linux/arch/arm/mach-omap2/gpmc-nand.c

161 lines
3.9 KiB
C

/*
* gpmc-nand.c
*
* Copyright (C) 2009 Texas Instruments
* Vimal Singh <vimalsingh@ti.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/kernel.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/mtd/nand.h>
#include <linux/platform_data/mtd-nand-omap2.h>
#include <asm/mach/flash.h>
#include "gpmc.h"
#include "soc.h"
#include "gpmc-nand.h"
/* minimum size for IO mapping */
#define NAND_IO_SIZE 4
static struct resource gpmc_nand_resource[] = {
{
.flags = IORESOURCE_MEM,
},
{
.flags = IORESOURCE_IRQ,
},
{
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device gpmc_nand_device = {
.name = "omap2-nand",
.id = 0,
.num_resources = ARRAY_SIZE(gpmc_nand_resource),
.resource = gpmc_nand_resource,
};
static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
{
/* platforms which support all ECC schemes */
if (soc_is_am33xx() || soc_is_am43xx() || cpu_is_omap44xx() ||
soc_is_omap54xx() || soc_is_dra7xx())
return 1;
/* OMAP3xxx do not have ELM engine, so cannot support ECC schemes
* which require H/W based ECC error detection */
if ((cpu_is_omap34xx() || cpu_is_omap3630()) &&
((ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
(ecc_opt == OMAP_ECC_BCH8_CODE_HW)))
return 0;
/*
* For now, assume 4-bit mode is only supported on OMAP3630 ES1.x, x>=1
* and AM33xx derivates. Other chips may be added if confirmed to work.
*/
if ((ecc_opt == OMAP_ECC_BCH4_CODE_HW_DETECTION_SW) &&
(!cpu_is_omap3630() || (GET_OMAP_REVISION() == 0)))
return 0;
/* legacy platforms support only HAM1 (1-bit Hamming) ECC scheme */
if (ecc_opt == OMAP_ECC_HAM1_CODE_HW)
return 1;
else
return 0;
}
/* This function will go away once the device-tree convertion is complete */
static void gpmc_set_legacy(struct omap_nand_platform_data *gpmc_nand_data,
struct gpmc_settings *s)
{
/* Enable RD PIN Monitoring Reg */
if (gpmc_nand_data->dev_ready) {
s->wait_on_read = true;
s->wait_on_write = true;
}
if (gpmc_nand_data->devsize == NAND_BUSWIDTH_16)
s->device_width = GPMC_DEVWIDTH_16BIT;
else
s->device_width = GPMC_DEVWIDTH_8BIT;
}
int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
struct gpmc_timings *gpmc_t)
{
int err = 0;
struct gpmc_settings s;
struct device *dev = &gpmc_nand_device.dev;
memset(&s, 0, sizeof(struct gpmc_settings));
gpmc_nand_device.dev.platform_data = gpmc_nand_data;
err = gpmc_cs_request(gpmc_nand_data->cs, NAND_IO_SIZE,
(unsigned long *)&gpmc_nand_resource[0].start);
if (err < 0) {
dev_err(dev, "Cannot request GPMC CS %d, error %d\n",
gpmc_nand_data->cs, err);
return err;
}
gpmc_nand_resource[0].end = gpmc_nand_resource[0].start +
NAND_IO_SIZE - 1;
gpmc_nand_resource[1].start =
gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
gpmc_nand_resource[2].start =
gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
if (gpmc_t) {
err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t);
if (err < 0) {
dev_err(dev, "Unable to set gpmc timings: %d\n", err);
return err;
}
}
if (gpmc_nand_data->of_node)
gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
else
gpmc_set_legacy(gpmc_nand_data, &s);
s.device_nand = true;
err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);
if (err < 0)
goto out_free_cs;
err = gpmc_configure(GPMC_CONFIG_WP, 0);
if (err < 0)
goto out_free_cs;
gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt)) {
dev_err(dev, "Unsupported NAND ECC scheme selected\n");
return -EINVAL;
}
err = platform_device_register(&gpmc_nand_device);
if (err < 0) {
dev_err(dev, "Unable to register NAND device\n");
goto out_free_cs;
}
return 0;
out_free_cs:
gpmc_cs_free(gpmc_nand_data->cs);
return err;
}