linux_dsm_epyc7002/drivers/of/of_mtd.c
Jean-Christophe PLAGNIOL-VILLARD 770d7c39af of/mtd/nand: add generic bindings and helpers
- nand-ecc-mode : String, operation mode of the NAND ecc mode.
  Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
  "soft_bch".
- nand-bus-width : 8 or 16 bus width if not present 8
- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stefan Roese <sr@denx.de>
2012-03-15 23:28:19 +08:00

86 lines
2.0 KiB
C

/*
* Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*
* OF helpers for mtd.
*
* This file is released under the GPLv2
*
*/
#include <linux/kernel.h>
#include <linux/of_mtd.h>
#include <linux/mtd/nand.h>
#include <linux/export.h>
/**
* It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h
* into the device tree binding of 'nand-ecc', so that MTD
* device driver can get nand ecc from device tree.
*/
static const char *nand_ecc_modes[] = {
[NAND_ECC_NONE] = "none",
[NAND_ECC_SOFT] = "soft",
[NAND_ECC_HW] = "hw",
[NAND_ECC_HW_SYNDROME] = "hw_syndrome",
[NAND_ECC_HW_OOB_FIRST] = "hw_oob_first",
[NAND_ECC_SOFT_BCH] = "soft_bch",
};
/**
* of_get_nand_ecc_mode - Get nand ecc mode for given device_node
* @np: Pointer to the given device_node
*
* The function gets ecc mode string from property 'nand-ecc-mode',
* and return its index in nand_ecc_modes table, or errno in error case.
*/
const int of_get_nand_ecc_mode(struct device_node *np)
{
const char *pm;
int err, i;
err = of_property_read_string(np, "nand-ecc-mode", &pm);
if (err < 0)
return err;
for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
if (!strcasecmp(pm, nand_ecc_modes[i]))
return i;
return -ENODEV;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode);
/**
* of_get_nand_bus_width - Get nand bus witdh for given device_node
* @np: Pointer to the given device_node
*
* return bus width option, or errno in error case.
*/
int of_get_nand_bus_width(struct device_node *np)
{
u32 val;
if (of_property_read_u32(np, "nand-bus-width", &val))
return 8;
switch(val) {
case 8:
case 16:
return val;
default:
return -EIO;
}
}
EXPORT_SYMBOL_GPL(of_get_nand_bus_width);
/**
* of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node
* @np: Pointer to the given device_node
*
* return true if present false other wise
*/
bool of_get_nand_on_flash_bbt(struct device_node *np)
{
return of_property_read_bool(np, "nand-on-flash-bbt");
}
EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);