diff options
Diffstat (limited to 'drivers/mtd/nand/ams-delta.c')
| -rw-r--r-- | drivers/mtd/nand/ams-delta.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/mtd/nand/ams-delta.c b/drivers/mtd/nand/ams-delta.c new file mode 100644 index 00000000000..d7897dc6b3c --- /dev/null +++ b/drivers/mtd/nand/ams-delta.c @@ -0,0 +1,237 @@ +/* + * drivers/mtd/nand/ams-delta.c + * + * Copyright (C) 2006 Jonathan McDowell <noodles@earth.li> + * + * Derived from drivers/mtd/toto.c + * + * 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. + * + * Overview: + * This is a device driver for the NAND flash device found on the + * Amstrad E3 (Delta). + */ + +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> +#include <linux/mtd/partitions.h> +#include <asm/io.h> +#include <asm/arch/hardware.h> +#include <asm/sizes.h> +#include <asm/arch/gpio.h> +#include <asm/arch/board-ams-delta.h> + +/* + * MTD structure for E3 (Delta) + */ +static struct mtd_info *ams_delta_mtd = NULL; + +#define NAND_MASK (AMS_DELTA_LATCH2_NAND_NRE | AMS_DELTA_LATCH2_NAND_NWE | AMS_DELTA_LATCH2_NAND_CLE | AMS_DELTA_LATCH2_NAND_ALE | AMS_DELTA_LATCH2_NAND_NCE | AMS_DELTA_LATCH2_NAND_NWP) + +/* + * Define partitions for flash devices + */ + +static struct mtd_partition partition_info[] = { + { .name = "Kernel", + .offset = 0, + .size = 3 * SZ_1M + SZ_512K }, + { .name = "u-boot", + .offset = 3 * SZ_1M + SZ_512K, + .size = SZ_256K }, + { .name = "u-boot params", + .offset = 3 * SZ_1M + SZ_512K + SZ_256K, + .size = SZ_256K }, + { .name = "Amstrad LDR", + .offset = 4 * SZ_1M, + .size = SZ_256K }, + { .name = "File system", + .offset = 4 * SZ_1M + 1 * SZ_256K, + .size = 27 * SZ_1M }, + { .name = "PBL reserved", + .offset = 32 * SZ_1M - 3 * SZ_256K, + .size = 3 * SZ_256K }, +}; + +static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte) +{ + struct nand_chip *this = mtd->priv; + + omap_writew(0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL)); + omap_writew(byte, this->IO_ADDR_W); + ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, 0); + ndelay(40); + ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, + AMS_DELTA_LATCH2_NAND_NWE); +} + +static u_char ams_delta_read_byte(struct mtd_info *mtd) +{ + u_char res; + struct nand_chip *this = mtd->priv; + + ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, 0); + ndelay(40); + omap_writew(~0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL)); + res = omap_readw(this->IO_ADDR_R); + ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, + AMS_DELTA_LATCH2_NAND_NRE); + + return res; +} + +static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf, + int len) +{ + int i; + + for (i=0; i<len; i++) + ams_delta_write_byte(mtd, buf[i]); +} + +static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len) +{ + int i; + + for (i=0; i<len; i++) + buf[i] = ams_delta_read_byte(mtd); +} + +static int ams_delta_verify_buf(struct mtd_info *mtd, const u_char *buf, + int len) +{ + int i; + + for (i=0; i<len; i++) + if (buf[i] != ams_delta_read_byte(mtd)) + return -EFAULT; + + return 0; +} + +/* + * Command control function + * + * ctrl: + * NAND_NCE: bit 0 -> bit 2 + * NAND_CLE: bit 1 -> bit 7 + * NAND_ALE: bit 2 -> bit 6 + */ +static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd, + unsigned int ctrl) +{ + + if (ctrl & NAND_CTRL_CHANGE) { + unsigned long bits; + + bits = (~ctrl & NAND_NCE) << 2; + bits |= (ctrl & NAND_CLE) << 7; + bits |= (ctrl & NAND_ALE) << 6; + + ams_delta_latch2_write(0xC2, bits); + } + + if (cmd != NAND_CMD_NONE) + ams_delta_write_byte(mtd, cmd); +} + +static int ams_delta_nand_ready(struct mtd_info *mtd) +{ + return omap_get_gpio_datain(AMS_DELTA_GPIO_PIN_NAND_RB); +} + +/* + * Main initialization routine + */ +static int __init ams_delta_init(void) +{ + struct nand_chip *this; + int err = 0; + + /* Allocate memory for MTD device structure and private data */ + ams_delta_mtd = kmalloc(sizeof(struct mtd_info) + + sizeof(struct nand_chip), GFP_KERNEL); + if (!ams_delta_mtd) { + printk (KERN_WARNING "Unable to allocate E3 NAND MTD device structure.\n"); + err = -ENOMEM; + goto out; + } + + ams_delta_mtd->owner = THIS_MODULE; + + /* Get pointer to private data */ + this = (struct nand_chip *) (&ams_delta_mtd[1]); + + /* Initialize structures */ + memset(ams_delta_mtd, 0, sizeof(struct mtd_info)); + memset(this, 0, sizeof(struct nand_chip)); + + /* Link the private data with the MTD structure */ + ams_delta_mtd->priv = this; + + /* Set address of NAND IO lines */ + this->IO_ADDR_R = (OMAP_MPUIO_BASE + OMAP_MPUIO_INPUT_LATCH); + this->IO_ADDR_W = (OMAP_MPUIO_BASE + OMAP_MPUIO_OUTPUT); + this->read_byte = ams_delta_read_byte; + this->write_buf = ams_delta_write_buf; + this->read_buf = ams_delta_read_buf; + this->verify_buf = ams_delta_verify_buf; + this->cmd_ctrl = ams_delta_hwcontrol; + if (!omap_request_gpio(AMS_DELTA_GPIO_PIN_NAND_RB)) { + this->dev_ready = ams_delta_nand_ready; + } else { + this->dev_ready = NULL; + printk(KERN_NOTICE "Couldn't request gpio for Delta NAND ready.\n"); + } + /* 25 us command delay time */ + this->chip_delay = 30; + this->ecc.mode = NAND_ECC_SOFT; + + /* Set chip enabled, but */ + ams_delta_latch2_write(NAND_MASK, AMS_DELTA_LATCH2_NAND_NRE | + AMS_DELTA_LATCH2_NAND_NWE | + AMS_DELTA_LATCH2_NAND_NCE | + AMS_DELTA_LATCH2_NAND_NWP); + + /* Scan to find existance of the device */ + if (nand_scan(ams_delta_mtd, 1)) { + err = -ENXIO; + goto out_mtd; + } + + /* Register the partitions */ + add_mtd_partitions(ams_delta_mtd, partition_info, + ARRAY_SIZE(partition_info)); + + goto out; + + out_mtd: + kfree(ams_delta_mtd); + out: + return err; +} + +module_init(ams_delta_init); + +/* + * Clean up routine + */ +static void __exit ams_delta_cleanup(void) +{ + /* Release resources, unregister device */ + nand_release(ams_delta_mtd); + + /* Free the MTD device structure */ + kfree(ams_delta_mtd); +} +module_exit(ams_delta_cleanup); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>"); +MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)"); |