      Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
+ *
+ *  Derived from drivers/mtd/spia.c
+ *      Copyright (C) 2000 Steven J. Hill (sjhill@cotw.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/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+#include <asm/sizes.h>
+
+#include <asm/hardware.h>
+#include <asm/arch/board.h>
+#include <asm/arch/gpio.h>
+
+struct at91_nand_host {
+       struct nand_chip        nand_chip;
+       struct mtd_info         mtd;
+       void __iomem            *io_base;
+       struct at91_nand_data   *board;
+};
+
+/*
+ * Hardware specific access to control-lines
+ */
+static void at91_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+       struct nand_chip *nand_chip = mtd->priv;
+       struct at91_nand_host *host = nand_chip->priv;
+
+       if (cmd == NAND_CMD_NONE)
+               return;
+
+       if (ctrl & NAND_CLE)
+               writeb(cmd, host->io_base + (1 << host->board->cle));
+       else
+               writeb(cmd, host->io_base + (1 << host->board->ale));
+}
+
+/*
+ * Read the Device Ready pin.
+ */
+static int at91_nand_device_ready(struct mtd_info *mtd)
+{
+       struct nand_chip *nand_chip = mtd->priv;
+       struct at91_nand_host *host = nand_chip->priv;
+
+       return at91_get_gpio_value(host->board->rdy_pin);
+}
+
+/*
+ * Enable NAND.
+ */
+static void at91_nand_enable(struct at91_nand_host *host)
+{
+       if (host->board->enable_pin)
+               at91_set_gpio_value(host->board->enable_pin, 0);
+}
+
+/*
+ * Disable NAND.
+ */
+static void at91_nand_disable(struct at91_nand_host *host)
+{
+       if (host->board->enable_pin)
+               at91_set_gpio_value(host->board->enable_pin, 1);
+}
+
+/*
+ * Probe for the NAND device.
+ */
+static int __init at91_nand_probe(struct platform_device *pdev)
+{
+       struct at91_nand_host *host;
+       struct mtd_info *mtd;
+       struct nand_chip *nand_chip;
+       int res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+       struct mtd_partition *partitions = NULL;
+       int num_partitions = 0;
+#endif
+
+       /* Allocate memory for the device structure (and zero it) */
+       host = kzalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
+       if (!host) {
+               printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
+               return -ENOMEM;
+       }
+
+       host->io_base = ioremap(pdev->resource[0].start,
+                               pdev->resource[0].end - pdev->resource[0].start + 1);
+       if (host->io_base == NULL) {
+               printk(KERN_ERR "at91_nand: ioremap failed\n");
+               kfree(host);
+               return -EIO;
+       }
+
+       mtd = &host->mtd;
+       nand_chip = &host->nand_chip;
+       host->board = pdev->dev.platform_data;
+
+       nand_chip->priv = host;         /* link the private data structures */
+       mtd->priv = nand_chip;
+       mtd->owner = THIS_MODULE;
+
+       /* Set address of NAND IO lines */
+       nand_chip->IO_ADDR_R = host->io_base;
+       nand_chip->IO_ADDR_W = host->io_base;
+       nand_chip->cmd_ctrl = at91_nand_cmd_ctrl;
+       nand_chip->dev_ready = at91_nand_device_ready;
+       nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
+       nand_chip->chip_delay = 20;             /* 20us command delay time */
+
+       platform_set_drvdata(pdev, host);
+       at91_nand_enable(host);
+
+       if (host->board->det_pin) {
+               if (at91_get_gpio_value(host->board->det_pin)) {
+                       printk ("No SmartMedia card inserted.\n");
+                       res = ENXIO;
+                       goto out;
+               }
+       }
+
+       /* Scan to find existance of the device */
+       if (nand_scan(mtd, 1)) {
+               res = -ENXIO;
+               goto out;
+       }
+
+#ifdef CONFIG_MTD_PARTITIONS
+       if (host->board->partition_info)
+               partitions = host->board->partition_info(mtd->size, &num_partitions);
+
+       if ((!partitions) || (num_partitions == 0)) {
+               printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
+               res = ENXIO;
+               goto release;
+       }
+
+       res = add_mtd_partitions(mtd, partitions, num_partitions);
+#else
+       res = add_mtd_device(mtd);
+#endif
+
+       if (!res)
+               return res;
+
+release:
+       nand_release(mtd);
+out:
+       at91_nand_disable(host);
+       platform_set_drvdata(pdev, NULL);
+       iounmap(host->io_base);
+       kfree(host);
+       return res;
+}
+
+/*
+ * Remove a NAND device.
+ */
+static int __devexit at91_nand_remove(struct platform_device *pdev)
+{
+       struct at91_nand_host *host = platform_get_drvdata(pdev);
+       struct mtd_info *mtd = &host->mtd;
+
+       nand_release(mtd);
+
+       at91_nand_disable(host);
+
+       iounmap(host->io_base);
+       kfree(host);
+
+       return 0;
+}
+
+static struct platform_driver at91_nand_driver = {
+       .probe          = at91_nand_probe,
+       .remove         = at91_nand_remove,
+       .driver         = {
+               .name   = "at91_nand",
+               .owner  = THIS_MODULE,
+       },
+};
+
+static int __init at91_nand_init(void)
+{
+       return platform_driver_register(&at91_nand_driver);
+}
+
+
+static void __exit at91_nand_exit(void)
+{
+       platform_driver_unregister(&at91_nand_driver);
+}
+
+
+module_init(at91_nand_init);
+module_exit(at91_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rick Bronson");
+MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");