linux-sg2042/drivers/mtd/nand/ams-delta.c

313 lines
7.3 KiB
C

/*
* drivers/mtd/nand/ams-delta.c
*
* Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
*
* Derived from drivers/mtd/toto.c
* Converted to platform driver by Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
* Partially stolen from drivers/mtd/nand/plat_nand.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 <mach/hardware.h>
#include <asm/sizes.h>
#include <linux/gpio.h>
#include <plat/board-ams-delta.h>
/*
* MTD structure for E3 (Delta)
*/
static struct mtd_info *ams_delta_mtd = NULL;
/*
* 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;
void __iomem *io_base = this->priv;
writew(0, io_base + OMAP_MPUIO_IO_CNTL);
writew(byte, this->IO_ADDR_W);
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 0);
ndelay(40);
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 1);
}
static u_char ams_delta_read_byte(struct mtd_info *mtd)
{
u_char res;
struct nand_chip *this = mtd->priv;
void __iomem *io_base = this->priv;
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 0);
ndelay(40);
writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
res = readw(this->IO_ADDR_R);
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 1);
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) {
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NCE,
(ctrl & NAND_NCE) == 0);
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_CLE,
(ctrl & NAND_CLE) != 0);
gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_ALE,
(ctrl & NAND_ALE) != 0);
}
if (cmd != NAND_CMD_NONE)
ams_delta_write_byte(mtd, cmd);
}
static int ams_delta_nand_ready(struct mtd_info *mtd)
{
return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
}
static const struct gpio _mandatory_gpio[] = {
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_NCE,
.flags = GPIOF_OUT_INIT_HIGH,
.label = "nand_nce",
},
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_NRE,
.flags = GPIOF_OUT_INIT_HIGH,
.label = "nand_nre",
},
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_NWP,
.flags = GPIOF_OUT_INIT_HIGH,
.label = "nand_nwp",
},
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_NWE,
.flags = GPIOF_OUT_INIT_HIGH,
.label = "nand_nwe",
},
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_ALE,
.flags = GPIOF_OUT_INIT_LOW,
.label = "nand_ale",
},
{
.gpio = AMS_DELTA_GPIO_PIN_NAND_CLE,
.flags = GPIOF_OUT_INIT_LOW,
.label = "nand_cle",
},
};
/*
* Main initialization routine
*/
static int __devinit ams_delta_init(struct platform_device *pdev)
{
struct nand_chip *this;
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
void __iomem *io_base;
int err = 0;
if (!res)
return -ENXIO;
/* 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;
/*
* Don't try to request the memory region from here,
* it should have been already requested from the
* gpio-omap driver and requesting it again would fail.
*/
io_base = ioremap(res->start, resource_size(res));
if (io_base == NULL) {
dev_err(&pdev->dev, "ioremap failed\n");
err = -EIO;
goto out_free;
}
this->priv = io_base;
/* Set address of NAND IO lines */
this->IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
this->IO_ADDR_W = io_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 (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
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;
platform_set_drvdata(pdev, io_base);
/* Set chip enabled, but */
err = gpio_request_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
if (err)
goto out_gpio;
/* Scan to find existence of the device */
if (nand_scan(ams_delta_mtd, 1)) {
err = -ENXIO;
goto out_mtd;
}
/* Register the partitions */
mtd_device_register(ams_delta_mtd, partition_info,
ARRAY_SIZE(partition_info));
goto out;
out_mtd:
gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
out_gpio:
platform_set_drvdata(pdev, NULL);
gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
iounmap(io_base);
out_free:
kfree(ams_delta_mtd);
out:
return err;
}
/*
* Clean up routine
*/
static int __devexit ams_delta_cleanup(struct platform_device *pdev)
{
void __iomem *io_base = platform_get_drvdata(pdev);
/* Release resources, unregister device */
nand_release(ams_delta_mtd);
gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
iounmap(io_base);
/* Free the MTD device structure */
kfree(ams_delta_mtd);
return 0;
}
static struct platform_driver ams_delta_nand_driver = {
.probe = ams_delta_init,
.remove = __devexit_p(ams_delta_cleanup),
.driver = {
.name = "ams-delta-nand",
.owner = THIS_MODULE,
},
};
module_platform_driver(ams_delta_nand_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");