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