diff options
Diffstat (limited to 'drivers/mtd/nand/at91_nand.c')
| -rw-r--r-- | drivers/mtd/nand/at91_nand.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/mtd/nand/at91_nand.c b/drivers/mtd/nand/at91_nand.c new file mode 100644 index 0000000..14b80cc --- /dev/null +++ b/drivers/mtd/nand/at91_nand.c @@ -0,0 +1,223 @@ +/* + * 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 */ + + if (host->board->bus_width_16) /* 16-bit bus width */ + nand_chip->options |= NAND_BUSWIDTH_16; + + 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"); |