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119 lines
2.8 KiB
119 lines
2.8 KiB
/* |
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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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