mtd: nand: gpmc: Add support for ELM

This adds support for the ELM (Error Location Module) found on
not-too-old OMAP SoCs. The driver has been taken from Linux-5.3-rc6
with interrupt support removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 53 insertions, 0 deletions

diff --git a/include/platform_data/elm.h b/include/platform_data/elm.h
new file mode 100644
index 0000000000..bc5d2edb1d
--- /dev/null
+++ b/include/platform_data/elm.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * BCH Error Location Module
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef __ELM_H
+#define __ELM_H
+
+enum bch_ecc {
+	BCH4_ECC = 0,
+	BCH8_ECC,
+	BCH16_ECC,
+};
+
+/* ELM support 8 error syndrome process */
+#define ERROR_VECTOR_MAX		8
+
+/**
+ * struct elm_errorvec - error vector for elm
+ * @error_reported:		set true for vectors error is reported
+ * @error_uncorrectable:	number of uncorrectable errors
+ * @error_count:		number of correctable errors in the sector
+ * @error_loc:			buffer for error location
+ *
+ */
+struct elm_errorvec {
+	bool error_reported;
+	bool error_uncorrectable;
+	int error_count;
+	int error_loc[16];
+};
+
+#if IS_ENABLED(CONFIG_MTD_NAND_OMAP_ELM)
+int elm_decode_bch_error_page(u8 *ecc_calc, struct elm_errorvec *err_vec);
+int elm_config(enum bch_ecc bch_type, int ecc_steps, int ecc_step_size,
+	       int ecc_syndrome_size);
+#else
+static inline int
+elm_decode_bch_error_page(u8 *ecc_calc, struct elm_errorvec *err_vec)
+{
+	return -ENODEV;
+}
+
+static inline int elm_config(enum bch_ecc bch_type, int ecc_steps,
+			     int ecc_step_size, int ecc_syndrome_size)
+{
+	return -ENOSYS;
+}
+#endif /* CONFIG_MTD_NAND_OMAP_ELM */
+
+#endif /* __ELM_H */