Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / of / of_mtd.c

diff --git a/kernel/drivers/of/of_mtd.c b/kernel/drivers/of/of_mtd.c
new file mode 100644 (file)
index 0000000..b7361ed
--- /dev/null
+++ b/kernel/drivers/of/of_mtd.c
@@ -0,0 +1,119 @@
+/*
+ * 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.
+ */
+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);