of/mtd/nand: add generic bindings and helpers

- nand-ecc-mode : String, operation mode of the NAND ecc mode.
  Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
  "soft_bch".
- nand-bus-width : 8 or 16 bus width if not present 8
- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Stefan Roese <sr@denx.de>

5 files changed, 116 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt
new file mode 100644
index 000000000000..03855c8c492a
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nand.txt
@@ -0,0 +1,7 @@
+* MTD generic binding
+
+- nand-ecc-mode : String, operation mode of the NAND ecc mode.
+  Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
+  "soft_bch".
+- nand-bus-width : 8 or 16 bus width if not present 8
+- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 268163dd71c7..fa666a93540c 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -90,4 +90,8 @@ config OF_PCI_IRQ
         help
           OpenFirmware PCI IRQ routing helpers
 
+config OF_MTD
+        depends on MTD
+        def_bool y
+
 endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index a73f5a51ff4c..aa90e602c8a7 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_OF_SELFTEST) += selftest.o
 obj-$(CONFIG_OF_MDIO)   += of_mdio.o
 obj-$(CONFIG_OF_PCI)    += of_pci.o
 obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
+obj-$(CONFIG_OF_MTD)    += of_mtd.o
diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
new file mode 100644
index 000000000000..e7cad627a5d1
--- /dev/null
+++ b/drivers/of/of_mtd.c
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+const 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_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);
diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h
new file mode 100644
index 000000000000..bae1b6094c63
--- /dev/null
+++ b/include/linux/of_mtd.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * OF helpers for mtd.
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_OF_MTD_H
+#define __LINUX_OF_NET_H
+
+#ifdef CONFIG_OF_MTD
+#include <linux/of.h>
+extern const int of_get_nand_ecc_mode(struct device_node *np);
+int of_get_nand_bus_width(struct device_node *np);
+bool of_get_nand_on_flash_bbt(struct device_node *np);
+#endif
+
+#endif /* __LINUX_OF_MTD_H */