| Jean-Christophe PLAGNIOL-VILLARD | 770d7c3 | 2012-01-28 12:12:36 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> |
| 3 | * |
| 4 | * OF helpers for mtd. |
| 5 | * |
| 6 | * This file is released under the GPLv2 |
| 7 | * |
| 8 | */ |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/of_mtd.h> |
| 11 | #include <linux/mtd/nand.h> |
| 12 | #include <linux/export.h> |
| 13 | |
| 14 | /** |
| 15 | * It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h |
| 16 | * into the device tree binding of 'nand-ecc', so that MTD |
| 17 | * device driver can get nand ecc from device tree. |
| 18 | */ |
| 19 | static const char *nand_ecc_modes[] = { |
| 20 | [NAND_ECC_NONE] = "none", |
| 21 | [NAND_ECC_SOFT] = "soft", |
| 22 | [NAND_ECC_HW] = "hw", |
| 23 | [NAND_ECC_HW_SYNDROME] = "hw_syndrome", |
| 24 | [NAND_ECC_HW_OOB_FIRST] = "hw_oob_first", |
| 25 | [NAND_ECC_SOFT_BCH] = "soft_bch", |
| 26 | }; |
| 27 | |
| 28 | /** |
| 29 | * of_get_nand_ecc_mode - Get nand ecc mode for given device_node |
| 30 | * @np: Pointer to the given device_node |
| 31 | * |
| 32 | * The function gets ecc mode string from property 'nand-ecc-mode', |
| 33 | * and return its index in nand_ecc_modes table, or errno in error case. |
| 34 | */ |
| 35 | const int of_get_nand_ecc_mode(struct device_node *np) |
| 36 | { |
| 37 | const char *pm; |
| 38 | int err, i; |
| 39 | |
| 40 | err = of_property_read_string(np, "nand-ecc-mode", &pm); |
| 41 | if (err < 0) |
| 42 | return err; |
| 43 | |
| 44 | for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++) |
| 45 | if (!strcasecmp(pm, nand_ecc_modes[i])) |
| 46 | return i; |
| 47 | |
| 48 | return -ENODEV; |
| 49 | } |
| 50 | EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode); |
| 51 | |
| 52 | /** |
| 53 | * of_get_nand_bus_width - Get nand bus witdh for given device_node |
| 54 | * @np: Pointer to the given device_node |
| 55 | * |
| 56 | * return bus width option, or errno in error case. |
| 57 | */ |
| 58 | int of_get_nand_bus_width(struct device_node *np) |
| 59 | { |
| 60 | u32 val; |
| 61 | |
| 62 | if (of_property_read_u32(np, "nand-bus-width", &val)) |
| 63 | return 8; |
| 64 | |
| 65 | switch(val) { |
| 66 | case 8: |
| 67 | case 16: |
| 68 | return val; |
| 69 | default: |
| 70 | return -EIO; |
| 71 | } |
| 72 | } |
| 73 | EXPORT_SYMBOL_GPL(of_get_nand_bus_width); |
| 74 | |
| 75 | /** |
| 76 | * of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node |
| 77 | * @np: Pointer to the given device_node |
| 78 | * |
| 79 | * return true if present false other wise |
| 80 | */ |
| 81 | bool of_get_nand_on_flash_bbt(struct device_node *np) |
| 82 | { |
| 83 | return of_property_read_bool(np, "nand-on-flash-bbt"); |
| 84 | } |
| 85 | EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt); |