From 6d9434ebb76157071164b32ad03fbed165c74382 Mon Sep 17 00:00:00 2001
From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Date: Mon, 24 Feb 2014 19:24:48 -0300
Subject: [PATCH] of_mtd: Add helpers to get ECC strength and ECC step size

This commit adds simple helpers to obtain the devicetree properties
that specify the ECC strength and ECC step size to use on a given
NAND controller.

Acked-by: Boris BREZILLON <b.brezillon.dev@gmail.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
 drivers/of/of_mtd.c    | 34 ++++++++++++++++++++++++++++++++++
 include/linux/of_mtd.h | 12 ++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
index a27ec94877e4..b7361ed70537 100644
--- a/drivers/of/of_mtd.c
+++ b/drivers/of/of_mtd.c
@@ -49,6 +49,40 @@ int of_get_nand_ecc_mode(struct device_node *np)
 }
 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
diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h
index cb32d9c1e8dc..e266caa36402 100644
--- a/include/linux/of_mtd.h
+++ b/include/linux/of_mtd.h
@@ -13,6 +13,8 @@
 
 #include <linux/of.h>
 int of_get_nand_ecc_mode(struct device_node *np);
+int of_get_nand_ecc_step_size(struct device_node *np);
+int of_get_nand_ecc_strength(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);
 
@@ -23,6 +25,16 @@ static inline int of_get_nand_ecc_mode(struct device_node *np)
 	return -ENOSYS;
 }
 
+static inline int of_get_nand_ecc_step_size(struct device_node *np)
+{
+	return -ENOSYS;
+}
+
+static inline int of_get_nand_ecc_strength(struct device_node *np)
+{
+	return -ENOSYS;
+}
+
 static inline int of_get_nand_bus_width(struct device_node *np)
 {
 	return -ENOSYS;