X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fof%2Fof_mtd.c;fp=kernel%2Fdrivers%2Fof%2Fof_mtd.c;h=b7361ed705375e6e49dbfde3bd9d7fce4f0c97a2;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/of/of_mtd.c b/kernel/drivers/of/of_mtd.c new file mode 100644 index 000000000..b7361ed70 --- /dev/null +++ b/kernel/drivers/of/of_mtd.c @@ -0,0 +1,119 @@ +/* + * Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD + * + * OF helpers for mtd. + * + * This file is released under the GPLv2 + * + */ +#include +#include +#include +#include + +/** + * 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. + */ +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_ecc_step_size - Get ECC step size associated to + * the required ECC strength (see below). + * @np: Pointer to the given device_node + * + * return the ECC step size, or errno in error case. + */ +int of_get_nand_ecc_step_size(struct device_node *np) +{ + int ret; + u32 val; + + ret = of_property_read_u32(np, "nand-ecc-step-size", &val); + return ret ? ret : val; +} +EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size); + +/** + * of_get_nand_ecc_strength - Get required ECC strength over the + * correspnding step size as defined by 'nand-ecc-size' + * @np: Pointer to the given device_node + * + * return the ECC strength, or errno in error case. + */ +int of_get_nand_ecc_strength(struct device_node *np) +{ + int ret; + u32 val; + + ret = of_property_read_u32(np, "nand-ecc-strength", &val); + return ret ? ret : val; +} +EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength); + +/** + * 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);