The /memory device tree bindings allow to store the ECC detection and correction bits through the ecc-detection-bits and ecc-correction-bits properties.
Our next patches rely on whether ECC is enabled, so let's add a helper to retrieve the ECC correction bits from the /memory node.
Signed-off-by: Maxime Ripard mripard@kernel.org --- include/linux/of.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/include/linux/of.h b/include/linux/of.h index a0bedd038a05..2fbee65a7aa9 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1510,10 +1510,35 @@ static inline int of_get_available_child_count(const struct device_node *np) num++;
return num; }
+/** + * of_memory_get_ecc_correction_bits() - Returns the number of ECC correction bits + * + * Search for the number of bits in memory that can be corrected by the + * ECC algorithm. + * + * Returns: + * The number of ECC bits, 0 if there's no ECC support, a negative error + * code on failure. + */ +static inline int of_memory_get_ecc_correction_bits(void) +{ + struct device_node *mem; + u32 val = 0; + + mem = of_find_node_by_path("/memory"); + if (!mem) + return -ENODEV; + + of_property_read_u32(mem, "ecc-correction-bits", &val); + of_node_put(mem); + + return val; +} + #define _OF_DECLARE_STUB(table, name, compat, fn, fn_type) \ static const struct of_device_id __of_table_##name \ __attribute__((unused)) \ = { .compatible = compat, \ .data = (fn == (fn_type)NULL) ? fn : fn }